Critical Care Reviews Newsletter

April 30th 2012

Welcome

Hello

Welcome to the 21st Critical Care Reviews Newsletter. Every week over two hundred clinical and scientific journals are monitored and the most important and interesting research publications in critical care are highlighted. These studies are added to the Journal Watch section of the website on a daily basis, as publication occurs. A link to either the full text or abstract, depending on the publishers degree of open access, is attached.

 

Reviews

Annals of Cardiac Anaesthesia

 

Journal of Anaesthesiology and Clinical Pharmacology

 

Journal of Anesthesia

 

Canadian Journal of Anaesthesia

 

Minerva Anaestesiologica:    

 

Research

Critical Care:     Routine Chest Radiograph

Ganapathy and colleagues performed a systematic review and meta analysis of randomized and quasi-randomized controlled trials (RCTs) and before-after observational studies comparing a strategy of routine CXRs to a more restrictive approach with CXRs performed in critically ill adults or children. Nine studies (39358 CXRs, 9611 patients) were included in the meta-analysis. Three trials (N=870) of moderate to good quality provided information on the safety of a restrictive routine CXR strategy; only 1 trial systematically assessed for missed findings. Pooled data from trials showed no evidence of effect of a restrictive approach on ICU mortality (risk ratio [RR] 1.04, 95% CI 0.84 to 1.28, P=0.72; 2 trials, N=776), hospital mortality (RR 0.98, 95% CI 0.68 to 1.41, P=0.91; 2 trials, N=259), ICU length of stay (weighted mean difference [WMD] -0.86 days, 95% CI -2.38 to 0.66 days, P=0.27; 3 trials, N=870), hospital length of stay (WMD -2.50 days, 95% CI -6.62 to 1.61 days, P=0.23; 2 trials, N= 259), or duration of mechanical ventilation (WMD -0.30 days, 95% CI -1.48 to 0.89 days, P=0.62; 3 trials, N=705). Adding data from 6 observational studies, 1 of which systematically screened for missed findings, gave similar results.

Full Text: Ganapathy. Routine chest x-rays in intensive care units: a systematic review and meta-analysis. Critical Care 2012,16:R68

 

Critical Care:     Contrast Nephropathy

Cely evaluated the effect of CT contrast on the develpment of acute kidney injury in a prospective matched cohort study of 53 pairs of critically ill patients scanned with or without radiocontrast enhancement. The study found that unmatched characteristics were similar among the pairs, including serum creatinine variability during the week preceding scanning (67+/-85% among contrast recipients, 63+/-62% among others) and clinical risk factors for renal failure. In 29 pairs, pre-scan measured clearances were less than 60 mL/min/1.73 m2. Following scanning measured clearance declined by at least 33% in 14 contrast and 19 non-contrast patients (95% CI for contrast associated difference in nephropathy rates 27% to 9%), while a 50% reduction in clearance persisted 3 days after scanning in 3 contrast and 9 non-contrast patients (95% CI for difference in rates 25% to 2%). The authors concluded that among established ICU patients declines in glomerular filtration following contrast enhanced scanning are common, but these changes are far more likely to be attributable to factors other than the contrast exposure itself.

Full Text: Cely. Risk of contrast induced nephropathy in the critically ill: a prospective, case matched study. Critical Care 2012,16:R67

 

Critical Care:     Pharmaconutrition

Manzanares et al performed a systematic review and meta-analysis in 21 placebo controlled randomized trials in critically ill patients to assess the efficacy of antioxidant micronutrients in the critically ill. The results from 20 studies were analyzed. Combined antioxidants were associated with a significant reduction in mortality (risk ratio [RR]= 0.82, 95% CI 0.72-0.93, P= 0.002); a significant reduction in duration of mechanical ventilation (weighed mean difference in days = -0.67, 95% CI -1.22,-0.13, P= 0.02); a trend towards a reduction in infections (RR= 0.88, 95% CI 0.76,1.02, P= 0.08); and no overall effect on ICU or hospital length of stay (LOS). Furthermore, antioxidants were associated with a significant reduction in overall mortality among patients with higher risk of death (> 10% mortality in control group) (RR 0.79, 95 % CI 0.68, 0.92, P = 0.003) whereas there was no significant effect observed for trials of patients with a lower mortality in the control group (RR = 1.14, 95% 0.72, 1.82, P=0.57). Trials using more than 500g per day of selenium showed a trend towards a lower mortality (RR= 0.80, 95% CI 0.63-1.02, P= 0.07) whereas trials using doses lower than 500g had no effect on mortality (RR 0.94, 95% CI 0.67-1.33, P= 0.75).

