Obstetric Anaesthesia

SWARAJ HOSPITAL & RESEARCH INSTITUTE

BOLANGIR, ODISHA  •  OBSTETRICS & GYNAECOLOGY CLINICAL PATHWAY SERIES

Clinician Reference Infographic

Obstetric Anaesthesia — Labour Analgesia & Caesarean

Obstetric anaesthesia has to protect two lives. This sheet gives how to assess a woman, how to choose labour analgesia and the anaesthetic for caesarean, what can go wrong, and how to be ready to rescue.

🎯 AT A GLANCE — OBSTETRIC ANAESTHESIA

A woman’s request is sufficient reason for pain relief in labour (ASA)

Epidural analgesia works best; do not withhold it because of the cervical dilation; early epidural does not raise the caesarean rate

Low-dose techniques give good pain relief with less motor block and fewer instrumental deliveries

Neuraxial anaesthesia is preferred for most caesareans; general anaesthesia is most suitable for urgent operations when there is no time; an epidural already in place can be topped up

The pregnant airway is difficult and the stomach is full: give aspiration prophylaxis before caesarean and have a failed-intubation plan

Spinal hypotension: phenylephrine is preferred to ephedrine unless the pulse is slow; do not delay the spinal waiting for a preload

Assess early, put the epidural in early in high-risk women, protect the airway, treat hypotension quickly, and always have the rescue equipment ready.

🚨 CALL THE SENIOR ANAESTHETIST EARLY IF…

She has cardiac disease, a spinal or brain lesion, spinal hardware or stimulator, or a personal or family history of malignant hyperthermia (Harvard CRICO)

She has a bleeding disorder, or platelets under 70,000 — review before labour if possible; no single platelet count is proved safe, so judge it for each woman

She has pre-eclampsia, twin pregnancy, obesity or a difficult airway history — consider an early catheter to avoid emergency general anaesthesia

She has had an anticoagulant — wait the right interval before a spinal or epidural (usually about 12 hours after a prophylactic dose and 24 hours after a treatment dose of low-molecular-weight heparin) (from memory)

There is sepsis, infection at the back, or heavy bleeding — neuraxial may be unsafe (from memory)

An intubation fails — follow the written failed-intubation protocol

STEP 1 · ASSESS — before labour or before the operation

🩺 PRE-ANAESTHETIC CHECK

The obstetric team examines her first; then the anaesthetist records health history, earlier anaesthetics, airway examination and baseline vital signs; tests only when indicated

Platelet count is not needed for every healthy woman; do it in hypertensive disorders or a bleeding tendency

Check for aspiration risk (obesity, diabetes, difficult airway) and for a non-reassuring fetal heart rate

Fasting: avoid solid food in labour; in uncomplicated labour allow modest clear fluids

For an elective caesarean: solids 6 to 8 hours before, clear fluids up to 2 hours before

Before caesarean give a non-particulate antacid, an H2 blocker and/or metoclopramide

Establish and keep IV access (18 gauge or larger) and hold a pre-procedure time-out

🌡️ WHO NEEDS A PRE-LABOUR ANAESTHETIC REVIEW

Condition	Why it matters
Difficult airway history, obesity	Emergency general anaesthesia is high-risk; plan an early catheter
Pre-eclampsia, platelets under 70,000, bleeding disorders	Clotting and airway oedema; neuraxial safety; early catheter
Cardiac lesions	Fluid shifts and vasodilation are poorly tolerated (from memory)
Spinal or intracranial lesions, spinal hardware	May alter or forbid neuraxial block
Malignant hyperthermia (personal or family)	Avoid triggering agents (from memory)
Twin pregnancy	Higher chance of operative delivery (from memory)

STEP 2 · CHOOSE — labour analgesia and caesarean anaesthesia

🧭 CHOOSING THE ANAESTHETIC

💉 LABOUR ANALGESIA

Method	How it is used	Notes
Low-dose epidural	Bupivacaine 0.1% with fentanyl 2 µg/mL; patient-controlled (PCEA) if available	Infusions of 0.125% or stronger are usually unnecessary; fentanyl cuts the bupivacaine dose by about half; PCEA lowers interventions and motor block
Combined spinal-epidural (CSE)	Intrathecal bupivacaine 2.5 mg with fentanyl 25 µg, then an epidural catheter	Slightly faster onset; no clear overall benefit over epidural
Traditional epidural	Plain bupivacaine 0.25% or stronger	More motor block, urinary retention and rescue top-ups; low-dose is preferred
Systemic drugs and nitrous oxide	When neuraxial is not possible or is refused	Less effective; monitor sedation and the baby (from memory)

