The effect of scalp nerve block combined with inhaled peppermint essential oil on postoperative pain in patients undergoing supratentorial tumor resection.

BACKGROUND

Post-craniotomy headache (PCH) is a common clinical occurrence after craniotomy. Scalp nerve block (SNB) is often used for pain control during craniotomy. Peppermint essential oil (PEO) may alleviate pain under certain injury conditions by activating TRPM8, but its application after craniotomy remains unclear. This study aimed to investigate the individual and combined effects, and potential interaction, of scalp nerve block (SNB) and inhaled peppermint essential oil (PEO) aromatherapy on postoperative pain, quality of recovery, and perioperative indicators in patients undergoing supratentorial tumor resection.

METHODS

One hundred patients scheduled for elective supratentorial tumor resection were randomly assigned to a control group (C group), scalp nerve block group (SNB group), peppermint essential oil group (PEO group), or combined SNB+PEO group (25 patients each). Numeric Rating Scale (NRS) pain scores, State Anxiety Inventory (SAI) scores, Quality of Recovery-15 (QoR-15) scores within 48 h postoperatively, extubation time, PACU stay duration, postoperative rescue analgesia rate, and postoperative hospital stay were recorded.

RESULTS

No significant interaction was found between SNB and PEO on pain scores at any time point. The Ropivacaine Group (SNB & SNB+PEO) showed significantly lower NRS scores than the Saline Group (C & PEO) immediately after extubation (0.5 [0.0, 2.0] vs. 2.0 [0.0, 4.0], P = 0.013). The Aromatherapy Group (PEO & SNB+PEO) had significantly lower scores than the Placebo Group (C & SNB) at 24 h postoperatively (1.0 [0.8, 2.0] vs. 2.5 [1.0, 4.0], P < 0.001). SNB was a protective factor against intraoperative hypertension. PEO significantly improved QoR-15 scores at 48 h.

CONCLUSION

The combination of SNB and PEO provides effective postoperative analgesia, improves recovery quality, reduces intraoperative hemodynamic fluctuations, and promotes early rehabilitation.