Critical Medicine – Emergency Medicine

VM
Ranieri, PM Suter, C Tortorella, et al (Universita di Bari, Italy; Universite de Geneva, Switzerland; Univ of Toronto, Canada)


Effect of Mechanical Ventilation on Inflammatory Mediators in Pateints with Acute Respiratory Distress Syndrome : A Randomized Controller Trial

JAMA 282: 54-61, 1999

      


Mechanical ventilation can escalate or cause an inflammatory response and acute lung injury. The influence of mechanical ventilation on the lung and systemic cytokine levels was assessed in patients with acute respiratory distress syndrome in a randomized controlled trial.

     


This study offers stimulating data in patients with ARDS, showing elevation of multiple cytokines in BAL fluid and plasma in patients treated with conventional ventilator settings, and a decrease in these mediators over a period of time in patients treated with a protection ventilation strategy. Patients in the protective protocol were treated with lower end-expiratory pressures, tidal volumes and fraction of inspired oxygen. The mechanisms by which ventilator-induced injury might be mediated remain uncertain, and clinical trials of lung protective strategies have yielded variable results. However, in this study, Ranieri and colleagues offer striking evidence for the link between mechanical ventilation and acute inflammatory lung injury, and the potential for benefit by limiting lung distention.

     

Goldhaber
SZ [Harvard Med school]

Pulmonary Embolism

N. Engl J Med 339 : 93-104, 1998

   

The best approach to diagnosis of pulmonary embolism
is a careful history and physical examination with
selective testing as indicated.

   

Dyspnea
is the major symptom.

   

Tachypnea
is the major sign.

   

A
massive embolism is suspected in patients with
Dyspnea, Syncope or cyanosis whereas with pleuritic
pain, cough or hemoptysis are more likely to have a
small embolism near the pleura.

   

To
rule out acute pulmonary embolism perfusion lung
scanning is still the most important test.

  

Main
stage of treatment is heparin.

  

Unless
contraindicated, patient should receive intensive
heparin anticoagulation – usually 5000 to 10000
units bolus followed by continuous infusion at a
rate of 18 units per kg per hour; which should be
given during the diagnostic working. This usually
produces a therapeutic partial thromboplastin time
of 60 to 80 seconds. Patients with venous thrombosis
associated with metastatic cancer may receive short
or long term heparin therapy to prevent recurrent
thrombosis.

  

Once a patient has reached a therapeutic partial
thromboplastin time – it is usually safe to start
warfarin therapy, although at least 5 days of
continuous intravenous heparin is 
recommended to achieve true anticoagulation.
Anticoagulation should continue preferably for 6
months and not 6 weeks to prevent recurrences.

   

Current
understanding of the importance of the right
ventricular dysfunction enables more accurate
prognosis in  patients
with pulmonary embolism. Finally, the take home
message is that surgeons should have a low threshold  
to evaluate seemingly minor post operative
complications viz, fever, tachycardia because many
of these patients have small pulmonary embolism that
are effectively treated by aggressive
anticoagulation.

   

Heyland
DK, for the Canadian Critical Care Trials Group
[Queen’s Univ, Kingston, Ont, Canada; et al]

The Clinical Utility of Invasive Diagnostic
Techniques in the Setting of Ventilator – Associated
Pneumonia

Chest
115: 1076-1084, 1999

   

Ventricular-associated
pneumonia [VAP] is often diagnosed on clinical
grounds alone and contributes to the morbidity,
mortality and costs of caring for critically ill
patients. Overdiagnosis may be disastrous with the
use of needless antibiotics and the delay in
recognition of the ‘true’ diagnosis.

   

The
utility of invasive investigations like bronchoscopy,
with protected brush catheter [PBC] bronchoalveolar
lavage [BAL] was evaluated in 92 patients receiving
ventilatory support with
a clinical suspicion of VAP.

   

The
results showed that VAP was often overdiagnosed
after BAL or PBC after these procedures. Patients
received fewer antibiotics. Both groups had similar
duration of mechanical ventilation and ICU stay.
Those who underwent PBC/BAL had a lower mortality.

  

Invasive
diagnostic testing may boost physicians confidence
in the diagnosis and management of VAP.

    

Kristen
Moller and Peter Skinhoj (Dept of Infectious
Diseases, Denmark)

Guidelines
for managing acute bacterial meningitis

BMJ,
Vol.320, 13 May 2000, pg.1290

   

Nearly one in four adults with acute
bacterial meningitis will die and many survivors
sustain neurological deficits. 
The outcome has not changed despite potent
antibiotics and specialised intensive care units.

