Speciality
Spotlight

 




 


Respiratory – Pulmonary – Asthma


 

 





Respiratory

      

  • C
    Bodner, for the Aberdeen WHEASE Group (Univ of Aberdeen, Scotland)


    Family size, childhood infection and Atopic disease 


    Thorax, 53: 28-32, 1998.

        


    The prevalence of asthma and other allergic disease among children in the developed countries has increased in the past 3 decades. 

       


    Bodner and Aberdeen have in this group reported on cross-sectional survey of 2111 subjects analysed for the determinants of asthma and atopy. They found that hay-fever and eczema were inversely related to family size but asthma less so. They also found a small increased risk for asthma with increasing number of childhood infection. Measles, however, demonstrated a small protective effect for asthma. The effect of childhood infections on this immunologic perturbation is unknown but is likely specific to the class or type of infection.

        

  • M Kraft, RJ Martin, S Wilson, et al (Univ of Colorado, Denver; Univ of Southampton, England)


    Lymphocyte and Eosinophilia influx into Aleovular Tissue in Nocturnal Asthma


    Am. J Resp.Crit Care Med 159: 228-234,1999.

        


    Inflammatory cytokines which are produced by T lymphocytes help the promotion of eosinophil migration from blood through the vascular endothelium and the key source for these cytokines probably is the CD4+ lymphocytes, which may also produce chemokines involved in eosinophil chemotaxis, survival, maturation as well as their activation. 

         


    The study has been performed into two separate groups. The patients were subjected to bronchoscopies followed by endobronchial and transbronchial biopsy specimens. Amongst patients suffering from nocturnal asthma and those without suffering from nocturnal asthma i.e. nonnocturnal asthma group. Bronchoscopies were performed in a random order, a week apart at 1 at 4pm and the other at 4am. The numbers of CD3+, CD4+, CD8+ cells and EG2+ eosinophils were measured in the epithelium, lamina propria and the alveolar tissues. 

        


    These studies from kraft and her colleagues at National Jewish have enlightened us with a role of alveolar tissue inflammation in asthma. The study demonstrates that there are an increased number of CD4+ lymphocytes in alveoli in patients with nocturnal asthma and with those correlated inversely with nighttime lung function. Whether this was causally related is unknown. More information is needed regarding the circulation of CD4 lymphocytes in the lungs and their release of potential mediators of asthma symptoms. These cells may be either innocent bystanders or be the result in the alveoli from the spilling over from the increased numbers in the airways. Further studies of optimal timing of anti-inflammatory mediators in patients with nocturnal asthma are needed.

         

  • BH Rowe, GW Bota, et al (Univ of Alberta, Edmonton, Canada; Sudbury Regional Hosp, Ont, Canada; univ of British Columbia, Vancouver Canada, et al)


    Inhaled Budesonide in Addition to Oral corticosteroids to prevent asthma relapse following discharge from the Emergency Dept. – A Randomized Control Trial.


    Jama 281: 2119-2126, 1999

      


    Systemic corticosteroid treatment can decrease acute asthma relapses after discharge from the emergency department. This study undertook to decide whether inhaled corticosteroids provide any additional benefit. 

      


    The study is double-blind placebo-controlled randomized clinical trial which was conducted over a period of 2 yrs on patients between ages from 16 to 60. 188 patients were included in this study and on discharge they were given non-tapering course of oral prednisolone which is 50mg/day for 7 days along with 1600 mg inhaled budesonide or a placebo. These patients were followed up for a period of 21 days. 

      


    This well performed study demonstrates a beneficial effect from the addition of inhaled corticosteroids at the time of discharge of an asthma patient from the emergency dept. For a variety of reasons, the emergency room physicians often do not add inhaled corticosteroids for asthma patients at discharge. Few of them being cost, lack of long term of follow up with the patient, interference with primary care physician’s role inadequate time to provide a metered dose inhaler technique information. 

      


    However, this study argues whether we should be changing our emergency department practice to include inhaled corticosteroids for a minimum of 3 week period probably even longer and to prove our point we need further studies to determine the optimal dosages and the length of treatment required.

        

  • SF Lanes, JE Garrett, et al (Epidemiology Resources Inc, Newton Lower Falls, Mass; Green Lane Hosp, Auckland, New Zealand, Vancouver Gen Hosp, BC, Canada; et al)


    The effect of adding atropine bromide and salbutamol in the treatment of acute asthma. This is a pooled analysis of 3 trials.


    Chest 114: 365-373,1998.

        


    For patients with acute asthma, it is not clear whether an addition of ipratropium bromide would result in bronchodilatation rather than just b2-agonist therapy. Three major randomized trials which have been performed were pulled into the study. An American study found no difference, whereas study from New Zealand showed significant advantage with the combination therapy and a Canadian study found a non-significant benefit. Results of these 3 trials have been pooled to estimate the effects of ipratropium bromide + salbutamol in patients with acute asthma. 

        


    Several studies have demonstrated that ipratropium bromide should be added to acute treatment for patients with asthma both in adult as well as in children. Zorc et al found a significant reduction in length of stay in emergency department and use of additional doses of albuterol. A reduction of length of stay is found in any busy urban emergency department. It is important to keep in mind that the effectiveness of ipratropium is primarily in acute treatment in the emergency dept. and it should not be continued in hospital setting for more than 36 hours. Thus it can be probably concluded that the additional use of ipratropium is not useful and will diminish any potential cost savings from the acute use of ipratropium.

        


    It is best to say the use of ipratropium bromide should be restricted to emergency dept. for a maximum period of upto 36 hours in case of acute asthmatic attack.

        

  • D
    Vervloet, T Ekstrom, et al (Hopital Sainte Marguerite, Marseilles, France; Univ Hosp, Sweden, Ospedale Civile, Osimo, Italy; et al)


    A 6-Month Comparison Between Formeterol and Salmerterol in Patients with Reversible Obstructive Airways Disease


    Respir Med 92: 836-842, 1998.

      


    The newer long acting B2-agonists including formoterol and salmeterol, can be prescribed for regular use by patients with asthma. The long-term treatment with these agents has important benefits including reduced symptomatology and improved lung function. Formoterol as well as salmeterol have not been directly compared for safety and efficacy. The efficacy and safety of 6 months of treatment have been compared in multi-randomised open trials. In-vitro studies have shown that mast cells following treatment with formoterol have significantly decreased in numbers a finding, which is not supported by studies with salmeterol. However, studies by Vervloet et al argues that in-vivo or in real life these differences may not be important. Further larger double-blind randomized controlled trial studies with formoterol when compared its efficacy with salmeterol are required to make this decision.

        


    The study by Palmquist et al argues that formeterol is more protective against methacholine induced bronchoconstriction than salmeterol. However the doses to achieve this protection which they have implemented are much higher than the currently recommended one for the use of either drug in clinical practice. The effect of Formeterol on the bronchodilating ability of short acting B-agonist such as albuterol over a period of time needs to be investigated.

         

  • F
    Pierart, JH Wildhaber, I Vrancken, et al (Princess Margaret Hosp for Children, Perth, Western Australia)


    Washing plastic spacers in household detergent reduces electrostatic charge and greatly improves delivery


    Eur.Res Jr. 1999.

      

    Plastic spacers have been widely used along with pressurized metered dose inhalers. However the electrostatic charge that accumulates on this devices has been shown to have significant impact on drug delivery. In-vitro studies suggested that the spacers coated with ionic detergent have reduced static and improved drug delivery and hence a study was undertaken to study the effects of these household detergents on the electrostatic charge on plastic spacers. 

       


    In the vitro studies all detergents increased the mean small particles Salbutamol output by almost by 50%. This increase in output was noted even for spacers coated with very dilute detergent in constitution as low as 1 : 10,000. Spacers developed an electrostatic charge within one week after coating. The charged remained low for at least 4 weeks. This is surprising finding that the use of household detergent to clean and keep dry on a spacer can improve drug delivery 3-fold. This simple technique is not well-known and nor it is found in current asthma management guideline.

      


    The study by Pierart et al demonstrates that any household detergent when diluted will decrease the electrostatic charge in spacers for up to almost 4 weeks. This interesting findings require further studies to be performed along with other medications and other chlorofluorocarbon-free propellants to confirm the results. It is also important that we start educating our patients on the proper care of spacers so as to optimize drug delivery.

