NORMAL LABOUR
PAIN RELIEF - ANALGESIA
Epidurals
Epidural anaesthesia is the blocking of nerve routes from the spinal cord with a local anaesthetic or painkilling medication.
This is the most effective way of relieving the pain of contractions, with complete relief of pain in 95% of labouring women. The procedure may be instituted at any time and does not interfere with uterine contractility. It may reduce the desire to bear down in the second stage of labour.
Epidural prevalence
Up to 40 per cent of women in UK hospitals have an epidural while giving birth the figure varying considerably from hospital to hospital.A fine catheter is introduced into the lumbar epidural space and a local anaesthetic agent such as bupivacaine is injected (Figure 1.). The addition of an opioid to the local anaesthetic 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. The procedure involves:
- Insertion of an intravenous cannula and preloading with no more than 500 ml of saline or Hartmann?s solution
- Insertion of the epidural cannula at the L3/L4 interspace and injection of the local anaesthetic agent at the minimum dose required for effective pain relief.
Figure 1. Epidural Anaesthesia.
Epidural anesthesia and analgesia
Indications
Injecting local anaesthetics into the epidural space is commonly performed for analgesia for women in labour. When a catheter is placed into the epidural space a continuous infusion or intermittent injection can be administed, when needed.
Cautions
- Anatomical abnormalities, such as spina bifida or scoliosis
- Previous spinal surgery (where scar tissue may hamper the spread of medication, or may cause an acquired tethered spinal cord)
- Certain problems of the central nervous system, including multiple sclerosis
- Certain heart-valve problems (such as aortic stenosis, where the vasodilation induced by the anesthetic may impair blood supply to the thickened heart muscle.)
Contraindications
- Lack of consent
- Bleeding disorder (coagulopathy) or anticoagulant medication (e.g. warfarin) - risk of spinal cord-compressing hematoma
- Infection near the point of insertion
- Infection in the bloodstream which may "seed" via the catheter into the (otherwise relatively impervious) central nervous system
- Uncorrected hypovolemia (reduced circulating blood volume)
Side effects?
- a drop in blood pressure. This occurs in most cases and is usually easily treated with drugs or by giving fluids through a drip. For this reason, your blood pressure must be checked at frequent intervals throughout the procedure.
- headache (also known as a spinal headache). This happens to 1 per cent of women who have an epidural and is due to the needle passing into the spinal space. It can be treated successfully by an anaesthetist.