 

Standardised guidelines are issued by British
Infection Society. Family
doctors may give benzylpenicillin before admission
to hospital. After
admission to hospital, widely accepted empirical
treatment is a third generation cephalosporine, such
as cefotaxim or ceftriaxone, with ampicillin
if listerial meningitis cannot be ruled out.
In patients with obvious meningococcal
disease, penicillin is the drug of choice.
Pneumococci are less susceptible to
penicillin and rifampicin is useful for truly
penicillin resistant penumococci.
Selection of appropriate treatment for
patients who are hypersensitive to beta-lactams is
difficult. Meropenem
or broad spectrum quinolones may be considered.
There is little evidence that they work.

  

Supportive treatment is debated.  Corticosteroids reduce neurological deficit in children with Haemophilus
influenzae or broad spectrum quinolones may be
considered.  There
is little evidence that they work.

  

Corticosteroids reduce neurological deficit in children with haemophilus
influenzae, but evidence in adults is lacking.
Glycerol or mannitol if there is intracranial
hypertension, full fluid replacement is necessary.

  

Speedy
diagnosis and treatment will serve patients well.

    

J
Briegel, H Forst, M Haller, et al (Ludwig-Maximilians-Universitat
Munchen, Munich)

Stress Doses of Hydrocortisone
Reverse Hyperdynamic Septic Shock: A Prospective,
Randomized, Double-blind, Single-center Study.

Crit Care Med 27:723-732, 1999.

   

Past studies have showed that stress doses of
hydrocortisone were ineffective in septic shock.  However, recent studies have shown that a patient in septic
shock may have relative adrenocortical
insufficiency.

    

In
septic shock, a 100mg loading dose of hydrocortisone
was given within 30 min, and followed by an infusion
of (0.18mg/kg/hr) hydrocortisone. 
After reversal of shock, the dose was reduced
to 0.08mg/kg/hr and continued for 6 days.

    

This
significantly reduces the duration of vasopressor
support and may shorten the time for resolution of
sepsis induced organ dysfunction.

    

MB
Malay, Jr Ashton RC, DW Landry, et al (Allegheny Gen
Hosp, Pittsburgh, Pa; Columbia, Univ, New York)

Low-Dose
Vasopressin in the Treatment of Vasodilatory Septic
Shock

J Trauma  47: 699-705, 1999.

   

Refractory
hypotension not responding to epinephrine in septic
shock is potentially fatal. 
It has been suggested that asopressin used
concomitantly could give better results.

   

The
vasopressor was infused at a rate of 0.04U/min. 
This permitted maintenance of arterial
pressure thus allowing withdrawal of vasopressors.

   

MWA
Angstwurm, J Schottdorf, J Schopohl, et la (Univ of
Munich, Germany)

Selenium
Replacement in Patients with Severe Systemic
Inflammatory Response Syndrome Improves Clinical
Outcome.

Crit Care Med 27: 1807-1813, 1999.

   

Systemic inflammatory response syndrome (SIRS)
causes substantial morbidity and mortality. It has
also been recorded that selenium concentrations are
reduced in SIRS. 
This is a pilot study on the effects of
selenium replacement on SIRS related morbidity and
mortality.

   

Selenium
was replaced as i.v. sodium selenite in a decreasing
dosage over a period of 10 days.

   

Within
30 days, patients had normal selenium and
glutathione peroxidose levels. 
There was significant reduction in Acute
Physiologic and Chronic Health Evaluation III scores
as compared to controls. 
Only 14% (as against 43% in controls) had
renal failure and the mortality was 34% against 54%
in the control group.

  

JE
Gadek, and the Enteral Nutrition in ARDS Study Group
(Ohio State Univ, Columbus; et al )

Effect
of Enteral Feeding with Eicosapentaenoic Acid, g-Linolenic
Acid, and Antioxidants in Patients with Acute
Respiratory Distress Syndrome.

Crit Care Med  27:
1409-1420, 1999.

   

Low carbohydrate, high fat nutritional support
for ventilated patients reduces demands on the
respiratory system and decreases the severity of the
inflammatory injury. 
Animal studies show that diets rich in
eicosapentaenoic acid, g-linolenic
acid and antioxidants can moderate inflammation. 
This is a prospective double blind randomized
controlled trial (multi-centered) to evaluate the
effect of a diet supplemented with EPA, GLA and
antioxidants on the clinical outcome of ARDS.

   

The
patients on the test diet required fewer days of
ventilatory support in ICU or on supplemental oxygen
and had less new organ failure. 
The infection rates were the same but the
test diet patients had fewer adverse events.

    

VM
Ranieri, PM Suter, C Tortorella, et al (Univ of
Toronto)

Effect
of Mechanical Ventilation on Inflammatory Mediators
in Patients with Acute Respiratory Distress
Syndrome: A Randomized Controlled Trial.

JAMA 282:54-61, 1999

    

Mechanical ventilation can escalate or cause an
inflammatory response and acute lung injury. 
The influence of mechanical ventilation on
the lung and systemic cytokine release was assessed
in patients with ARDS.

   

Two
groups were assessed (1) a control group and (2) a
lung protective strategy group.

