Effect of mechanical ventilation in the prone position on clinical outcomes in patients with acute hypoxemic respiratory failure: a systematic review and meta-analysis

Background: Mechanical ventilation in the prone position is used to improve oxygenation in patients with acute hypoxemic respiratory failure. We sought to determine the effect of mechanical ventilation in the prone position on mortality, oxygenation, duration of ventilation and adverse events in patients with acute hypoxemic respiratory failure. Methods: In this systematic review we searched MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials and Science Citation Index Expanded for articles published from database inception to February 2008. We also conducted extensive manual searches and contacted experts. We extracted physiologic data and clinically relevant outcomes. Results: Thirteen trials that enrolled a total of 1559 patients met our inclusion criteria. Overall methodologic quality was good. In 10 of the trials (n = 1486) reporting this outcome, we found that prone positioning did not reduce mortality among hypoxemic patients (risk ratio [RR] 0.96, 95% confidence interval [CI] 0.84–1.09; p = 0.52). The lack of effect of ventilation in the prone position on mortality was similar in trials of prolonged prone positioning and in patients with acute lung injury. In 8 of the trials (n = 633), the ratio of partial pressure of oxygen to inspired fraction of oxygen on day 1 was 34% higher among patients in the prone position than among those who remained supine (p < 0.001); these results were similar in 4 trials on day 2 and in 5 trials on day 3. In 9 trials (n = 1206), the ratio in patients assigned to the prone group remained 6% higher the morning after they returned to the supine position compared with patients assigned to the supine group (p = 0.07). Results were quantitatively similar but statistically significant in 7 trials on day 2 and in 6 trials on day 3 (p = 0.001). In 5 trials (n = 1004), prone positioning was associated with a reduced risk of ventilator-associated pneumonia (RR 0.81, 95% CI 0.66–0.99; p = 0.04) but not with a reduced duration of ventilation. In 6 trials (n = 504), prone positioning was associated with an increased risk of pressure ulcers (RR 1.36, 95% CI 1.07–1.71; p = 0.01). Most analyses found no to moderate between-trial heterogeneity. Interpretation: Mechanical ventilation in the prone position does not reduce mortality or duration of ventilation despite improved oxygenation and a decreased risk of pneumonia. Therefore, it should not be used routinely for acute hypoxemic respiratory failure. However, a sustained improvement in oxygenation may support the use of prone positioning in patients with very severe hypoxemia, who have not been well-studied to date.

[1]  C. Waydhas,et al.  Prone positioning improves oxygenation in post-traumatic lung injury--a prospective randomized trial. , 2004, The Journal of trauma.

[2]  D. Altman,et al.  Measuring inconsistency in meta-analyses , 2003, BMJ : British Medical Journal.

[3]  Bryan Ac Conference on the scientific basis of respiratory therapy. Pulmonary physiotherapy in the pediatric age group. Comments of a devil's advocate. , 1974 .

[4]  C. Roussos,et al.  Prone position in early and severe acute respiratory distress syndrome: a design for a definitive randomized controlled trial. , 2007, Anesthesia and analgesia.

[5]  S D Walter,et al.  A comparison of methods to detect publication bias in meta‐analysis , 2001, Statistics in medicine.

[6]  C. Waydhas,et al.  Effect of Prone Position on Lung Surfactant Composition and Function in Multiple Trauma Patients with Respiratory Dysfunction* , 2005, European Journal of Trauma.

[7]  A. Sutton,et al.  Comparison of two methods to detect publication bias in meta-analysis. , 2006, JAMA.

[8]  J. Vincent,et al.  Prone positioning in acute respiratory failure: survey of Belgian ICU nurses , 2002, Intensive Care Medicine.

[9]  G. Rubenfeld,et al.  Causes and timing of death in patients with ARDS. , 2005, Chest.

[10]  A. Artigas,et al.  The American-European consensus conference on ARDS, Part 2 and the Consensus Committee , 1998 .

[11]  N. Laird,et al.  Meta-analysis in clinical trials. , 1986, Controlled clinical trials.

[12]  T. Yamakura,et al.  Beneficial effect of a prone position for patients with hypoxemia after transthoracic esophagectomy , 2002, Critical care medicine.

[13]  J. Chiche,et al.  High frequency oscillatory ventilation compared with conventional mechanical ventilation in adult respiratory distress syndrome: a randomized controlled trial [ISRCTN24242669] , 2005, Critical care.

[14]  Quoc V. Le,et al.  Effects of systematic prone positioning in hypoxemic acute respiratory failure: a randomized controlled trial. , 2004, JAMA.

[15]  G. Tognoni,et al.  Ventilation in the prone position. The Prone-Supine Study Collaborative Group. , 1997, Lancet.

[16]  ntonio,et al.  EFFECT OF PRONE POSITIONING ON THE SURVIVAL OF PATIENTS WITH ACUTE RESPIRATORY FAILURE , 2001 .

[17]  J. Bazin,et al.  Influence du drainage bronchique dans l'amélioration des échanges gazeux observée en décubitus ventral au cours du SDRA , 2000 .

[18]  A. Pesenti,et al.  Decrease in Paco2 with prone position is predictive of improved outcome in acute respiratory distress syndrome* , 2003, Critical care medicine.

[19]  Joseph Beyene,et al.  Meta-Analysis: Low-Dose Dopamine Increases Urine Output but Does Not Prevent Renal Dysfunction or Death , 2005, Annals of Internal Medicine.

