BackgroundComplementary and integrative medicine may be effective for postoperative outcomes. This study aimed to determine the effect of lemon inhalation aromatherapy on pain, nausea, and vomiting and neurovascular assessment in patients for lower extremity fracture surgery.MethodsThis is a randomized clinical trial study. Ninety patients who had undergone lower extremity fracture surgery were randomly assigned to the intervention (lemon aromatherapy) and control groups. Lemon aromatherapy was started in the morning of the surgery and extended at two-hour intervals until the end of the surgery, in the recovery room, and 16 h after surgery. Numerical pain and nausea and vomiting scales, the Rhodes Index of Nausea, Vomiting, and Retching, and the WACHS Neurovascular Observation Chart were used to assess the outcomes before and after the intervention (in the recovery room and 4, 8, 12, and 16 h post-surgery). The data were analyzed using the Wilcoxon test, ANCOVA, and Repeated Measure ANCOVA.ResultsA significant difference was observed between the groups in terms of the intensity of pain (P< 0.001) and nausea and vomiting (P= 0.001) during the study period. Moreover, a significant difference was found between groups as to the frequency and severity of nausea, vomiting, and retching. The amount and duration of postoperative vomiting and nausea were significantly lower in the intervention group compared to the control group. In addition, lemon inhalation aromatherapy decreased the frequency of anti-emetic drug administration in the recovery room (P= 0.04) and 16 h post-surgery (P= 0.03).ConclusionsThis study indicated that aromatherapy reduced pain intensity, postoperative nausea, vomiting, and retching, as well as the incidence of anti-emetic drug administration. Therefore, using lemon inhalation aromatherapy to relieve pain and reduce nausea and vomiting is suggested for lower extremity fracture patients who have undergone surgery.Trial registrationThis study was registered in the Iranian Registry of Clinical Trail (Number = 57,331, IRCT20130616013690N10, approved 24/07/2021) (https://www.irct.ir/trial/57331).