TRANSESOPHAGEAL ELECTROVENTILATION - OPTIMIZATION AND IMPROVEMENT

For electroventilation, short duration pulse trains (0.1 ms) were appl ied between two axillary pads (transchest) and compared with transesop hageal electroventilation where pulses passed between the same pads to an esophageal electrode in apneic, pentobarbitone-anesthetized pigs. Significantly greater tidal volumes were produced by transesophageal e lectroventilation in comparison with transchest. As measured by mainta ined tidal volumes, duration of inspiratory air now, peak now, percent age hemoglobin oxygen saturation (%SaO(2)), and end tidal carbon dioxi de concentration (ETCO(2)), the optimal requirements for transesophage al electroventilation were pulse frequency 40 Hz, 0.7 s duration pulse s, at 60 to 100 V, pulse width 0.1 ms, with the esophageal electrode p roximal to the gastroesophageal junction without producing brachial pl exus stimulation. The efficiency of transesophageal electroventilation falls off rapidly following ventricular fibrillation. Thus, the appli cation of this technique would be in respiratory arrest with maintaine d circulation, eg, in drug-induced respiratory depression, severe smok e inhalation, severe emphysema, high cervical cord lesion, and weaning from prolonged mechanical ventilation.