         

  • WH Tsai, WW Flemons, WA Whitelaw, et al (Univ of Calgary, alta, Canada)


    A comparison of Apnea-Hypopnea Indices Dervied From different Definitions of
    Hypopnea.


    Am J Respir Crit Care Med 159: 43-48, 1999.

      


    The apnea-hypopnea index is traditionally used to define obstructive sleep apnea. It is calculated as the sum of apneas plus hypopneas per hour of sleep. Apnea has been widely defined as cessation of airflow for more than 10 seconds; however a variety of definitions for hypopnea index exists and 1 survey found that no 2 laboratories used the same definition. The authors have studied the effects of 4 different arousal and desaturation -based polysomnographic scoring criteria for the apnea-hypopnea index and the measured prevalence of obstructive sleep apnea were compared in view of the lack of standard
    criteria for hypopnea.

      


    This article helps us to confront a major existing problem with the assessment sleep disordered breathing, the fact that hypopneas still remains to be defined in a precise manner. The term ‘hypopnea’ means different things to different people and the severity or presence prevalence, and response to tratment of ‘sleep apnea; depend on how hypopneas are defined. Hopefully, the Sleep Heart Health Study which is underway currently will lay an important groundwork to establish consistent definitions of sleep-disordered breathing events.

        

  • P Mayer, M Dematteis, JL Pepin, et al (Univ Hosp, Grenoble, France; Univ of Montreal)


    Peripheral Neuropathy in Sleep Apnea: A Tissue Marker of the Severity of Nocturnal Desaturation


    Am J Respir Crit Care Med 159:213-219, 1999.

      


    Patients with chronic airflow obstruction and chronic hypoxemia have been reported to have autonomic nervous system dysfunction. In patients with hypoxic chronic obstructive pulmonary disease and in diabetics, a modified tolerance of peripheral nerves to transient, experimentally induced limb ischemia has been reported. Peripheral nerve function in patients with obstructive sleep apnea without a recognised cause of neuropathy has been assessed with an ischemic test. This type of dysfunction may represent an early and quantifiable tissue marker of the consequences of nocturnal hypoxemia.

         


    Seventeen patients with severe obstructive sleep apnea without daytime hypoxemia were compared with 10 controls in this particular study. It was found that in patients with sleep obstructive sleep apnea, pre-ischemia senosry and mixed nerve potential amplitudes and sensory conduction velocity were lower than in controls, despite higher supramaximal stimulation. Seven patients with obstructive sleep apnea manifested resistance to ischemic nerve conduction failure during ischemia, whereas the other 10 patients and the 10 controls did not show this. 

        


    The authors have elegantly shown us that neuropathy correlates, at least partly, with hypoxemia. Obesity is a cofounder that simply cannot be controlled for in this kind of study. Perhaps the neuropathy associated with sleep apnea may partly explain the high prevalence of restless legs syndrome in these patients.

       

  • M
    Ferrer, TT Bauer, A Torres, et al (Univ of Barcelona)


    Effect of Nasogastric tube Size on Gastroesophageal Reflux and Microaspiration in Intubated Patients,


    Ann Intern Med 130: 991- 994, 1999.

       


    Gastroesophageal reflux is a risk factor for nosocomial pneumonia. Data regarding the use of a small-bore tube for prevention of nosocomial pneumonia are insufficient to allow its recommendation. Gastroesophageal reflux and microaspiration of gastric contents to the lower airways were compared in a randomized, 2 period cross over study in patients intubated with a conventional large-bore nasogastric tube or a small bore tube.

        


    This elegant study found no difference in aspiration of radiolabeled gastric contents with small bore nasogastric tubes. The authors correctly noted that because the small bore tubes may be more difficult to place, may become kinked or clogged more easily, and are more expensive, their use is not warranted as a measure to reduce pulmonary complications.

          

  • Cheng D, Iriarte GC (Kaiser Permanente, Downey,
    Calif)


    The Paper Clip Nasal Dilator


    Laryngoscope 108: 1247-1248, 1998.

        

    A narrow nasal valve results in serve nasal obstruction.

       

    Plastic coated nasal clip shaped and inserted in rounded end of nostril, kept for one month serves the purpose very well.

         

  • Filler
    RM, Forte V, Chait P (Univ of Toronto; Hosp for Sick Children, Toronto)


    Tracheobronchial Stenting for the Treatment of Airway Obstruction



    J Pediatr Surg 33: 304-311, 1998


        

    A balloon expandable stent, the Palmaz stent, was inserted into 16 children with a variety of major airway obstructions. Thirty stents were inserted in 24 separate procedures during the 5 yrs.

       

    Results showed they are extremely useful in the treatment of neonates and infants with localized tracheomalacia and bronchomalacia in those with airway obstruction caused by surgery for congenital tracheal stenosis, in patients with incurable congenital heart disease. The stents can be inserted easily and can be left for long periods if necessary.

       

    More clinical studies need to be performed using improved stent designs, to optimize the results – G.R. Holt.

          

  • Gozal D [Tulane Univ. New Orleans, La]


    Sleep-Disordered Breathing and School Performance in Children


    Pediatrics 102: 616-620, 1998

        


    About 2% of children have obstructive sleep apnea syndrome called OSAS. Failure to recognize and treat OSAS in this age group causes significant morbidity, but the possible cognitive consequences are not known. This study examined the incidence and academic consequences of sleep-associated gas-exchange abnormalities [SAGEA] in children. Pulse oximetry and transcutaneous partial pressure of carbon dioxide during sleep were monitored.

        


    The SAGEA abnormality was found in 18% of the children, in those children who underwent in tonsillectomy and adenoidectomy for OSAS with SAGEA showed a significant improvement in their school performances grade from 2.43 to 2.87. The untreated children showed no improvement nor did the children who did not have SAGEA. 

        


    We suggest that children with obstructive sleep apnea syndrome should be treated early for a better school performance and learning. 

         

  • Jouveshomme S, Dautzenberg B, Bakdach H, et al [Hopital Pitie-Salpetriere, Paris: Centre Medico Chirurgical du Val d’Or, St Cloud, France]


    Preliminary Results of Collapse Therapy with Plombage for Pulmonary Disease Caused by Multidrug-resistant Mycobacteria


    Am J Respir Crit Care Med 157: 1609-1615, 1998

        

    Although excisional surgery is recommended for patients with pulmonary diseases resulting from multidrug-resistant mycobacteria, two thirds of patients are high risk and therefore not eligible.

       


    Patients who had multidrug-resistant strains of mycobacteria and extensive bilateral cavitary disease were treated with collapse therapy.

         


    The cavitary portion of the lungs was collapsed and the intercostal extra periostal space was filled with 5 to 18 polystyrene spheres that were 4 cm in diameter.

       


    Collapse therapy is an effective treatment for high –risk patients with pulmonary disease caused by multidrug-resistant
    mycobacteria.

        

  • Aquino SL, Chiles C, Halford P [Wake Forest Univ, Winston-Salem, NC]


    Distinction of Consolidative Bronchioloalveolar Carcinoma From Pneumonia- Do CT Criteria Work?


    AJR 171: 359-363, 1998

       

    About 30% of bronchioalveolar carcinomas [BACs] are of the consolidative type. Certain chest CT findings are reportedly helpful in identifying pulmonary consolidation as BAC.

        


    In addition to consolidation, the review focused on features such as nodules and ground-glass opacities; cysts, or cavities within the consolidation. 

       


    In the BAC group, all patients had consolidation, more often with a peripheral distribution. 

        


    Findings that were present significantly more often in patients with consolidative BAC were coexisting nodules and a peripheral pattern of consoliation.

       


    Consolidative BAC should be suspected in adult patients with normal immunity who had a nonresolving peripheral consolidative pneumonia, particularly when associated nodules are present.

       

  • Valji AM, Maziak DE, Shamji FM, et al [Ottawa Civic Hosp, Ont, Canada]


    Postoneumonectomy Syndrome: Recognition and Management


    Chest 114: 1766-1769, 1998

       

    Postpneumonectomy syndrome [PPS] is caused by extreme shift and rotation of the mediastinum after pneumonectomy. It can produce 

       


    symptomatic proximal airway obstruction and airway trapping.

       


    Clinical diagnosis of PPS was made with the aid of chest radiographs, 2-dimensional echocardiography, pulmonary function tests, CT scans, and awake fiberoptic bronchoscopy.

