Tag Archives: pain

New Ways to Talk about Labor Pain V: Research on Effectiveness of 3 Mechanisms

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In 2012, a new Cochrane review of pain management for women in labor was released. Although it had positive things to say about the non-pharmacological techniques, it also said that research into their efficacy was unclear due to limited evidence…

“WHAT WORKS: Evidence suggests that epidural, combined spinal epidural (CSE) and inhaled analgesia effectively manage pain in labour, but may give rise to adverse effects. … WHAT MAY WORK: There is some evidence to suggest that immersion in water, relaxation, acupuncture, massage and local anaesthetic nerve blocks or non-opioid drugs may improve management of labour pain, with few adverse effects.¬† Evidence was mainly limited to single trials. …INSUFFICIENT EVIDENCE: There is insufficient evidence to make judgements on whether or not hypnosis, biofeedback, sterile water injection, aromatherapy, TENS, or parenteral opioids are more effective than placebo… Most methods of non-pharmacological pain management are non-invasive and appear to be safe for mother and baby, however, their efficacy is unclear, due to limited high quality evidence.”

A 2014 review by Chaillet, et al (Chaillet, et al. (2014) Nonpharmacologic approaches for pain management during labor compared with usual care: a meta-analysis. Birth, 41(2): 122-37. http://www.ncbi.nlm.nih.gov/pubmed/24761801) is a significant addition to the research about non-drug approaches.

Chaillet, et al pooled techniques into three categories. If you’ve read my posts from the past few days, you’ll be familiar with these concepts. Also, see the chart at the top of this post for more information.

  • Gate Control mechanism = apply non-painful stimuli on the painful area. Methods included massage, bath, positions, walking, and birth ball. The theory is that this will block some of the intensity of the pain.
  • Diffuse Noxious Inhibitory Control (counter-irritant) = create pain or discomfort anywhere on the body. Methods included acupressure, acupuncture, TENS, sterile water injections. The theory is that this discomfort causes the body to release endorphins which reduce pain intensity. (Birth combs also fit in this category although they were not included in the research.)
  • Central Nervous System Control (cognitive/support techniques). Methods included¬† attention focus, education, relaxation, hypnosis, continuous labor support.

By pooling studies together, you get larger sample sizes which increases the statistical significance of the results. Note, all techniques were compared to “usual care” which might have ranged broadly depending on the preparation of the laboring family and the support they were given by caregivers. It is possible that some in the “usual care” groups were also using a variety of coping techniques. So, the true difference between people who use some coping techniques and those who use none may be even greater than these results indicate.

The results of this review were:

  • Gate Control mechanism. Those who used these techniques had lower pain intensity (as predicted), were less likely to use epidural, and needed less Pitocin.
  • Diffuse Noxious Inhibitory Control (counter-irritant). Those who used these techniques had lower pain intensity, were less likely to use epidural, and more satisfied with birth. (Two trials found women felt safer, more relaxed, and more in control.)
  • Central Nervous System Control (cognitive/support techniques) Those who used these techniques were less likely to use epidural, Pitocin, less likely to need instrumental delivery or cesarean, and had a higher satisfaction with birth. The CNSC did not reduce the intensity of the pain so much as they reduced the unpleasantness of the pain. (See more on intensity and unpleasantness here.) So, although labor still hurt a lot, women felt better able to cope – more like they were working with labor pain.

The most effective technique overall was continuous labor support, such as that offered by a doula. The effectiveness of support was already demonstrated in a Cochrane review by Hodnett et al, (Hodnett E, Gates S, et al.. Continuous support for women during in childbirth. Cochrane Database Syst Rev. 2013. CD003766)

The best results in pain coping were from combining the labor support and education which reduce the unpleasantness of pain with gate control or DNIC techniques that reduce the intensity of the pain.

Recommended: be sure to also check out Henci Goer’s discussion of this study on Science and Sensibility.

New Ways to Talk about Labor Pain, IV: Bonapace Method

The Bonapace Method for reducing pain during childbirth can be used instead of, or in conjunction with, a traditional childbirth education class.

This method does not just teach pain coping techniques, but also teaches about the role of labor pain, how pain messages are transmitted in the body, and three mechanisms that help moderate the perception of pain. Those mechanisms are:

Cognitive structuring / central nervous system control (CNSC). Understanding labor pain and progression – what’s happening and why – enhances a sense of self-control. Focusing on something positive (like a self-affirmation) helps with labor pain.

Gate ControlTheory. Non-painful stimulation blocks part of the pain message transmitted by the spinal cord. Note: Bonapace interprets this differently than I have see elsewhere, saying specifically that it is pleasant sensation applied where the pain is located. The description on their website says “To activate this mechanism during childbirth, the fingers must be run lightly over the painful area, particularly during contractions.”

Diffuse Noxious Inhibitory Control (DNIC). (I call this counter-irritation) Creating a second pain elsewhere on the body (i.e. not where you’re already hurting). The brain wants to reduce the pain’s effect on the body as a whole, so releases endorphins to do so. But the sensations near the second pain are still felt because the body is assessing them. (So, under this theory, holding a birth comb tightly causes a release of endorphins which helps with the labor pain, but the user is still aware of the pressure points from the comb on their palm.) In the Bonapace method, sensitive points on the body (trigger areas) are massaged by the partner, causing pain.

In a journal article (“Evaluation of the Bonapace Method: a specific educational intervention to reduce pain during childbirth”, J Pain Res 6: 653-661 at http://www.dovepress.com/articles.php?article_id=14256), Bonapace et al, compare the results of a “traditional childbirth training program” (TCTP) with the Bonapace method. Study participants chose which class to take from these options.

The TCTP was a 4 week class, with a total of 8 hours of class time, started around the 23rd week of pregnancy. It covered A&P of childbirth, exercises, stages of labor, variations, pain meds and newborn care. Relaxation, visualization, massage, and labor positions were not taught. Only breathing techniques were practiced.

The Bonapace class was 4 weeks, 8 hours, starting in the 30th week. The entire program was dedicated to pain management and partner participation. It covered 1) CNSC through breathing, relaxation, and cognitive understanding of labor pain and endorphins, 2) Gate control – non-painful stimuli such as walking and light back massage between contractions, and 3) DNIC where the partner did painful massage of acupuncture triggers points in the lower back, hands, and buttocks.

39 women participated in the full study. In labor, every 15 minutes, participants were asked to rate their pain on two scales: intensity and unpleasantness. (If pain medications were given, they stopped assessing pain after the medication. If that participant had pain scores for two phases of labor, they were kept in the study, if not, they were dropped.

Those who had learned the Bonapace method had an average of 45% less pain intensity and 47% less unpleasantness than those who had received the “traditional” childbirth education. No difference was found in the use of pain medication.

The reduction in intensity of pain was consistent for nulliparous and multiparous parents. On the “unpleasant” ratings, there was a larger reduction in scores for nulliparous than multiparous. This is likely due to anxiety… a nulliparous woman with no birth experience and no training / childbirth preparation is likely to be anxious about labor pain (and, of course, anxiety increases pain). With the TCTP, her anxiety may have been somewhat reduced and thus her pain unpleasantness would be reduced, but with the Bonapace method, her anxiety and thus unpleasantness were much more reduced.

This study indicates that being given information about the physiology of pain, and plenty of education in clear, simple techniques to manage it, has a significant impact on pain intensity and pain coping.