Isoflurane versus fentanyl: hemodynamic effects in cancer patients treated with anthracyclines

Cancer patients treated with anthracycline derivatives are at risk for perioperative cardiovascular decompensation. The authors studied hemodynamic performance before, during, and after laparotomy in 14 anthracycline-treated patients with ovarian carcinoma. General anesthesia was maintained with 70% N₂O in O₂, and patients were randomized to receive supplementation with either isoflurane, 0.59% end-tidal ± 0.04 (mean ± SE), or fentanyl, 2.67 μg/ kg ± 0.49 as a loading dose, and a total dose of 7.16 μg/kg ± 0.71. The degree of hemodynamic stability relative to the baseline was assessed. There was no obvious superiority of either technique prior to the skin incision. However, during and immediately after surgery, a clearer tendency for isoflurane-N₂O to result in better hemodynamic stability was found. lsoflurane-N₂O demonstrated significantly smaller change scores in systemic vascular resistance (SVR) and cardiac index (Cl). At the start of surgery, the isoflurane-N₂O change in SVR was 228.08 dyne · sec · cm^-5 compared to 479.58 for the fentanyl patients, (P = 0.002); at the end of surgery the corresponding means were -12.09 and 703.14 dyne · sec · cm^-5, respectively, (P = 0.002). Isoflurane-N₂O was associated with significantly greater CI stability in the early postoperative period: the isoflurane-N₂O mean change was -0.081 L/min/m², versus -0.993 for the fentanyl-N₂O patients, (P = 0.005). The authors conclude that anthracycline-treated patients who do not have overt evidence of cardiomyopathy can be safely anesthetized with either anesthetic technique. However, during surgery and in the early postoperative period, an isoflurane-N₂O technique appears to offer better hemodynamic stability.