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Critical Care Reviews Newsletter

August 11^th 2013

Welcome

Hello

Welcome to the 88th Critical Care Reviews Newsletter, bringing you the best critical care research published in the past week, plus a wide range of free full text review articles and guidelines from over 300 clinical and scientific journals.

This week's research studies include interventional investigations into intra-aortic balloon pump use in cardiac surgery, sepsis biomarker guided therapy, extubation in traumatic brain injury and immunoglobulin therapy in severe influenza; meta analyses compare dexmedetomidine with propofol for ICU sedation and evaluate the efficacy of artificial liver support systems; while observational studies examine the effect of anaesthesia and surgery on the development of dementia, the perioperative effect of unexpected quantitative platelet disorders, the utility of adrenomedullin for sepsis prediction, the association of enterocyte injury with outcomes, the benefit of correcting haemostatic disorders pre-thoracocentesis and the association of blood transfusions with mortality in cardiac surgery.

This week's guidelines focus on mechanical circulatory support and theatre safety. There are editorials on septic shock and publishing, as well as commentaries on hydroxyethyl starches and clinical reasoning.

Amongst the clinical review articles are papers on intracerebral haemorrhage, delirium, status epilepticus, heart failure biomarkers, extracorporeal CO₂ removal, ventilator-associated pneumonia, renal failure, massive haemorrhage, MERS CoV, haemostasis, resuscitation fluids, anaphylaxis, snakebite envenomation, pre-eclampsia and intra-operative management of the critically ill patient. There is a basic science article on bioengineering, a non-clinical paper on preparing an abstract for a scientific meeting, and an intriguing science paper describing how worms glow immediately before dying. There are also the latest papers made open access from the major critical care journals.

If you are in need of CPD points, there is a new CPD quiz, on airway pressure release ventilation.

The topic for This Week's Papers is critical care gases, starting with a paper on nitric oxide in tomorrow's Paper of the Day.

If you only read one of this week's 92 articles, try the commentary by Chappel on hydroxyethyl starches in Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine.

Research

Interventional Trials

Critical Care Medicine: Coronary Artery Bypass Grafting

In a single-center prospective randomized controlled trial, comparing preincision intra-aortic balloon pump with no intervention in 110 subjects undergoing coronary operations, with a poor left ventricular ejection fraction (< 35%) and no hemodynamic instability, Rannucci and colleagues demonstrated, with IABP therapy, no improvement in the primary outcome of major postoperative morbidity rate (IABP 40% versus control 31%; odds ratio 1.49, 95% CI 0.68-3.33) and no differences in cardiac index either pre- or post-operatively. Interestingly, although systemic mean arterial blood pressure was lower in the IABP treated group on arrival in ICU (80.1 +/- 15.1 mmHg versus 89.2 +/- 17.9 mmHg; p=0.01), fewer IABP treated patients required a dopamine infusion (24% versus 44%; p=0.043).

Abstract: Ranucci. A Randomized Controlled Trial of Preoperative Intra-Aortic Balloon Pump in Coronary Patients With Poor Left Ventricular Function Undergoing Coronary Artery Bypass Surgery (SCORE Study). Crit Care Med 2013;epublished August 5th

Critical Care Medicine: Sepsis Biomarker Guided Therapy

In a dual centre open clinical trial, 94 patients with severe sepsis or septic shock were randomized to procalcitonin (n=49) or C-reactive protein (n=45) guided antibiotic therapy. There was no difference in the median duration of antibiotic therapy for the first episode of infection (procalcitonin 7.0 days (Q1-Q3, 6.0-8.5) versus CRP 6.0 days (Q1-Q3, 5.0-7.0), p = 0.13; hazard ratio 1.206, 95% CI, 0.774-1.3, p = 0.13). There were 21 deaths in each group (p = 0.836).

Abstract: Oliveira. Procalcitonin Versus C-Reactive Protein for Guiding Antibiotic Therapy in Sepsis: A Randomized Trial. Crit Care Med 2013;epublished August 5th

American Journal of Respiratory and Critical Care Medicine: Extubation in Traumatic Brain Injury

Using a before and after design in two ICUs in one university hospital, Roquilly and colleagues showed, in 499 brain injured patients (299 pre- and 200 post-intervention), an extubation readiness bundle was associated with lower tidal volume (p<0.01), higher PEEP (p<0.01), and higher enteral intake in the first 7 days (p=0.01), as well as reduced duration of ventilation (14.9±11.7 days versus 12.6±10.3 days, p=0.02), with a hazard ratio for extubation of 1.28 (95% CI 1.04-1.57; P=0.02) in the intervention phase. There were more ICU-free days at day 90 in the intervention phase versus control phase (57±29 versus 50±33, p<0.01), although there was no difference in 90 day mortality (control 28.4% versus intervention 23.5%, p=0.22).

