Inhalation Anesthesia with High Frequency Jet Ventilation

Jang, Young Jin; Jung, Yong Hun; Yang, Hong Seuk

Abstract

High frequency jet ventilation(HFJV) induces adequate gas exchange with tidal volume smaller than that of other conventional ventilation method. In critically ill patients, HFJV reduces the unwanted hemodynamic effects of conventional ventilation caused by the increase in intrathoracic pressure. But general anesthesia with jet ventilator has been dependent only on intravenous anesthetics. Therefore, this study was done to administer inhalation anesthetics(N2O, enflurane) during HFJV. This study was carried out from June 1992 to January 1993 in the 64 operated patients who beIonged to ASA class I, II in Chung Ang University Hospital The 22 patients using conventional ventilation were control group and the other 42 patients who had inhalation anesthesia by using HFJV were experimental group. In all patients, blood pressure and heart rate were checked on preinduction, postinductive 0, 5, 10, 15, 20, and 30 minutes. The result were as follows I) Systolic blood pressure was increased just on postinduction in both groups(P<0.05). It was decreased from postinductive 5 minutes to 30 minutes in control group, but there was no change in experimental group(P<0.05). 2) Diastolic blood pressure was increaeed just on postinduction in both groups(P<0.05). But it was increased from postinductive 5 minutes to 30 minutes in experimental group(P<0.05). 3) Mean blood pressure was increased just on postinduction in both groups(P<0.05). It was increased from postinductive 5 minutes to 15 minutes in control group and from postinductive 5 minutes to 30 minutes in experimental group(P<0.05). 4) Heart rate was increased just on postinduction and postinductive 5 minutes in control groupg <0.05), and increased from postinductive 0 minute to postinductive 30 minutes in experimental group(P<0.05). 5) pH was increased on postinductive 30 minutes compared to that of preinduction in both groups(P <0.05). 6) PaCO2 was more decreased on postinductive 30 minutes than preinduction in both groups (P<0.05), but there was no clinical significance. And PaO2 was increased at postinductive 30 minutes(P<0.05), which resulted from the increase of FiO2. As above results, inhalation anesthesia with HFJV is supposed to be useful if the difficulty of controlling the concentration of inhalation anesthetics and the contamination of operating room by expelled inhalation anesthetics were solved.