[39] Analgesia and Anaesthesia During Labour Flashcards
When should strategies for the relief of pain during labour be discussed with the mother?
During the antenatal period
What are the techniques for relieving pain during labour aimed at?
Reducing the level of pain experienced in labour whilst invoking minimal risk for the mother and her baby
How does the level of pain experienced during labour vary?
Varies widely, with some experiencing very little pain, whilst others suffer from abdominal or back pain of increasing intensity throughout their labour
What is the result of the wide variety in pain experienced during labour?
Any programme of pain relief must be tailored to the individual
What is the best mode of pain relief in labour advised based on?
- If the mother is nulliparous or multiparous
- Current cervical dilatation
- Rate of progress in labour
- Extent to which the mother is feeling the pain
How is a decision regarding pain relief in labour reached?
The mother decides based on the advice given
What does the programme of pain relief in labour often involve?
A combination of methods, starting from least to most effective method
What is the only method of pain relief during labour that provides complete pain relief during labour?
Epidural anaesthesia
What are the types of pain relief during labour?
- Narcotic analgesia
- Inhalation analgesia
- Complementary therapies
- Regional anaesthesia
What are the options for narcotic pain relief during labour?
- Pethidine
- Morphine
- Remifentanil
Is remifentanil widely used?
I dont think so it just says some centres so probs not a main one
What is the advantage of remifentanil?
It is an ultra short-acting opioid that produces a superior analgesia to pethidine and has less of an effect on neonatal respiration
What are the common side effects of opiates?
- Nausea and vomiting in the mother
- Respiratory depression in the baby
When is the effect of opiates on the neonatal particularly important?
When the drug is given within 2 hours of delivery
What are opiates often administered with?
Anti-emetics
What effect might using opiates during labour have after labour?
Might interfere with breastfeeding
When is inhalation analgesia used in labour?
Early in labour, until the mother switches to much stronger analgesics
What is inhalational analgesia best used for in labour?
Short-term pain relief in the late first and second stage of labour
What is the most widely used inhalation analgesia used in labour?
Entonox
What is Entonox?
A 50/50 mixture of nitrous oxide and oxygen
What is the advantage of Entonox in labour?
The gas is self administered, which avoids overdosing as they drop the mask off
When is Entonox inhaled?
As soon as the contraction starts
Who has nitrous oxide been shown to have adverse effects on?
Birth attendants
When does nitrous oxide have adverse effects on birth attendants?
If exposure is prolonged
What adverse effects might nitrous oxide have on birth attendants?
- Decreased fertility
- Bone marrow changes
- Neurological changes
How are the adverse effects of nitrous oxide on birth attendants avoided?
Forced air change every 6-10 hours, which is effective in reducing nitrous oxide levels
What complementary therapies are there for pain relief in labour?
- Breathing and relaxation techniques
- Massage techniques taught to birth companions
- Acupuncture
Should you offer acupunture as analgesia during labour?
Do not offer, but do not stop the woman doing it if she wants
How is immersion in water during labour claimed to provide analgesia?
Increases maternal relaxation and reduces analgesic requirements
When is immersion in water during labour supported?
For healthy women with uncomplicated pregnancies
What did a Cochrane review find regarding the use of immersion in water during labour?
It reduces the use of analgesia and reported maternal pain, without adverse effects on labour duration, operative delivery, or neonatal outcome
What is the most effective and widely used pain relief during labour?
Epidural (obviously)
In what % of labouring women does epidural provide complete pain relief?
95%
When during labour can an epidural be inserted?
Any time
Do epidurals interfere with uterine contractility?
No
What is the problem with epidural, in terms of the progress of labour?
It may reduce the desire to bear down in the second stage of labour
Why might an epidural reduce the desire to bear down in the second stage of labour?
Due to lack of pressure sensation at the perineum, and reduced uterine activity due to loss of the Ferguson reflex
What is the Ferguson reflex?
Increased uterine activity due to reflex release of oxytocin due to the presenting part stretching the cervix and upper vagina
How is an epidural inserted?
A fine catheter is introduced into the lumbar epidural space, which is then preloaded with no more than 500ml of saline or Hartmann’s solution. Then, a local anaesthetic agent such as bupivacaine is injected, at the minimum dose required for effective pain relief
Where is the lumbar epidural space?
L3-4 interspace
What is the advantage of the addition of an opioid to the local anaesthetic in epidural?
It greatly reduces the dose requirement of bupivacaine, thus sparing the motor fibres to the lower limbs and reducing the classic complications of hypotension and abnormal fetal heart rate
What monitoring should be done in a patient who has had an epidural?
- BP
- Pulse rate
- Fetal heart rate
Why might the maternal position need to be adjusted with an epidural?
To achieve desired analgesic effect
What are the complications of epidural anaesthesia?
- Hypotension
- Accidental dural puncture
- Post-dural headache
How can hypotension caused by epidural anaesthesia be avoided?
- Pre-loading
- The use of low-dose anaesthetic agents and opioid solutions
What % of epidurals does accidental dural puncture occur in?
Less than 1%
What % of mothers will develop a headache if a 16 or 18 gauge needle is used for epidural?
70%
What should be done if a post-dural headache persists for more than 24 hours?
Should be treated with an epidural blood patch
What are the contraindications for epidural?
- Maternal refusal
- Coagulopathy
- Local or systemic infection
- Uncorrected hypovolaemia
- Inadequate or inexperienced staff or facilities
When is spinal anaesthetic commonly used in delivery?
For operative delivery
Why is spinal anaesthetic not used for pain relief in labour?
Due to the superior safety of epidural anaesthesia, and the ability to top epidural up with suitable doses or as continuous infusion to get pain relief over a long period of time
When can local anaesthetic be useful in delivery?
For women who have not had an epidural, but require forceps or vacuum extraction delivery, or for repair of episiotomy tear
What are the most commonly performed local anaesthetic nerve blocks in delivery?
- Paracervical blockage
- Pundendal nerve blockade
What does a paracervical blockade involve?
Infiltration of local anaesthetic agents into the paracervical tissues
What is the limitation of a paracervical blockage for childbirth?
- Rarely used for obstetric procedures
- Greater chance of side effects to the fetus should it enter a vessel
What does a pundendal nerve blockade involve?
Infiltration around the pundendal nerve as it leaves the pundendal canal and inferior haemorrhoidal nerve
Describe the use of a pundendal nerve blockade?
It used to be used a lot in operative vaginal deliveries, but now used less frequently and has been replaced by epidural anaesthesia
What is often used when giving local anaesthesia for episiotomy or tear repair?
Infiltration directly into the perineal tissues over the site
What care should be taken when diving local anaesthesia over the perineal tissues for episiotomy or tear repair?
Not to accidentally inject the drug IV
What might happen if you accidentally inject local anaesthetic IV during episiotomy or perineal tear repair?
May get toxic symptoms such as cardiac arrhythmias and convulsions, especially with larger dosage
