Aerosol delivery and humidification with the Boussignac continuous positive airway pressure device.

BACKGROUND: A simple method for effective bronchodilator aerosol delivery while administering continuing continuous positive airway pressure (CPAP) would be useful in patients with severe bronchial obstruction. OBJECTIVE: To assess the effectiveness of bronchodilator aerosol delivery during CPAP generated by the Boussignac CPAP system and its optimal humidification system. METHODS: First we assessed the relationship between flow and pressure generated in the mask with the Boussignac CPAP system. Next we measured the inspired-gas humidity during CPAP, with several humidification strategies, in 9 healthy volunteers. We then measured the bronchodilator aerosol particle size during CPAP, with and without heat-and-moisture exchanger, in a bench study. Finally, in 7 patients with acute respiratory failure and airway obstruction, we measured work of breathing and gas exchange after a ß(2)-agonist bronchodilator aerosol (terbutaline) delivered during CPAP or via standard nebulization. RESULTS: Optimal humidity was obtained only with the heat-and-moisture exchanger or heated humidifier. The heat-and-moisture exchanger had no influence on bronchodilator aerosol particle size. Work of breathing decreased similarly after bronchodilator via either standard nebulization or CPAP, but P(aO(2)) increased significantly only after CPAP aerosol delivery. CONCLUSIONS: CPAP bronchodilator delivery decreases the work of breathing as effectively as does standard nebulization, but produces a greater oxygenation improvement in patients with airway obstruction. To optimize airway humidification, a heat-and-moisture exchanger could be used with the Boussignac CPAP system, without modifying aerosol delivery.

Constant flow insufflation of oxygen as the sole mode of ventilation during out-of-hospital cardiac arrest.

BACKGROUND: Constant flow insufflation of oxygen (CFIO) through a Boussignac multichannel endotracheal tube has been reported to be an efficient ventilatory method during chest massage for cardiac arrest. METHODS: Patients resuscitated for out-of-hospital cardiac arrest were randomly assigned to standard endotracheal intubation and mechanical ventilation (MV; n =457) or use of CFIO at a flow rate of 15 l/min (n=487). Continuous chest compressions were similar in the two groups. Pulse oximetry level was recorded every 5[Symbol: see text]min. Outcome of initial resuscitation, hospital admission, complications, and discharge from the intensive care unit (ICU) were analyzed. The randomization scheme was changed during the study, but the in-depth analysis was performed only on the first cohort of 341 patients with CFIO and 355 with MV, because of randomization problems in the second part. RESULTS: No difference in outcome was noted regarding return to spontaneous circulation (CFIO 21%, MV 20%), hospital admission (CFIO 17%, MV 16%), or ICU discharge (CFIO 2.4%, MV 2.3%). The level of detectable pulse saturation and the proportion of patients with saturation above 70% were higher with CFIO. Ten patients with MV but only one with CFIO had rib fractures. CONCLUSIONS: CFIO is a simplified alternative to MV, with favorable effects regarding oxygenation and fewer complications, as observed in this group of patients with desperate prognosis.