Noninvasive continuous positive airway pressure delivered by helmet in hematological malignancy patients with hypoxemic acute respiratory failure

Objective: To compare the efficacy of early administration of noninvasive continuous positive airway pressure (nCPAP) delivered by the helmet vs. face mask to treat hematological malignancy patients with fever, pulmonary infiltrates, and hypoxemic acute respiratory failure. Design and setting: Prospective clinical study with historical matched controls in the hematology department of a university hospital. Patients and interventions: Seventeen hematological malignancy patients with hypoxemic acute respiratory failure defined as: moderate to severe dyspnea, tachypnea (>30-35 breaths/min), use of accessory muscles and paradoxical abdominal motion, and PaO2/FIO2 ratio less than 200. Each patient was treated with nCPAP by helmet outside the ICU in the hematological ward. Arterial oxygen saturation, heart rate, respiratory rate, and blood pressure were monitored to identify early nCPAP failure. Seventeen historical-matched controls treated in the same department with face mask CPAP were selected as control population; matching criteria were age, sex, diagnosis, and PaO2/FIO2 ratio. Primary end-points were improvement in gas exchanges and the need for endotracheal intubation. Results: Oxygenation improved in all patients after nCPAP. No patient failed helmet nCPAP because of intolerance while eigh patients in the mask group did so. nCPAP could be applied continuously for a longer period of time in the helmet group (28.44+/-0.20 vs. 7.5+/-0.45 h). Conclusions: Early nCPAP with helmet improves oxygenation in selected immunosuppressed patients with hypoxemic acute respiratory failure. Tolerance of helmet nCPAP seems better than that of nCPAP delivered by mask.