Anaesthetic injections

Drugs and anaesthetics Before accepting any drugs their possible effects should be considered carefully. Questions to ask What to ask if you are offered drugs for easing pain in labour Drugs and their effects How drugs can effect you and your baby. Addiction The link between drugs for pain in labour and later drug addiction in the child.

Anaesthetic drugs can be given by injection to relieve pain during labour.

An anaesthetist is required to administer an epidural or spinal anaesthetic. Obstetricians and GPs can give pudendal blocks and doctors or midwives may give local anaesthetics.

Epidural anaesthetic

An injection of local anaesthetic into the epidural space around the spinal cord which numbs the body below the injection site and thus relieves the pain from contractions.

It is the preferred anaesthetic for a woman having a Caesarean section, in which case the anaesthetic is injected into the spine a little higher up to give more widespread numbness.

Route administered:
A procedure similar to an epidural except that the injection of the anaesthetic is made into the sac of cerebrospinal fluid that surrounds the end of the spinal cord.

Dosage:
If full strength anaesthetic is used then the numbness will be complete and the mother will be unable to move her limbs, as the nerves supplying the muscles to the legs will be completely anaesthetised.

Low dose epidurals use a half or quarter strength dose, and this will numb sensation and remove the pain of the contractions whilst not affecting the nerve supply to muscles. The mother will be able to move her legs and sit up, whilst not feeling any sensation.

Sometimes, the low dose of local anaesthetic is mixed with Pethidine or Fentanyl (a similar opiate) allowing less of each drug to be used, while still giving good pain relief. Greater mobility and fewer side effects are also reported.

Time lag:
Between 5 and 15 minutes from injection.

Duration:
About 3 hours for a full strength anaesthetic, proportionally less for low dose epidurals.

When given:

• For pain relief, at any time in first stage, but usually once labour is fully established.
• Prior to a Caesarean section.
• To reduce high blood pressure during labour.

Effects on the mother
Advantages:

	1.	A usually reliable method of pain relief, with complete loss of sensation from the waist down.
	2.	Can help to control high blood pressure.
	3.	Facilitates a forceps delivery if complications are present.
	4.	Allows the mother to be conscious during a Caesarean section.
	5.	Relief from pain may allow greater relaxation and more rapid dilation.
	6.	Relieving the pain may increase the mother's positive feelings about labour and birth.

Disadvantages:

	1.	The mother will be confined to bed, with resultant loss of mobility. If the dosage is half or quarter strength, she may be able to sit up, even move around, if well supported.
	2.	In 10-15% of cases, the anaesthetic may not take completely leaving some areas not fully anaesthetised.
	3.	Administration of an epidural slows the labour down so that oxytocic drugs may be needed to keep contractions going.
	4.	The mother's blood pressure can fall dramatically following an epidural and this is sometimes used as a reason for using an epidural. A drip will always be inserted prior to epidural administration in case treatment for low blood pressure becomes necessary.
	5.	There is an increased likelihood that the mother's temperature will rise the longer an epidural is in place. If this happens the baby's temperature will also rise, increasing the risk of fetal distress.
	6.	It may be difficult to empty the bladder and a catheter is frequently necessary.
	7.	In inexperienced hands, the covering of the spinal cord may be punctured. This will result in a leaking of spinal fluid and the mother will have a severe headache (perhaps for several days) until the puncture wound heals and the leaking stops. It may be possible to repair the leak by injecting a small amount of the woman's own blood into the epidural space. As this clots, it forms a patch over the hole, sealing it from further leaks. If successful, the headache will disappear almost immediately.
	8.	The muscles of the pelvic floor are relaxed by the anaesthetic and as a result the baby's head is less likely to rotate, and a forceps delivery may be necessary.
	9.	With a full strength epidural, the mother will feel no urge to push unless it is allowed to wear off before second stage commences. Forceps may be needed to lift the baby out.
	10.	The mother will have a reduced sensation of giving birth to her baby.
	11.	Tenderness over the area where the needle was inserted is common in the days following birth.
	12.	There is an absence of tone in the muscles that support the lower vertebrae and sacroiliac joints especially with a full epidural in place. This causes lack of stability in the joints, and moving the mother may cause them to become misaligned, leading to chronic backache that may last weeks or months following the birth.
	13.	If the baby is affected by the drugs, the mother may perceive her baby as difficult and hard to settle, making breastfeeding and nurturing more difficult. This perception can persist for some months.
	14.	Paraplegia is a very, very rare but unpredictable complication.

Effects on the baby
Advantages:

	1.	The mother will be able to make immediate contact following a Caesarean section, and may be able to breastfeed.
	2.	Reduced risk of fetal distress if the mother's high blood pressure can be reduced.
	3.	The mother may feel more positive about labour, birth and the baby if she is free of pain.

Disadvantages:

	1.	The baby will be affected by the drugs used, depending on the length of their exposure before birth. Common reactions include irritability, an inability to settle easily and a tendency to startle easily. These effects may last several weeks.
	2.	If any obstetric complications occur as a result of the epidural, these will have additional side effects on the baby.
	3.	Should further intervention become necessary, such as an oxytocin drip, forceps, vacuum extraction, episiotomy or Caesarean section, the baby will be affected by these procedures. See separate entries for summaries.
	4.	Any obstetric intervention or complication increases the likelihood of separation of mother and baby in the early post-natal period.

Spinal analgesia

A quick acting anaesthetic useful for emergency use for Caesarean section.

