Comparison of the myocardial effects of desflurane and isoflurane in healthy patients: assessment by continuous oesophageal aortic blood flow echo-Doppler

Experimentally, desflurane causes a moderate positive inotropic effect and a transient increase in arterial pressure with rapid increases in concentra tion compared with isoflurane. We used a continuous oesophageal aortic bloo d flow echo-Doppler device to study the myocardial effects of equi-anaesthe tic concentrations of isoflurane and desflurane in 32 healthy patients unde rgoing superficial surgery. After induction of anaesthesia with midazolam, etomidate and fentanyl, general anaesthesia was maintained in 16 patients w ith 0.6% end-expired concentration of isoflurane and in 16 patients with 3% end-expired concentration of desflurane. Isoflurane induced a rapid decrea se in aortic blood flow (ABF) which remained almost stable whereas desflura ne induced an early, moderate and transient increase in ABF(1 min after int roduction of the halogenated agent, mean ABF was 107 (SD 3)% in the desflur ane group vs 95 (9)% in isoflurane group compared with control values befor e introduction of the inhalation agent; P=0.005), followed by a marked seco ndary decrease in ABF. The maximal decrease in ABF reached 71 (15)% of its initial value in the desflurane group compared with 80 (14)% in the isoflur ane group (ns). Neither agent caused significant changes in other variables except for PECO2' which decreased in both groups. Continuous ABF echo-Dopp ler monitoring demonstrated an early transient positive inotropic effect of desflurane.