Low tidal volume ventilation is associated with reduced mortality in HIV-infected patients with acute lung injury

Thorax. 2008 Nov;63(11):988-93. doi: 10.1136/thx.2008.095786. Epub 2008 Jun 5.

Abstract

Background: Respiratory failure remains the leading indication for admission to the intensive care unit (ICU) and a leading cause of death for HIV-infected patients in spite of overall improvements in ICU mortality. It is unclear if these improvements are due to combination anti-retroviral therapy, low tidal volume ventilation for acute lung injury, or both. A study was undertaken to identify therapies and clinical factors associated with mortality in acute lung injury among HIV-infected patients with respiratory failure in the period 1996-2004. A secondary aim was to compare mortality before and after introduction of a low tidal volume ventilation protocol in 2000.

Methods: A retrospective cohort study was performed of 148 consecutive HIV-infected adults admitted to the ICU at San Francisco General Hospital with acute lung injury requiring mechanical ventilation. Demographic and clinical information including data on mechanical ventilation was abstracted from medical records and analysed by multivariate analysis using logistic regression.

Results: In-hospital mortality was similar before and after introduction of a low tidal volume ventilation protocol, although the study was not powered to exclude a clinically significant difference (risk difference -5.4%, 95% CI -21% to 11%, p = 0.51). Combination antiretroviral therapy was not clearly associated with mortality, except in patients with Pneumocystis pneumonia. Among all those with acute lung injury, lower tidal volume was associated with decreased mortality (adjusted odds ratio 0.76 per 1 ml/kg decrease, 95% CI 0.58 to 0.99, p = 0.043), after controlling for Pneumocystis pneumonia, serum albumin, illness severity, gas exchange impairment and plateau pressure.

Conclusions: Lower tidal volume ventilation is independently associated with reduced mortality in HIV-infected patients with acute lung injury and respiratory failure.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Acute Lung Injury / complications
  • Acute Lung Injury / mortality
  • Acute Lung Injury / physiopathology*
  • Adult
  • Cohort Studies
  • Female
  • HIV Infections / complications
  • HIV Infections / mortality
  • HIV Infections / physiopathology*
  • Hospitalization
  • Humans
  • Male
  • Respiration, Artificial
  • Respiratory Distress Syndrome / complications
  • Respiratory Distress Syndrome / mortality
  • Respiratory Distress Syndrome / physiopathology*
  • Retrospective Studies
  • Tidal Volume / physiology