    

At
baseline physiologic characteristics and cytokine
concentrations were similar. 
But after 24 and 36 hours, there were
significant between-group differences in tidal
volume, end-inspiratory plateau pressures and PEEP.  The lung protective strategy group had significantly better
results.  It
could be concluded that mechanical ventilation can
produce a cytokine response that may be diminished
by minimising overdistension and recruitment and
derecruitment of the lung.

   

PC
Hebert, for the Canadian Critical Care Trials Group
(Univ of Ottawa, Canada; et al)

A Multicenter, Randomized, Controlled Clinical Trial of Transfusion
Requirements in Critical Care,

N Engl J Med 340: 409-417, 1999.

   

The optimal transfusion strategy for cirtically
ill anaemia patients has not been standardised. 
A randomised, controlled study was undertaken
comparing a restrictive (when Hb <7.0gms/dL) with
a liberal approach (when Hb <10gms/dL).

  

The study was conducted on 838 critically ill
patients randomly assigned to one of the two groups.

   

The overall 30 days mortality was similar. 
Mortality rates were significantly lower in
the restrictive group in less acutely ill patients
but was similar in critically ill patients. 
The mortality during hospitalization was
significantly lower in the restrictive group.

  

S
Deb, B Martin, L Sun, et al (Natl Naval Med Ctr,
Bethesdam Md; Walter Reed Army Med Ctr, Washington,
DC; Uniformed Services Univ of the Health
Sciences, Bethesda, Md)

Resuscitation With Lactated Ringer’s Solution in Rats with Hemorrhagic
Shock Induces Immediate Apoptosis.

J Trauma: Injury Infect Crit Care 
46: 582-589, 1999.

     

For patients in haemorrhagic shock, reperfusion
injury can cause cell damage, leading to cell death
and organ failure. 
Apoptotic cell death is thought to play an
important role in the pathophysiology of
haemorrhagic shock. 
The effects of resuscitation with lactated
Ringer’s solution on cell apoptosis were assessed.

   

It was seen that the use of lactated Ringer’s
solution for resuscitation caused a significant
increase in cell apoptosis in the small intestine
and the liver as compared with other agents used for
resuscitation.

   

FA Luchette, BRH Robinson, LA Friend, et al (Univ of
Cincinnati, Ohio)

Adrenergic Antagonists Reduce Lactic Acidosis in Response to Hemorrhagic
Shock

J Trauma : Injury Infect Crit Care 
46: 873-880, 1999.

  

During haemorrhagic shock, lactic acidosis and
plasma catecholamines are significantly increased. 
The increase in circulating catecholamines
have a greater effect on the post haemorrhagic
lactic acidosis than do poor perfusion and tissue
hypoxia.

   

The use of a-blockers
with a b-blocker
significantly reduces plasma lactate levels, but had
no effect on tissue perfusion. 
In an in-vitro study propranolol eliminated
the increased lactate production by muscle in
response to epinephrine.

    

The results question the use of lactate clearance as
a resuscitation end point for patients with
haemorrhagic shock.

   

E Barquist, E Fein, D Shadick, et al (Univ of Miami,
Fla)

A Randomized Prospective Trial of Amphotericin B Lipid Emulsion Versus
Dextrose Colloidal Solution in Critically ill
Patients.

J Trauma 
47: 336-340, 1999.

   

Amphotericin B is the drug of choice in fungal
infections in critically ill patients. 
However, it carries at least a 50% risk of
nephrotoxicity, inspite of preventive measures.

   

A trial was conducted using a combination of
Amphotericin B with 20% intralipid solution in
critically ill patients with positive fungal
cultures of peritoneum, sputum or blood. 
The dose was 1mg/kg/d as against 0.5mg/kg/d
given to controls (with 5% dextrose).  

    

It was found to have less nephrotoxicity than
Amphotericin with Dextrose. 
It can safely be given at a higher total
cumulative dose.

   

RS
Hotchkiss, PE Swanson, CM Knudson, et al (Washington
Univ, St Louis)

Overexpression of Bcl-2 in Transgenic Mice Decreases Apoptosis and
Improves Survival in Sepsis.

J Immunol 162: 4148-4156, 1999

   

Sepsis is associated with extensive lymphocyte
apoptosis, which may reduce  nflammation, but
impairs host defences.

   

The effect of Bcl-2 (a protein product) has been
shown to prevent apoptotic cell death. 
Its effect on lymphocyte 
apoptosis was studied in a rat model
comparing 2 sets. (1) transgenic mice that
selectively overexpressed B cl-2 in T lymphocytes as
well as in endotoxin 
resistant species and (2) the endotoxin
sensitive species.

   

The Bcl-2 overexpressors showed complete protection
against sepsis induced apoptosis. 
The protective effect may result from the
preservation of mitochondrial membrane potential.