       


    After complete mobilization of the mediastinum, anterior pericardiorrhaphy was done before the pericardium was anchored in the parasternal chest wall with suture. A Silastic prothesis filled with saline solution was placed to correct overshifting of the mediastinum.

        


    The diagnosis of PPS should be considered in all patients with progressive dyspnea after pneumonectomy. Repositioning of the mediastinum by means of a prosthesis filled with saline solution and anterior pericardiorrhaphy is a simple procedure and offers immediate and lasting symptomatic relief.

        

  • Martin
    Riedel (Germany)

    Editorial – Emergency diagnosis of pulmonary
    embolism

    Heart June 2001, vol.85: 607-609

       


    Emergency diagnosis of pulmonary embolism is the
    first prerequisite of saving the life of the
    patient.   CT has emerged as a very valuable tool. 
    It is both widely available and results are
    almost as good as angiography.

        


    Transthoracic echocardiography (TTE) is also widely
    available. It
    is non-invasive and very accurate in diagnosis of
    floating emboli. Transesophageal echocardiography
    (TOE) is perhaps even superior to TTE. It visualizes the proximal pulmonary
    arteries. When pulmonary embolism is suspected, TTA followed by TOE and
    CT gives very specific and precise diagnosis to
    enable surgery if indicated.

         

  • RJ
    Cerfolio, RP Tummala, WL Holman, et al ((Univ of
    alabam, Birmingham)

    A Prospective Algorithms for the Management of
    Air-Leaks After Pulmonary Section.

    Annalls Thorac Surg 1998

        

    Air leaks commonly occur following pulmonary
    resection leading to prolongation and the length of
    hospital stay. There have been very few objective
    data in regards to the management of these air
    leaks. The author have reported an algorithm that
    was applied to the post-operative management of
    chest tubes and air leaks. In a prospective series
    of 101 consecutive patients who had been subjected
    to elective pulmonary section.

        

    The newer classification suggested by them was
    applied to air leaks. Classifying them as those
    present only on forced expression, those present
    only during inspiration, those present during
    inspiration or those being continuous. All chest
    tubes were kept at 20cm suction on the postoperative
    day 2 and then they were converted to water seal. If
    both pneummothorax air leaks persisted on post operative
    day 3, the chest tube was placed to 10 cm of
    suction. Air leaks persisting after postoperative
    day 7 were treated by using talc slurry pleurodesis.

         

    It is indeed a novel approach and an organized
    approach as suggested by the authors. It is an
    interesting finding that most of the air leaks had
    disappeared by day 4 in the postoperative period,
    but those present on day 4 were still there on day
    7. The authors have suggested on the basis of their
    findings that definite pleurodesis should be carried
    out as soon as day 5.

        

  • Vitamin
    A Supplementation for Extremely – Low – Birth Weight
    Infants


    Tyson JE, for the National Institute of Child Health
    and Human Development Neonatal Research Network (Univ
    of Texas, Dallas; et al)

    N Engl J Med 340 : 1962-1968, 1999

         

    Extremely – low – birth – weight infants are at risk
    for chronic lung disease and sepsis. Administration
    of vitamin A 5000 IU intramuscularly 3 times a week
    for 4 weeks decreased biochemical evidence of
    vitamin A deficiency and slightly reduced the risk
    of chronic lung disease.

         

    Vitamin A is an essential micronutrient in the
    regeneration of epithelial tissue and also essential
    for septation of the lung and the differentiation of
    alveoli.

       

  • Quekel
    LGBA, Kessels AGH, Goei R, et al

    Miss Rate of Lung Cancer on the Chest Radiograph in Clinical Practice

    Chest 115: 720-724, 1999

        

    Despite best efforts, some Non Small Cell Lung Cancer [NSCLC] tumours are missed on chest radiographs. The miss rate for these tumours and the resultant implications for prognosis were evaluated. 

       

    Medical records and chest radiographs were retrospectively reviewed for 396 patients who were treated for primary
    NSCLC. Two independent radiologists reviewed all chest radiographs to determine whether any lesions had been missed in earlier radiographs, if a previously missed lesion was identified, a third independent radiologist confirmed its presence. 

        

    The time between the first appearance of the lesion on the chest radiograph and the date of histopathologic diagnosis was calculated to measure the delay in diagnosis. Findings showed that NSCLC presented as a nodular lesion in 259 of the 396 patients [65.4%]; the lesion was definitely missed in 49 [19%]; in fact the lesion was missed twice on consecutive chest radiographs in 16 patients and 6 patients it was missed 3 times or more.

         

    Location of the tumour did not influence the miss rate. However superimposing structures were significantly more common in the patients with missed lesions [71% vs 2%]. Additionally missed lesions were significantly smaller [median diameters 16 vs 40 mms]; most of the lesions 10 mms or less were missed in 71%.

        

    The median delay in the diagnosis of missed lesions was 472 days which was significantly longer than the 29 days for diagnosis of detected lesions. The extra delay resulted in the conversion of the tumours from stage T1 to T2 in 21 patients with missed lesions [43%]. Of the remaining 28 patients with missed lesions 22 continued to remain in stage T1 and 6 in stage T2.

        

    The authors conclude that miss rate of 19% [in other reported series from 20% to 50%] has a definite impact on prognosis and therefore remains a cause of concern.

        

  • C
    Wyser, P Stulz, M Soler, et al (Univ Hosp, Basel, Switzerland)

    Prospective Evaluation of an Algorithm for the Functional Assessment of Lung Resection Candidates.

    Am J Respir Crit Care Med 159: 1450-1456, 1999.

       


    The risk of postoperative complications is increased in patients with impaired pulmonary function and exercise testing and predicted postoperative function have been gaining importance in the assessment of candidates for lung resection surgery. The authors have worked out an algorithm for preoperative functional evaluation and they studied this algorithm prospectively.

      


    One hundred thirty-seven patients with clinically resectable lesions were studied. The algorithm incorporated cardiac history, including an electrocardiogram, and the 3 parameters of forced expiratory volume in 1 second, diffusing capacity of the lungs for carbon monoxide, and maximal oxygen uptake, and their respective predicted postoperative values were calculated on the basis of radionuclide perfusion scans.

      


    These patients were subjected to surgeries, 85 being lobectomies, 38 pneumonectomies, and 9 segmental or wedge resection surgeries. Five patients were considered functionally inoperable. Extubation within 24 hours was possible for all patients. 

      


    This algorithm resulted in a low complication rate, including mortality and morbidity and it seems to be very practical approach to the patient who is being considered for lung resection. The split function which they have used refers to a lung perfusion study that measures the amount of isotope perfusion to each lung. It does not require any intubation or split lung pulmonary function testing so it is relatively easy and practical. With only 2 postoperative deaths of a result of cardiopulmonary failure and both of these individuals were marginal at best as they had a maximum oxygen uptake of only
    10mg/kg.ml.

       

  • S
    Tich, M Seidlitz, E Dodin, et al (rush-Presbyterian-St. Luke’s Med Ctr, Chicago; Univ of Illinois, Chicago; Univ of Minnesota, Minneapolis)

    The Short-term Effects of Digoxin in Patients with Right Ventricular Dysfunction from Pulmonary Hypertension.

    Chest 114: 787-792, 1998.



    Digoxin as a treatment for congestive heart failure has been effectively proved in cases of patients with left ventricular systolic dysfunction. However, it is not recommended for patients with cor pulmonale because of the perception of increased toxic effects. The authors have studied a short-term gain with IV digoxin at 1mg and monitoring the patients after 2 hours in an invasive manner when neurohormonal studies were done.



    In patients with pulmonary hypertension and right ventricular failure, they have shown that digoxin produced a modest increase in cardiac output and a significant reduction in circulating norepinephrine, but there were no detectable effects of digoxin on baroreceptor response. 



    The favorable results in this study encourage a trial of digoxin therapy in patients with pulmonary hypertension and right ventricular failure. However as the study was a very short term we need to see whether there are really any favourable effects on clinical outcome on a long-term basis.

       

  • BL
    Davidson, (Allegheny Univ, Philedelphia)

    A Controlled Comparison of Directly Observed
    Therapy vs Self administered Therapy for Active
    Tuberculosis in the Urban United States.

    Chest 114: 1239 – 1243, 1998



    The single best way to control and prevent
    tuberculosis is successfully completed 
    treatment of advise disease. This required that
    patients take medication for at least 6 dmonths.
    Directly observed therapy (DOT) is a successful, yet
    controversial approach; patients only take
    medication while being surprised and observed.

