Newsletter 130 / June 1st 2014




Welcome to the 130th 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, guidelines, commentaries and editorials from hundreds of clinical and scientific journals.

This week's research studies include a before-and-after study on oxygenation during mechanical ventilation; meta analyses on prone position ventilation, high frequency oscillatory ventilation and hyperoxia after cardiac arrest; and two post cardiac arrest observational studies on glucose levels and blood gas tensions. Additional studies investigate candida infections, long-term severe sepsis outcomes, fluid challenge, delirium, physician end-of-life preferences, pulmonary embolism, non-invasive ventilation, and acute lung injury.

This week's guidelines address clostridium difficile colitis, idiopathic pulmonary fibrosis and developing performance measures from clinical practice guidelines. There is one study critique on the Proseva study. Editorials discuss social media, open access research, stroke and nutrition, while commentaries focus on ARDS, artificial pancreas, post-operative cognitive dysfunction, opioid overdose, capital punishment, pre-hospital care, infection control and spinal cord disorders. There are two case reports on locked-in patients and upper airway oedema.

Amongst the numerous clinical review articles are papers on cerebral protection post cardiac arrest, intra-operative goal-directed therapy, extra-corporeal life support, prone position ventilation, pancreatic necrosectomy, acute liver failure, liver transplantation, compartment syndrome and paediatric septic shock.

The topic for This Week's Papers is acute coronary syndromes, starting with a paper on the electrocardiogram in ACS in tomorrow's Paper of the Day.

Critical Care Reviews Meeting

The latest speaker to be announced for the Critical Care Reviews Meeting is Dr John Hinds, an anaesthetic intensivist and prehospital motor sports expert, who recently stole the show at the smaccGOLD conference. Check out his pro-con debate on the use of Cricoid Pressure, with his incredible "Cases from the Races" talk due out soon.

Big Announcement

Critical Care Reviews continues to grow, with news of an exciting big announcement out next week.....

Back to Top ↑



Before and After Study

Suzuki and colleagues compared a conservative approach to oxygen therapy (target Spo2 of 90–92%) with conventional oxygen therapy in 105 adult patients requiring mechanical ventilation for more than 48 hours, and found:

  1. basic data
    • 3,169 datasets on 799 mechanical ventilation days
  2. conservative oxygen therapy was associated with
    • a lower
      • median time-weighted average Spo2
        • 95.5% (IQR 94.0 to 97.3) versus 98.4% (97.3 to 99.1) (p < 0.001)
      • partial pressure of oxygen
        • 83 torr (71–94) versus 107 torr (94–131) (p < 0.001)
      • median Fio2
        • 0.27 (0.24–0.30) versus 0.40 (0.35–0.44) (p < 0.001).
      • median total amount of oxygen delivered during mechanical ventilation
        •  5,122 L (1,837–10,499 L) vs 15,580 L (8,263–29,351 L), p < 0.001
  3. no difference
    • in the evolution of the Pao2/Fio2 ratio
    • biochemical or clinical outcomes

Abstract:  Suzuki. Conservative Oxygen Therapy in Mechanically Ventilated Patients: A Pilot Before-and-After Trial. Crit Care Med 2014;42(6):1414-1422

Back to Top ↑

Meta Analyses

Sud pooled data from 11 randomized controlled trials comparing prone with supine positioning during mechanical ventilation in a total of 2,341 patients with the acute respiratory distress syndrome, and found:
  1. In 6 trials (n = 1,016) that used a protective ventilation strategy with reduced tidal volumes
    • prone positioning significantly reduced mortality
      • risk ratio 0.74, 95% CI 0.59 to 0.95; I2 = 29%
  2. a high overall quality of evidence
  3. a low risk of bias in all trials except one, which was small
  4. low statistical heterogeneity (I2 < 50%) for most of the clinical and physiologic outcomes

Full Text:  Sud. Effect of prone positioning during mechanical ventilation on mortality among patients with acute respiratory distress syndrome: a systematic review and meta-analysis. CMAJ 2014;epublished May 26th

Hu et al reviewed data from nine randomized controlled trials (n=2,242) evaluating the interaction between prone positioning and both PEEP and duration of proning in the acute respiratory distress syndrome, and found:
  1. compared with supine positioning, prone positioning was associated with a decrease in mortality in patients with severe ARDS (PaO2/FiO2 <=100 mmHg) at days
    • 28- to 30
      • RR 0.71; 95% CI 0.57 to 0.89; P = 0.003; n = 508
      • when duration of prone positioning was greater than 12 hours/day
        • RR 0.73; 95% CI 0.54 to 0.99; P = 0.04; n = 1,067
    • 60-day
      • when PEEP > 10 cmH2O
        • RR 0.82; 95% CI 0.68 to 0.99; P = 0.04; n = 518
    • 90-day
      • when PEEP > 10 cmH2O
        • RR 0.57; 95% CI 0.43 to 0.75; P <0.0001; n = 516
Full Text:  Hu. The effect of prone positioning on mortality in patients with acute respiratory distress syndrome: a meta-analysis of randomized controlled trials. Critical Care 2014;18:R109