   

The aim of the study is to assess the influence of
preoperative portal vein embolization on the
long-term outcome of liver resection for colorectal
metastases.  

    

30 patients underwent PVE and 88 patients did
not before resection of 4 or more liver segments. 
The groups were comparable in terms of sex,
age, number and type of metastases (synchronous vs
metachronous) and number of courses of neoadjuvant
chemotherapy.

    

The main criterion for PVE was that resection was
technically feasible but contraindicated because the
remnant liver was too small (as estimated by CT scan
volumetry). 
It was done when the estimated rate of
remnant functional liver parenchyma (ERRFLP) was 40%
or less.

   

PVE was feasible in all patients. 
There were no deaths with a complication rate
of 3%. 
The post ERRFLP was significantly increased
as compared to pre PVE value. 
Liver resection was performed in 19 patients
(63%) with a mortality of 4% and complication rate
of 7%. 
The survival rates after hepatectomy in both
groups were comparable.

   

The authors conclude that PVE allows more patients
with unresectable liver metastases to benefit from
surgery.

   

Lena
Gamrin, Pia Essen, Eric Hultman, et al (The
Department of Anesthesiology and Intensive Care and
Clinical Chemistry II, Huddinge University Hospital,
Karolinska Institute, Stockholm, Sweden; and the
Department of S6urgery at State University of New
York,Stony Brook, New York)

Protein-Sparing Effect in Skeletal Muscle of Growth Hormone Treatment in
Critically III Patients.

Annals of Surgery, April 2000, 231(4), 577-586.

  

This study investigates the effect of growth
hormone (GH) treatment on skeletal muscle protein
catabolism in patients with multiple organ failure
in the ICU.

   

20 critically ill ICU patients were randomized into
2 groups – one as control and the other with GH
(0.3U/kg/day). Percutaneous muscle biopsy was taken
before and 5 days after treatment starting on day 3
to 42 of the patient’s ICU stay. 
Protein content, protein synthesis, water
nucleic acids and free amino acids were analysed.

   

The fractional protein synthesis rate and muscle
free glutaminic increased in 
the GH group. 
Total intramuscular water did not increase
but the intracellular water increased.

   

It is concluded that treatment with GH in patients
with multiple organ failure, stimulated muscle
protein synthesis, increased muscle free glutaminic
and increased into a cellular water.

  

Byers
RJ, Eddleston JM, Pearson RC, et al [Univ of
Manchester, Manchester Royal Infirmary, England]

Dopexamine Reduces the Incidence of Acute
Inflammation in the Gut Mucosa After Abdominal
Surgery in High-risk Patients

Crit
Care Med 27: 1787-1793, 1999

   

About
20% of critically ill patients have acute
inflammation in the stomach/duodenum. 
Dopexamine has dopaminergic receptor agonist
properties but no alpha or beta [1] effects. 
It may exhibit anti-inflammatory effects.  Thus, a study was devised to examine endoscopically and
histologically the effect of Dopexamine on gut
mucosa. The study represented the side arm of a
large, prospective, randomized, controlled,
multicenter European Study [Effect
of Dopexamine on Outcome after Major Abdominal
Surgery].

  

38 patients with at least one high risk
criterion, who were undergoing major abdominal
surgery of at least 1.5 hours’ duration, were
submitted to endoscopy and biopsy of the upper
gastrointestinal tract immediately after anesthesia. 
After being stabilized, patients received
placebo [Group A, n=12], 0.5 micro-g/Kg per minute
of dopexamine [Group B, n=13], and 
2.0 micro-g/kg  
per minute  
of  
dopexamine 
[ Group C, n=13]. At 72 hours, endoscopy and
biopsy were repeated in 27 patients. 
Upper gut blood flow was estimated using
tonometry.  pH
was calculated at baseline, after surgery, and
2,6,12,24,30 and 36 hours after surgery.

   

Gastric pH decreased significantly and similarly in
all the three groups, with the greatest increase
being recorded at the end of surgery. 
Erythema or hemorrhagic changes were found in
33.3% of Group A, 38.5% of Group B, and 15.4% of
Group C. Erosive disease was seen in 25%, 7.7% and
38.5% respectively. 
At 72 hours, endoscopy revealed that the
number of patients with no detectable abnormality
had decreased to 25%, 20%, and 33.3% respectively. 
Polymorphonuclear neutrophil proliferation
was seen in 86%, 37.5% and 37.5% respectively. 
There was no correlation between endoscopy
and histologic findings.

  

Dopexamine
does protect against the ill effects of decreased pH
during surgery though it does not prevent such a
decrease.

  

Hebert
PC, et al for the Canadian Critical Care Trials
Group [Univ. of Ottawa, Ontario]

A Multicentric, Randomized Controlled Clinical
Trial of Transfusion Requirements in Critical Care

N
Engl J Med 340:409-417, 1999

  

The
optimal transfusion strategy for critically ill
anemic patients has not been determined. 
To understand the potential risks and
benefits of transfusions in critically ill patients,
a randomized, controlled clinical trial compared a
restrictive versus a liberal approach to red cell
transfusions.