[20]  J. Bazin,et al.  [Effect of bronchial drainage on the improvement in gas exchange observed in ventral decubitus in ARDS]. , 2000, Annales francaises d'anesthesie et de reanimation.

[21]  L. Hudson,et al.  Causes of Mortality in Patients with the Adult Respiratory Distress Syndrome , 1985, The American review of respiratory disease.

[22]  J. Marini,et al.  The pragmatics of prone positioning. , 2002, American journal of respiratory and critical care medicine.

[23]  D. Wypij,et al.  Effect of prone positioning on clinical outcomes in children with acute lung injury: a randomized controlled trial. , 2005, JAMA.

[24]  D. Chiumello,et al.  Physical and biological triggers of ventilator-induced lung injury and its prevention , 2003, European Respiratory Journal.

[25]  Sangeeta Mehta,et al.  High-frequency oscillatory ventilation for acute respiratory distress syndrome in adults: a randomized, controlled trial. , 2002, American journal of respiratory and critical care medicine.

[26]  M. Chan,et al.  Effects of prone position on inflammatory markers in patients with ARDS due to community-acquired pneumonia. , 2007, Journal of the Formosan Medical Association = Taiwan yi zhi.

[27]  H. Saltzman,et al.  Conference on the scientific basis of respiratory therapy. , 1974, The American review of respiratory disease.

[28]  A. Huggett,et al.  Phyto-oestrogens in soy-based infant formula , 1997, The Lancet.

[29]  P. Bongrand,et al.  Comparison of prone positioning and high-frequency oscillatory ventilation in patients with acute respiratory distress syndrome* , 2005, Critical care medicine.

[30]  A. C. Bryan Conference on the scientific basis of respiratory therapy. Pulmonary physiotherapy in the pediatric age group. Comments of a devil's advocate. , 1974, The American review of respiratory disease.

[31]  T. Ibrahim,et al.  Inhaled Nitric Oxide and Prone Position: How Far They Can Improve Oxygenation in Pediatric Patients with Acute Respiratory Distress Syndrome? , 2007 .

[32]  S. Thompson,et al.  Quantifying heterogeneity in a meta‐analysis , 2002, Statistics in medicine.

[33]  J. Arnold,et al.  Clinical trial design--effect of prone positioning on clinical outcomes in infants and children with acute respiratory distress syndrome. , 2006, Journal of critical care.

[34]  C. Guérin,et al.  Does gas exchange response to prone position predict mortality in hypoxemic acute respiratory failure? , 2006, Intensive Care Medicine.

[35]  Arthur S Slutsky,et al.  Combining high-frequency oscillatory ventilation and recruitment maneuvers in adults with early acute respiratory distress syndrome: The Treatment with Oscillation and an Open Lung Strategy (TOOLS) Trial pilot study* , 2005, Critical care medicine.

[36]  M. Curley,et al.  Prone positioning can be safely performed in critically ill infants and children* , 2006, Pediatric critical care medicine : a journal of the Society of Critical Care Medicine and the World Federation of Pediatric Intensive and Critical Care Societies.

[37]  L. Hirsch Competing interests: none declared. , 2006 .

[38]  T. Bein,et al.  [Positioning therapy in intensive care medicine in Germany. Results of a national survey]. , 2007, Der Anaesthesist.

[39]  L. Papazian,et al.  High‐frequency oscillatory ventilation following prone positioning prevents a further impairment in oxygenation* , 2007, Critical care medicine.

[40]  M. Chan,et al.  Reply to Friedrich et al , 2008 .

[41]  Peter C Gøtzsche,et al.  Data extraction errors in meta-analyses that use standardized mean differences. , 2007, JAMA.

[42]  B. Blackwood,et al.  Nursing the ARDS patient in the prone position: the experience of qualified ICU nurses. , 2001, Intensive & critical care nursing.

[43]  Rafael Fernández,et al.  A multicenter trial of prolonged prone ventilation in severe acute respiratory distress syndrome. , 2006, American journal of respiratory and critical care medicine.

[44]  John T Granton,et al.  Effect of nitric oxide on oxygenation and mortality in acute lung injury: systematic review and meta-analysis , 2007, BMJ : British Medical Journal.

[45]  C. Begg,et al.  Operating characteristics of a rank correlation test for publication bias. , 1994, Biometrics.

[46]  G. Tognoni,et al.  Ventilation in the prone position , 1997, The Lancet.

[47]  G R Bernard,et al.  The American-European Consensus Conference on ARDS, part 2: Ventilatory, pharmacologic, supportive therapy, study design strategies, and issues related to recovery and remodeling. Acute respiratory distress syndrome. , 1998, American journal of respiratory and critical care medicine.

[48]  M. Lamy,et al.  The American-European Consensus Conference on ARDS. Definitions, mechanisms, relevant outcomes, and clinical trial coordination. , 1994, American journal of respiratory and critical care medicine.

[49]  D. Schoenfeld,et al.  Ventilation with lower tidal volumes as compared with traditional tidal volumes for acute lung injury and the acute respiratory distress syndrome. , 2000, The New England journal of medicine.

[50]  R. Mellins Pulmonary Physiotherapy in the Pediatric Age Group1 , 1974 .

[51]  P. Beuret,et al.  Prone position as prevention of lung injury in comatose patients: a prospective, randomized, controlled study , 2002, Intensive Care Medicine.