Full Text: Roquilly. Implementation of an Evidence-based Extubation Readiness Bundle in 499 Brain-Injured Patients - a Before-After Evaluation of a Quality Improvement Project. Am J Respir Crit Care Med 2013;epublished August 7th

Chest: Influenza A (H1N1)

In a multicenter, prospective, double-blind, randomized controlled trial, Hung et al demonstrated in 35 patients with severe A(H1N1) influenza being treated with standard antiviral treatment and requiring ventilatory support, hyperimmune IV immunoglobulin (n=17), sourced from patients convalescing from 2009 pandemic influenza A(H1N1), in comparison with normal IV immunoglobulin (n=18), was associated with reduced respiratory viral load at days 5 (p=0.04) and 7 (p=0.02), as well as reduced mortality in the subgroup who received treatment within 5 days of symptom onset (OR 0.14; 95% CI 0.02-0.92; p=0.04)

Abstract: Hung. Hyperimmune IV Immunoglobulin Treatment: A Multicenter Double-Blind Randomized Controlled Trial for Patients With Severe 2009 Influenza A(H1N1) Infection. Chest 2013;144(2):464-473

Meta Analysis

Journal of Surgical Research: Dexmedetomidine versus Propofol

Pooling 10 randomized controlled trials (n = 1,202), dexmedetomidine, in comparison with propofol, was associated with decreased ICU length of stay (five studies, n=655; mean difference, −0.81 d; 95% CI −1.48 to −0.15), decreased incidence of delirium (three studies, n=658; RR 0.40; 95% CI 0.22–0.74), with no difference in either duration of mechanical ventilation (five studies, n=895; mean difference 0.53 h; 95% CI −2.66 to 3.72) or ICU mortality (five studies, n=267; RR 0.83; 95% CI 0.32–2.12). Dexmedetomidine was associated with an increased risk of hypertension (three studies, n=846 patients; RR 1.56; 95% CI 1.11–2.20).

Abstract: Xia. Clinical benefits of dexmedetomidine versus propofol in adult intensive care unit patients: a meta-analysis of randomized clinical trials. J Surg Res 2013;epublished July 24th

Experimental and Therapeutic Medicine: Artificial Liver Support

In 19 randomized controlled trials, including 566 patients with acute liver failure (ALF) and 371 patients with acute-on-chronic liver failure (AOCLF), artificial liver support systems were associated with reduced mortality and reduced bridging to liver transplantation in patients with AOCLF, but not in patients with ALF. Bioartificial liver support systems were correlated with decreased mortality in patients with AHF. Artificial liver support systems were associated with reductions in total bilirubin in both liver failure groups, with neither bioartificial or artificial systems affecting the incidence of hepatic encephalopathy or bleeding.

Full Text: Zheng. Artificial and bioartificial liver support systems for acute and acute-on-chronic hepatic failure: A meta-analysis and meta-regression. Experimental and Therapeutic Medicine 2013;epublished July 30th

Observational Studies

British Journal of Psychiatry: Post-Operative Dementia

In a retrospective study utilising data from the Taiwan National Health Insurance Research database, comparing a cohort of 24,901 patients aged 50 years and older who underwent anaesthesia and surgery with a control group of 110,972 randomly selected age- and sex-matched patients, in the 2- to 7-year follow-up period, more anesthetized patients were diagnosed with dementia (2.65% versus 1.39%; hazard ratio 1.99; 95% CI 1.81 - 2.17). This group also had a reduced mean interval to dementia diagnosis.

