Feasibility Study of the Use of Bilevel Positive Airway Pressure for Respiratory Support in the Emergency Department

Abstract

Study objective: To determine the feasibility of bilevel positive airway pressure (BiPAP) support for acute respiratory distress (ARD) in the emergency department. Methods: A convenience sample of patients in ARD as a result of any nontraumatic cause was recruited for a prospective, noncontrolled clinical trial in the ED of an urban tertiary care teaching hospital. Hemodynamically unstable patients and those requiring immediate endotracheal intubation were excluded. After an initial arterial blood gas (AGB) analysis was obtained, the patient was placed on BiPAP (Bi-PAP S/T noninvasive ventilator; Respironics, Incorporated) by nose mask or face mask to provide noninvasive pressure support at 5 cm H 2O. Settings were titrated to patient tolerance and satisfactory pulse oximetry. After at least 30 minutes on a stable setting, arterial blood gases were remeasured. The cause of respiratory distress, vital signs, assessment of need for intubation, arterial blood gas results, and patient disposition were recorded. Success of noninvasive support was defined as the presence of (1) improvement in ABG parameters, (2) clinical improvement and decrease in evident dyspnea, and (3) avoidance of endotracheal intubation and mechanical ventilation. Results: Fifty patients were studied. Causes of ARD included acute congestive heart failure (CHF; n=16), exacerbation of chronic obstructive pulmonary disease (COPD; n=9), mixed COPD/CHF (n=3), pneumonia (n=10), status asthmaticus (n=6), and other causes of acute respiratory failure (eg, stroke, overdose; n=6). Noninvasive management was successful in 43 patients (86%), with patients in all etiologic categories being equally likely to respond favorably to therapy. All patients were admitted to the hospital, but 52.5% of those who ordinarily would have required ICU beds were admitted to lower (and less costly) levels of care. Three patients were eventually intubated, all after admission to the ICU on BiPAP. Two patients did not tolerate BiPAP, and two others were considered ED treatment failures but were not intubated because of advance directives. Conclusion: As has been reported from other critical care settings, use of BiPAP is feasible and has potential utility in the management of ARD in the ED. [Pollack CV Jr, Torres MT, Alexander L: Feasibility study of the use of bilevel positive airway pressure for respiratory support in the emergency department. Ann Emerg Med February 1996;27:189-192.]