What is the first‑line anesthetic technique and drug regimen for a scheduled or urgent caesarean delivery, and how should hypotension and contraindications be managed?

First-Line Anesthetic Technique for Caesarean Delivery

Neuraxial anesthesia (spinal or epidural) is the preferred first-line technique for both scheduled and urgent caesarean delivery, with single-shot spinal anesthesia being the most commonly used method due to its rapid onset, reliability, and superior safety profile compared to general anesthesia. 1

Primary Technique Selection

Spinal Anesthesia (First Choice)

• Single-shot spinal anesthesia is used in 92.5% of French obstetric units and is recommended as the primary technique 2
• Use pencil-point spinal needles instead of cutting-bevel needles to reduce post-dural puncture headache risk 1
• Spinal anesthesia provides equivalent speed to general anesthesia when performed by skilled practitioners, with very low failure rates 3

Epidural Anesthesia (Alternative)

• For urgent caesarean delivery, extending a well-functioning labor epidural catheter is as fast as general anesthesia and should be utilized 3
• Epidural top-up can be performed during preparation and transport to the operating room 3
• Used in only 4.5% of scheduled cases as primary technique 2

General Anesthesia (Reserved for Specific Emergencies)

• General anesthesia should be reserved for extreme emergencies including: profound fetal bradycardia, ruptured uterus, severe hemorrhage, severe placental abruption, and umbilical cord prolapse 1
• Major disadvantages include risk of failed intubation ("cannot intubate, cannot ventilate" scenarios) and awareness rates of 0.26-1% 3

Drug Regimen for Spinal Anesthesia

Local Anesthetic Dosing

• Hyperbaric bupivacaine 0.5% is the most widely used local anesthetic in the UK 1
• Standard dose: 9-12 mg of hyperbaric bupivacaine for scheduled caesarean delivery 4
• Reduced dose (7.5-11.3 mg) should be used if spinal follows recent epidural dosing within 30 minutes 4
• Target sensory level: T4 dermatome 1

Opioid Adjuncts

• Add intrathecal long-acting opioid for postoperative analgesia: either 100 µg preservative-free morphine OR 300 µg diamorphine 1
• Short-acting opioid (fentanyl 10-25 µg) may be added to improve intraoperative block quality 1, 4

Patient Positioning

• Leave patient sitting for 2 minutes after spinal injection, then position supine with left uterine displacement 4
• Maintain uterine displacement until delivery regardless of anesthetic technique 1

Hypotension Management

Prophylactic Measures

• Intravenous fluid preloading reduces maternal hypotension frequency, but do not delay spinal placement to administer a fixed fluid volume 1
• Maintain left uterine displacement throughout 1

Vasopressor Selection

• Both phenylephrine and ephedrine are acceptable for treating hypotension during neuraxial anesthesia 1
• Phenylephrine is increasingly preferred as ephedrine is associated with lower umbilical cord pH values 1
• Hypotension after spinal anesthesia typically stabilizes after a few boluses of phenylephrine 1
• In COVID-19 patients, hypotension rates were higher (86%) with 2% lidocaine loading and 0.75% ropivacaine maintenance 1

Contraindications to Neuraxial Anesthesia

Absolute Contraindications

• Patient refusal 1
• Coagulopathy or thrombocytopenia—check hemostasis before epidural in severe COVID-19 or preeclampsia 1
• Severe maternal hemorrhage with hemodynamic instability 1
• Severe respiratory distress contraindicating neuraxial technique 1

Relative Contraindications Requiring Assessment

• Sepsis or infection at injection site 1
• Severe hypovolemia (correct before proceeding)
• Increased intracranial pressure

Important Clarifications

• Severe preeclampsia is NOT a contraindication—spinal anesthesia is safe and preferred in this population 5
• COVID-19 infection is NOT a contraindication—neuraxial techniques are first choice to avoid intubation risks 1
• Mean ephedrine requirements in severe preeclampsia are minimal (5.2 mg for spinal, 6.3 mg for epidural) 5

Monitoring Requirements

• Non-invasive blood pressure, ECG, and oxygen saturation monitoring throughout 1
• Assess sensory block height every 5 minutes until no further extension observed 1
• Continue fetal heart rate monitoring in operating theater 1

Antibiotic Prophylaxis

• Administer intravenous first-generation cephalosporin within 60 minutes before skin incision 1
• For women in labor or with ruptured membranes, add azithromycin for additional infection reduction 1

Common Pitfalls to Avoid

• Never delay spinal anesthesia to complete a predetermined fluid bolus volume 1
• Avoid epidural boluses in the 30 minutes immediately preceding spinal injection if converting from epidural 4
• Do not use cutting-bevel spinal needles—always use pencil-point needles 1
• Avoid nitrous oxide for labor analgesia in COVID-19 settings due to aerosolization risk 1