Anesthesiology APPLIED Exam › Regional anesthesia and acute pain

TAP, ESP, PECS, QL and fascia iliaca blocks

Regional anesthesia and acute pain·~4 min read· Physician-reviewed✓ Sourced · 5

Stem

A 61-year-old woman, 70 kg, needs an urgent open sigmoid colectomy through a lower midline laparotomy for a perforated diverticulum. She takes rivaroxaban for atrial fibrillation; her last dose was 20 hours ago. She has COPD and is frightened of opioids after severe constipation and confusion with them last year. The surgeon asks whether you can "do a block instead of an epidural."

Question

What regional technique would you offer her, and how would you do it safely?

Ideal answer

HeadlineBilateral TAP blocks after induction, inside an opioid-sparing plan: the recent rivaroxaban rules out an epidural and any deep, noncompressible block, which I hold to the same intervals.

Midaxillary TAP, between internal oblique and transversus abdominis, covering T10 to T12 and some L1 for her lower midline incision, somatic pain only;¹^,2 I tell her it will not cover visceral pain.
Total dose first: 2 mg/kg bupivacaine is 140 mg,³ as bilateral blocks mean a large total; that is 56 mL of 0.25%, about 20 mL per side, diluted with saline when needed.⁴
5 mL aspirated increments under continuous needle visualization,¹ so an intravascular injection shows before the full dose; lipid emulsion available, monitoring after the block.
Scheduled acetaminophen, ketamine during the case, small titrated opioids, for the visceral pain TAP misses.

Watch for: Local anesthetic toxicity into recovery, not just during injection.

Breaking down the answer

Deep blocks follow neuraxial rules — a QL is held to neuraxial intervals (see neuraxial-anticoagulation-guidelines); naming that trade-off is judgment.
Use the consensus names — TAP is injection between internal oblique and transversus abdominis; ESP is between the erector spinae and the transverse process; QL has anterior, lateral and posterior variants.² Precise names are part of organization and presentation.
TAP is somatic only — overall coverage reaches T6 to T12-L1, but the midaxillary approach covers mainly T10 to T12, and 20–30 mL per side is typical.¹ A subcostal approach adds the upper abdomen.²
QL once the interval is met — my choice off anticoagulation: posterior injection spreads toward the paravertebral space, giving sensory block from about T4 to L1 and some visceral analgesia, more consistently than TAP;⁴ but it sits deep beside the kidney, where bleeding cannot be compressed.
Chest wall equivalents — PECS I is now the interpectoral plane block (pectoralis major and minor) and the second PECS II injection is the pectoserratus plane block (pectoralis minor and serratus anterior).²

Follow-up question

Ten minutes after you finish the second TAP injection, still under general anesthesia, her QRS widens, she has runs of ventricular ectopy, and her blood pressure falls to 72/40. What do you do?

Follow-up answer

HeadlineLocal anesthetic systemic toxicity, shown first by the heart because general anesthesia hides the neurologic warnings. I call for help and the lipid kit.

I tell the surgeon; no more local anesthetic. 100% oxygen to prevent hypoxia and acidosis. 20% lipid emulsion: a bolus of about 1.5 mL/kg, roughly 100 mL, over 2 to 3 minutes, then an infusion, repeating the bolus if she stays unstable.⁵ If she arrests, CPR with reduced epinephrine doses of 1 mcg/kg or less, and no vasopressin, calcium channel blockers, beta-blockers or more local anesthetic.⁵ I alert the nearest cardiopulmonary bypass team early, reassess rhythm and pressure continuously, and monitor her for hours after she stabilizes, because toxicity can recur.

Pitfalls that cost points

Forgetting that a QL block can weaken the leg and send the patient to the floor.
Calculating volume per side but never the total milligram dose.

Rapid-fire

Q: What is the fascia iliaca block meant to reach? A: The femoral and lateral femoral cutaneous nerves, and possibly the obturator, with 30 to 40 mL.³

Q: Why prefer a suprainguinal fascia iliaca approach? A: It produces greater cranial spread and has anatomical logic for better coverage.³

Q: What are the TAP block's specific complications? A: Bowel or liver injury, intraperitoneal injection, LAST, block failure and infection.¹

Q: Where is the deep serratus anterior plane injection? A: Between the serratus anterior and the rib.²

Numbers to know

Item	Value
TAP volume	20–30 mL per side¹
Midaxillary TAP coverage	T10–T12, some L1¹
QL possible coverage	T4–L1⁴
Bupivacaine ceiling used here	2 mg/kg (140 mg at 70 kg)³
Fascia iliaca volume	30–40 mL³
Lipid bolus, <70 kg	~1.5 mL/kg over 2–3 min⁵

Sources

1.Transversus Abdominal Plane Block · OpenAnesthesia · openanesthesia.org
2.Standardizing nomenclature in regional anesthesia: an ASRA-ESRA Delphi consensus study of abdominal wall, paraspinal, and chest wall blocks · ASRA / ESRA (Reg Anesth Pain Med 2021;46:571-80), 2021 · rapm.bmj.com
3.Fascia Iliaca Compartment Block: An Update (Anaesthesia Tutorial of the Week 489) · WFSA, 2023 · resources.wfsahq.orgToxic dose of bupivacaine given as 2 mg/kg in the equipment list.
4.Quadratus Lumborum Blocks (Anaesthesia Tutorial of the Week 433) · WFSA · resources.wfsahq.org
5.Checklist for Treatment of Local Anesthetic Systemic Toxicity · ASRA, 2020 · asra.com

Facts on this page were checked against these sources on Oct 15, 2026. Guidelines change; confirm doses against current institutional protocols.