Effect of aromatherapy with peppermint, ginger, and lavender on postoperative nausea severity after oral surgery under general anaesthesia: A single-blind randomized controlled trial.

OBJECTIVES

This study aimed to examine whether aromatherapy with peppermint (Mentha piperita Mitcham), ginger (Zingiber officinale), and lavender (Lavandula angustifolia) reduces the severity of nausea in patients experiencing postoperative nausea after oral surgery under general anaesthesia.

DESIGN

Single-centre, stratified (volatile inhaled anaesthetics used or not and sex, with balanced randomization), single-blind, placebo-controlled study conducted in Japan.

SETTING

Hokkaido University Hospital.

INTERVENTIONS

Totally, 182 patients were randomized into two groups of aromatherapy: aroma group comprising three essential oils-peppermint, ginger, and lavender-each diluted to 1 % (each dose as pure essential oil was 0.01 ml) and control group with purified water only. Of these, 32 patients in the aroma group and 25 in the control group complained of postoperative nausea and were treated with intervention.

MAIN OUTCOME MEASURES

Change in nausea severity at the onset of postoperative nausea.

RESULTS

Nausea severity before the intervention did not differ between groups. Aromatherapy significantly reduced nausea severity (p < 0.001). The percentages of antiemetics used were 30.77 % and 52.38 % in the aroma and control groups, respectively, with no significant difference. The aroma group showed significantly higher satisfaction (p < 0.001). No adverse events were observed during the study.

CONCLUSIONS

This study indicated that aromatherapy with peppermint, ginger, and lavender significantly improved patient satisfaction and severity of postoperative nausea after oral surgery under general anaesthesia. Therefore, given the benefits of aromatherapy, it would be advantageous to consider a combination of measures that include aromatherapy, as one of the multimodal antiemetic measures. This trial was registered at the Japan Registry of Clinical Trials (jRCTs: 01121002).