Low tidal volume ventilation is associated with reduced mortality in HIV-infected patients with acute lung injury
- 1Division of Pulmonary and Critical Care Medicine, San Francisco General Hospital, University of California, San Francisco, California, USA
- 2Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- 3Department of Anesthesia, San Francisco General Hospital, University of California, San Francisco, California, USA
- 4Department of Medicine, San Francisco General Hospital, University of California, San Francisco, California, USA
- 5Division of Pulmonary & Critical Care Medicine, Boston University, Boston, Massachusetts, USA
- 6HIV/AIDS Division, San Francisco General Hospital, University of California, San Francisco, California, USA
- Dr J L Davis, San Francisco General Hospital, 1001 Potrero Avenue, Room SK1, San Francisco, CA 94110, USA; lucian.davis{at}ucsf.edu
- Received 12 January 2008
- Accepted 29 April 2008
- Published Online First 5 June 2008
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.
Footnotes
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Funding: NIH 5T32HL007185–30 (JLD), NIH P30AI027763–15 (JLD), NIH 1F32HL088990–01 (JLD), NIH K23HL072837 (AM), NIH R01HL083461 (AM), NIH K24HL087713 (LH), NIH R01 HL090335 (LH).
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Competing interests: None.
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Ethics approval: The Committee on Human Research at the University of California, San Francisco approved the study protocol.
