Objective: To evaluate the clinical efficacy of noninvasive continuous positive airway pressure ventilation (CPAP) using a new interface, constituted by a cephalic plastic helmet, in comparison with a standard facial mask.
Design and setting: A prospective pilot study with matched-control group, in the emergency department of a teaching hospital.
Patients and methods: Eleven consecutive adult patients with acute hypoxemic respiratory failure related to cardiogenic pulmonary edema (whether hypercapnic or not) were enrolled in the study, after failure of the initial medical treatment. Each patient treated with CPAP, using the helmet in addition to a standardized medical treatment, was matched with historical control-patient treated with CPAP using a standard facial mask, and selected by gender, age, and PaCO2 levels on admission. Primary end points were improvements of gas exchanges and clinical parameters of respiratory distress. tolerance was evaluated after each CPAP trial.
Results: The 22 patients and controls had similar characteristics at baseline. PaCO2 levels, and clinical parameters improved similarly in both groups. No interface intolerance was reported whether using standard facial mask or the helmet. No complications were observed in either group. The helmet allowed CPAP administration for a longer period of time (p=0.045). In-hospital mortality was not different between the two groups.
Conclusion: Despite a high dead-space volume (9-15 l), this new helmet interface is an efficient alternative to standard face mask during CPAP, even in cases of severe respiratory acidosis and hypercapnia. It allowed to provide long-duration CPAP, without any adverse events or clinical intolerance.