Critically ill patients are at risk for significant oxidative stress; however, several small analyses have proposed that supplementation with glutamine, with or without antioxidants, may improve survival. Heyland and colleagues from the Canadian Critical Care Trials Group conducted an international, multicenter study to test the hypothesis that 28-day mortality in critically ill adults would be reduced by supplementation with glutamine, with or without antioxidants. Results were published in a recent issue of The New England Journal of Medicine.
In a randomized factorial, double-blinded, multicenter trial, consecutive adults admitted to an intensive care unit (ICU) and receiving mechanical ventilation were enrolled. Additionally, patients were required to have two or more organ failures related to their critical illness. Subjects were randomized to one of four groups: placebo, glutamine, antioxidants (selenium, beta carotene, vitamins E and C), or antioxidants plus glutamine. The primary outcome was 28-day mortality; several secondary outcomes were also studied. Read the rest of this entry »
Permissive hypercapnia is a well-accepted ventilator strategy for the management of acute respiratory distress syndrome as well as other causes of respiratory failure, such as the respiratory distress syndrome seen in premature infants. Multiple studies have demonstrated that both myocardial contractility and systemic vascular resistance (SVR) decrease with hypercapnic acidosis, the ultimate effect being that cardiac function is maintained or even augmented. The effects of hypercapnic acidosis on cardiac function in the preterm infant have not been elucidated. In a prospective observational study, published in the May issue of The Journal of Pediatrics, the authors analyzed paired blood gases and echocardiograms from 29 hemodynamically stable preterm infants at 30 weeks’ gestation or less.
Samples were taken within the first two weeks of life, either during the transitional period (days 1-3) or post-transitional period (days 4-14). In all, there were 103 paired blood gases and echocardiograms from 21 subjects in the transitional period and 44 paired studies from 15 subjects in the post-transitional period. Each echocardiographic examination included measurements for shortening fraction (which is a load-dependent measure of contractility), stress-velocity index (which is a load-independent measure of contractility), left and right ventricular output, assessment of the ductus arteriosus, myocardial performance index, and SVR. Read the rest of this entry »
Observational and qualitative studies have suggested positive benefits associated with family presence during cardiopulmonary resuscitation (CPR). Family presence may help alleviate the emotional burden and improve the bereavement process. Concerns about interference with resuscitative efforts and medicolegal ramifications have yet to be answered in rigorously designed studies. Patricia Jabre and colleagues in France conducted a multicenter, randomized controlled trial to determine if family presence during CPR was associated with a reduction in the likelihood of posttraumatic stress disorder (PTSD)-related symptoms. Results were published in the March 14 issue of The New England Journal of Medicine.
This prospective, cluster-randomized controlled trial was performed in the prehospital environment in France from 2009 to 2011. At least one first-degree relative per patient was included. Control groups consisted of emergency medical teams that did not routinely give the option for family members to be present during CPR. The experimental group used a communication guide to invite the relative to the resuscitation scene. Ninety days after resuscitation, a trained psychologist conducted a series of assessments for anxiety, depression and PTSD-related symptoms. The primary end point was the proportion of relatives with PTSD-related symptoms, while secondary end points included the effect of family presence on medical efforts at resuscitation, the well-being of the healthcare team, and the filing of medicolegal claims. Read the rest of this entry »
Although anemia may cause an increase in morbidity and mortality rates in critically ill pediatric patients, transfusion of packed red blood cells (pRBCs) carries significant risks, which have also been demonstrated in pediatric cardiac surgery patients. However, studies related to these risks have had problems with confounding and the use of pRBCs that were not leukoreduced. Kneyber et al address these concerns in their study testing whether transfusion of leukocyte-depleted pRBCs within the first 48 hours after cardiac surgery would be independently associated with prolonged duration of mechanical ventilation. Results were published in the March 2013 issue of Pediatric Critical Care Medicine.
The authors used propensity score analysis to limit the confounding by indication or treatment selection bias that occurs when one attempts to distinguish a risk factor or a risk marker. In his accompanying editorial, Lacroix comments that the relationships between anemia, transfusion and severity of illness are so intertwined that only a randomized trial can determine the causal nature of transfusion and increased morbidity. However, the first step in determining whether a variable is the cause of morbidity involves the completion of a descriptive study that can establish significant associations. Read the rest of this entry »
Ventilator-associated pneumonia (VAP) is an important complication in intensive care unit (ICU) patients. Current guidelines in the United States strongly recommend that surveillance be conducted for bacterial pneumonia in ICU patients, but diagnostic criteria have been criticized for the lack of sensitivity and specificity, especially regarding multidrug-resistant (MDR) pathogens. Brusselaers and investigators from Ghent University in Belgium performed a systematic review and meta-analysis to determine the sensitivity and specificity of surveillance cultures in predicting pathogens in VAP. Their results were published in the March issue of Intensive Care Medicine.
A systematic review of the literature was conducted using several major data sources. No language restrictions were applied. All studies had to include lower respiratory tract sampling before any clinical suspicion of VAP. Studies were assessed according to current Quality Assessment of Studies of Diagnostic Accuracy Included in Systematic Reviews (QUADAS) guidelines. A mixed-effect regression model was calculated to perform a meta-analysis. A Bayes nomogram was constructed, and heterogeneity was assessed with forest plot analyses and calculation of the I2 statistic. Read the rest of this entry »