        

    The study quoted herewith had involved 319 patients
    with confirmed active TB who began an outpatient
    drug therapy over period of a year.

         

    The study represents a contemporary trial in the
    United States evaluating the completion rates of DOT
    versus  SAT. The completion rates at 6 months
    and 8 months were 52% for DOT and 35% for SAT.
    Evaluating the completion rates calculated at 12
    months in the trial, the completion of therapy was
    70% for DAT and 53% for SAT. In order to successful
    treat TB and to prevent the development of multidrug
    resistant TB, we need to be treating the majority of
    patients with DOT programs which has been
    recommended by the Centers for Disease Control and
    Prevention as well as the WHO

        

  • E
    Pizzichini, MMM Pizzichini, P Gibson, et al (McMaster Univ, Hamilton, Ont; John Hunter Hosp, Newcastle, Australia; Mayo Clinic and Found, Rochester, Minn)

    Sputum Eosinophilia Predicts Benefit from Prednisone in Smokers With Chronic Obstructive Bronchitis.

    Am J Respir Crit Care Med 158: 1511-1517, 1998.

          

    Corticosteroid treatment has improved the on-doubt of its usefulness in patients with asthma and decreasing airway eosinophilia. However, its role in the treatment of chronic obstructive bronchitis is controversial. The authors present a placebo-controlled, crossover trial to determine whether the presence of sputum eosinophils predicts benefit from prednisone in 18 smokers with severe chronic obstructive bronchitis.

        

    Their findings that the presence of significantly elevated eosinophilia in the sputum identified a subset of patients who had objective improvements in effort, dyspnea, quality of life, and in their FEV1 interests us. It not only reduced sputum eosinophilia in these patients, but also reduced sputum fibrinogen concentrations. Thus supporting the concept that the use of prednisone may reduce airway fibrosis and remodeling, thereby slowing the progression of the disorder.

         

    In fact the findings of sputum eosinophilia may be further implemented in seeing if these patients do benefit with long term inhaled corticosteroids rather subject them to an exposure to systemic corticosteroids.

          

  • BL
    Charous, EF Halpern, GC Steven (Milwaukee Med Clinic, Wis)

    Hydroxychloroquine Improves Airflow and Lowers Circulating IgE Levels in Subjects With Moderate Symptomatic Asthma.

    J Allergy Clin Immunol 102: 198-203, 1998.

       

    Hydroxychloroquine, which is a disease-modifying agent, has an established efficacy in rheumatologic diseases. Its mechanism of action is thought to involve its ability to interfere with lysozome function and, thereby, inhibit of antigen processing and presentation, and subsequent T-cell activation.

       

    It has been used in asthma as a steroid sparing agent. Its uncommonly benign toxicity profile allows consideration of its use in these patients. The authors have conducted a double-blind, placebo-controlled trial of hydrochloroquine in patients with moderate symptomatic asthma.

        

    The authors have demonstrated the ability of hydrochloroquine to statistically significantly improve FEV1, morning and evening peak flows, and requirement for B2-agonists. Immune parameters that improved included the mean total IgE concentration. One final important comment is that as with hydrocholoroquine’s known mode of action in rheumatologic disease, the onset of efficacy in asthma was slow, and these changes did not occur until 30 weeks into the trial. A larger study group is required to further prove its efficacy.

       

  • Ann Ekberg – Jansson, Sven Larsson et al


    Editorial – Preventing exacerbations of chronic bronchitis and COPD.


    BMJ, 26 May, 2001; pg.1259-1260.

      


    Exacerbations of COPD affect quality of life and cost of managing the disease. Recent data show good correlation between hypersecretion and long-term deterioration of ventilatory function in these patients. This is why mucolytics may influence disease progression in COPD.

       


    Cochrane review reports a meta-analysis of 22 studies of 10 drugs. Treated patients showed a significant reduction over controls in the number of exacerbations and number of days each exacerbation lasted. No difference in lung function or in adverse effects was seen.

      


    Drug contributing most to the beneficial effects seems to be acetylcysteine -possibly by antioxidative effect. Ambroxol also reduces exacerbations – due to mucolytic effect and antioxidative effects. It is also a secretagogue for surfactant (this has antibacterial properties).

      


    Orally administered bacterial lysates that stimulate immune system have been used for several years. OM 85 BV, a lysate of 8 pulmonary pathogens has been evaluated in a meta-analysis.

       


    The present Cochrane report, together with that on oral vaccination with whole killed H.influenzae and the meta-analysis treatment with OM85 BV indicates that different therapeutic regimes might prevent exacerbations of chronic bronchitis and
    COPD.

           

  • Adrian K Dixon

    The non-invasive diagnosis of pulmonary embolus

    The pretest probability helps determine the best imaging method.



    BMJ, Vol.323, 25 August, 2001, pg.412


       

    Pulmonary embolus is a very elusive diagnosis. Doctors are well aware of venous thrombosis but still many doctors are not well informed of pulmonary embolism.

       

    Pulmonary angiography is the gold standard for diagnosis but it is invasive perceived as dangerous and not widely available. The non-invasive diagnostic procedures are not easily available.

          

    “Lung scan” is used either as a technetium-99m labelled aerosol or krypton-81m. These are sometimes substituted by spiral computed
    tomography.

         

  • C H Compton, J Gubb, et al for the International Study Group.

    Cilomilast, a selective phosphodiesterase-4 inhibitor for treatment of patients with chronic obstructive pulmonary disease: a randomized, dose-ranging study.

    The Lancet 2001; 358: 265-70

          


    Phosphodiesterase-4 inhibitor for example theophylline (non-selective) has been used for the treatment of COPD (chronic obstructive pulmonary disease). Their efficacy is marginal but there is no other treatment.

         


    Cilomilast is an orally active, potent, selective phosphodiesterase type 4 inhibitor. In a clinical trial, cilomast 15mg twice daily has been found to be effective in the maintenance treatment of
    COPD.

          

  • Richard N. Channick, Gerald Simonneau et al 

    Effects of the Dual Endothelin-Receptor Antagonist Bosentan in Patients With Pulmonary Hypertension: A Randomised Placebo-Controlled Study 

    Lancet, Vol.358, October 6, 2001, Pg. 1119-23

          


    Summary: Endothelin-1, a powerful vasoconstrictor and mitogen might be a cause of pulmonary hypertension. Bosentan (Ro 47-0203), an orally active non-peptide antagonist of both endothelin receptor subtypes (ETA and ETB) has been shown to decrease inflammatory reactions, prevent increase in permeability of pulmonary vessels and prevent development of fibrosis in animals with pulmonary inflammation.

          


    This is a double-blind, placebo-controlled study in 32 patients with pulmonary hypertension (primary or associated with scleroderma). Patients were randomly assigned to bosentan or placebo for a minimum of 12 weeks. The primary endpoint was change in exercise capacity. Secondary endpoints included changes in cardiopulmonary haemodynamics, Borg dyspnoea index, WHO functional class, and withdrawal due to clinical worsening.

        


    Interpretation of the study was that bosentan increases exercise capacity and improves haemodynamics in patients with pulmonary hypertension, suggesting that endothelin has an important role in pulmonary hypertension.

            

  • Pulmonary Embolism Prevention (PEP) Trial Collaborative Group

    Prevention of pulmonary embolism and deep vein thrombosis with low dose aspirin: Pulmonary Embolism Prevention (PEP) trial.

    Lancet, vol.355, 15 April 2000; 1295

            

    Previous trials of antiplatelet therapy for the prevention of venous thromboembolism have individually been inconclusive, but a meta-analysis of their results indicated reductions in the risks of deep-vein thrombosis and of pulmonary embolism in various high-risk groups. The aim of this large randomized placebo-controlled trial was to confirm or refute these apparent benefits.

            

    During 1992-1998, 148 hospitals in Australia, New Zealand, South Africa, Sweden and the UK randomised 13 356 patients undergoing surgery for hip fracture, and 22 hospitals in New Zealand randomized a further 4088 patients undergoing elective arthroplasty. Study treatment was 160mg daily aspirin or placebo, started preoperatively and continued for 35 days. Patients received any other thromboprophylaxis thought necessary. Follow-up was of mortality and of in-hospital morbidity up to days 35.

