Analgesia in Labour

Last updated 05.10.12

 

Index

 

Definition

-  Analgesia used during labour

 

Pain during Labour

-  Uterus supplied by T11-L3

-  Perineum supplied by S2-S3

-  Labour Stages

-  1st stage pain from dilation of cervix & lower uterus

-  90 sec delay btwn contraction & max pain

-  2nd stage pain from stretching of perineum & compression of pelvic structures

-  Pain usually increases in severity through labour

-  Severity of pain in labour

-  15-35% nil to moderate pain in labour

-  30% severe pain

-  20% very severe or unbearable pain

 

Pain Mx

-  Optimum pain relief w min side effects to mother & baby

-  Non-Rx

-  Antenatal care & education

-  Psychoprophylaxis

-  Hypnosis

-  TENS, Acupuncture

-  Rx

-  NO

-  Opiates

-  Regional

-  Epidural

 

 

 

NO Inhalational Analgesia

<Analgesia in Labour>

 

Features

-  Most common

-  0-70% nitrous w wall O2

-  Antnox 50% w O2 common

-  Satisfactory for 50% women

-  Partial relief for 25%

-  45-60 sec to take effect therefore commence NO when contractions are palpable

 

Complications

-  Maternal hypocapnia

-  Maternal disorientation & uncooperation

-  Not suitable for prolonged use

-  Nausea & vomiting

 

 

 

Opiods

<Analgesia in Labour>

 

Features

-  Narcotic (opiate) type analgesia

-  Morphine & Pethidine most common

-  Provides sedation & pain relief

-  Careful use close to delivery: neonatal sedation/resp depression

-  Prescibe based on VE & progress of labour

 

Morphine

-  IV max effect 5-10 min

-  IM max effect 40-50 min

-  10mg (incrementally for IV)

-  If 2-3 doses required consider alt analgesia

-  50% not effective, 25% reasonable, 25% slight

 

Pethidine

-  50-100mg IM

 

Complications

-  Nausea & vomiting 50%

-  Neonatal neurobehavioural depression, hypotonia

-  Max at 2-4 hrs post IM dose

-  Mother T/2 = 3-4 hrs, Foetal T/2 = 10hrs

-  Factor to consider during neonatal resuscitation

 

 

 

Regional Analgesia

<Analgesia in Labour>

 

Features

-  Epidural most common

-  80% completely effective, 15% partial, 5% nil

-  Due to placement

 

Types

-  Epidural Catheter

-  Most common

-  Single Shot Epidural

-  Rapid onset

-  No repeated top ups

-  Increased risk of systemic toxicity

-  Combined Spinal Epidural (CSE)

-  Rapid onset

-  Repeated doses possible

 

Indications

-  Maternal request

-  Breech, twins, trial of labour, VBAC

-  Pre-eclampsia

-  Maternal cardiac disease

 

Contraindications

-  Coagulopathy

-  INR needs to be <1.3

-  Cease anticoagulants

-  Clopidogrel 7-14/7

-  Enoxaparin 12-24hrs prior, 6-12hrs post

-  Infection at site

-  Uncorrected hypovolaemia

-  Severe pre-eclampsia with thrombocytopaenia

 

Complications/Side Effects

-  Prutitis

-  Nausea

-  Mx

-  Ondansetron or Naloxone 50-100mg IV

-  Dural puncture: headache <1%

-  60% chance if dural puncture

-  Mx

-  Analgesia: Codeine, Paracetamol

-  +/- Caffeine

-  +/- Sumitriptan 6mg S/C

-  Blood patch at >24hrs, >10ml

-  Ineffective block

-  Subdural block

-  Massive subarachnoid injection

-  High block/total spinal

-  Tingling, weakness in arms & hands

-  Respiratory depression

-  Bradycardia, hypotension

-  Mx

-  ABC

-  Left lateral tilt

-  +/- Ephedrine, Metaraminol

-  +/- IV fluids

-  Cord injury/nerve damage 1:200,000

-  Infection

-  Superficial site infection

-  Meningitis

-  Epidural abscess

-  Back pain, fever, leukocytosis

-  Staph aureus most common

-  Labour

-  Decreased urge to push

-  Increased duration of second stage labour by on avg 1hr

-  Increased assisted delivery rate (forceps, vacuum)

-  Not effected by reducing epdural block

-  Does NOT increase LUSCS rate