[Isoflurane anesthesia with combined use of low dose fentanyl for open heart surgery]

The hemodynamic and respiratory effects of high dose fentanyl anesthesia and those of isoflurane anesthesia with combined use of low dose fentanyl were compared in 40 patients undergoing open heart surgery. Twenty patients (Group Fen) were anesthetized with high dose fentanyl (about 100 micrograms.kg-1), other twenty patients (Group Iso) were anesthetized with isoflurane (inhalation of 1.0-2.0%) combined with low dose fentanyl (about 8 micrograms.kg-1). Between the two groups, there were no significant differences in HR, CI, SVI, MPAP, MRAP, PVRI, RVCWI, LVSWI, DO2I, SvO2, and P/F ratio. In group Iso, there were significant decreases in mean arterial pressure (MAP) and systemic vascular resistance index (SVRI) at the time of sternotomy and before the cardiopulmonary bypass. In group Fen, a significant increase in VO2I occurred at the time of sternotomy. In ICU, catecholamine concentrations were significantly lower, and the duration of its use was significantly shorter in group Iso. Group Iso required significantly less time to awakening and to extubating. Therefore, group Iso shortened the length of ICU stays. In conclusion, isoflurane with combined use of low dose fentanyl anesthesia is an acceptable method of anesthesia for open heart surgery.