Full Text: Manzanares. Antioxidant micronutrients in the critically ill: a systematic review and meta-analysis. Critical Care 2012,16:R66

 

Critical Care Medicine:    Thyroid Hormone Replacement in Brain Death Potential Orga Donors

In a systematic review MacDonald et al identifed 4 four placebo-controlled randomized controlled trials investigating the efficacy of thyroid hormone replacement in potential brain dead organ donors. In 209 donors, administration of thyroid hormone (n = 108) compared with placebo (n = 101) had no significant effect on donor cardiac index (pooled mean difference, 0.15 L/min/m2; 95% confidence interval –0.18 to 0.48). Interestingly, in the non-controlled studies identified by the systematic review, all case series and retrospective audits reported a beneficial effect of thyroid hormone administration, while all seven randomized controlled trials reported no benefit of thyroid hormone administration either alone or in combination with other hormonal therapies. 

Abstract: MacDonald. A systematic review and meta-analysis of clinical trials of thyroid hormone administration to brain dead potential organ donors. Crit Care Med 2012;40(5):1635-1644

 

Critical Care Medicine:     Central Venous Catheterization

Parienti et al performed a systematic review and meta-analysis to determine if nontunneled subclavian central venous catheters are associated with a lower risk of catheter-associated infection than femoral or internal jugular vein catheters. Ten studies (3250 subclavian, 3053 internal jugular, and 1554 femoral vein) met the inclusion criteria, one of which was randomized (136 subclavian vein and 134 femoral vein). Subclavian vein catheters were left in place significantly longer than alternative catheters (mean difference: 2 days, 95% CI [0.9–3.1], I2 = 92%, p < .001). The subclavian vein site was associated with fewer catheter-associated infections (1.3 compared to 2.7 per 1000 catheter days for alternative sites, incidence density ratio 0.50; 95% CI [0.33– 0.74], I2 = 0%, p < .001). The same was true when comparisons were stratified by alternative sites (subclavian vein vs. internal jugular vein, incidence density ratio 0.46; 95% CI [0.30–0.70], I2 = 0%; subclavian vein vs. femoral vein, incidence density ratio 0.27; 95% CI [0.15–0.48], I2 = 31%). The authors concluded that although the subclavian site may be associated with a lower risk of catheter-associated infection, a large, randomized, controlled trial comparing each catheter site complication is warranted before the subclavian site can be unequivocally recommended as a first choice for central venous catheter insertion.

Critical Care Medicine:     Statins for Acute Respiratory Distress Syndrome

In a single centre observational study, Bajwa et al evaluated the association between statin use and the subsequent development of ARDS in 2,743 patients with risk factors for the development of ARDS. ARDS developed in 738 (26%) patients; 413 patients (15%) received a statin within 24 hrs of intensive care unit admission. Those who had received a statin within 24 hrs had a lower rate of development of ARDS (odds ratio 0.56; 95% CI 0.43–0.73; p < .0001). After multivariate adjustment for potential confounders, this association remained significant (odds ratio 0.69; 95% CI 0.51–0.92; p = .01). However, after propensity score matching, the association was not statistically significant (odds ratio 0.79; 95% confidence interval 0.57–1.10; p = .16). Statin use was not associated with reduced acute respiratory distress syndrome mortality, organ dysfunction, or ventilator-free days.

Abstract: Bajwa. Statin therapy as prevention against development of acute respiratory distress syndrome: An observational study.Crit Care Med 2012;40(5):1470-1477

 

Annals of Internal Medicine:     Coronary Stents

In a meta-analysis, De Luca performed a meta-analysis comparing outcomes between drug eluting stents (DES) and bare-metal stents (BMS) in primary angioplasty. Individual patient data were obtained from 11 of 13 trials identified, including a total of 6298 patients (3980 [63.2%] randomized to DES [99% sirolimus-eluting or paclitaxel-eluting stents] and 2318 [36.8%] randomized to BMS). At long-term follow-up (mean [SD], 1201 [440] days), DES implantation significantly reduced the occurrence of target-vessel revascularization (12.7% vs 20.1%; hazard ratio [95% CI], 0.57 [0.50-0.66]; P < .001, P value for heterogeneity, .20), without any significant difference in terms of mortality, reinfarction, and stent thrombosis. However, DES implantation was associated with an increased risk of very late stent thrombosis and reinfarction.

