Efficacy of aromatherapy with Lavandula angustifolia oil on postoperative pain after cardiac surgery: A randomized clinical trial

To evaluate the effect of aromatherapy through inhalation of Lavandula angustifolia essential oil in relieving pain during the immediate postoperative period of patients undergoing cardiac surgery. A single-blind, randomized and controlled clinical trial, with 52 patients in the immediate postoperative period of cardiac surgery were randomly distributed into experimental (n = 26) and control (n = 26) groups. The primary outcome was whether or not pain was relieved and secondary outcomes included changes in vital signs, sleep and facial relaxation. The control group received industry standard care and application of an essential oil-free ceramic diffuser necklace. The experimental group received the inhalation intervention with pure Lavandula angustifolia essential oil, with a drop of the oil on a ceramic diffuser necklace at a distance of 15-20 cm from the patient's nose for 30 min. Pain was measured using the Numerical Visual Scale, and vital signs using the multiparametric monitor before the intervention, 10 minutes after its start and 30 minutes after the total end of inhalation. Face relaxation was assessed before and after the intervention and sleep was assessed at the end of inhalation. There was a decrease in pain levels (p < 0.001) 30 min after the end of inhalation in the Experimental Group, with a decrease in the measurements of Mean Blood Pressure (p= 0.008) and Respiratory Rate (p = 0.011). Furthermore, facial relaxation and sleep had a large effect size of 2.54 and 1.28, respectively. Lavandula angustifolia essential oil was effective in relieving pain, causing sleep and relaxation, proving to be a low-cost and easy-to-use tool that the nursing team can use in their care.