Analgesia & Anaesthesia for labour and delivery

Dr Isameldin Elamin MD DOWH MBBS

Assistant Professor

Obstetrics & Gynaecology

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What is anaesthesia?

• Definition- Anaesthesia means the loss of the sensations of touch, pressure, pain and temperature in any part of the body, or in the whole of it.

• Anaesthesia can be given in various ways and

does not always make you unconscious; it can just be used to stop pain in an area of the body, this is called local anaesthesia.

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• General anaesthesia is used when the patient needs to be in a state of controlled

unconsciousness and free of pain during an operation. A combination of drugs is given

either as gas to breathe into the lungs, or as an injection.

Any drug or agent producing anaesthesia is called an anaesthetic.

What is Analgesia ?

• Analgesics are a group of drugs-they act by either reducing capacity of the nerve fibres to sense pain or by reducing pain recognition by the higher Centres of the brain.

• Broadly divided into:– Opioids- like Morphine and Fentanyl, are potent

analgesics which are used for reducing severe pain before, during and after surgery . They can be given by intramuscular, intravenous and intrathecal (into subarahnoid space around the spinal nerve roots) routes.

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Non-opioids- Paracetamol and Non-Steroidal Anti Inflammatory Drugs (NSAID’s) are commonly used

for managing pain following minor surgical procedures or when the pain following major

surgery begins to subside.

Why do we need to use analgesia and anaesthesia for labour and delivery ?

• Labour is a painful process. Some patients will not tolerate the pain easily. Such patients can be helped by giving analgesic drugs by different routes during labour, thus reducing their pain.

• During vaginal delivery, when an incision is given on the perineum (episiotomy) , local anaesthesia can be used to reduce the pain during the suturing of the wound.

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If the patient needs a Caesarean section for delivery, she will need adequate anaesthesia for safe conduct of the operation. She will also need pain relief after the operation is over.

Local anaesthetics

• Local anaesthetic drugs are injected near to the set of nerves which carry signals from that area of the body to the brain . They are also used to infiltrate surgical wounds at the end of an operation.

• Two commonly used local anaesthetics are:• Lignocaine- Is a quick and short acting local

anaesthetic used for surface infiltration, and spinal/ epidural anaesthesia. It’s length of action is 1-2 hours.

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Bupivacaine-a slow and long acting local anaesthetic used for infiltration, and spinal/epidural anaesthesia. It’s length of action is 4-8 hours.

This method is used during repair of episiotomy after vaginal delivery.

Regional anaesthesia is used for operations on larger or deeper parts of the body.

Local anaesthetic drugs are injected near to the set of nerves which carry signals from that area of the body to the brain.

Spinal Block Spinal anaesthesia is a major form of regional anaesthesia, performed by injecting an anaesthetic drug between two of the vertebrae of the lower back into the fluid between the discs. This blocks the nearby spinal nerves, causing a complete loss of feeling from that point down the body

Regional Anaesthesia

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“Epidural anaesthesia requires a fine tube catheter to be left in the epidural space, through which further injections or an infusion of anaesthetic drugs can be given.

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Contraindications to regional anesthesia

• Absolute Contraindications

• Patient refusal• Coagulopathy • Sepsis or infection at needle insertion site• Uncorrected hypovolemia (e.g., ongoing

hemorrhage)

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Relative Contraindications

• Prior back surgery (including Harrington rod placement)

• Certain cardiac lesions, especially stenotic valvular lesions (e.g., aortic stenosis)

• • Increased intracranial pressure

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General Anaesthesia

• General anaesthesia is the induction of a state of unconsciousness, with absence of pain sensation and paralysis of skeletal muscle over the entire body. It is induced through the administration of anaesthetic drugs and is used during surgical procedures.

• There are two major types of anaesthetics used for general anaesthesia:-

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Inhalation anaesthetics, are compounds that enter the body through the lungs and are carried by the blood to body tissues . The most commonly used

anaesthetic vapours used in Obstetrics are Sevoflurane, Halothane and Isoflurane.

Intravenous anaesthetics may be used to either induce anaesthesia or for the maintenance of

anaesthesia throughout a surgical procedure. They are administered intravenously.

Physiological changes in pregnancy affecting anaesthesia

• Increased body weight . • Increased uterine size

causing compression of the vena cava in supine

• position —can lead to hypotension due to less blood returning to the heart.

• Maternal blood volume increases.

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Physiological Changes of Pregnancy affecting Anesthesia…

• Increased airway swelling, so there is increased risk of trauma to airway.

• Food in the stomach takes longer to go down into the intestine. So there can be contents in the stomach which can enter the lungs if she has vomiting during anaesthesia- leads to aspiration pneumonia.

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There is reduced drug dose required for both general and regional anaesthesia techniques, due to the increased blood circulation during pregnancy.

Different methods of anaesthesia used in labour and delivery are:

•Local infiltration

•Pudendal block

•Epidural block

•Spinal block

•General anesthesia

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Different methods

• For pain relief in labour;– Opioid injections.– Epidural block.

• For vaginal delivery and episiotomy repair:– Pudendal block– Local infiltration.

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•For Caesarean section:Spinal block.Epidural block.General anaesthesia.

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