Pain relief in Labour and Anaesthesia for obstetrics Flashcards
What are the criteria for ideal pain relief in labour?
- Provides good analgesia
- Safe for baby and mother
- Predictable and constant effects
- Be reversible
- Easy to administer
- Under control of mother
What are non-pharmacologcal methods of pain relief in labour?
- Breathing exercises
- Aromatherapy
- Warm baths
- Acupuncture
- Hypnotherapy
- TENS machine
When is a TENS machine most useful in labour?
Early labour - loses effect as labour progresses
What pharmacological methods can be used in labour for pain relief?
- Entonox gas
- Strong opiates
- Local anaesthesia
- Epidural anaesthesia
- Spinal anaesthesia
What is entonox?
50% nitrous oxide, 50% oxygen
What are the benefits of entonox?
- Self-administered
- Quick onset
- Short half life
What are side effects of entonox?
- Faint
- Nausea
- Vomiting
What opitates are used in labour?
- Pethidine
- Morphine
- Remifentanyl PCA
- Diamorphine
What are side effects to opiods?
- Nausea + vomiting
- Drowsiness
- Resp depression - woman and noenate
What forms of local anaesthesia are most commonly used in labour?
Lignocaine
What are features of local anaesthetic toxicity?
- Perioral tingling
- Praesthesiae
- Confusion
- Drowsiness
- Light-headedness
- Seizures
- Coma
- Cardiac arrest
What is inolved in an epidural anaesthesia?
Injection of local anaesthesia and opiate medication into the epidural space
What are contraindications to epidural anaesthesia?
- Thrombocytopenia
- Coagulopathy
- Raised ICP
- Local sepsis
- Septic chock
- Allergy to local anaesthesia
What are advantages of epidural anaesthesia?
- Effective analgesia
- Can be adjusted if need be
- Effective after delivery if repair of vaginal tears needed
- Best for baby
- Can prevent raised BP in pre-eclampsia
What are dcomplications of epidural anaesthesia?
- Hypotension
- Epidural haematoma/abscess
- Respiratory depression
- Neurological deficit
- Dural puncture
What fibres are anaesthatised in an epidural nerve block?
T11-S5
What are epidrual anaesthesias useful for managing?
- Breech presentation
- OP position
- Multiple pregnancy
- Preterm delivery
- Pre-eclampsia
- Forceps delivery
Where are local anaesthesia and opiod medications injected for spinal anaesthesia?
Subarachnoid space
What are advantages of spinal anaesthesia?
- Dense, anaesthetic bilateral block
- Can stay awake and maintain own airway
What are disadvantages of spinal anaesthesia?
- Causes hypotension
- Need for urinary catheter
- Risk dural puncture
- Small risk of nerve damage
Where is a pudendal nerve block injected?
1cm beyond a point just below and medial to the ischial spine on each side
What are the main uses for a puedendal nerve block?
Instrumental delivery
What are options for simple anaesthesia during pregnancy?
- Paracetamol
- Dihydrocodeine/Codeine
- Aspirin
When should you avoid aspirin in labour?
Increases bleeding risk
Why should you not use ibuprofen in pregnancy?
Can cause:
- Premature closure of DA
- Foetal oliguria
- Oligohydramnios
- Risk of bleeding in foetus
When does visceral labour pain occur?
First stage - due to progressive mechanical dilatation of the cervix, distention of lower uterine segment and contraction of the uterine muscles. Also attributed to myometrial and cervical ischaemia occuring during contractions
Where do pain fibres which are involved in visceral pain from labour originate from?
T10-L1
When does somatic labour pain occur?
Late first stage and second stage - due to stretching and distention of the pelvic floor, perineum and vagina due to descent of the foetus
What spinal level is somatic labour pain transmitted to?
- S2-S4 - via pudendal nerve and perineal branches of posterior cutaneous nerve of the thigh
- L1-L2 - branches of ilioinguinal and genitofemoral nerve
