Background: Respiratory failure remains the leading indication for intensive care unit admission 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 antiretroviral therapy, low tidal-volume ventilation for acute lung injury, or both.
Objectives: Our aims were 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: We performed a retrospective cohort study of 148 consecutive HIV-infected adults admitted to the ICU at San Francisco General Hospital with acute lung injury requiring mechanical ventilation. We abstracted demographic and clinical information, including data on mechanical ventilation, from medical records, and performed 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% Confidence Interval -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% Confidence Interval 0.58 - 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 was independently associated with reduced mortality in HIV-infected patients with acute lung injury and respiratory failure.