Gu and colleagues pooled data from six randomized controlled trials (n=1,608) comparing high-frequency oscillatory ventilation with conventional mechanical ventilation as the initial mode of ventilation for adult ARDS patients, and found:
  1. high-frequency oscillatory ventilation was associated with
    • no difference in
      • mortality
        • at day 28 / 30
          • RR 1.051 (95% CI 0.813 to 1.358)
        • in ICU 
          • RR 1.218 (95% CI 0.925 to 1.604)
      • ventilation failure
        • RR 0.892 (95% CI 0.435 to 1.829)
      • duration of mechanical ventilation 
        • RR 0.079 (95% CI -0.045 to 0.203)
      • barotrauma 
        • RR 1.205 (95% CI 0.834 to 1.742)
      • hypotension 
        • RR 1.326 (95% CI 0.271 to 6.476)
    • reduced risk of
      • oxygenation failure
        • RR 0.557 (95% CI 0.351 to 0.884)

Full Text:  Gu. In adult acute respiratory distress syndrome patients, is high-frequency oscillatory ventilation more effective and safer than conventional protective ventilation? a meta-analysis of randomized controlled trials. Critical Care 2014;18:R111

Wang et al reviewed 14  observational studies to examine the effect of hyperoxia on outcomes after return of spontaneous circulation in cardiac arrest patients, and found:

  1. hyperoxia was
    • associated with
      • increased in-hospital mortality
        • OR 1.40; 95% CI 1.02 to 1.93; I2 69.27%; 8 studies
    • not associated with
      • worsened neurological outcome
        • OR 1.62; 95% CI 0.87 to 3.02; I2 55.61%; 2 studies
  2. the results were inconsistent in subgroup and sensitivity analyses

Abstract:  Wang. The Effect of Hyperoxia on Survival Following Adult Cardiac Arrest: A Systematic Review and Meta-analysis of Observational Studies. Resuscitation 2014;epublished May 31st

Back to Top ↑

Observational Studies

Daviaud et al conducted a French single centre, database study in in 381 patients resuscitated from out-of-hosptial cardiac arrest between 2006 and 2010, examining the the relationship between blood glucose levels and outcome, and found:

  1. 36% had a favorable outcome (cerebral performance category 1–2)
  2. a favourable outcome was associated with
    • lower median blood glucose level
      • 7.6 mmol/L (6.3 to  9.8) vs 9.0 mmol/L (IQR 7.1 to 10.6) (P < 0.01)
    • lower median blood glucose level variation
      • 7.1 (4.2 to 11) vs 9.6 (5.9 to 13.6) mmol/L (P < 0.01)
  3. independent predictors of poor outcome were
    • increased median blood glucose level over the first 48 hours
      • OR 0.43, 95% CI 0.24 to 0.78, P = 0.006
    • a progressive increase in median blood glucose level was associated with a progressive increase in the proportion of patients with a poor outcome

Abstract:  Daviaud. Blood glucose level and outcome after cardiac arrest: insights from a large registry in the hypothermia era. Intensive Care Med 2014;40(6):855-862

Vaahersalo and colleagues performed a prospective cohort study in 21 Finnish ICUs, assessing the effects of mean and time-weighted oxygen and carbon dioxide levels, divided into predefined categories from lowest to highest, during the first 24 hours of postcardiac arrest care in 409 patients, and found:

  1. basic data
    • average of 8 Pao2 and Paco2 measurements per patient
  2. mean 24 hours Paco2 level was an independent predictor of good outcome
    • OR  1.054; 95% CI 1.006 to 1.104; p = 0.027
  3. mean 24 hours Pao2 value was not an independent predictor of good outcome
    • odds ratio 1.006; 95% CI 0.998 to 1.014; p = 0.149
  4. time spent in the Paco2 band higher than 45 mm Hg was associated with good outcome
    • OR 1.015; 95% CI 1.002 to 1.029; p = 0.024, for each percentage point increase in time
  5. time spent in different oxygen categories were not associated with good outcome

Abstract:  Vaahersalo. Arterial Blood Gas Tensions After Resuscitation From Out-of-Hospital Cardiac Arrest: Associations With Long-Term Neurologic Outcome. Critical Care Med 2014;42(6):1463-1470

Back to Top ↑

Additional Studies

Observational Studies

Back to Top ↑

Guidelines & Position Statements

Back to Top ↑

Study Critique

Back to Top ↑


Back to Top ↑



Case Report

Back to Top ↑ 

Clinical Review Articles












Back to Top ↑

I hope you find these brief summaries and links useful.


Until next week