Anaes · Neuraxial anaesthesia
Epidural anaesthesia and analgesia
Also known as Epidural · Thoracic epidural · Lumbar epidural · Loss of resistance · Epidural test dose · High block · Epidural top-up
Exam-exhaustive epidural anaesthesia: thoracic vs lumbar, loss of resistance, test dose, top-up and failure modes, absolute/relative contraindications, ASRA anticoagulation timing principles, and high/total spinal recognition.
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Target exams
Red flags
- Sudden dense ascending block after top-up = intrathecal injection until proven otherwise — airway, vasopressors, CPR if needed.
- Severe back pain + progressive deficit after epidural = haematoma/abscess until proven otherwise — urgent MRI and decompression.
- Anticoagulation timing for insertion and catheter removal is non-negotiable (ASRA principles).
- Wet tap with Tuohy = high PDPH risk — document, follow-up, blood patch pathway.
- Unilateral or patchy block is a failure mode — do not keep topping up blindly without assessing catheter function.
Meet the patient
A fit sixty-eight-year-old is listed for an open sigmoid colectomy on an enhanced-recovery pathway, and the plan is a thoracic epidural for postoperative analgesia. He takes aspirin for ischaemic heart disease and his surgeon has charted therapeutic enoxaparin for venous thromboembolism prophylaxis — and the timing of both against your needle and your catheter removal is the conversation that decides whether this block happens at all.[1]
The epidural is the taught gold standard for dynamic pain after major open abdominal and thoracic surgery and the workhorse of labour analgesia — taught place; [1] owns only the anticoagulation-timing discipline below, not these roles — but it is high-stakes: a high block stops breathing, an unrecognised haematoma paralyses, and a wrong-route injection kills. Every line of technique below exists to prevent one of those three.[1]
References8ShowHide
- [1]Horlocker TT, Vandermeuelen E, Kopp SL, et al. Regional Anesthesia in the Patient Receiving Antithrombotic or Thrombolytic Therapy: American Society of Regional Anesthesia and Pain Medicine Evidence-Based Guidelines (Fourth Edition). Reg Anesth Pain Med, 2018.PMID 29561531
- [2]Neal JM, Barrington MJ, Fettiplace MR, et al. The Third American Society of Regional Anesthesia and Pain Medicine Practice Advisory on Local Anesthetic Systemic Toxicity: Executive Summary 2017. Reg Anesth Pain Med, 2018.PMID 29356773
- [3]Frerk C, Mitchell VS, McNarry AF, et al. Difficult Airway Society 2015 guidelines for management of unanticipated difficult intubation in adults. Br J Anaesth, 2015.PMID 26556848
- [4]Thomas JM, Schug SA Recent advances in the pharmacokinetics of local anaesthetics. Long-acting amide enantiomers and continuous infusions. Clin Pharmacokinet, 1999.PMID 9989343
- [5]Kutlesić M, Kutlesić R [Epidural analgesia in labor: specific characteristics, dilemmas and controversies]. Med Pregl, 2012.PMID 23214341
- [6]Jain D, Gandhi K, Gupta M, et al. A survey on labor epidural test dose practices in India. J Anaesthesiol Clin Pharmacol, 2025.PMID 40026751
- [7]Zhang M, Zhang L, Chen D, et al. Epidural-related maternal fever and metabolomic changes: a pilot exploratory study. Int J Obstet Anesth, 2026.PMID 42361496
- [8]Cook TM, Counsell D, Wildsmith JA, et al. Major complications of central neuraxial block: report on the Third National Audit Project of the Royal College of Anaesthetists. Br J Anaesth, 2009.PMID 19139027