End-tidal partial pressure of CO2 as an estimate of arterial partial pressure of CO2 during various ventilatory regimens in halothane-anesthetized dogs.
The correlation between end-tidal partial pressure of CO2 (PETCO2) and arterial PCO2 (PaCO2) was studied in six halothane-anesthetized dogs maintained under four different ventilatory regimens: (A) spontaneous breathing; (B) assisted positive-pressure ventilation; (C) intermittent manual inflation; and (D) ventilator-controlled breathing. For procedures A, B, and D together, there was a strong correlation between PETCO2 and PaCO2 (r = 0.8) that was highly significant at P less than 0.0001 for PETCO2 values between 31.3 and 61 mm of Hg. In spontaneous and controlled breathing, PETCO2 is representative of PaCO2 and provides a useful noninvasive tool for monitoring the patient maintained under general anesthesia. Furthermore, data suggest that any ventilatory support of the anesthetized patient markedly improves blood gas and acid-base status compared with that of the unsupported, spontaneously breathing animal.
D000769:Anesthesia, Inhalation / Q000662:veterinary*; D000818:Animals; D002245:Carbon Dioxide / Q000032:analysis / Q000097:blood*; D004285:Dogs / Q000502:physiology*; D005260:Female; D006221:Halothane; D008297:Male; D010313:Partial Pressure; D012119:Respiration
D002245:Carbon Dioxide; D006221:Halothane