            

    These results, along with those of the previous meta-analysis, show that aspirin reduces the risk of pulmonary embolism and deep-vein thrombosis by at least a third throughout a period of increased risk. Hence there is now good evidence for considering aspirin routinely in a wide range of surgical and medical groups at high risk of venous
    thromboembolism.

           


 



 

 

Speciality Spotlight

 

 

Respiratory
      

  • C Bodner, for the Aberdeen WHEASE Group (Univ of Aberdeen, Scotland)
    Family size, childhood infection and Atopic disease 
    Thorax, 53: 28-32, 1998.
        
    The prevalence of asthma and other allergic disease among children in the developed countries has increased in the past 3 decades. 
       
    Bodner and Aberdeen have in this group reported on cross-sectional survey of 2111 subjects analysed for the determinants of asthma and atopy. They found that hay-fever and eczema were inversely related to family size but asthma less so. They also found a small increased risk for asthma with increasing number of childhood infection. Measles, however, demonstrated a small protective effect for asthma. The effect of childhood infections on this immunologic perturbation is unknown but is likely specific to the class or type of infection.
        

  • M Kraft, RJ Martin, S Wilson, et al (Univ of Colorado, Denver; Univ of Southampton, England)
    Lymphocyte and Eosinophilia influx into Aleovular Tissue in Nocturnal Asthma
    Am. J Resp.Crit Care Med 159: 228-234,1999.
        
    Inflammatory cytokines which are produced by T lymphocytes help the promotion of eosinophil migration from blood through the vascular endothelium and the key source for these cytokines probably is the CD4+ lymphocytes, which may also produce chemokines involved in eosinophil chemotaxis, survival, maturation as well as their activation. 
         
    The study has been performed into two separate groups. The patients were subjected to bronchoscopies followed by endobronchial and transbronchial biopsy specimens. Amongst patients suffering from nocturnal asthma and those without suffering from nocturnal asthma i.e. nonnocturnal asthma group. Bronchoscopies were performed in a random order, a week apart at 1 at 4pm and the other at 4am. The numbers of CD3+, CD4+, CD8+ cells and EG2+ eosinophils were measured in the epithelium, lamina propria and the alveolar tissues. 
        
    These studies from kraft and her colleagues at National Jewish have enlightened us with a role of alveolar tissue inflammation in asthma. The study demonstrates that there are an increased number of CD4+ lymphocytes in alveoli in patients with nocturnal asthma and with those correlated inversely with nighttime lung function. Whether this was causally related is unknown. More information is needed regarding the circulation of CD4 lymphocytes in the lungs and their release of potential mediators of asthma symptoms. These cells may be either innocent bystanders or be the result in the alveoli from the spilling over from the increased numbers in the airways. Further studies of optimal timing of anti-inflammatory mediators in patients with nocturnal asthma are needed.
         

  • BH Rowe, GW Bota, et al (Univ of Alberta, Edmonton, Canada; Sudbury Regional Hosp, Ont, Canada; univ of British Columbia, Vancouver Canada, et al)
    Inhaled Budesonide in Addition to Oral corticosteroids to prevent asthma relapse following discharge from the Emergency Dept. – A Randomized Control Trial.
    Jama 281: 2119-2126, 1999
      
    Systemic corticosteroid treatment can decrease acute asthma relapses after discharge from the emergency department. This study undertook to decide whether inhaled corticosteroids provide any additional benefit. 
      
    The study is double-blind placebo-controlled randomized clinical trial which was conducted over a period of 2 yrs on patients between ages from 16 to 60. 188 patients were included in this study and on discharge they were given non-tapering course of oral prednisolone which is 50mg/day for 7 days along with 1600 mg inhaled budesonide or a placebo. These patients were followed up for a period of 21 days. 
      
    This well performed study demonstrates a beneficial effect from the addition of inhaled corticosteroids at the time of discharge of an asthma patient from the emergency dept. For a variety of reasons, the emergency room physicians often do not add inhaled corticosteroids for asthma patients at discharge. Few of them being cost, lack of long term of follow up with the patient, interference with primary care physician’s role inadequate time to provide a metered dose inhaler technique information. 
      
    However, this study argues whether we should be changing our emergency department practice to include inhaled corticosteroids for a minimum of 3 week period probably even longer and to prove our point we need further studies to determine the optimal dosages and the length of treatment required.
        

  • SF Lanes, JE Garrett, et al (Epidemiology Resources Inc, Newton Lower Falls, Mass; Green Lane Hosp, Auckland, New Zealand, Vancouver Gen Hosp, BC, Canada; et al)
    The effect of adding atropine bromide and salbutamol in the treatment of acute asthma. This is a pooled analysis of 3 trials.
    Chest 114: 365-373,1998.
        
    For patients with acute asthma, it is not clear whether an addition of ipratropium bromide would result in bronchodilatation rather than just b2-agonist therapy. Three major randomized trials which have been performed were pulled into the study. An American study found no difference, whereas study from New Zealand showed significant advantage with the combination therapy and a Canadian study found a non-significant benefit. Results of these 3 trials have been pooled to estimate the effects of ipratropium bromide + salbutamol in patients with acute asthma. 
        
    Several studies have demonstrated that ipratropium bromide should be added to acute treatment for patients with asthma both in adult as well as in children. Zorc et al found a significant reduction in length of stay in emergency department and use of additional doses of albuterol. A reduction of length of stay is found in any busy urban emergency department. It is important to keep in mind that the effectiveness of ipratropium is primarily in acute treatment in the emergency dept. and it should not be continued in hospital setting for more than 36 hours. Thus it can be probably concluded that the additional use of ipratropium is not useful and will diminish any potential cost savings from the acute use of ipratropium.
        
    It is best to say the use of ipratropium bromide should be restricted to emergency dept. for a maximum period of upto 36 hours in case of acute asthmatic attack.
        

  • D Vervloet, T Ekstrom, et al (Hopital Sainte Marguerite, Marseilles, France; Univ Hosp, Sweden, Ospedale Civile, Osimo, Italy; et al)
    A 6-Month Comparison Between Formeterol and Salmerterol in Patients with Reversible Obstructive Airways Disease
    Respir Med 92: 836-842, 1998.
      
    The newer long acting B2-agonists including formoterol and salmeterol, can be prescribed for regular use by patients with asthma. The long-term treatment with these agents has important benefits including reduced symptomatology and improved lung function. Formoterol as well as salmeterol have not been directly compared for safety and efficacy. The efficacy and safety of 6 months of treatment have been compared in multi-randomised open trials. In-vitro studies have shown that mast cells following treatment with formoterol have significantly decreased in numbers a finding, which is not supported by studies with salmeterol. However, studies by Vervloet et al argues that in-vivo or in real life these differences may not be important. Further larger double-blind randomized controlled trial studies with formoterol when compared its efficacy with salmeterol are required to make this decision.
        
    The study by Palmquist et al argues that formeterol is more protective against methacholine induced bronchoconstriction than salmeterol. However the doses to achieve this protection which they have implemented are much higher than the currently recommended one for the use of either drug in clinical practice. The effect of Formeterol on the bronchodilating ability of short acting B-agonist such as albuterol over a period of time needs to be investigated.
         

  • F Pierart, JH Wildhaber, I Vrancken, et al (Princess Margaret Hosp for Children, Perth, Western Australia)
    Washing plastic spacers in household detergent reduces electrostatic charge and greatly improves delivery
    Eur.Res Jr. 1999.
      
    Plastic spacers have been widely used along with pressurized metered dose inhalers. However the electrostatic charge that accumulates on this devices has been shown to have significant impact on drug delivery. In-vitro studies suggested that the spacers coated with ionic detergent have reduced static and improved drug delivery and hence a study was undertaken to study the effects of these household detergents on the electrostatic charge on plastic spacers. 
       
    In the vitro studies all detergents increased the mean small particles Salbutamol output by almost by 50%. This increase in output was noted even for spacers coated with very dilute detergent in constitution as low as 1 : 10,000. Spacers developed an electrostatic charge within one week after coating. The charged remained low for at least 4 weeks. This is surprising finding that the use of household detergent to clean and keep dry on a spacer can improve drug delivery 3-fold. This simple technique is not well-known and nor it is found in current asthma management guideline.
      
    The study by Pierart et al demonstrates that any household detergent when diluted will decrease the electrostatic charge in spacers for up to almost 4 weeks. This interesting findings require further studies to be performed along with other medications and other chlorofluorocarbon-free propellants to confirm the results. It is also important that we start educating our patients on the proper care of spacers so as to optimize drug delivery.
         