   

The
study group consisted of 838 critically ill patients
admitted to hospitals or ICUs in Canada, over a 4
year period.  Consecutive
critically ill normovolemic patients were randomly
assigned to either a restrictive strategy
[transfusion when hemoglobin level fell below 7.0 g/dL],
or a liberal strategy [transfusion when hemoglobin
level fell below 10 g/dl]. 
The primary outcome measure was 30-day death
from all causes. 
Secondary outcomes included 60-day death from
all causes.

   

The
overall 30-day mortality rate was not significantly
different in the two groups. 
Mortality rates were lower in younger, less
acutely ill patients in the restrictive group,
though not in patients with severe cardiac disease. 
The mortality rate during hospitalization was
significantly lower in the restrictive group
compared to the liberal transfusion strategy group.

   

Restrictive
red cell transfusion strategy [hemoglobin levels
below 7.0 g/dL], was as effective as, and in some
cases superior to, the liberal transfusion strategy
[hemoglobin levels below 10 g/dL], in critically ill
normovolemic anemic patients, except in those with
severe cardiac disease.

  

Hanson
CW III, Deutschman CS, Anderson HL III, et al [Univ
of Pennsylvania, Philadelphia : Univ of California,
Irvine]

Effects
of an Organized Critical Care Service on Outcomes
and Resource Utilization : A Cohort Study

Crit Care Med 27: 270-274, 1999

   

Practice
patterns are under scrutiny at both institutional
and national levels to eliminate inefficiency, lower
costs, and improve clinical results. 
Critical care medicine would seem to be
particularly susceptible to the current forces of
change.  The
cost and effectiveness of two patterns of critical
care practice, in an academic medical center, were
examined to determine whether presence of an
on-site, organized, supervised critical care service
improves care and reduces resource utilization.

  

Two patients cohorts admitted to a surgical
intensive care unit [SICU] were compared. One group
received care from an on-site critical care team,
supervised by an intensive care specialist. 
The other group received care from a team
with patient care responsibilities in multiple sites
supervised by a general surgeon. The primary outcome
measures were duration of stay, resource
utilization, complication rates, resultant effects
on added investigations, consultations, and terminal
outcomes.

  

The results showed patients receiving care from an
on-site critical care service had higher Acute
Physiology and Chronic Health Evaluation II [APACHEII]
scores, yet they spent less time in SICU, used fewer
resources, had fewer complications, and had lower
total hospital charges. 
These differences were more pronounced with
increasing severity of illness.

  

Pronovest
PJ, Jenckes MW, Dorman T, et al [John Hopkins Univ,
Baltimore, MD]

Organizational
Characteristics of Intensive Care Units Related to
Outcomes of Abdominal Aortic Surgery

JAMA 281: 1310-1317, 1999

  

ICUs at different institutions vary widely in
terms of morbidity and mortality rates. 
The effects of ICU structure and care
processes on these outcomes are not known. 
The effects of ICU organization on the
clinical and economic outcomes for patients
undergoing abdominal aortic surgery were studied.

  

Hospital
data on 2987 patients on whom abdominal aorta
surgery was performed, in the state of Maryland,
over a two year period, was analyzed. 
Data on organizational characteristics of
ICUs were obtained from medical directors. 
The main outcomes assessed were in-hospital
mortality, and length of total hospital and ICU
stay.

  

The
in-hospital mortality rates ranged from 0% to 66%.
ICUs that did not have daily rounds by an ICU
physician showed a 3-fold increase in in-hospital
mortality after adjustment for patient demographic,
co-morbidity, severity of illness, hospital and
surgeon volume, and hospital characteristics. 
Other outcomes, such as cardiac arrest, acute
renal failure, septicemia, and reintubation, were
also more likely at centers without daily rounds by
an ICU physician.

      

Leape
LL, Cullen DJ, Clapp MD, et al [Harvard School of
Public Health : Massachusetts Gen. Hospital; Brigham
and Women’s Hosp., Boston]

Pharmacist
Participation on Physicians Rounds and Adverse Drug
Events in the Intensive Care Unit

JAMA 282: 267-270, 1999

   

Although studies show that pharmacist review of
ICU prescription orders prevents mistakes and lowers
drug costs by reducing drug use, there have been no
studies on the benefits of having a pharmacist
present in the ICU at the time drugs are prescribed. 
The efficacy of pharmacist participation in a
medical ICU in preventing adverse drug events [ADEs]
was tested in a controlled clinical trial.

    

Between
February 1 and July 31, 1993 [Phase 1
Preintervention] and October 1, 1994 and July 7,
1995 [Phase 2 postintervention], the effect of
pharmacist intervention was tested in a 17-bed ICU
[the study unit] and compared with no pharmacist
intervention in a 15-bed coronary care unit with
similar occupancy rate [the control unit].

