Effect of ultrasound guided superficial cervical plexus block on incidence and severity of postoperative nausea and vomiting in tympanomastoid operations in adults: Randomized controlled study

Background

The study aims to assess efficacy of superficial cervical plexus (SCP) block on Postoperative nausea and vomiting (PONV) incidence and severity in adults undergoing tympanomastoid operations.

Methods

Adult Patients American Society of Anesthesiologists (ASA) I-II in the age group 20–45 years, of both sex undergoing tympanomastoid operation under General Anesthesia (GA) scheduled for operation time from 30 min to 4 h. Ninety consenting patients were randomly allocated to two groups; saline or control group (n = 45) and SCP block (n = 45) received GA with SCP block. The primary outcome is incidence and severity of PONV over 24 h. other outcomes include number of patients required rescue antiemetic, hemodynamics, postoperative pain, first analgesic request, side effects of drugs used and incidence of complications related to the block.

Results

PONV incidence was lower in block group compared to control group {9 (20%) versus 17 (37.8%)}, p value 0.063, odds ratio (95% confidence interval 0.78 (0.59–1.01)). Need for rescue antiemetic was significantly lower in block group 14 patients (31.1%) compared to control group 34 patients (75.6%) (pvalue <0.001). Total intra operative opoids consumption was significantly lower in block group compared to control group (p value 0.002).There was no significant statistical difference between groups regarding need for postoperative analgesia and pain assessment times using visual analogue scale (VAS) score.There were no recorded complications related to the blocks in both groups.

Conclusion

Among adult patients undergoing tympanomastoid operations, the use of ultrasound (US) guided SCP block reduced the severity of PONV in early postoperative period. The overall incidence of PONV during 24 h was slightly lower in SCP block group however it was not statistically significant.