Critical Care Reviews Newsletter
February 19th 2012
Welcome to the 11th Critical Care Reviews Newsletter. Every weekend some of the more important studies in critical care, which were published that week, are highlighted. These studies are added to the Journal Watch section of the website on a daily basis, as publication occurs.
Acta Anaesthesiologica Scandinavica
Cabrini et al performed a systematic review and meta analysis, totaling 13 randomized trials (n=1130), to evaluate the superiority between different types of percutaneous dilatational tracheostomy (PDT). The techniques included multiple dilators, single-step dilatation, guide wire dilating forceps, rotational dilation, retrograde tracheostomy, and balloon dilation techniques. The different techniques and devices appeared largely equivalent, with the exception of retrograde tracheostomy, which was associated with more severe complications and more frequent need of conversion to other techniques when compared with guide wire dilating forceps and single-step dilatation techniques. Single-step dilatation technique was associated with fewer failures than rotational dilation, and fewer mild complications in comparison with balloon dilation and guide wire dilating forceps (all P < 0.05).
The Cochrane Library
Stem Cell Therapy for Acute Myocardial Infarction
In a systematic review and meta-analysis, Clifford and colleagues evaluated 33 randomized controlled trials (n=1765) to investigate the efficacy of stem cell therapy in acute myocardial infarction. Although a significant degree of heterogenity was present, stem cell therapy was associated with some improvements, but not mortality (RR 0.70, 95% CI 0.40 to 1.21) or morbidity (re-infarction, hospital re-admission, restenosis and target vessel revascularisation). The improvements included left ventricular ejection fraction, which was maintained up to 61 months, reduced left ventricular end systolic and end diastolic volumes and reduced infarct size. A dosing effect was also apparent, with a correlation between improved effects and increased dose and earlier timing of administration of stem cells.
In a double-blind, placebo-controlled, multicentre Phase IIa study, Morris and colleagues evaluated the safety and tolerability of AZD9773, an ovine, polyclonal, anti-human TNF-alpha Fab preparation, in 70 patients with severe sepsis. In 2:1 randomization, patients received either one of five escalating doses of AZD9773, or placebo. The mean baseline APACHE score was 25.9, with baseline characteristics similar across the 5 cohorts. AZD9773 levels increased with increasing dose and had a terminal half-life of 20 hours. For patients who received multiple-doses , serum TNF-alpha concentrations decreased to near-undetectable levels within 2 hours of commencing AZD9773 infusion. The intervention was well tolerated.
Full Text: Morris. A placebo-controlled, double-blind, dose-escalation study to assess the safety, tolerability, and pharmacokinetics and pharmacodynamics of single and multiple intravenous infusions of AZD9773 in patients with severe sepsis and septic shock. Critical Care 2012,16:R31
Testa and colleagues perfomed an observational study examining the ultility of Emergency Department chest ultrasound in patients suspected of H1N1 influenza. An abnormal ultrasound pattern was detected in 32/34 patients with pneumonia (94.1%). In 16 patients with an initial normal chest radiograph, an interstitial syndrome on ultrasound was present in 15, with 10 (62.5%) ultimately having H1N1 influenza. Patients with an abnormal chest radiograph, who ultimately were diagnosed with H1N1 influenza, mainly had an alveolar pattern on chest ultrasound. Ultrasonic interstitial syndrome was found in 5/33 controls (15.1%). There were 2/34 (5.9%) false negative cases and 5/33 (15.1%) false positives cases, with a sensitivity of 94.1%, specificity 84.8%, positive predictive value 86.5% and negative predictive value 93.3%. Chest ultrasound was well tolerated and quick (median 9 minutes, range 7-13 minutes).
In an observational study over a 30 months period, Droogh and colleagues report that 55 technical problems arose during 353 inter-hospital patient transfers. Examples of how they influenced transport and how they may be resolved are provided.