  

ADEs
were compared for 75 randomly selected patients in
each of the 3 groups from amongst all patients
admitted to the study unit in Phase 1 and 2, and all
patients admitted to the control unit in Phase 2. An
experienced pharmacist made daily morning rounds
with ICU personnel in the study unit; an experienced
pharmacist was available for consultation but did
not make daily rounds in the control unit. 
Outcome measures included measurements of
ADEs, interventions the pharmacist made, and the
acceptance of pharmacist interventions by the
physicians and nurses.

    

The
overall rate of preventable ordering and ADEs/1000
patient days decreased by 66% in the study unit from
Phase 1 to 2, with significant savings in drugs
costs.  The
rate of ADEs came down significantly in the study
group from Phase 1 to 2. In the control group the
rate of ADEs continued to remain high.

   

Of
the 398 pharmacist interventions reported, 366 were
related to ordering and 362 were accepted by the
physicians.  Pharmacist
– initiated clarifications or correction of
incomplete orders, wrong dose, wrong frequency,
inappropriate choice, or duplicate therapy accounted
for 46% of interventions. 
Drug interactions or adverse reactions were
prevented in 22 cases. 

    

The
presence of a pharmacist at rounds in ICUs
significantly reduces incidence of ADEs and result
in substantial cost savings.

    

Darouiche
RO for the Catheter Study Group [Baylor College of
Medicine, Houston, et al]

A
Comparison of Two Antimicrobial -Impregnated Central
Venous Catheters

N. Engl J Med 340: 1-8, 1999

   

Previous studies have shown that rates of
central venous catheter colonization and catheter
related blood stream infection can be significantly
reduced through the use of catheters impregnated
with minocycline and rifamycin or with chlorhexidine
and silver sulphadiazine. 
However, no studies have directly compared
the benefits of the two types of catheter.
Minocycline/rifamycin and chlorhexidine/silver
sulphadiazine catheters were compared for their
ability to prevent colonization and catheter-related
blood stream infections.

   

The
prospective, multicenter trial included adult
patients considered at high risk for
catheter-related infection who were likely to
require a central venous catheter for 3 days or
longer.  The
patients were randomized to receive polyurethane
triple-lumen catheters impregnated with minocycline/rifamycin
on the luminal and external surfaces or with
chlorhexidine/silver sulphadiazine on the external
surface only. Catheter tips and subcutaneous
segments were cultured by both the roll-plate and
sonication methods after removal, with peripheral
blood cultures performed as indicated. 
The analyses included a total of 738
catheters with evaluable culture results.

   

The
two catheter groups were similar in their clinical
characteristics and infection risk factors. 
The catheter colonization rate was 8.3% with
monocycline/rifamycin impregnated catheters vs 22.8%
in the other group. The former were also associated
with lower rate of blood stream infection [0.3% vs
3.4%]. The authors emphasize that adequate aseptic
technique must complement the use of monocycline/rifamycin
impregnation of central venous catheters.

        
 

D.S.
Walsh, P. Siritongtaworn, K. Pattanapanyasat. P.
Thavichaigarn, P. Kongcharoen, N. Jiarakul, P.
Tongtawe, K. Yongvanitchit, C. Komoltri, C.
Dheeradhada, F.C. Pearce, W.P. Wiesmann and H.K
Webster [**]

[**
Department of Immunology and Medicine, US Army
Medical Component, Armed Forces Research Institute
of Medical Sciences, Departments of Surgery,
Hematology and Clinical epidemiology, Siriraj
Hospital, Department of Surgery, Pharmongkutklao
[Royal Thai Army] Hospital, and Department of
Surgery, Police Hospital, Bangkok, Thailand and
Division of Surgery, Walter Reed Army Institute of
Research, Washington, DC, USA ]

Lymphocyte Activation After Non-Thermal Trauma

Br.
J. of  Sur.,  Volume 87, Number 2, February, 2000, Pg. 223-230

   

Service
injury causes immunologial changes that may
contribute to a poor outcome. Longitudinal
characterization of lymphocyte response patterns may
provide further insight into the basis of these
immunological alterations.

  

Venous
blood obtained seven times over 2 weeks from 61
patients with injury severity scores over 20 was
assessed for lymphocyte and activation markers
together 
with serum 
levels of interleukin [IL]2, IL-4, soluble
IL-2 receptor [sIL-2R], soluble CD4 [sCD4], soluble
CD8 [sCD8] and interferon g.

   

Severe
injury was associated with profound changes in the
phenotypic and activation profile in the phenotypic
and activation profile of circulating lymphocytes.
Activation was indicated by increased number of T
cells expressing CD25, sIL-2R and sCD4 and sCD8 were
found in-patients with sepsis syndrome.