Abstract: Chen. Risk of dementia after anaesthesia and surgery. Br J Psychiatry 2013;epublished July 25th

Anesthesiology: Perioperative Thrombocytopaenia

In a retrospective study utilising data from the American College of Surgeons National Surgical Quality Improvement database, Glance and colleagues showed in 316,644 patients having noncardiac surgery who did not have clinical indications for preoperative coagulation testing, thrombocytopenia or thrombocytosis occurred in 1 in 14 patients. The degree of thrombocytopaenia was relevant, with patients with mild thrombocytopenia (101-150 × 10³/mm³), moderate-to-severe thrombocytopenia (<100 × 10³/mm³), and thrombocytosis (≥450 × 10³/mm³) being more likely to be transfused than normocytopaenic patients (7.3%, 11.8%, 8.9%, 3.1%, respectively - I think, it's poorly described) and had significantly higher 30-day mortality rates (1.5%, 2.6%, 0.9%, 0.5%, respectively). Mild thrombocytopenia (adjusted odds ratio 1.31, 95% CI 1.11-1.56) and moderate-to-severe thrombocytopenia (AOR 1.93, 95% CI, 1.43-2.61) were associated with increased risk of 30-day mortality.

Abstract: Glance. Preoperative Thrombocytopenia and Postoperative Outcomes after Noncardiac Surgery. Anesthesiology 2013;epublished July 30th

BioMed Research International: Sepsis Prediction

In a prospective observational study assessing adrenomedullin as a predictor for the development of severe sepsis and septic shock within 3 days in 372 emergency department patients, adrenomedullin levels were higher in those who developed sepsis (41.63 ± 6.55 versus 31.31 ± 7.71 ng/L, p<0.001; AUC 0.847) and was the only independent predictor of outcome. With a cutoff value of 41.24 ng/L, the sensitivity was 67.6%, the specificity was 90.0%, the positive predictive value was 61.5%, the negative predictive value was 92.2%, the positive likelihood ratio was 6.78, and the negative likelihood ratio was 0.36.

Full Text: Chen. The Predictive Value of Adrenomedullin for Development of Severe Sepsis and Septic Shock in Emergency Department. BioMed Research International 2013;2013:960101

Critical Care Medicine: Enterocyte Damage

In a single centre, prospective observational study in 103 critically ill patients, at ICU admission increased intestinal fatty acid-binding protein (a marker of enterocyte damage) was associated with catecholamine support, higher lactate concentration, higher SOFA score, and higher INR (all p ≤ 0.001); while a reduced plasma citrulline (a marker of functional enterocyte mass) ≤ 10 μmol/L was associated with higher intra-abdominal pressure, higher plasma CRP, and more frequent antibiotic use (all p ≤ 0.005). At ICU admission, SOFA score >12, plasma citrulline <12.2 μmol/L, and plasma intestinal fatty acid-binding protein concentration >355 pg/mL were all independently associated with 28-day mortality (odds ratio 4.39, 95% CI 1.48-13.03; odds ratio 5.17, 95% CI 1.59-16.86; and odds ratio 4.46, 95% CI 1.35-14.74, respectively).

Abstract: Piton. Enterocyte Damage in Critically Ill Patients Is Associated With Shock Condition and 28-Day Mortality. Crit Care Med 2013;epublished June 18th

Chest: Procedures during Coagulopathy

In 1,009 ultrasound-guided thoracenteses, consisting of 706 procedures in 538 patients with abnormal preprocedural coagulation parameters (INR > 1.6, serum platelet values < 50 × 10⁹/L, or both) which were not corrected before the thoracentesis, and 303 procedures in 235 patients who received a transfusion of platelets or fresh frozen plasma prior to thoracentesis, there were no complications in those without preprocedure therapy (0 of 706 or 0.0%; 95% CI 0%-0.68%) and four in those who did receive haemostatic therapy (four of 303 or 1.32%; 95% CI 0.51%-3.36%).

Abstract: Hibbert. Safety of Ultrasound-Guided Thoracentesis in Patients With Abnormal Preprocedural Coagulation Parameters. Chest 2013;144(2):456-463

Transfusion: Blood Transfusion

In a propensity-matched cohort study, comparing 857 cardiac surgical patients who received a blood transfusion with 857 matched cardiac surgical patients who were not transfused, blood transfusion was associated with higher operative mortality (2.3% versus 0.4%, p < 0.0001), as well as decreased survival at 5 years (82.0% versus 89.3%, p < 0.007), although not during the first 2 postoperative years. Patients receiving cryoprecipitate havd twice the mortality risk (adjusted hazard ratio 2.106, p = 0.002).

Abstract: Shaw. Blood transfusion in cardiac surgery does increase the risk of 5-year mortality: results from a contemporary series of 1714 propensity-matched patients. Transfusion 2013;epublished August 2nd