Objectives/hypothesis: Controlled hypotension is used to improve surgical conditions during microscopic and endoscopic sinus surgery. New short-acting anesthetics such as propofol and remifentanil allow exact control of intraoperative blood pressure and thus might be valuable tools to improve intraoperative conditions for the otorhinolaryngological surgeon. Intravenous anesthesia was compared with traditional balanced anesthesia by subjective assessment of surgical conditions made by two experienced otorhinolaryngological surgeons.
Study design: Prospective, randomized, patient- and observer-blinded study.
Methods: Ninety consecutive patients were randomly assigned to receive intravenous anesthesia with propofol 5 to 8 mg.kg-1.h-1 and remifentanil 10 to 30 microg.kg-1.h-1 or with isoflurane (0.4-1.0 vol%) and repetitive doses of 0.5 to 1 mg alfentanil. An injectable vasodilator was used in both groups to keep mean arterial pressure between 60 and 70 mm Hg (8-9.3 hecto-pascal). The attending otorhinolaryngological surgeon was unaware of the type of anesthesia administered. Immediately after the operation the surgeons rated surgical conditions (bleeding from the surgical field) on a visual analogue scale (0-10 cm) and on a verbal rating scale.
Results: Blood pressure was not different between the two groups, but heart rate was lower in the intravenous anesthesia group (mean heart rate in the intravenous anesthesia group, 62 beats per min [95% confidence interval, 52-72]; mean heart rate in the balanced anesthesia group, 75 beats per min [95% confidence interval, 67-83]). Surgical conditions were rated to be significantly better (P <.0001) during anesthesia with propofol-remifentanil (median rating: 2.8; 25th/75th percentile: 2.0/3.4) compared with isoflurane-alfentanil (median rating: 4.9; 25th/75th percentile: 3.6/7.6).
Conclusions: Intravenous anesthesia using propofol-remifentanil provides better surgical conditions compared with a traditional balanced anesthesia technique using isoflurane-alfentanil. It is hypothesized that lower cardiac output caused by decreased heart rate during deep general anesthesia is responsible for this result.