Labor Epidural Placement
Patient phenotype
Term pregnant woman in active labor (4-7 cm typically). Wants pain relief. Most are healthy; some with PIH, GDM, BMI 40+, prior failed regional. May be cooperative or in extreme distress.
Procedure
Sterile prep, identify L3-4 or L4-5 interspace, loss-of-resistance technique to enter epidural space, advance catheter, test dose, infusion of dilute local + opioid. ~10-20 min.
Anesthetic plan
Loss-of-resistance technique. Bupivacaine 0.0625-0.125% + fentanyl 2 mcg/mL infusion at 8-12 mL/hr after bolus. Patient-controlled epidural analgesia (PCEA) common. Goal: analgesia without dense motor block.
Setup
- ·Sterile field + epidural kit (17g Tuohy needle, 19-20g catheter, LOR syringe, lidocaine for skin)
- ·BP cuff, pulse ox
- ·PIV with 1L NS or LR running
- ·Phenylephrine drawn (50-100 mcg boluses)
- ·Test dose: 3 mL of 1.5% lidocaine + 1:200,000 epi (15 mcg epi)
Biggest concerns by phase
Coagulation + platelet count assessment
Platelet > 70K generally safe. PIH may have rapidly dropping platelets — recheck if last value > 6h old. Anticoagulation per ASRA guidelines (LMWH, warfarin, DOACs all have hold times). Bedside chat with OB + check labs.
Patient positioning + cooperation in labor
Sitting (most common — better landmark identification in BMI > 35) or lateral. Help patient curl into 'angry cat' position. Time placement between contractions if possible (patient holds still). Reassure + verbal coaching.
Test dose interpretation
After negative aspiration: inject 3 mL of 1.5% lido + 15 mcg epi. Wait 60-90 sec. Tachycardia + HTN within 30 sec → IV (intravascular). Motor block within 3 min → intrathecal. Neither → epidural placement confirmed.
Maternal hypotension management
Sympathectomy from epidural → hypotension → fetal heart rate decel possible. Pre-load 500-1000 mL crystalloid before bolus. Phenylephrine 50-100 mcg if BP drops. Maintain LUD always.
Inadequate analgesia — incremental troubleshooting
Low block (perineum spared): top up + reassess. One-sided block: pull catheter back 1 cm + bolus + reposition. Patchy: replace if persistent. Convert to spinal/CSE if epidural fails before C/S needed.
Continuous monitoring + complication watch
Hourly BP + FHR. Watch for: dural puncture (CSF dripping at insertion = wet tap, expect PDPH 12-72h post-delivery), high spinal (rapid sensory ascent — manage as crash spinal), epidural hematoma (back pain + new neuro deficit — emergency MRI + neurosurgery).
Mock-defense scenarios
Practice answering these out loud. The probes show what an examiner is listening for.
You've placed a labor epidural at L3-4. Test dose is negative. After the initial bolus of 10 mL of 0.125% bupi + 100 mcg fentanyl, the patient suddenly says her hands feel weird, then 'I can't feel my arms.' BP drops 110 → 70. What's happening and what do you do?
What an examiner probes for
- ▹Recognizes high spinal — likely intrathecal injection despite test dose
- ▹First moves: O₂, LUD, phenylephrine + atropine, prepare to support airway
- ▹Trendelenburg only if airway secured
- ▹Anticipates: may need intubation, GA C/S if continued progression
- ▹Anticipates: PDPH + neuro complications later
Sources
- ASA Practice Advisory: OB Anesthesia
- Chestnut OB Anesthesia 6e
- SOAP guidelines
Anatomy reference
Sourced reference images. 4 matches for "spinal cord lumbar epidural".
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