I was having a conversation with a woman via
twitter about back pain in labour. The woman said the birth was 'excruciating'
because of back pain. I mentioned the use of intradermal sterile water
injections (ISWI) to alleviate back pain in labour.
The woman said she had been
offered them but decided against it because she was told that they "really
hurt going in" and she was scared to have them.
Another woman tweeted
that she'd
"never heard of those! I had two posteriors and the back pain
was intense …"
It seemed a blog post on intradermal sterile water
injections could be useful.
Giving birth is an experience rich with emotional,
physical and psychological sensations. How we cope with those sensations (or
not) has many facets.
Most women feel a strong pressure in their
lower back as their baby’s head rotates and pushes the sacrum out on the way
down the birth canal in second stage. I've been told that in Thailand, those
sensations are known as 'the opening of the gate' – which is a wonderful
description of the sacrum swinging back to allow the baby’s head to descend and
turn as it meets the pelvic floor.
Women who expect that sensation recognise
that their baby is close to being born when they feel that pressure.
That
sensation is followed by a feeling that their hips are being pushed apart as
the baby descends further down the woman’s pelvis and comes around the 's' bend.
For some women, back pain, especially if it occurs
in the first stage of labour, is 'intense' and can be unbearable. Some women can
find it difficult to relax, ‘let go’ and welcome the sensations and impending
birth of their baby with the pain they feel in their lower back in second
stage.
Movement, heat, water and counter pressure are some
of the ways that women find useful to help them alleviate and/or manage the
pain. Other techniques include positioning and/or lifting parts of the woman's
pelvis to change the shape of the woman’s pelvis and to help shift the baby’s head’s
position in the pelvis.
I first heard about the use of intradermal sterile
water injections (ISWI) for back pain in labour when I was manager of a
stand-alone birthing service. I read an article by Peart, James and
Deocampo (2006) in the journal Birth Issues and was fascinated.
The
main reason for women transferring in labour from our birthing service was to
have an epidural to relieve intractable back pain when none of the usual
strategies worked. Although the numbers of women transferring to the tertiary
referral hospital were small, women would have preferred to stay at the
birthing centre, so any ideas that could help them manage the sensations of
labour were welcome.
I invited Janice DeoCampo, one of the authors of
the paper, to the birth centre and teach us what to do. We were delighted when
she agreed to come. We invited midwives from the surrounding hospitals to be
part of the workshop. About forty midwives enjoyed the day learning about this
remarkable and non-narcotic pain-relieving technique. Janice told us she saw
the technique used very effectively in Sweden and that was what fuelled her
passion to bring the procedure back to Australia.
We had a wonderful service manager, Dr Anne Saxton,
who was very supportive and after much proposal writing and refining, we
finally gained ethical clearance and permission from the health service for the
new procedure to be midwife-initiated in all the hospitals in the region. A
study by Lee (2012) found that despite a desire by midwives to use ISWI to help
women in labour, few were actually doing so. In my experience there needs to be
good support from maternity service management when negotiating the legal and
bureaucratic requirements to get acceptance of this still relatively new,
midwife-initiated procedure.
So what is
it?
Intradermal sterile water injections (ISWI) are
given under the skin, into the layer known as the dermis, as close to the
surface (epidermis) as possible. You can see those layers in the diagram below.
Sterile water (0.5ccs) is drawn up into 2 tuberculin syringes. The recommendations
are that sterile water is injected via 25g needles, bevel up, in four sites;
approximately 0.1- 0.2cc administered at each site (see diagram below from
Peart, James & Deocampo, 2006). Two midwives are needed for the
administration of the sterile water, both injecting the water at the same time.
When the water is injected in the
optimal way, a small 'bleb' is raised in the skin which sends the signal to the
spinal cord to switch on the 'gate' that controls deeper pain messages up the
spine to the brain.
The history of the use of gate
control methods of pain relieve is very interesting.
Counter
irritation or ‘gate’ control methods of pain management
The earliest use of “counter irritation” was
in 1945 (Gammon and Starr; Parsons and Goetzl) with the use of mustard plasters
to reduce pain by inducing an analgesic effect. According to these authors, the
best result occured when the counter irritant is administered directly over or
near the vicinity of the pain site (Gammon and Star 1941). In 1965
Malzack and Wall (1965) hypothesized that nerve impulses, evoked by injury, are
influenced in the spinal cord by other nerve cells that act like gates, either
preventing impulses getting through, or facilitating their passage. Intradermal
sterile water injection (ISWI) is thought to trigger the gate control
mechanism.
