Hemodynamics and tissue oxygenation during balanced anesthesia with a high antinociceptive contribution: an observational study.

BACKGROUND: In particular surgical conditions, a balanced anesthesia with a high-antinociceptive contribution is required. This may induce cardiovascular impairment and thus compromise tissue oxygenation. In this prospective observational study, we investigated the hemodynamic stability and tissue oxygen saturation (StO2) in 40 patients with a high-antinociceptive general anesthesia, goal-directed fluid therapy, and norepinephrine. In addition, optimal surgical conditions and safe and fast emergence are pivotal parts of anesthetic management.

METHODS: In high-antinociceptive propofol/remifentanil anesthesia with bispectral index (BIS) between 40 and 60, norepinephrine was administered to maintain mean arterial pressure (MAP) above 80% of individual baseline. Fluid was administered if the ∆ plethysmographic waveform amplitude exceeded 10%. Surgical and recovery conditions, hemodynamic responses, and tissue oxygenation were investigated.

RESULTS: Mean (SD) StO2 at the left thenar eminence increased from 83 (6)% before to 86 (4)% 20 min after induction of anesthesia (p <0.05). Cardiac index dropped from 3.0 (0.7) to 2.1 (0.4) L min(-1) (p <0.05), MAP from 109 (16) to 83 (14) mm Hg, and heart rate from 73 (12) to 54 (8) bpm (p <0.05). Thirteen out of 40 patients received a fluid bolus. The median (range) norepinephrine administration rate was 0.05 (0.0-0.10) μg kg(-1) min(-1). After complete akinesia in all patients during surgery, a median (IQR) extubation time of 311 (253-386) s was observed.

CONCLUSIONS: This high-antinociceptive balanced anesthesia with goal-directed fluid and vasopressor therapy adequately preserved StO2 and hemodynamic homeostasis.

TRIAL REGISTRATION: ISRCTN20153044.