Effect of inhaled aromatherapy on sleep quality in critically ill patients: A systematic review and network meta‐analysis

AIM: This study aimed to compare the effect of inhaled aromatherapy using various essential oils on the sleep quality of critically ill patients. BACKGROUND: Inhalation of essential oils significantly promotes the physiological and psychological health of patients in intensive care units (ICUs). However, research identifying and ranking the effects of different essential oils on the sleep quality of critically ill patients is lacking. DESIGN: This study followed the PRISMA Extension Statement for Reporting of Systematic Reviews Incorporating Network Meta-Analyses of Health Care Interventions (PRISMA-NMA) guidelines. METHODS: A comprehensive search of five databases (Embase, MEDLINE, the Cochrane Library, CINAHL and PsycINFO) was conducted from their inception to March 15, 2023 (with an additional eligible study included dated August 14, 2023). Google Scholar was used as a supplementary method. Frequentist NMA was used to determine the effects of various essential oils. Certainty of evidence (CoE) was assessed using Confidence in Network Meta-Analysis (CINeMA). RESULTS: A total of 11 trials involving 690 critically ill patients were included in the analysis. The NMA of inhaled aromatherapy revealed that the combination of lavender, Matricaria recutita, and neroli essential oils (ratio 6:2:0.5) resulted in the most significant improvement in sleep quality compared to usual care, followed by Rosa damascene, peppermint, Citrus aurantium, pure sunflower oil and lavender oil alone. The overall CoE for the results was rated as low. CONCLUSIONS: The results of this study indicate that a combination of lavender, Matricaria recutita and neroli essential oils significantly positively affected sleep quality among critically ill patients. Despite the low quality of evidence, inhaled aromatherapy is non-invasive and easy to use. RELEVANCE TO CLINICAL PRACTICE: Inhaled aromatherapy can effectively improve sleep quality among critically ill patients. PATIENT OR PUBLIC CONTRIBUTION: No patient or public contribution applies to this work. STUDY REGISTRATION: The study protocol was registered to the PROSPERO International Prospective Register of Systematic Reviews (protocol number CRD42023433194).