EFFICACY OF CARDIOPULMONARY-RESUSCITATION USING INTRATRACHEAL INSUFFLATION

The effects of constant-flow insufflation (CFI) of air in the trachea at the distal end of a modified endotracheal tube as the sole mode of ventilation during cardiopulmonary resuscitation (CPR) were studied in pigs. The ventilatory effect of CFI (15 +/- 2 L/min) generating a pos itive pressure of about 10 cm H2O with concomitant chest compression w as studied first. In nine sedated, paralyzed animals disconnected from the ventilator, CFI alone did not significantly alter the decrease in Pa-o2 and the rise in Pa-Co2 observed during apnea. By contrast, the combination of precordial compression and CFI (CFI-CPR) maintained art erial blood gases over a 4-min period at the level obtained during mec hanical ventilation. In the second part of the study, ventricular fibr illation was induced and CFI-CPR was compared with standard CPR using conventional mechanical ventilation during two successive 4-min period s, in random order. Ventilatory parameters were identical in the two s ituations, whereas hemodynamic parameters were similar or better with CFI-CPR than with standard CPR. Significant differences were observed between standard CPR and CFI-CPR for systolic aortic pressure (72 +/- 22 versus 82 +/- 27 mm Hg, respectively; p < 0.02) and for systolic (3 22 +/- 216 versus 431 +/- 237 ml/s; p < 0.01) and mean (116 +/- 106 ve rsus 143 +/- 108 ml/s; p < 0.01) common carotid blood flows. The ease of use of CFI together with its beneficial hemodynamic effects suggest s that CFI deserves to be investigated further as a mode of ventilatio n during CPR.