   

Polytrauma
is associated with dramatic alterations in the
phenotypic and activation profile of circulating
lymphocytes which are generally independent of
clinical course. In contrast several lymphocyte
soluble factors including sCD4 and SIL-2R,
paralleled the clinical course. These data provide
new insight into lymphocyte responses after injury
and suggest the further assessment of soluble
factors as clinical correlates. 

   

Helen
F Galley , ( Academic Unit of Anaesthesia and
Intensive Care, Department of Medicine, Aberdeen ).

Commentary –  Renal Dose Dopamine : Will the
message now get through ?

Lancet, Vol.356, 23/30 December, 2000, pg. 2112

  

Deterioration in renal function is common in
critically ill patients under intensive care. It
lengthens patient’s stay in the intensive – care
unit and their risk of death. Management of such
cases is restricted to supportive measures and
critical care doctors are eager for any new approach
that might prevent the onset of renal dysfunction or
hasten its recovery.

  

Dopamine is used in intensive – care units as an
inotropic and vosoactive agent. At low or
“renal” doses (0.5 to 2.0 mg/kg per min )
its actions are mainly dopaminergic . In laboratory
animals and healthy volunteers low doses of dopamine
increase renal blood flow and GFR and inhibit
proximal tubular reabsorption of sodium, which
result in natriuresis. Such findings have not been
clearly shown in patients in intensive care. Despite
no evidence of benefit, low-dose dopamine has been
widely used for preventing renal failure in the
critically ill patients.

  

The large study conducted by the Australian
and  NewZealand Intensive Care Society (ANZICS),
clinical trials group confirms the lack of renal
protection offered by low-dose dopamine in the
critically ill. Dopamine can also be harmful . There
is no justification for using “renal dose”
dopamine in the critically ill.

         

Auleley G-R, Ravaud P, Giraudeau B, et al (Assistance Publique-Hopitaux de Paris; Saint-Louis Hosp, Paris; Cochin Hosp, Paris; et al)

Implementation of the Ottawa Knee Rules in France: A Multicenter Randomized Controlled Trial 

JAMA 277: 1935-1939, 1997

        

This is a multicenter randomized clinical controlled trial involving 5 Paris University teaching hospitals (2 for intervention and 3 as controls) to evaluate the impact of this rule during a 5 month intervention period as well as to note the effect of using posters alone to sustain the effect of the rules.

        

Control hospitals were given data collection forms, but not preprinted rules. In the intervention group, meetings were held to explain and distribute the rules. These rules were also posted in the emergency departments and data collection forms were distributed. The outcome was measured as the number of patients referred for radiography. There were 1005 controls and 906 patients in the intervention group. 

      

Before intervention 98.5% of controls and 98% of intervention group were referred for radiography. During intervention, 99.6% of controls and 76% of intervention group requested radiographs (reduction of 22.4% in intervention group).

       

In the postintervention period 83.1% were referred for radiography in the intervention group against 98% in control group.

        

Implementation of the Ottawa ankle rules resulted in a significant reduction in the number of radiographs requested.

       

Tuli S, Tator CH, Fehlings MG, et al (Univ of Toronto)

Occipital Condyle Fractures

Neurosurgery 41: 368-377, 1997

        

Occipital condyle fractures (OCF) present a diagnostic challenge.

       

This is a retrospective study of 93 patients (medical records and radiographs) who had sustained trauma and had undergone CT scan of the skull and cervical spine.

       

Of 93 cases studied, 3 had OCF (2 women 64 years and a 27-year old man). 2 had vehicular accidents and one had a fall down a flight of stairs. All 3 had neck pain but no cranial nerve deficits. CT identified OCF in 2 patients only and missed the diagnosis in one (eventually diagnosed by a high resolution CT scan during retrospective study).

        

Review of literature showed 58 living patients with OCF and 38 diagnosed at autopsy. Cranial nerve deficits were seen in 31%; delayed deficits in 38%.

       

Cervical spine X rays revealed no fracture in 96%. A new classification of OCF is proposed on the degree of ligamentous laxity and presence of displacement observed on CT and by the determination of O-C1-C2 instability

        

Plewa MC, Delinger M (St Vincent Mercy Med Ctr, Toledo, Ohio; Med College of Ohio, Toledo)

The False-positive Rate of Thoracic Outlet Syndrome Shoulder Maneuvers in Healthy Subjects 

Acad Emerg Med 5: 337-342, 1998

       

This study has been conducted on 53 healthy volunteers who had no symptoms of Thoracic Outlet Syndrome (TOS).

        

Shoulder maneuvers including Adson’s test (AT), costoclavicular maneuver (CCM), elevated arm stress test (EAST), and supraclavicular pressure (SCP) were performed for diagnostic evaluation. Participants were evaluated for pulse quality and the presence of pain/paresthesias.

