Inhaled nitric oxide has been demonstrated to improve oxygenation in critically ill patients requiring mechanical ventilation. We therefore performed a retrospective review to determine the outcome of patients with hematological malignancies and acute respiratory failure who received inhaled nitric oxide (INO) in a multidisciplinary intensive care unit of a single tertiary referral medical center. Thirteen patients with hematological malignancies who required endotracheal intubation and mechanical ventilation and received INO for acute respiratory failure between January 1998 and December 2002 were identified. Mean +/- standard deviation (SD) age was 47.6 (+/-13.2) years. The mean +/- SD Acute Physiology and Chronic Health Evaluation (APACHE) III score on the day of ICU admission was 94.1 +/- 33.7 with a mean (SD) predicted probability of ICU death of 42.4% (+/-28.6). Mean APACHE III score on the day of initiating INO was 107.6 (+/-34.4) with a predicted mortality in the intensive care unit of 72.7% (+/-23.3). Mean PaO(2) to FiO(2) (PF) ratios (+/-SD) prior to, and immediately after, the initiation of INO were 62.6 (+/-28.2) and 111 (+/-65.1), respectively (P < 0.001). The median duration of INO therapy was 41.8 h (interquartile range, 6.3-98.2). Patients with hematological malignancies and acute respiratory failure to whom INO was administered had clinical deterioration since ICU admission. Despite a marked initial improvement in arterial oxygen tension, all patients ultimately died in the intensive care unit, 8 of them within 48 h of initiating INO. Therefore, despite initial improvement in oxygenation, we did not observe any survival benefit to INO in this setting.