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 vasopressin 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.
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 inflammation, 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.
Heyland DK, for the Canadian Critical Care Trials Group [Queens 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.