Many people vomit or feel nauseous after surgery, and it’s important to find effective ways to ease these unpleasant symptoms. One of the updated Cochrane Reviews in March 2018 looks at the effect of aromatherapy and we asked Sonia Hines from the Queensland Centre for Evidence‐Based Nursing & Midwifery in Australia to tell us more about the latest results.
John: Hello, I'm John Hilton, editor in the Cochrane Editorial and Methods department. Many people vomit or feel nauseous after surgery, and it’s important to find effective ways to ease these unpleasant symptoms. One of the updated Cochrane Reviews in March 2018 looks at the effect of aromatherapy and we asked Sonia Hines from the Queensland Centre for Evidence‐Based Nursing & Midwifery in Australia to tell us more about the latest results.
Sonia: Up to a third of all patients suffer moderate to severe nausea and vomiting following general anaesthesia and aromatherapy has been recommended for use with postoperative nausea and vomiting for a long time. However, good quality evidence has been hard to come by.
Aromatherapy uses various scented products to try to influence how people feel physically, mentally, or emotionally; but our updated review shows that the current evidence for aromatherapy as a treatment for postoperative nausea and vomiting is patchy and not very convincing.
This update of our 2012 review adds evidence from seven new studies, bringing us to 16 included studies; and, overall, the evidence quality continues to range from moderate to very low.
Two of the studies were in children, with the other 14 focused on adults. The studies applied aromatherapy at the first complaint of nausea after surgery and measured nausea for up to two days. The aromatherapy substances that were tested included isopropyl alcohol, peppermint oil, ginger, or mixtures that included ginger, spearmint, peppermint and cardamom; or lavender, peppermint, ginger, and spearmint oils. These were compared with a variety of alternatives, such as saline or water placebo, controlled breathing, other aromatherapy substances, anti-nausea medications, or a combination of these.
Overall, aromatherapy was not effective in reducing nausea severity three minutes or more after treatment in comparison to saline, water or controlled breathing placebo. However, more participants who received aromatherapy were nausea-free at the end of treatment and fewer participants who received aromatherapy required anti-nausea medication.
In terms of nausea duration, the time to 50% relief of symptoms was faster with isopropyl alcohol vapour than with two of the drugs commonly used for postoperative nausea and vomiting, ondansetron or promethazine. And, aromatherapy using isopropyl alcohol vapour inhalation provided rapid, short-term relief of nausea and reduced the need for these types of anti-nausea drug to be given as rescue therapy. Furthermore, patient satisfaction with aromatherapy appeared high in the four studies that measured satisfaction.
However, when we look at the overall picture, the evidence for using aromatherapy to treat postoperative nausea and vomiting remains not very convincing.
John: If you would like to read more about the individual trials in the review and this evidence base as a whole, visit Cochrane Library dot com and search 'postoperative aromatherapy' to find the full review.