Obstetric analgesia and anaesthesia — structured oral station (12 minutes)

Opening prompt — "She wants pain relief and is worried the epidural will cause a caesarean. Talk me through your counselling."

Model response — say it in this order: ^[1]

• "I would counsel her honestly. The Cochrane review found epidural gives better pain relief and satisfaction than non-epidural methods, with no increase in caesarean section and no long-term backache. That directly answers her worry."^[1]
• "There is an overall increase in assisted vaginal birth, but modern low-dose mobile techniques reduce it — COMET showed normal vaginal birth rose from 35.1% to about 43% with low-dose techniques versus traditional dense blocks."^[2]
• "I would explain the common side effects — hypotension, itch, accidental dural puncture — and the rare serious ones, and document her consent. If she declines, remifentanil PCA is the systemic alternative — RESPITE halved epidural conversion versus pethidine, 19% to 41% — but it needs one-to-one monitoring."^[3]

Probe 1 — "She agrees to the epidural. Describe your technique."

• "IV access and monitoring first. Position sitting or lateral, flexed. Full aseptic technique — gown, gloves, drapes, chlorhexidine. Identify L3/4 or L4/5 in the midline. Advance the Tuohy needle with loss of resistance to saline through the ligamentum flavum. Thread the catheter 3 to 5 cm, aspirate, give a test dose, then a loading dose of low-dose bupivacaine with fentanyl. Document the level."^[1]

Probe 2 — "You need to convert to a caesarean. How do you give a spinal?"

• "Hyperbaric bupivacaine 0.5%, typically 12.5 to 15 mg intrathecally, with an intrathecal opioid for postoperative analgesia."^[6]
• "Before the incision I test to a bilateral T4 block with cold or pinprick and document it. An untested block is an unsafe block."^[6]
• "I prevent hypotension before it happens: a prophylactic phenylephrine infusion started at intrathecal injection, left uterine displacement, and co-loading with crystalloid. The international consensus prefers phenylephrine over ephedrine because it causes less fetal acidosis."^[6]

Probe 3 — "You had an accidental dural puncture during the epidural. Two days later she has a severe postural headache. What now?"

• "The postural character plus the known dural puncture is post-dural puncture headache — but first I exclude the red flags: fever, focal neurology, seizure, altered consciousness, or loss of the postural component. Any of those triggers imaging for an alternative diagnosis."^[10]
• "If it is simple PDPH: supportive measures first — reassurance, lie flat for comfort, hydration, regular analgesia, caffeine. If it is severe or persists beyond 24 to 48 hours and she cannot care for her baby, I offer an epidural blood patch — 20 to 30 mL of her own venous blood into the epidural space. A first patch relieves the majority."^[10]

Probe 4 — "A different woman needs a category 1 caesarean. You induce general anaesthesia and cannot intubate. Walk me through it."

This is the station within the station. Say the algorithm in order: ^[5]

• "Plan A: optimised laryngoscopy, maximum two attempts, call for senior help early."
• "Plan B: supraglottic airway, up to two attempts. Plan C: face-mask ventilation, with or without cricoid pressure."
• "And the decision point: can I oxygenate her, and what is the fetal status? If I can oxygenate and the fetus is not dying, I wake her and return with a regional technique. If the fetus is dying and the airway is lost, I proceed with the supraglottic airway. Plan D — front-of-neck access, scalpel-bougie cricothyroidotomy — if I cannot oxygenate by any other route."^[5]

Probe 5 — "She is terrified of waking up under general anaesthetic. How do you reassure her?"

• "I explain that we give an adequate dose of anaesthetic and monitor the depth of anaesthesia. NAP5 found obstetric GA over-represented in awareness reports — usually the scenario of a paralysed woman under-dosed on hypnotic — so we specifically avoid under-dosing. I document the discussion and her consent."^[7]