Comparison of surgical field visibility during propofol or desflurane anesthesia for middle ear microsurgery

BACKGROUND: To compare surgical field visibility between patients given propofol/remifentanil (PR) or desflurane/remifentanil (DR) anesthesia. METHODS: A total of 80 adult patients undergoing middle ear microsurgery due to cholesteatoma otitis media with American Society of Anesthesiologists physical status I and II were randomly assigned to the PR or DR groups. The depth of anesthesia was titrated to maintain a Bispectral index (BIS) between 40 and 50. Remifentanil was titrated to maintain the mean blood pressure within ±30% change of the pre-induction value. Surgical field visibility was rated at several timepoints by the surgeons using the Boezaart scores. RESULTS: Average Boezaart scores for surgical field visibility at different time points were < 2 in both PR and DR groups. Surgical field visibility score was lower in the PR group than in the DR group. Requirement for remifentanil was higher in the PR group (850 (488/1330) μg) than in the DR group (258 (143/399) μg, P < 0.0001). The site effect concentration of remifentanil was higher in the PR group (3.6(2.8/5.0)ng/ml) than in the DR group (1.7 (1.0/1.6) ng/ml, P < 0.0001). Hemodynamic profile (i.e., heart rate and mean blood pressure) was similar between groups (P > 0.05). Extubation time (PR group, 21 min vs. DR group, 19 min; P = 0.199) and post-anesthesia care unit time (PR group, 37 min vs. DR group, 34 min; P = 0.324) were comparable between groups. CONCLUSION: Although PR anesthesia resulted in lower surgical field visibility scores than DR anesthesia, both groups had scores < 2, meaning no clinical differences between the two groups. DR provided acceptable operative conditions as well, albeit more remifentanil consumption was noted in the DR group. TRIAL REGISTRATION: China Clinical Research Information Service, ChiCTR-1,800,015,537. Registered 5 April 2018. Date of enrolment of the first participant to the trial: 2 May 2018.