Aromatherapy for pain relief in labor

Aromatherapy


Aromatherapy uses the application of essential oils on the patient’s skin or pillow in order to produce relaxation and healing effects. Essential oils are lipid soluble and rapidly absorbed into the bloodstream when applied externally, inhaled or ingested, and are excreted with the urine or exhaled during breathing. Although the oils are most commonly applied to the skin, in France they practice what is called medical aromatherapy which involves ingestion of oils. Most studies on safety of aromatherapy have been performed on animals and are not necessarily directly transferable to humans. It seems unlikely however that essential oils may accumulate in the body and cause harm. Some caution is advised in patients with the disorders of the kidneys and liver.

The effects of essential oils have been demonstrated in animals. Various oils show different properties: some relieve spasms while some may exacerbate it. Oils may have antioxidant and anti-inflammatory properties, may enhance liver function and even have anticarcinogenic effects. It was found, for example, that boswellic acids from frankincense essential oil display strong anti-inflammatory properties by supressing the enzyme human leukocyte elastase (HLE) action. This enzyme has been implicated in several respiratory diseases, including cystic fibrosis, acute bronchitis, glomerular nephritis and rheumatoid arthritis. At this stage the role of aromatherapy in clinical medicine is limited.

The practitioners of aromatherapy claim that it is effective in relieving pain. However, it is most often used together with massage, which has long been known to be useful for this purpose. Massage stimulates the release of various mediators and neurotransmitters such as endorphins and is useful in the treatment of chronic and muscular pain. Whether the addition of essential oils increases the pain-relieving benefits of massage beyond relieving anxiety is not clear. Lavender has been shown to have local anaesthetic effects in animals, and other oils which are present in eucalyptus species and cajeput have similar action. While there may be a potential to use these oils in the management of pain the studies on animals cannot be extrapolated to humans and further research is needed.

Aromatherapy has been used to relieve some symptoms associated with pregnancy, such as morning sickness, stretch marks, varicose veins, heartburn, haemorrhoids, backache and exhaustion. However, none of these claims are supported by clinical evidence. More relevant to our discussion, there are studies evaluating the use of aromatherapy for pain relief in labor.

The results of the largest trial were published in 2000. The study lasted from 1990 to 1998 and recruited 8,058 patients in a large British teaching hospital. Women were offered aromatherapy to relieve anxiety, pain, nausea and vomiting and to strengthen contractions. Routine observations of those who accepted treatment were then compared with 17,799 patients who did not use aromatherapy. The results of the study show that aromatherapy was increasingly popular among mothers and midwives. More than 50% of women rated it as helpful, and only 14% found it unhelpful. Quoted from the abstract of the study “the administration of aromatherapy did appear to reduce the need for additional pain relief in a proportion of mothers”. More than 8% of primiparas and 18% of multiparas used no conventional pain relief during labor after using essential oils. The use of epidurals was lower among those who used aromatherapy: 29% vs 44% in first time mothers and 14% vs 17% in multiparas. The study also showed that aromatherapy may have the potential to augment labor contractions in women in dysfunctional labor. Adverse effects of aromatherapy were low, about 1%. The main conclusion confidently stated that “the study represents a successful example of the integration of a complementary therapy into mainstream midwifery practice”.

The patients were not randomized, and the probability of bias with such study design is high. But even if we ignore this fact, as with most other alternative modes of pain relief the effects of aromatherapy for relieving labor pain are modest at best. It may be considered a good alternative to pethidine or nitrous oxide (the magnitude of the effect is comparable between these methods), but its does not come even close to epidural.

References:

1. Maddocks-Jennings W, Wilkinson JM. Aromatherapy practice in nursing: literature review. Journal of Advanced Nursing, 48(1), 93–103

2. Trout KK. The Neuromatrix Theory of Pain: Implications for Selected Nonpharmacologic Methods of Pain Relief for Labor. J Midwifery Womens Health 2004;49:482–488

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Dr. Eugene Smetannikov is a practicing anesthesiologist with the interest in obstetric anesthesia. He is the author of the most comprehensive book on the subject, The Truth About Labor Epidural