  • WH Tsai, WW Flemons, WA Whitelaw, et al (Univ of Calgary, alta, Canada)
    A comparison of Apnea-Hypopnea Indices Dervied From different Definitions of Hypopnea.
    Am J Respir Crit Care Med 159: 43-48, 1999.
      
    The apnea-hypopnea index is traditionally used to define obstructive sleep apnea. It is calculated as the sum of apneas plus hypopneas per hour of sleep. Apnea has been widely defined as cessation of airflow for more than 10 seconds; however a variety of definitions for hypopnea index exists and 1 survey found that no 2 laboratories used the same definition. The authors have studied the effects of 4 different arousal and desaturation -based polysomnographic scoring criteria for the apnea-hypopnea index and the measured prevalence of obstructive sleep apnea were compared in view of the lack of standard criteria for hypopnea.
      
    This article helps us to confront a major existing problem with the assessment sleep disordered breathing, the fact that hypopneas still remains to be defined in a precise manner. The term ‘hypopnea’ means different things to different people and the severity or presence prevalence, and response to tratment of ‘sleep apnea; depend on how hypopneas are defined. Hopefully, the Sleep Heart Health Study which is underway currently will lay an important groundwork to establish consistent definitions of sleep-disordered breathing events.
        

  • P Mayer, M Dematteis, JL Pepin, et al (Univ Hosp, Grenoble, France; Univ of Montreal)
    Peripheral Neuropathy in Sleep Apnea: A Tissue Marker of the Severity of Nocturnal Desaturation
    Am J Respir Crit Care Med 159:213-219, 1999.
      
    Patients with chronic airflow obstruction and chronic hypoxemia have been reported to have autonomic nervous system dysfunction. In patients with hypoxic chronic obstructive pulmonary disease and in diabetics, a modified tolerance of peripheral nerves to transient, experimentally induced limb ischemia has been reported. Peripheral nerve function in patients with obstructive sleep apnea without a recognised cause of neuropathy has been assessed with an ischemic test. This type of dysfunction may represent an early and quantifiable tissue marker of the consequences of nocturnal hypoxemia.
         
    Seventeen patients with severe obstructive sleep apnea without daytime hypoxemia were compared with 10 controls in this particular study. It was found that in patients with sleep obstructive sleep apnea, pre-ischemia senosry and mixed nerve potential amplitudes and sensory conduction velocity were lower than in controls, despite higher supramaximal stimulation. Seven patients with obstructive sleep apnea manifested resistance to ischemic nerve conduction failure during ischemia, whereas the other 10 patients and the 10 controls did not show this. 
        
    The authors have elegantly shown us that neuropathy correlates, at least partly, with hypoxemia. Obesity is a cofounder that simply cannot be controlled for in this kind of study. Perhaps the neuropathy associated with sleep apnea may partly explain the high prevalence of restless legs syndrome in these patients.
       

  • M Ferrer, TT Bauer, A Torres, et al (Univ of Barcelona)
    Effect of Nasogastric tube Size on Gastroesophageal Reflux and Microaspiration in Intubated Patients,
    Ann Intern Med 130: 991- 994, 1999.
       
    Gastroesophageal reflux is a risk factor for nosocomial pneumonia. Data regarding the use of a small-bore tube for prevention of nosocomial pneumonia are insufficient to allow its recommendation. Gastroesophageal reflux and microaspiration of gastric contents to the lower airways were compared in a randomized, 2 period cross over study in patients intubated with a conventional large-bore nasogastric tube or a small bore tube.
        
    This elegant study found no difference in aspiration of radiolabeled gastric contents with small bore nasogastric tubes. The authors correctly noted that because the small bore tubes may be more difficult to place, may become kinked or clogged more easily, and are more expensive, their use is not warranted as a measure to reduce pulmonary complications.
          

  • Cheng D, Iriarte GC (Kaiser Permanente, Downey, Calif)
    The Paper Clip Nasal Dilator
    Laryngoscope 108: 1247-1248, 1998.
        
    A narrow nasal valve results in serve nasal obstruction.
       
    Plastic coated nasal clip shaped and inserted in rounded end of nostril, kept for one month serves the purpose very well.
         

  • Filler RM, Forte V, Chait P (Univ of Toronto; Hosp for Sick Children, Toronto)
    Tracheobronchial Stenting for the Treatment of Airway Obstruction
    J Pediatr Surg 33: 304-311, 1998
        
    A balloon expandable stent, the Palmaz stent, was inserted into 16 children with a variety of major airway obstructions. Thirty stents were inserted in 24 separate procedures during the 5 yrs.
       
    Results showed they are extremely useful in the treatment of neonates and infants with localized tracheomalacia and bronchomalacia in those with airway obstruction caused by surgery for congenital tracheal stenosis, in patients with incurable congenital heart disease. The stents can be inserted easily and can be left for long periods if necessary.
       
    More clinical studies need to be performed using improved stent designs, to optimize the results – G.R. Holt.
          

  • Gozal D [Tulane Univ. New Orleans, La]
    Sleep-Disordered Breathing and School Performance in Children
    Pediatrics 102: 616-620, 1998
        
    About 2% of children have obstructive sleep apnea syndrome called OSAS. Failure to recognize and treat OSAS in this age group causes significant morbidity, but the possible cognitive consequences are not known. This study examined the incidence and academic consequences of sleep-associated gas-exchange abnormalities [SAGEA] in children. Pulse oximetry and transcutaneous partial pressure of carbon dioxide during sleep were monitored.
        
    The SAGEA abnormality was found in 18% of the children, in those children who underwent in tonsillectomy and adenoidectomy for OSAS with SAGEA showed a significant improvement in their school performances grade from 2.43 to 2.87. The untreated children showed no improvement nor did the children who did not have SAGEA. 
        
    We suggest that children with obstructive sleep apnea syndrome should be treated early for a better school performance and learning. 
         

  • Jouveshomme S, Dautzenberg B, Bakdach H, et al [Hopital Pitie-Salpetriere, Paris: Centre Medico Chirurgical du Val d’Or, St Cloud, France]
    Preliminary Results of Collapse Therapy with Plombage for Pulmonary Disease Caused by Multidrug-resistant Mycobacteria
    Am J Respir Crit Care Med 157: 1609-1615, 1998
        
    Although excisional surgery is recommended for patients with pulmonary diseases resulting from multidrug-resistant mycobacteria, two thirds of patients are high risk and therefore not eligible.
       
    Patients who had multidrug-resistant strains of mycobacteria and extensive bilateral cavitary disease were treated with collapse therapy.
         
    The cavitary portion of the lungs was collapsed and the intercostal extra periostal space was filled with 5 to 18 polystyrene spheres that were 4 cm in diameter.
       
    Collapse therapy is an effective treatment for high –risk patients with pulmonary disease caused by multidrug-resistant mycobacteria.
        

  • Aquino SL, Chiles C, Halford P [Wake Forest Univ, Winston-Salem, NC]
    Distinction of Consolidative Bronchioloalveolar Carcinoma From Pneumonia- Do CT Criteria Work?
    AJR 171: 359-363, 1998
       
    About 30% of bronchioalveolar carcinomas [BACs] are of the consolidative type. Certain chest CT findings are reportedly helpful in identifying pulmonary consolidation as BAC.
        
    In addition to consolidation, the review focused on features such as nodules and ground-glass opacities; cysts, or cavities within the consolidation. 
       
    In the BAC group, all patients had consolidation, more often with a peripheral distribution. 
        
    Findings that were present significantly more often in patients with consolidative BAC were coexisting nodules and a peripheral pattern of consoliation.
       
    Consolidative BAC should be suspected in adult patients with normal immunity who had a nonresolving peripheral consolidative pneumonia, particularly when associated nodules are present.
       

  • Valji AM, Maziak DE, Shamji FM, et al [Ottawa Civic Hosp, Ont, Canada]
    Postoneumonectomy Syndrome: Recognition and Management
    Chest 114: 1766-1769, 1998
       
    Postpneumonectomy syndrome [PPS] is caused by extreme shift and rotation of the mediastinum after pneumonectomy. It can produce 
       
    symptomatic proximal airway obstruction and airway trapping.
       
    Clinical diagnosis of PPS was made with the aid of chest radiographs, 2-dimensional echocardiography, pulmonary function tests, CT scans, and awake fiberoptic bronchoscopy.
       