Critical Care Medicine
Vasopressors in Septic Shock
In a systematic review and meta analysis, De Backer and colleagues compared the use of noradrenaline with dopamine in the management of septic shock. Five observational studies (1,360 patients) and six randomized studies (1,408 patients) were identified (noradrenaline, n=1474; dopamine, n=1294). In the observational studies, after exclusion of a single study responsible for significant heterogeneity, the use of dopamine was associated with increased risk of death (RR 1.23; 95% CI 1.05–1.43; p < 0.01). The randomized trials, which did not demonstrate heterogenetity or publication bias, also associated dopamine use with increased risk of death (RR 1.12; 95% CI 1.01–1.20; p = 0.035); and in two studies reporting arrthymias, dopamine again was associated with increased risk of arrthymias (RR 2.34, 95% CI 1.46-3.77; p=0.001).
In a two-centre prospective, randomized, double-blind, placebo-controlled trial, Wang and colleagues investigated the efficacy and safety of intravenous haloperidol for delirium prevention in 457 patients critically ill elderly patients after noncardiac surgery. Subjects were randomized at admission to ICU to receive IV bolus 0.5mg haloperidol, followed by continuous infusion at 0.1mg/h for 12 hours (n=229), or placebo (n=228). The incidence of delirium within the first 7 days was 15.3% (35/229) in the haloperidol group and 23.2% (53/228) in the control group (p = 0.031). The mean time to onset of delirium and the mean number of delirium-free days were significantly longer (6.2 days [95% CI 5.9−6.4] vs. 5.7 days [95% CI 5.4−6.0]; p = 0.021; and 6.8 ± 0.5 days vs. 6.7 ± 0.8 days; p = 0.027, respectively) with haloperidol therapy. Similarly, the median length of ICU stay was significantly shorter (21.3 hrs [95% CI 20.3−22.2] vs. 23.0 hrs [95% CI 20.9–25.1]; p = 0.024) in the haloperidol group. All-cause 28-day mortality did not differ between the two groups (0.9% [2/229] vs. 2.6% [6/228]; p = 0.175). There were no drug-related side effects.
Tejerina and colleagues prospectively investigated all autopsies performed over a 25 year period in their institution, to determine the incidence of major mised diagnoses that would have altered management (type 1 error) or not altered management (type 2 error). Of 2,857 deaths during the study period, autopsies were performed in 866 patients (30.3%) with reports available in 834 patients. 7.5% (n=63) had a type I error and 11.4% (n=95) had type II errors. The most frequently missed diagnoses were pulmonary embolism, pneumonia, secondary peritonitis, invasive aspergillosis, endocarditis and myocardial infarction. Autopsy results were inconclusive in 22 patients (2.6%). Although the rate of clinical diagnosis of pneumonia has decreased, overall the rate of diagnostic discrepancy remained relatively constant the 25 year period.
Organ Donation after Cardiac Death
In a prospective multicenter study of observational data, examining the interval between withdrawal of active therapy and death, Wind et al identified all potential cases of organ donation after cardiac death in The Netherlands between May 2007 and June 2009. Of 242 possible cases, 211 entered analysis; 76% died within 60 mins, and 83% died within 120 mins after withdrawal of life-sustaining treatment. The median time to death was 20 mins (range 1 min to 3.8 days). Using clinical judgement, intensivists predicted death within 60 and 120 mins with a sensitivity of 73% and 89%, respectively, and a specificity of 56% and 25%, respectively.
The American Journal of Gastroenterology
Stress Ulcer Prophylaxis
Barkun et al conducted a meta analysis comparing the efficacy of proton pump inhibitors with type 2 histamine receptor anatgonists for the prevention of gastric stress ulceration in critically ill adults. In 8 randomized controlled trials and five abstracts (n=1587), compared with H2RA, prophylactic PPI administration significantly decreased the incidence of bleeding (OR=0.30; 95% CI: 0.17–0.54; NNT=39; 95% CI: 21–303). No statistical differences were noted for the development of nosocomial pneumonia (7 studies, n=1,017, OR=1.05; 95% CI: 0.69–1.62) or mortality (8 studies, n=1,260, OR=1.19; 95% CI: 0.84–1.68).
Abstract:Barkun. Proton Pump Inhibitors vs. Histamine 2 Receptor Antagonists for Stress-Related Mucosal Bleeding Prophylaxis in Critically Ill Patients: A Meta-Analysis. The American Journal of Gastroenterology; 31 January 2012
I hope you find these brief summaries useful.
Until next week