Obstetric Analgesia

Question 1

What is the definition of analgesia?

Answer 1

Analgesia is the lack of pain.

Question 2

What is anaesthesia, and how does it differ from analgesia?

Answer 2

Anaesthesia is the lack of sensation, often accompanied by analgesia; patients can be either unconscious or awake.

Question 3

Define conscious sedation.

Answer 3

Conscious sedation involves administering drugs to induce a tranquil state allowing procedures.

Question 4

Why is the obstetric patient unique?

Answer 4

The obstetric patient is unique because it involves two lives.

Question 5

What physiological changes occur in pregnancy that affect analgesia?

Answer 5

Physiological changes in pregnancy include cardiovascular, respiratory, gastrointestinal, haematological changes, and airway alterations.

Question 6

How does polypharmacy affect the foetus?

Answer 6

Polypharmacy can lead to CNS and respiratory depression in the foetus.

Question 7

What are the cardiovascular changes in pregnancy relevant to obstetric analgesia?

Answer 7

Increased cardiac output and aorto-caval compression.

Question 8

Describe respiratory changes during pregnancy.

Answer 8

Decreased functional residual capacity (FRC) and increased oxygen consumption.

Question 9

What gastrointestinal changes occur during pregnancy?

Answer 9

Increased gastric reflux and reduced gastric emptying.

Question 10

How does pregnancy affect the susceptibility of nerve fibres to anaesthetic agents?

Answer 10

Increased susceptibility of nerve fibres to anaesthetic agents.

Question 11

What are the pain pathways during the first stage of labour?

Answer 11

Pain from the uterus and cervix is transmitted via T10 – L1 nerves.

Question 12

Describe the pain pathways during the second stage of labour.

Answer 12

Pain from stretching of the birth canal and perineum is transmitted via S2 – S4 nerves.

Question 13

How does pain affect the maternal cardiovascular system during labour?

Answer 13

Pain increases catecholamines, causing tachycardia, increased contractility, and systemic vascular resistance (SVR).

Question 14

What is the impact of pain on maternal respiratory physiology?

Answer 14

Pain increases minute ventilation, leading to respiratory alkalosis.

Question 15

How does pain influence placental function during labour?

Answer 15

Pain causes vasoconstriction of umbilical vessels, reducing placental blood flow.

Question 16

How does pain affect the gastrointestinal system during labour?

Answer 16

Pain reduces gastric emptying, increasing aspiration risk.

Question 17

Describe the metabolic effects of pain during labour.

Answer 17

Pain-induced catecholamine levels cause maternal hyperglycaemia and lipolysis, leading to foetal distress.

Question 18

What factors contribute to the severity of labour pain?

Answer 18

Factors include being primigravid or having a history of dysmenorrhea.

Question 19

Why is it important to relieve labour pain?

Answer 19

Effective pain relief has physiological, psychological, and physical benefits.

Question 20

What are the non-pharmacological methods of pain relief in labour?

Answer 20

Non-pharmacological methods include psychological support, massage, TENS, and aromatherapy.

Question 21

What are some examples of physical non-pharmacological pain relief techniques?

Answer 21

Examples include Lamaze technique, hydrotherapy, and acupuncture.

Question 22

Describe TENS and its use in labour.

Answer 22

TENS involves low-voltage electrical impulses via electrodes placed over specific dermatomes.

Question 23

What are the main pharmacological methods of pain relief in labour?

Answer 23

Pharmacological methods include opiate and non-opiate analgesics and inhalational agents.

Question 24

What are the common opiates used in labour analgesia?

Answer 24

Common opiates include pethidine, fentanyl, remifentanyl, pentazocine, and tramadol.

Question 25

How is pethidine used, and what are its side effects?

Answer 25

Pethidine is given intramuscularly; side effects include respiratory depression.

Question 26

Describe the properties and use of fentanyl in labour analgesia.

Answer 26

Fentanyl is a potent synthetic opioid with a rapid onset but can cause respiratory depression.

Question 27

What are the characteristics of remifentanyl?

Answer 27

Remifentanyl is an ultra-short-acting opioid with a rapid onset, often used in continuous infusions.

Question 28

What is the main advantage and disadvantage of pentazocine?

Answer 28

Pentazocine is an agonist-antagonist opioid with limited respiratory depression due to its ceiling effect.

Question 29

Describe the use and side effects of tramadol in labour.

Answer 29

Tramadol is a non-selective opioid receptor agonist with common side effects of nausea and sedation.

Question 30

What non-opiate analgesic is used in labour, and what are its common side effects?

Answer 30

Ketamine is a non-opiate analgesic with side effects including nausea and hallucinations.

Question 31

What is entonox, and how is it used in labour?

Answer 31

Entonox is a 50:50 mix of oxygen and nitrous oxide, providing rapid but limited analgesia.

Question 32

Describe the use of volatile anaesthetic agents in labour.

Answer 32

Volatile agents like isoflurane provide analgesia but can cause maternal sedation.

Question 33

What is the most effective form of labour analgesia?

Answer 33

Regional analgesia is the most effective form of labour analgesia.

Question 34

What are the pre-requisites for establishing regional techniques in labour?

Answer 34

Trained staff, equipment, IV access, and resuscitation facilities are required.

Question 35

What are the indications for regional anaesthesia in labour?

Answer 35

Indications include maternal request, pre-eclampsia, cardiac or respiratory disease.

Question 36

List the absolute contraindications for regional techniques in labour.

Answer 36

Absolute contraindications include maternal refusal, allergy, infection, and coagulopathy.

Question 37

What are the relative contraindications to regional techniques?

Answer 37

Relative contraindications include untreated infections and significant haemorrhage.

Question 38

What are the advantages of regional techniques in labour?

Answer 38

Advantages include reduced maternal exhaustion, maintained uteroplacental blood flow, and reduced foetal acidosis.

Question 39

List some disadvantages and complications of regional techniques.

Answer 39

Disadvantages include hypotension, shivering, and potential for instrumental delivery.

Question 40

What drugs are used in the epidural/subarachnoid space for labour analgesia?

Answer 40

Local anaesthetics used include bupivacaine and ropivacaine; adjuvants include opioids and non-opioids.

Question 41

Describe the ‘walking’ epidural and its advantages.

Answer 41

The ‘walking’ epidural allows mobility but may provide less pain relief.

Question 42

What are the regimens for epidural top-ups?

Answer 42

Regimens include intermittent boluses, patient-controlled epidural analgesia, and continuous infusion.

Question 43

What is a pudendal nerve block, and when is it used?

Answer 43

A pudendal nerve block provides analgesia for the second stage of labour or instrumental delivery.

Question 44

What are the anaesthesia options for caesarean section?

Answer 44

Options include general anaesthesia, spinal, epidural, or combined spinal-epidural techniques.

Question 45

What is the role of postoperative management in obstetric analgesia?

Answer 45

Postoperative management involves monitoring, analgesia, and managing vital signs and complications.