🏥 ANAESTHESIA FOR CAESAREAN SECTION

Technique	When	Notes
Spinal	Most elective and many urgent caesareans	Heavy bupivacaine with fentanyl (from memory); intrathecal morphine 0.1 to 0.2 mg gives good pain relief for many hours; more than 0.2 mg adds nothing but side effects
Epidural top-up, or CSE	She already has a catheter	Onset can match spinal for urgent caesarean
General anaesthesia	Very urgent delivery; neuraxial contraindicated, refused or failed	Aspiration prophylaxis, left tilt, preoxygenation, rapid sequence induction, and a difficult-airway kit with a surgical airway available

Hypotension after spinal: keep the uterus displaced to the left, give phenylephrine unless she is bradycardic, and use fluids or leg wrapping to reduce it. Do not delay the block for a preload. Phenylephrine gives better umbilical artery pH than ephedrine.

STEP 3 · PROTECT — complications and rescue

🛟 COMPLICATIONS AND WHAT TO DO

Problem	Recognise	Act
Hypotension	Dizziness, nausea, falling blood pressure after the block	Left uterine displacement, vasopressor, fluids
High or total spinal	Numb arms, breathlessness, slurred speech, slow pulse, collapse (from memory)	Call for help, oxygen, support the airway and breathing, vasopressor, tilt (from memory)
Local anaesthetic toxicity	Numb lips, metallic taste, buzzing in the ears, fits, arrhythmia (from memory)	Stop the injection, call for help, airway and oxygen, control fits, give lipid emulsion (lipid rescue must be available)
Failed intubation or aspiration	Cannot see the cords or place the tube; desaturation	Follow the protocol: face-mask ventilation with cricoid pressure, or a laryngeal mask; a surgical airway is the last resort
Post-dural puncture headache	Headache worse upright, starting a day or two after the block (from memory)	Fluids, simple analgesia and rest; epidural blood patch if severe or persistent (from memory)
Itch, nausea after neuraxial opioid	Dose-related; serious respiratory depression is rare	Treat the symptoms and monitor sedation and breathing
Haemorrhage or cardiac arrest	Shock, collapse	Large-bore IV, blood and warmers; resuscitate with uterine displacement; deliver the baby if there is no response within 4 minutes

🗣️ WHAT TO TELL HER

An epidural or spinal takes away most of the pain, but she may feel touch and pressure; she stays awake for a caesarean and can see and hold the baby (from memory)

Common effects are low blood pressure, itching and nausea; headache, and weakness in the legs for a few hours (from memory)

Serious problems such as nerve injury or infection are rare; explain them and obtain consent (from memory)

An epidural in labour does not raise her chance of a caesarean

She can still have pain relief later in labour; it is never too late if a safe option exists (from memory)

⚠️ COMMON PITFALLS

Withholding an epidural until a set dilation

Strong infusions that cause motor block and urinary retention

Delaying a spinal to complete a fluid preload

Leaving out aspiration prophylaxis, or no left tilt

No failed-intubation protocol or difficult airway kit in the theatre

Placing the catheter late in a high-risk woman and ending with an emergency general anaesthetic

Not monitoring after intrathecal or epidural morphine

Neuraxial block in a woman with unrecognised low platelets or recent anticoagulant

Memory Aid

SAFER

Five steps for the safe obstetric anaesthetic.

S

Screen early — airway, platelets, clotting, anticoagulants

A

Aspiration prophylaxis — fasting, antacid, H2 blocker

F

Fight hypotension — left tilt, phenylephrine, fluids

E

Early catheter — in every high-risk woman

R

Rescue ready — failed-intubation protocol, lipid, resuscitation

Remember: good analgesia, a safe airway and a rescue plan: the three things that protect a mother.

Swaraj Hospital & Research Institute · Department of Obstetrics & Gynaecology, Bolangir, Odisha

Clinician-facing summary. Checked against: Harvard CRICO (RMF) “Guideline 28: Anesthesia in Obstetrics” (pre-anaesthetic evaluation, IV access, high-risk conditions for early review, equipment, failed-intubation protocol, lipid rescue) and a summary of the ASA Practice Guidelines for Obstetric Anesthesia (2007) (fasting, aspiration prophylaxis, labour analgesia regimens, caesarean technique, hypotension, intrathecal morphine, difficult airway, cardiac arrest). The ASA summary is older than current practice; newer guidance may differ on fasting and techniques. Items marked “from memory” (anticoagulant intervals, sepsis, high spinal and toxicity features, headache, counselling, systemic analgesia) were not checked. Doses and protocols vary by unit and country: follow your anaesthetic department’s protocol.