Noninvasive pressure support ventilation vs. continuous positive airway pressure in acute hypercapnic pulmonary edema.

OBJECTIVE: This study compared noninvasive pressure support ventilation (NIPSV) and continuous positive airway pressure (CPAP) in patients with acute hypercapnic pulmonary edema with regard to resolution time.

DESIGN AND SETTING: Randomized prospective study in an emergency department.

PATIENTS AND PARTICIPANTS: We randomly assigned 36 patients with respiratory failure due to acute pulmonary edema and arterial hypercapnia (PaCO(2) >45 mmHg) to NIPSV (n=18) or CPAP through a face mask (n=18).

MEASUREMENTS AND RESULTS: Electrocardiographic and physiological measurements were made over 36 h. There was no difference in resolution time defined as clinical improvement with a respiratory rate of fewer than 30 breaths/min and SpO(2)of 96% or more between CPAP and NIPSV groups. Arterial carbon dioxide tension was significantly decreased after 1 h of ventilation (CPAP, 60.5+/-13.6 to 42.8+/-4.9 mmHg; NIPSV, 65.7+/-13.6 to 44.0+/-5.5 mmHg); respective improvements were seen in pH (CPAP, 7.22+/-0.11 to 7.37+/-0.04; NIPSV, 7.19+/-0.11 to 7.38+/-0.04), SpO(2) (CPAP, 86.9+/-3.7% to 95.1+/-2.6%; NIPSV, 83.7+/-6.6% to 96.0+/-2.9%), and respiratory rate (CPAP, 37.9+/-4.5 to 21.3+/-5.1 breaths/min; NIPSV, 39.8+/-4.4 to 21.2+/-4.6 breaths/min). No significant differences were seen with regards to endotracheal intubation and in-hospital mortality.

CONCLUSIONS: NIPSV proved as effective as CPAP in the treatment of patients with acute pulmonary edema and hypercapnia but did not improve resolution time.