As the skin is the outer barrier for the body, anything that
threatens the skin gets transmitted to the brain quickly, shutting off the slower pain messages from inside the body, so the individual can take evasive action and escape the 'threat'. In 1975, Dr
Michael Odent acknowledged the use of sterile water injections for sacral pain
in labour having observed that pain itself is actually an obstacle to dilation. The best thing is that ISWI provides a form of
non-pharmacological pain relief that has no harmful effects and they don't stop movement. The woman who uses ISWI for back pain can still move freely and is not hooked up to either intravenous fluids or continuous monitoring systems.
Controlled studies using sterile water
injections has been conducted for their use in relieving pain from renal colic,
phantom limb pain, chronic neck and shoulder pain from whiplash and chronic
lower back pain. Well-designed RCT’s have consistently demonstrated a dramatic
analgesic effect on lower back pain in labour from ISWI at 4 points in the
lower back area, approximately corresponding to the borders of the
sacrum.
Women's satisfaction with this
method does vary, but it is a simple and inexpensive way of providing a
medication-free option to women who prefer to avoid or delay the use of
epidural block (EDB) or for those women for whom the option of EDB is not
available or not wanted. As ISWI doesn’t fit into classic understanding of pain relief,
clinicians are sceptical until the obvious and dramatic relief has been
witnessed. This simple measure deserves further evaluation but on the present
available data would seem a worthwhile option for use as a non-pharmacological
method to reduce lower back pain in labour.
A systematic literature review (Fogarty
2008) found the following benefits of sterile water injections:
- rapid and effective low back pain relief during labour
- no apparent side effects
- simple to use and a high level of success
- non-pharmacological
- decrease the use of epidural anaesthesia
- delay the use of epidural anaesthesia
- may be used while waiting for an anaesthetist
- may decrease the caesarean section birth rate
- may be used in first and second stage of labour
- have applications for use in rural/remote areas and developing countries where alternative treatments are not available
- have a role to play with their analgesic effect on pelvic floor one, cervical tension and fetal rotation
· While evidence suggests that ISWI are
more helpful in the early stages of labour rather than later, anecdotally and experientially, they have been found to be just as effective in late
first stage or second stage for women whose back pain interferes with
pushing. In fact, the woman's pelvis can relax so completely when the back pain is gone, the baby can rotate and emerge quite quickly after the injections are given!
Touching, massage or rubbing the
area of injection is to be avoided as it defeats the purpose of using sterile
water to get the ‘sting’, as the ‘sting is the thing’ that interrupts the
deeper pain signals. Research by Lee et al, 2011) on the number of sites
injected found that using the four sites as indicated in the illustration above
is more effective, but also found to be more painful for women. In practice, we
found two sites above and distal to the site of pain to be effective. We also
found these injections could be used for intractable suprapubic pain in labour.
When women indicate they want something for the back pain labour, they are asked to point to the site of their pain and rate
their back pain before and after the water injections on the Visual Analogue Scale (VAS)
below.
We’ve found that the score has to
be above 6 for the ‘sting’ of the actual injection to be considered ‘worth it’ by
the woman. In practice, it is rare for
the intradermal sterile water injections to not have a positive effect on the reduction
of pain for the woman, especially if her pain score was high. Women are provided with an information sheet
and a consent form for Intradermal sterile water injections in labour when they
book into the service. Some people wonder why sterile normal saline isn’t used
instead of sterile water, as the pain of injection would be less. The sting of
the sterile water seems to be key to the ‘gate control’ mechanism of pain
pathways and the normal saline would not therefore be as effective, if it was
effective at all.
Here's an interview about the technique on Belly Belly
Despite our practical experiences
with this procedure and the volumes of research so far, more information is
needed on the effects of intradermal sterile water blocks on obstetric
outcomes, women’s experiences, the effect of repeated injections, its mode of
action and the effects of varying dosages, locations as well as the number of
sites injected.
Have you had experiences with sterile water injections either as a midwife or a birthing woman? What were your experiences like? Do you recommend them?
References
Fogarty, V. (2008) Intradermal sterile water injections for the
relief of low back pain in labour – A systematic review of the literature, Women and Birth, 21 pp. 157-163.
Lee, N.,
Webster, J., Beckmann, M., & Gibbons, K. (2013). Comparison of a single vs.
a four intradermal sterile water injection for relief of lower back pain for
women in labour: A randomised controlled trial. Midwifery, 29 (6),
585-591.
Melzack, R., & Wall, P. (1965). Pain
Mechanisms: A New Theory. Science, 150 (3699), 971-979. Retrieved
from http://www.jstor.org.ezproxy1.library.usyd.edu.au/stable/1717891
Peart K, James W, Deocampo J: "Use of sterile
water injections to relieve back pain in labour." Birth Issues
2006, 15 (1):18-22.
