It may also improve sleep quality, according to results from a small clinical trial.
The use of peppermint essential oil aromatherapy may reduce the intensity of pain and improve sleep quality after open-heart surgery, suggests the results of a small controlled clinical trial published online in the journal Neurology. BMJ Supportive and Palliative Care.
Cardiac surgery is a major procedure that requires separation of the sternum and mechanical respiratory support, both of which carry a high risk of severe pain, stress and insomnia, the researchers noted.
Effective pain relief may speed patient recovery and reduce the risk of postoperative complications, the researchers add, but pain and the drugs used to treat it can increase the need for mechanical ventilation and postoperative complications, mortality, length of hospital stay, and health care costs.
The researchers suggest that drug alternatives might be safer options, or might simply enhance the effectiveness of existing painkillers.
Aromatherapy may be one such alternative, but its effectiveness is unclear. Published studies have shown that inhaling essential oils may be effective, and peppermint essential oil is already widely used in palliative care.
So researchers wanted to investigate whether peppermint essential oil could reduce pain and improve sleep quality in patients after open-heart surgery.
Sixty-four adults were randomly assigned to receive either 0.1 ml of 10% essential peppermint oil or 10 ml of distilled water 30 minutes before removal of the breathing tube, and then administered via nebulizer three times a day for a total of seven doses until the second evening after the procedure.
Both groups were similar with regard to sex, age, weight, type of surgery, duration of general anesthesia (hours), length of intubation, amount of analgesia, and time spent on mechanical respiratory support.
The Numeric Pain Rating Scale and St. Mary’s Hospital Sleep Questionnaire were used to assess changes in pain severity and sleep quality, respectively.The final analysis included 59 patients, 30 in the aromatherapy group and 29 in the comparison group.
After two days, the aromatherapy group had a mean pain severity score of 3.22 compared with 4.56 for the comparison group, a statistically significant difference, the researchers found.
The average sleep scores on day 1 were 20.10 and 25.76 for the aromatherapy and comparison groups, respectively, but dropped to 18.63 and 22.62, respectively, on day 2, showing a statistically significant difference between the two groups. Higher scores indicate poorer sleep quality.
Patients who received peppermint oil aromatherapy required less pharmacological pain relief than patients in the comparison group.
To explain their findings, the researchers suggest that the main components of peppermint oil – carvone, limonene and menthol, but especially menthol – may be key to its analgesic effect.
The researchers also point to previously published studies that have confirmed the relaxing and sedative effects of peppermint oil. Patients who awaken in intensive care after cardiac surgery experience significant post-operative stress and pain, so reducing these factors should improve sleep quality, the researchers suggest.
This was a small study, and the researchers acknowledged that they could not rule out environmental influences such as light and noise on patients’ sleep quality, which may have influenced the scores obtained.
However, they concluded: “The results indicate that inhalation of peppermint essential oil reduces pain intensity in patients following open-heart surgery, resulting in reduced patient use of pain medication.”
“Also, the use of this herbal product can improve the quality of patients’ sleep on the first night after surgery and make them more comfortable. Considering the effect of inhaling peppermint essential oil on pain and sleep quality, we can conclude that this herbal product can be safely used as a complementary treatment to relieve pain and make patients more comfortable after cardiac surgery.”
03/08/23
Notes for editors
the study: Pain and sleep after open heart surgery – Inhaled peppermint essence: a double-blind randomized clinical trial doi 10.1136/spcare-2023-004214
journal: BMJ Supportive and Palliative Care
Funding: Undeclared
Link to the Academy of Medical Sciences’ press release label system
http://press.psprings.co.uk/
Externally peer reviewed? Yes
Type of evidence: Double-blind randomized controlled trial
Subject: People