Route administered:
A procedure similar to an epidural, except that the injection of anaesthetic is into the spinal cord itself.

Dosage:
Only one tenth of the amount of anaesthetic (bupivacaine) is necessary compared to an epidural. Sometimes is it mixed with either pethidine or fentanyl. Is given as one-shot procedure (not topped up regularly).

Time lag:
Anaesthesia is usually achieved within 5 minutes.

Duration:
Lasts between 75 and 120 minutes.

When given:

For Caesarean section, especially in an emergency situation if an epidural is not already in place. Foe elective Caesarean sections. When the placenta needs to be removed manually.

Effects on the mother
Advantages

	1.	A quick acting anaesthetic in an emergency situation.
	2.	A very reliable form of anaesthetic, with very low failure rate in experienced hands.
	3.	Uses less anaesthetic, so reduces the risk of side effects.
	4.	Reduced risk of headache, as a very fine needle is used.

Disadvantages

	1.	Requires an experienced anaesthetist as it is a more technically difficult procedure.
	2.	Risk of a severe headache if several attempts are needed for successful placement.
	3.	Unable to be topped up if the anaesthesia proves inadequate. Other pain-killing drugs may have to be given in addition, or a general anaesthetic.
	4.	Too much anaesthetic may cause a profound drop in blood pressure which will require prompt treatment.
	5.	Nausea and vomiting may occur.

Effects on the baby
Advantages

	1.	May enable the baby to be born faster in an emergency.
	2.	Less exposure to drugs than for epidural anaesthetics.

Disadvantages

	1.	The baby may be affected by the drugs used.
	2.	A sudden drop in blood pressure may lead to fetal distress.
	3.	If any complication occurs as a result of the procedure (such as the need for a general anaesthetic), this may have effects on the baby.

Pudendal block

This is an injection of local anaesthetic into the perineal area to numb the outlet.

Route administered
The anaesthetic is injected through the walls of the vagina into the nerves on both sides of the vagina. This deadens the whole of the pelvic outlet.

Time lag:
The anaesthetic will take effect immediately.

Duration:
The area will stay numb long enough to enable any necessary stitching to be done after the birth.

When given:
At the beginning of second stage.

Effects on the mother
Advantages:

	1.	Numbs the perineum
	2.	Allows an early episiotomy
	3.	Allows a pain-free birth

Disadvantages:

	1.	Reduces the urge to push, which may delay second stage or require the use of forceps.
	2.	The mother cannot feel the baby being born
	3.	If an early episiotomy is done, then extensive bruising of tissues and blood loss will occur

Effects on the baby
Advantages:

1.

The baby may be born faster if episiotomy is done

Disadvantages:

1.

The baby may be affected by exposure to the anaesthetic

Local anaesthesia of the perineum

Local anaesthetic is usually injected into the perineum before an episiotomy is performed. If the episiotomy is done when the area is somewhat numb from stretching, then the anaesthetic may not be needed. It will be given prior to stitching the wound. If the mother tears during the birth the area will be anaesthetised before stitching occurs.

Route administered
A series of small injections are made into the area where the cut will be made or where the stitches will be placed.

Time lag:
Immediate effect.

Duration:
The area will stay anaesthetised long enough to allow the stitching to be done.

When given

• During second stage prior to performing an episiotomy
• After the birth, prior to stitching up the wound or tear

Effects on the mother
Advantages:

	1.	Numbs the area so that the episiotomy will not be felt
	2.	Numbs the area so that the stitching will be pain-free

Disadvantages:

1.

The injections can be painful

Effects on the baby
Advantages:

1.

The baby will not receive any appreciable amount of drug because the birth is imminent

Disadvantages:

1.

The baby may be affected by exposure to the anaesthetic

References

Howell C J. Epidural versus non-epidural analgesia for pain relief in labour (Cochrane Review). In: The Cochrane Library, Issue 4, 2002. www.nicsl.com.au/cochrane/index.asp

Enkin M, Keirse M, Renfrew M, & Neilson J. A Guide to Effective Care in Pregnancy and Childbirth 3rd Edition, Oxford University Press, London, 1999.

May A. Epidurals for Childbirth, Oxford University Press, Oxford, 1994.

Wagner, M. Pursuing the Birth Machine - the search for appropriate perinatal technology, ACE Graphics, Sydney, 1994.

Howell C J, Chalmers I,. A review of prospectively controlled comparisons of epidural with non-epidural forms of pain relief during labour. International Journal of Obstetric Anaesthesia, 1992 Vol 1, pp 93-110.

MacArthur C, Lewis M, Knox E G, Investigation of long term problems after obstetric epidural anaesthesia, BMJ 1992; 304 pp 1279-82.

Rosenblatt D, Elsey E. Lieberman B, Redshaw M, Caldwell J, Notarianni L, Smith R & Beard R, The influence of maternal analgesia on neonatal behaviour: II Epidural bupivacaine British Journal of Obstets & Gynae 1981, Vol 88 pp 407-413.

Sepkoski C, Lester B, Ostheimer G, Brazelton T. The effects of maternal epidural anaesthesia on neonatal behaviour during the first month, Developmental Medicine and Child Neurology, 1992, 34, 1072-1080.

Ransjo-Arvidson A-B, Matthiesen A-S, Lilja G, Nissen E, Widstrom, A-M, Uvnas-Moberg K, Maternal analgesia during labor disturbs newborn behaviour: effects on breastfeeding, temperature and crying. Birth Vol 28:1 March 2001.