Abstract: De Luca. Drug-Eluting vs Bare-Metal Stents in Primary Angioplasty: A Pooled Patient-Level Meta-analysis of Randomized Trials (DESERT study). Arch Intern Med 2012;172:611-621

 

British Journal of Anaesthesia:     Cardiac Output Measurement

Using data from a public, electronic ICU patient database, Zhang et al compared 1482 pairs of radial arterial pressure waveforms, using a unique long time interval analysis (LTIA), and thermodilution CO measurements (via single bolus injections) from 169 patients. Although the overall root-mean-squared-error of the LTIA technique was 18.8%, the authors concluded the LTIA technique attained an overall accuracy that may be considered clinically acceptable after taking into account the known thermodilution error and became progressively more accurate than previous techniques with increasing CO changes.

Abstract. Awad. Effects of an intraoperative infusion of 4% succinylated gelatine (Gelofusine®) and 6% hydroxyethyl starch (Voluven®) on blood volume. Br J Anaesth 2012 epublished ahead of print

 

Critical Care:     Ventilator-Associated Pneumonia

In an analysis of the 339 patients enrolled in the ACCURASYS study, Forel and colleagues investigated the incidence, outcome, and risk factors of bacterial VAP complicating severe ARDS in patients ventilated using a standardized lung-protective strategy. Ninety-eight patients (28.9%) presented at least one episode of microbiologically documented bacterial VAP, including 41 (41.8%) who died in the ICU, compared to 74 (30.7%) of the 241 patients without VAP (P=0.05). After adjustment, age and severity at baseline, but not VAP, were associated with ICU death.  Factors independently associated with an increased risk to develop a VAP were male sex, and worse admission Glasgow Coma Scale score. Tracheostomy, enteral nutrition and the use of a subglottic secretion drainage device were protective.

Full Text: Forel. Ventilator-associated pneumonia and ICU mortality in severe ARDS patients ventilated according to a lung-protective strategy. Critical Care 2012;16:R65

 

JAMA:     Coronery Stem Cell Therapy

Perin and colleagues performed a phase 2 randomized double-blind, placebo-controlled trial to determine if bone marrow mononuclear cells, administered through transendocardial injections, improves myocardial perfusion, reduces left ventricular end-systolic volume (LVESV), or enhances maximal oxygen consumption in patients with coronary artery disease or LV dysfunction, and limiting heart failure or angina. 153 patients were enrolled and 92 were randomized to receive therapy. Changes in LVESV index (−0.9 mL/m2 [95% CI, −6.1 to 4.3]; P = .73), maximal oxygen consumption (1.0 [95% CI, −0.42 to 2.34]; P = .17), and reversible defect (−1.2 [95% CI, −12.50 to 10.12]; P = .84) were not statistically significant. There were no differences found in any of the secondary outcomes, including percent myocardial defect, total defect size, fixed defect size, regional wall motion, and clinical improvement.

Abstract: Perin. Effect of Transendocardial Delivery of Autologous Bone Marrow Mononuclear Cells on Functional Capacity, Left Ventricular Function, and Perfusion in Chronic Heart Failure: The FOCUS-CCTRN Trial. JAMA 2012;307:1717-1726

 

British Journal of Dermatology:    Toxic Epidermal Necrolysis

Huang and colleagues performed a meta-analysis of 17 studies investigating the efficacy of intravenous immunoglobulin (IVIg) treatment against toxic epidermal necrolysis (TEN). The mortality of TEN patients treated with IVIg was 19.9%. Pooled odds ratio (OR) for mortality from six observational controlled studies comparing IVIg and supportive care was 1.00 (95% CI, 0.58-1.75; p= 0.99). Pooled OR for mortality in patients treated with high-dose IVIg versus supportive care was 0.63 (95% CI, 0.27-1.44; p= 0.27). Adults treated with high-dose IVIg exhibited significantly lower mortality than low-dose IVIg (50% versus 18.9% respectively, p=0.022); however, multivariate logistic regression model adjustment, indicated IVIg dose does not correlate with mortality (high versus low dose: OR, 0.494; 95% CI, 0.106-2.300; p= 0.369). Pediatric patients treated with IVIg had significantly lower mortality than adults (0% versus 21.6%, p= 0.001). The authors conclude that although high-dose IVIg exhibited a trend toward improved mortality and IVIg treatment in children had good prognosis, the evidence does not support a clinical benefits of IVIg.

Abstract: Huang. The efficacy of intravenous immunoglobulin for the treatment of toxic epidermal necrolysis: A systematic review and meta-analysis. Br J Dermatol 2012; epubished ahead of print

(many thanks to Donal for submitting this to the website)

 

 

I hope you find these brief summaries useful.


Until next week

Rob

 

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