Gupta N, et al. - This study appraised desflurane with and without labetalol for producing hypotensive anesthesia in middle ear surgery. Desflurane was found to be effective for inducing deliberate hypotension in middle ear microsurgery. Desflurane plus labetalol was found to be related to decreased need of desflurane, absence of reflex tachycardia, faster induction of hypotension, faster recovery from anesthesia, and less postoperative sedation.

Methods

• Researchers administered general anesthesia in 60 adult patients undergoing elective middle ear surgery and randomly divided them into two groups – Group D and Group L.
• The target mean arterial pressure (MAP) was 55–65 mmHg during hypotensive period.
• Group D patients received an increasing concentration of desflurane alone and Group L patients received 3% desflurane plus labetalol (loading dose 0.3 mg/kg intravenously, followed by 10 mg increments every 10 min).
• Researchers used Student's t-test and paired t-test to compare the hemodynamic parameters.
• They also noted visibility of the operative field, anesthetic and rescue drug requirement, partial pressure of oxygen in arterial blood, time taken for induction and reversal of hypotension and recovery characteristics.

Results

• Findings reported that target MAP was achieved in both the groups.
• Researchers observed that Group D was associated with a higher mean heart rate compared with Group L (77.3 ± 11.0/min vs. 70.5 ± 2.5/min, respectively; P < 0.001) during the hypotensive period, along with a higher requirement for desflurane (P = 0.000) and metoprolol (P = 0.01).
• They noted that time taken to achieve target MAP was lesser in Group L compared with Group D (33.7 ± 7.1 vs. 39.8 ± 6.2 min, respectively; P = 0.000).
• Data reported that time taken to return to baseline MAP was faster in Group D (P = 0.03).
• In addition, it was shown that emergence time was longer with desflurane alone (P = 0.000) resulting in greater sedation (P = 0.000) in the immediate postoperative period.