Transcript Analgesia in Labour - Max Brinsmead MB BS PhD

Analgesia in Labour
Max Brinsmead MB BS PhD
May 2015
This Talk
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Pain in Labour
– Who gets it and how bad
– Pain & satisfaction with the birth experience
– The role of endorphins
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Non – Pharmacological Options
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Position for labour
Breathing and relaxation
Massage and Touch
Distraction and Music
Acupuncture and Hypnosis
Transcutaneous Electrical Nerve Stimulation (TENS)
Other methods e.g. Aromatherapy
Labouring in Water
The role of antenatal education
The role of a support person
This Talk (2)
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Pharmacological Options
– Nitrous oxide by inhalation
– Narcotics
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Advantages and Disadvantages
Choice of drug, dose and route
– Sterile Water by Injected Papule
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Anaesthetic Techniques
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Epidural and Caudal
Spinal
Paracervical Block
Pudendal Block
Perineal infiltration
(not considered)
Pain in Labour
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80 – 90% of women describe their pain in
labour as “very severe” or “intolerable”
Pain does not correlate with...
– Age
– Education
– Social class
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Satisfaction with “the birth experience” does
not correlate either with the pain of labour or
with satisfaction with analgesia
– Only 60% of women are “moderately satisfied” with
their analgesia and
– 20% still rate their pain as “severe”
Pain in Labour (2)
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Patient’s rating of pain in labour and satisfaction
with analgesia VARIES according to when they
are studied:
– In labour
– Immediately postpartum
– Several weeks postpartum
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This is due to the amnesic effects of labour and
is presumably mediated by endorphins
– “Nature’s opiates”
– Which are elevated by pregnancy and...
– Highest in labour
Pain in Labour (3)
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Patient’s reaction to the pain of labour will vary
according to her expectations
– Personal
– Cultural
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The continuum ranges from...
– “No woman needs to suffer”
– Therefore it is our role to remove it completely
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To...
– It is “natural” or “ordained”
– And a “part of the experience”
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Most women are somewhere in between
– so your role is to establish rapport and find out where they are
Pain in Labour (4)
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In providing analgesia carers of labouring
women need to...
– Examine their own beliefs and values
– Respect a patient’s right to choose
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Because a sense of control is important
– And what correlates with satisfaction with labour is
the attitude and support provided by the carer
Position in Labour
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Pain is greatest when the patient lies on her
back
Patients should be encouraged to adopt a
position of comfort
There is evidence that remaining upright and
mobile improves labour efficiency
Mobility may be encouraged by the use of
Birth Balls...
– But RCTs have not been done
Breathing & Relaxation
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Limited studies show benefit
Harmless to mothers and babies
Provided that prolonged breath-holding is
avoided
So patients who wish to use this should be
supported
Massage & Therapeutic
Touch
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Has been studied by RCT
Shown to reduce the pain of labour
Reduces anxiety and stress
And resulted in better mood and less
postnatal depression in one study
Distraction & Music
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Has been studied by one RCT
Reduces both the pain and distress from
pain
Harmless to mothers and babies
Acupuncture and
Acupressure
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Has been studied in 4 RCTs
Reduces the need for pharmacological pain
relief and epidural anaesthesia
Reduces the need for augmentation of
contractions
But not the rate of spontaneous birth
Hypnosis
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Has been studied in 5 RCTs
Reduces the need for pharmacological pain
relief
And the need for augmentation of
contractions
Transcutaneous Electrical
Nerve Stimulation (TENS)
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Has been studied in 10 RCTs
None showed any reduction in pain or use of
further analgesia
Some actually showed an increase in pain
scores
So this method should not be offered
But I allow TENS by patients who wish to do so
Aromatherapy
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Has been studied in one RCT
Found no effect on pain or the need for
other analgesia
And no effect on the rate of spontaneous
birth
But I allow aromatherapy by patients who
wish to do so
Labouring in Water
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Studies consistently show that women who have
access to water (bath or shower) resort to epidural
anaesthesia less frequently
– Please note that this does not mean “water births”
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Does not affect any other outcome...
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Length of labour
Rate of SVD
Infant outcomes (Apgars etc)
Maternal trauma (to the perineum)
Infant or maternal infection
But keep temperature <37.50 C
– And keep it clean
Antenatal Education
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Reported pain in labour is influenced by a patient’s
expectations
– So preparation for childbirth is one important component
of antenatal care
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However antenatal education does not influence...
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The use of analgesia in labour
Length of labour
Rate of SVD, assisted birth & need for Caesarean
Infant outcomes (Apgars etc)
Any measure of maternal outcome
With the exception of satisfaction if the education is
provided by the same person who provides intrapartum
care
Role of a Support Person
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Rates of spontaneous birth are possibly
increased...
– and length of labour is reduced by
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One to one care from an empathetic person
This can be provided by a female companion or
“doula”
Whether this role can be taken by a patient’s male
partner has not be confirmed
But it is a shame if his only role at a birth is to
protect his wife from uncaring midwives!
Nitrous Oxide by
Inhalation (Entonox)
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Is a weak analgesic agent
That “takes the edge off” the pain of labour
Rapidly effective and rapidly excreted
Can be used anywhere (including in water)
Has no effect on the progress of labour
Causes dizziness/light headedness in 5 – 36%
Success in its use is all about timing
And this requires a little practice
NICE recommends that Entonox be available to all
labouring women
Narcotic Analgesics
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Intensively used and studied for >50 years
But there are only a few placebo-controlled RCTs
Is a relatively poor analgesic agent when compared to
epidural anaesthesia
Causes nausea and drowsiness in women
– This can interfere with her ability to cooperate in the 2nd stage
of labour
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Should always be administered with an anti emetic
drug
– Which actually enhances its analgesic effects
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The main problem is its potential to cause respiratory
depression in the neonate
– And a reluctance to feed which can last several days
Neonatal Depression from
Narcotics
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Depends on maternal metabolism of the drug
And this varies from woman to woman
But the effect is “dose related” and...
Because the breakdown metabolites of Pethidine are
also a respiratory depressant in the neonate
The greatest potential for harm comes from repeated
doses
Whilst the effect can be totally reversed by Naloxone...
This drug is often misused in neonatal resuscitation &
has not been shown to be effective by RCT
Neonatal Depression from
Narcotics (2)
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Because early studies suggested that the
transplacental passage of narcotics is greatest in
the first 2 hours after maternal administration
Most midwifery and obstetric texts counsel against
their use if delivery is expected within 2 hours
However, because of the wide individual variation
in metabolism...
It is my view that no woman should be denied her
FIRST dose of a narcotic at any stage in labour
– But beware of the mother who goes to sleep when she
should be pushing!
Narcotic Analgesia
Choice of Agent, Dose & Route of
Administration
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There are a large number of studies available
Some suggest small advantages for Diamorphine &
Meptazinol over Pethidine
But the best outcomes are achieved by the PCA
administration of an intravenously administered shortacting narcotic e.g. Remifentanil
Where such resources are not possible...
There is quite a lot to be said for the use of Pethidine 50
mg IV and 50 mg IM
Provided the IM injection is not into subcutaneous fat
– Upper arm is recommended over lower limb
– Why do the ED docs always use SC morphine?
Sterile Water by Injection
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The intradermal injection of 0.1 ml of sterile
water into 1 – 4 sites of lumbosacral skin has
been shown by RCT to reduce back ache in
labour by up to 60% for up to 2 hrs
Causes a “bee sting” like pain
– Presumably works by “inhibitory gate control”
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Useful for the patient with an OP
When an epidural is not possible
Not endorsed by NICE
Sterile Water by Injected
Papules
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