VENTILATORY EFFECTS OF ACTIVE COMPRESSION-DECOMPRESSION IN DOGS

Study objective: To determine the ventilatory effect of active compres sion-decompression CPR and to compare it with two other techniques, st andard manual cardiac massage and mechanical cardiac massage. Design: Prospective, randomized laboratory investigation. Participants: Mongre l dogs. Interventions: Nine adult mongrel dogs were anesthetized, intu bated, and mechanically ventilated. They were instrumented to measure arterial pressure, esophageal pressure, airway pressure, end-tidal car bon dioxide concentration, and minute ventilation. Results: After indu ction of ventricular fibrillation, three sequences of cardiac massage were performed randomly during mechanical ventilation, standard cardia c massage, mechanical cardiac massage, and active compression-decompre ssion technique. The animals then were disconnected from the ventilato r, and the three sequences were performed again. Active compression-de compression created negative minimum esophageal pressures and signific antly decreased the minimum airway pressure as compared with the other techniques. Whatever the ventilatory condition, minute ventilation wa s increased dramatically during active compression-decompression. Conc lusion: In this model of cardiac arrest, an important increase in minu te ventilation was observed during active compression-decompression. T his effect was significantly greater than the increases observed with other techniques of cardiac massage and was related to the negative pr essure generated by active decompression.