    After complete mobilization of the mediastinum, anterior pericardiorrhaphy was done before the pericardium was anchored in the parasternal chest wall with suture. A Silastic prothesis filled with saline solution was placed to correct overshifting of the mediastinum.
        
    The diagnosis of PPS should be considered in all patients with progressive dyspnea after pneumonectomy. Repositioning of the mediastinum by means of a prosthesis filled with saline solution and anterior pericardiorrhaphy is a simple procedure and offers immediate and lasting symptomatic relief.
        

  • Martin Riedel (Germany)
    Editorial – Emergency diagnosis of pulmonary embolism
    Heart June 2001, vol.85: 607-609
       

    Emergency diagnosis of pulmonary embolism is the first prerequisite of saving the life of the patient.   CT has emerged as a very valuable tool.  It is both widely available and results are almost as good as angiography.
        

    Transthoracic echocardiography (TTE) is also widely available. It is non-invasive and very accurate in diagnosis of floating emboli. Transesophageal echocardiography (TOE) is perhaps even superior to TTE. It visualizes the proximal pulmonary arteries. When pulmonary embolism is suspected, TTA followed by TOE and CT gives very specific and precise diagnosis to enable surgery if indicated.
         

  • RJ Cerfolio, RP Tummala, WL Holman, et al ((Univ of alabam, Birmingham)
    A Prospective Algorithms for the Management of Air-Leaks After Pulmonary Section.
    Annalls Thorac Surg 1998
        
    Air leaks commonly occur following pulmonary resection leading to prolongation and the length of hospital stay. There have been very few objective data in regards to the management of these air leaks. The author have reported an algorithm that was applied to the post-operative management of chest tubes and air leaks. In a prospective series of 101 consecutive patients who had been subjected to elective pulmonary section.
        
    The newer classification suggested by them was applied to air leaks. Classifying them as those present only on forced expression, those present only during inspiration, those present during inspiration or those being continuous. All chest tubes were kept at 20cm suction on the postoperative day 2 and then they were converted to water seal. If both pneummothorax air leaks persisted on post operative day 3, the chest tube was placed to 10 cm of suction. Air leaks persisting after postoperative day 7 were treated by using talc slurry pleurodesis.
         
    It is indeed a novel approach and an organized approach as suggested by the authors. It is an interesting finding that most of the air leaks had disappeared by day 4 in the postoperative period, but those present on day 4 were still there on day 7. The authors have suggested on the basis of their findings that definite pleurodesis should be carried out as soon as day 5.
        

  • Vitamin A Supplementation for Extremely – Low – Birth Weight Infants
    Tyson JE, for the National Institute of Child Health and Human Development Neonatal Research Network (Univ of Texas, Dallas; et al)
    N Engl J Med 340 : 1962-1968, 1999
         
    Extremely – low – birth – weight infants are at risk for chronic lung disease and sepsis. Administration of vitamin A 5000 IU intramuscularly 3 times a week for 4 weeks decreased biochemical evidence of vitamin A deficiency and slightly reduced the risk of chronic lung disease.
         
    Vitamin A is an essential micronutrient in the regeneration of epithelial tissue and also essential for septation of the lung and the differentiation of alveoli.
       

  • Quekel LGBA, Kessels AGH, Goei R, et al
    Miss Rate of Lung Cancer on the Chest Radiograph in Clinical Practice
    Chest 115: 720-724, 1999
        
    Despite best efforts, some Non Small Cell Lung Cancer [NSCLC] tumours are missed on chest radiographs. The miss rate for these tumours and the resultant implications for prognosis were evaluated. 
       
    Medical records and chest radiographs were retrospectively reviewed for 396 patients who were treated for primary NSCLC. Two independent radiologists reviewed all chest radiographs to determine whether any lesions had been missed in earlier radiographs, if a previously missed lesion was identified, a third independent radiologist confirmed its presence. 
        
    The time between the first appearance of the lesion on the chest radiograph and the date of histopathologic diagnosis was calculated to measure the delay in diagnosis. Findings showed that NSCLC presented as a nodular lesion in 259 of the 396 patients [65.4%]; the lesion was definitely missed in 49 [19%]; in fact the lesion was missed twice on consecutive chest radiographs in 16 patients and 6 patients it was missed 3 times or more.
         
    Location of the tumour did not influence the miss rate. However superimposing structures were significantly more common in the patients with missed lesions [71% vs 2%]. Additionally missed lesions were significantly smaller [median diameters 16 vs 40 mms]; most of the lesions 10 mms or less were missed in 71%.
        
    The median delay in the diagnosis of missed lesions was 472 days which was significantly longer than the 29 days for diagnosis of detected lesions. The extra delay resulted in the conversion of the tumours from stage T1 to T2 in 21 patients with missed lesions [43%]. Of the remaining 28 patients with missed lesions 22 continued to remain in stage T1 and 6 in stage T2.
        
    The authors conclude that miss rate of 19% [in other reported series from 20% to 50%] has a definite impact on prognosis and therefore remains a cause of concern.
        

  • C Wyser, P Stulz, M Soler, et al (Univ Hosp, Basel, Switzerland)
    Prospective Evaluation of an Algorithm for the Functional Assessment of Lung Resection Candidates.
    Am J Respir Crit Care Med 159: 1450-1456, 1999.
       
    The risk of postoperative complications is increased in patients with impaired pulmonary function and exercise testing and predicted postoperative function have been gaining importance in the assessment of candidates for lung resection surgery. The authors have worked out an algorithm for preoperative functional evaluation and they studied this algorithm prospectively.
      
    One hundred thirty-seven patients with clinically resectable lesions were studied. The algorithm incorporated cardiac history, including an electrocardiogram, and the 3 parameters of forced expiratory volume in 1 second, diffusing capacity of the lungs for carbon monoxide, and maximal oxygen uptake, and their respective predicted postoperative values were calculated on the basis of radionuclide perfusion scans.
      
    These patients were subjected to surgeries, 85 being lobectomies, 38 pneumonectomies, and 9 segmental or wedge resection surgeries. Five patients were considered functionally inoperable. Extubation within 24 hours was possible for all patients. 
      
    This algorithm resulted in a low complication rate, including mortality and morbidity and it seems to be very practical approach to the patient who is being considered for lung resection. The split function which they have used refers to a lung perfusion study that measures the amount of isotope perfusion to each lung. It does not require any intubation or split lung pulmonary function testing so it is relatively easy and practical. With only 2 postoperative deaths of a result of cardiopulmonary failure and both of these individuals were marginal at best as they had a maximum oxygen uptake of only 10mg/kg.ml.
       

  • S Tich, M Seidlitz, E Dodin, et al (rush-Presbyterian-St. Luke’s Med Ctr, Chicago; Univ of Illinois, Chicago; Univ of Minnesota, Minneapolis)
    The Short-term Effects of Digoxin in Patients with Right Ventricular Dysfunction from Pulmonary Hypertension.
    Chest 114: 787-792, 1998.

    Digoxin as a treatment for congestive heart failure has been effectively proved in cases of patients with left ventricular systolic dysfunction. However, it is not recommended for patients with cor pulmonale because of the perception of increased toxic effects. The authors have studied a short-term gain with IV digoxin at 1mg and monitoring the patients after 2 hours in an invasive manner when neurohormonal studies were done.

    In patients with pulmonary hypertension and right ventricular failure, they have shown that digoxin produced a modest increase in cardiac output and a significant reduction in circulating norepinephrine, but there were no detectable effects of digoxin on baroreceptor response. 

    The favorable results in this study encourage a trial of digoxin therapy in patients with pulmonary hypertension and right ventricular failure. However as the study was a very short term we need to see whether there are really any favourable effects on clinical outcome on a long-term basis.
       

  • BL Davidson, (Allegheny Univ, Philedelphia)
    A Controlled Comparison of Directly Observed Therapy vs Self administered Therapy for Active Tuberculosis in the Urban United States.
    Chest 114: 1239 – 1243, 1998

    The single best way to control and prevent tuberculosis is successfully completed  treatment of advise disease. This required that patients take medication for at least 6 dmonths. Directly observed therapy (DOT) is a successful, yet controversial approach; patients only take medication while being surprised and observed.
        
    The study quoted herewith had involved 319 patients with confirmed active TB who began an outpatient drug therapy over period of a year.
         