        

All maneuvers resulted in change of pulse quality but most commonly with EAST. Paresthesias were also most often seen with EAST (only in the upper extremity, not radiating to neck, head or chest in any case).

        

There was no pain with the AT and CCM maneuvers and pain was seen in only one case with SCP. Overall, pulse alteration, pain and paresthesias were present in 74%, 21% and 47%, respectively, of participants.

         

No participants had positive findings with all maneuvers. Outcomes with reasonable false positive rates included pain with AT (7%), CCM (7%), SCP (10%), or any two shoulder (TOS) maneuvers (10%).

         

In TOS, pulse alternations and paresthesias (after shoulder maneuvers are unreliable in general).

        

Pandey R, McNally E, Ali A, et al (John Radcliffe Hosp, Oxford England)

The Role of MRI in the Diagnosis of Occult Hip Fractures

Injury 29: 61-63, 1998

      

Traumatic hip fractures are common particularly in the elderly. Clinical examination and initial radiography may be inconclusive. Misdiagnosis significantly alters prognosis, morbidity, management and length of hospital stay and cost of treatment.

      

In this study, MRI was performed on 33 patients with posttraumatic painful hips and negative radiographs. Fractures were diagnosed when an area of intermediate signal intensity on the T1-weighted images, representing trabecular edema, traversed by a low signal intensity line depicted by the fracture.

      

10 of 33 cases revealed no fracture. None of these subsequently went on to fracture – 100% true negative findings. 

       

The MRIs revealed that 40% of patients had a fractured neck of the femur, 15% had intertrochanteric fractures, and 11% had other fractures around the hip. One patient had a tumor.

      

MRI is recommended in all patients with traumatic significant hip pain and negative plain radiographs.

      

Reinus WR, Strome G, Zwemer FL Jr (Washington Univ, St. Louis) 

Use of Lumbosacral Spine Radiographs in a Level II Emergency Department 

AJR 170: 443-447, 1998

        

This study determines the reasons clinicians ask for lumbosacral spine radiographs in an emergency department. The study includes 482 patients examined for low backache in a level II emergency department (ED).

         

Physicians were asked to complete a request form before ordering a lumbosacral spine X ray.

        

The most common indications for the X ray were low back pain (92%) and trauma (36%), in 42% patient expectation and medicolegal concern related to insurance or litigation. 88% of patients had a neurologic deficit. 4% had history of neoplasm.

         

The most common suspected lesion was strain and fracture (56% and 20% respectively). 86% had normal findings or spondylosis. Fractures were detected in 55%, of these 10 were definitely acute fractures. 7 had osseous metastases. 37 patients with neurologic deficits had findings that did not correlate with abnormalities observed on lumbosacral spine X rays. Decompression was not needed in any of the fractures.

        

Weiss HB, Friedman DI, Coben JH (Univ of Pittsburgh, Pa)

Incidence of Dog Bite Injuries Treated in Emergency Departments 

JAMA 279: 51-53, 1998

       

The incidence and characteristics of dog bite injuries for the United States have been calculated.

       

This is a retrospective study. The E-code E906.0 was used to determine the incidence of dog bites treated in Emergency Departments (ED).

       

The annualized weighted estimate of the incidence of new dog bites and related injuries in EDs of USA over the 3-year period observed was 333,687, a rate of 12.9/10,000 persons. They represented 0.4% of all ED visits during this period. 

      

This works out as 914 new dog bite injuries requiring ED visits. The median age of the patients was 15 years. Children between 5-9 years had the highest incidence (60.7/10,000). Children more than adults were likely to have bites on the neck, face and head (73% vs 30%). The highest incidence is in the summer. More than 50% of dog bites occurred at home.

      

94% of cases were treated in ED and sent home. The remainder required admission. There was a 4% hospitalization rate among nearly 334,000 dog bites treated on EDs in USA.

      

Jacobson JA, Powell A, Craig JG, et al (Henry Ford Hosp, Detroit)

Wooden Foreign Bodies in Soft Tissue: Detection at US 

Radiology 206: 45-48, 1998

      

Radiolucent foreign bodies (FB) are extremely difficult to detect. It is imperative to detect and remove them, as retained FBs may lead to severe infections and may lead to malpractice lawsuits.

       

The use of ultrasonography (US) for detection of wooden FBs implanted in cadaveric specimen has been evaluated.

       

Using 5-mm-long incisions in the plantar soft tissues of 3 cadaver feet, wooden FBs were randomly placed. Ten FBs 5 mm x 1 mm and ten of the size of 2.5 mm x 1 mm were implanted.

       

US was performed to detect the presence of a FB. There was a 86.7% sensitivity for detection of the 25 mm x 1 mm sized FB and 96.7% specificity. There was an overall negative predictive value of 83%. A positive predictive value of 98%, specificity of 96.7% and a sensitivity of 90%.

       

US is an effective tool for detecting wooden FBs in soft tissue that are radiolucent.