Comparison of the Effect of Inhalation Aromatherapy with 10% and 30% Peppermint Essential Oils on the Severity of Nausea in Abdominal Surgery Patients

BACKGROUND: One of the most common surgical complications is nausea. Regarding the contradictory findings on the effect of aromatherapy with peppermint on the severity of nausea, in the present study, we aimed at comparing the effect of aromatherapy with 10% and 30% peppermint essential oils on the severity of nausea in surgical patients. METHODS: This single-blind randomized controlled trial was conducted at the surgical ward of Imam Reza Hospital in Kermanshah, Iran. A total of 120 patients undergoing abdominal surgery were randomly divided into three groups of 10% peppermint, 30% peppermint, and control (40 patients in each group) using a random number table. In each of the intervention groups, 0.2 ml of 10% and 30% peppermint essential oil was inhaled. In the control group, the same amount of distilled water colored with green food coloring was inhaled. The severity of nausea was measured by nausea visual analog scale (NVAS) before and 10 minutes after the intervention. RESULTS: In the 10% peppermint group, the mean severity of nausea before the intervention was 52.3 ± 13.7 out of 100, which reduced to 40.5 ± 13.5 after the intervention (p < 0.001). In the 30% peppermint group, the mean severity scores of nausea before and after the intervention were 60.2 ± 15.0 and 39.7 ± 12.4, respectively (p < 0.001). In the control group, the mean severity scores of nausea before and after the intervention was not statistically significant. There was no significant difference between the two intervention groups in terms of the mean severity of nausea after the intervention. CONCLUSIONS: It can be concluded that 10% and 30% peppermint essential oils are equally effective on the severity of nausea.