    The study represents a contemporary trial in the United States evaluating the completion rates of DOT versus  SAT. The completion rates at 6 months and 8 months were 52% for DOT and 35% for SAT. Evaluating the completion rates calculated at 12 months in the trial, the completion of therapy was 70% for DAT and 53% for SAT. In order to successful treat TB and to prevent the development of multidrug resistant TB, we need to be treating the majority of patients with DOT programs which has been recommended by the Centers for Disease Control and Prevention as well as the WHO
        

  • E Pizzichini, MMM Pizzichini, P Gibson, et al (McMaster Univ, Hamilton, Ont; John Hunter Hosp, Newcastle, Australia; Mayo Clinic and Found, Rochester, Minn)
    Sputum Eosinophilia Predicts Benefit from Prednisone in Smokers With Chronic Obstructive Bronchitis.
    Am J Respir Crit Care Med 158: 1511-1517, 1998.
          
    Corticosteroid treatment has improved the on-doubt of its usefulness in patients with asthma and decreasing airway eosinophilia. However, its role in the treatment of chronic obstructive bronchitis is controversial. The authors present a placebo-controlled, crossover trial to determine whether the presence of sputum eosinophils predicts benefit from prednisone in 18 smokers with severe chronic obstructive bronchitis.
        
    Their findings that the presence of significantly elevated eosinophilia in the sputum identified a subset of patients who had objective improvements in effort, dyspnea, quality of life, and in their FEV1 interests us. It not only reduced sputum eosinophilia in these patients, but also reduced sputum fibrinogen concentrations. Thus supporting the concept that the use of prednisone may reduce airway fibrosis and remodeling, thereby slowing the progression of the disorder.
         
    In fact the findings of sputum eosinophilia may be further implemented in seeing if these patients do benefit with long term inhaled corticosteroids rather subject them to an exposure to systemic corticosteroids.
          

  • BL Charous, EF Halpern, GC Steven (Milwaukee Med Clinic, Wis)
    Hydroxychloroquine Improves Airflow and Lowers Circulating IgE Levels in Subjects With Moderate Symptomatic Asthma.
    J Allergy Clin Immunol 102: 198-203, 1998.
       
    Hydroxychloroquine, which is a disease-modifying agent, has an established efficacy in rheumatologic diseases. Its mechanism of action is thought to involve its ability to interfere with lysozome function and, thereby, inhibit of antigen processing and presentation, and subsequent T-cell activation.
       
    It has been used in asthma as a steroid sparing agent. Its uncommonly benign toxicity profile allows consideration of its use in these patients. The authors have conducted a double-blind, placebo-controlled trial of hydrochloroquine in patients with moderate symptomatic asthma.
        
    The authors have demonstrated the ability of hydrochloroquine to statistically significantly improve FEV1, morning and evening peak flows, and requirement for B2-agonists. Immune parameters that improved included the mean total IgE concentration. One final important comment is that as with hydrocholoroquine’s known mode of action in rheumatologic disease, the onset of efficacy in asthma was slow, and these changes did not occur until 30 weeks into the trial. A larger study group is required to further prove its efficacy.
       

  • Ann Ekberg – Jansson, Sven Larsson et al
    Editorial – Preventing exacerbations of chronic bronchitis and COPD.
    BMJ, 26 May, 2001; pg.1259-1260.
      
    Exacerbations of COPD affect quality of life and cost of managing the disease. Recent data show good correlation between hypersecretion and long-term deterioration of ventilatory function in these patients. This is why mucolytics may influence disease progression in COPD.
       
    Cochrane review reports a meta-analysis of 22 studies of 10 drugs. Treated patients showed a significant reduction over controls in the number of exacerbations and number of days each exacerbation lasted. No difference in lung function or in adverse effects was seen.
      
    Drug contributing most to the beneficial effects seems to be acetylcysteine -possibly by antioxidative effect. Ambroxol also reduces exacerbations – due to mucolytic effect and antioxidative effects. It is also a secretagogue for surfactant (this has antibacterial properties).
      
    Orally administered bacterial lysates that stimulate immune system have been used for several years. OM 85 BV, a lysate of 8 pulmonary pathogens has been evaluated in a meta-analysis.
       
    The present Cochrane report, together with that on oral vaccination with whole killed H.influenzae and the meta-analysis treatment with OM85 BV indicates that different therapeutic regimes might prevent exacerbations of chronic bronchitis and COPD.
           

  • Adrian K Dixon
    The non-invasive diagnosis of pulmonary embolus
    The pretest probability helps determine the best imaging method.

    BMJ, Vol.323, 25 August, 2001, pg.412
       
    Pulmonary embolus is a very elusive diagnosis. Doctors are well aware of venous thrombosis but still many doctors are not well informed of pulmonary embolism.
       
    Pulmonary angiography is the gold standard for diagnosis but it is invasive perceived as dangerous and not widely available. The non-invasive diagnostic procedures are not easily available.
          
    “Lung scan” is used either as a technetium-99m labelled aerosol or krypton-81m. These are sometimes substituted by spiral computed tomography.
         

  • C H Compton, J Gubb, et al for the International Study Group.
    Cilomilast, a selective phosphodiesterase-4 inhibitor for treatment of patients with chronic obstructive pulmonary disease: a randomized, dose-ranging study.
    The Lancet 2001; 358: 265-70
          
    Phosphodiesterase-4 inhibitor for example theophylline (non-selective) has been used for the treatment of COPD (chronic obstructive pulmonary disease). Their efficacy is marginal but there is no other treatment.
         
    Cilomilast is an orally active, potent, selective phosphodiesterase type 4 inhibitor. In a clinical trial, cilomast 15mg twice daily has been found to be effective in the maintenance treatment of COPD.
          

  • Richard N. Channick, Gerald Simonneau et al 
    Effects of the Dual Endothelin-Receptor Antagonist Bosentan in Patients With Pulmonary Hypertension: A Randomised Placebo-Controlled Study 
    Lancet, Vol.358, October 6, 2001, Pg. 1119-23
          
    Summary: Endothelin-1, a powerful vasoconstrictor and mitogen might be a cause of pulmonary hypertension. Bosentan (Ro 47-0203), an orally active non-peptide antagonist of both endothelin receptor subtypes (ETA and ETB) has been shown to decrease inflammatory reactions, prevent increase in permeability of pulmonary vessels and prevent development of fibrosis in animals with pulmonary inflammation.
          
    This is a double-blind, placebo-controlled study in 32 patients with pulmonary hypertension (primary or associated with scleroderma). Patients were randomly assigned to bosentan or placebo for a minimum of 12 weeks. The primary endpoint was change in exercise capacity. Secondary endpoints included changes in cardiopulmonary haemodynamics, Borg dyspnoea index, WHO functional class, and withdrawal due to clinical worsening.
        
    Interpretation of the study was that bosentan increases exercise capacity and improves haemodynamics in patients with pulmonary hypertension, suggesting that endothelin has an important role in pulmonary hypertension.
            

  • Pulmonary Embolism Prevention (PEP) Trial Collaborative Group
    Prevention of pulmonary embolism and deep vein thrombosis with low dose aspirin: Pulmonary Embolism Prevention (PEP) trial.
    Lancet, vol.355, 15 April 2000; 1295
            
    Previous trials of antiplatelet therapy for the prevention of venous thromboembolism have individually been inconclusive, but a meta-analysis of their results indicated reductions in the risks of deep-vein thrombosis and of pulmonary embolism in various high-risk groups. The aim of this large randomized placebo-controlled trial was to confirm or refute these apparent benefits.
            
    During 1992-1998, 148 hospitals in Australia, New Zealand, South Africa, Sweden and the UK randomised 13 356 patients undergoing surgery for hip fracture, and 22 hospitals in New Zealand randomized a further 4088 patients undergoing elective arthroplasty. Study treatment was 160mg daily aspirin or placebo, started preoperatively and continued for 35 days. Patients received any other thromboprophylaxis thought necessary. Follow-up was of mortality and of in-hospital morbidity up to days 35.
            
    These results, along with those of the previous meta-analysis, show that aspirin reduces the risk of pulmonary embolism and deep-vein thrombosis by at least a third throughout a period of increased risk. Hence there is now good evidence for considering aspirin routinely in a wide range of surgical and medical groups at high risk of venous thromboembolism.
           

 

 

By |2022-07-20T16:41:15+00:00July 20, 2022|Uncategorized|Comments Off on Respiratory – Pulmonary – Asthma

About the Author: