ESP, PECS, fascia iliaca, QL (2028)
Stem
At the ultrasound station, the scenario card describes a 59-year-old man, 76 kg, after a right video-assisted thoracoscopic lobectomy, who needs chest wall analgesia. The standardized patient sits upright, leaning forward. The examiner at the machine asks for the nerve block task: an erector spinae plane block at T5. Linear and curvilinear probes are available, and you have 2 minutes 30 seconds.
Question
Show me the block: where does the probe go, which structures do you name, and where does your needle tip go?
Ideal answer
HeadlineA fascial plane on bone: the T5 transverse process is my landmark and backstop; the tip goes between erector spinae and the process.
- Seated, leaning forward; count from C7 to T5. A linear probe parasagittal over the spinous process, then about 2 cm laterally.1
- Name the layers from the top. Trapezius, rhomboid major, erector spinae on flat, square-topped bright lines with acoustic shadow: the transverse processes.1 Pleura between them means too lateral, over the ribs.1
- In-plane, cranial to caudal, onto the transverse process. The local anesthetic goes between the deep surface of erector spinae and the transverse process.2
- Test 1 to 3 mL, then 20 to 30 mL. I watch it lift the muscle off the bone and spread up and down.1
Watch for: Maximum dose calculated for his weight first, and toxicity monitoring, because it is a high-volume plane block.
Breaking down the answer
- These four blocks are new for 2028 — the outline adds the erector spinae plane, PECS I and II, fascia iliaca and quadratus lumborum blocks, each with "testing to start 2028."3 Same template: probe orientation, two structures, needle-tip location.4
| Block | Probe and position | Structures to name | Needle-tip target |
|---|---|---|---|
| ESP | Linear, parasagittal ~2 cm from midline at T51 | Trapezius, rhomboid major, erector spinae, transverse process | Between erector spinae and transverse process2 |
| PECS I (interpectoral) | Paramedian sagittal below the clavicle at the coracoid, rotated inferolaterally5 | Pectoralis major, pectoralis minor, pectoral branch of thoracoacromial artery | Between pectoralis major and minor, at the third rib5 |
| PECS II second injection (pectoserratus) | Slide laterally to ribs 3–45 | Pectoralis minor, serratus anterior, ribs | Between pectoralis minor and serratus anterior, at the fourth rib5 |
| QL | Curvilinear, transverse just above the iliac crest; lateral or wedge-supine6 | Shamrock: psoas, quadratus lumborum, erector spinae around the L4 transverse process | Lateral, posterior or anterior (transmuscular) to the QL, by variant2 |
| Fascia iliaca (suprainguinal) | Linear, parasagittal just medial to the ASIS, slid inferomedially7 | "Bow tie" of sartorius and internal oblique, iliacus, deep circumflex iliac artery | Under the fascia iliaca, over iliacus7 |
- Use the consensus names — PECS I is now the interpectoral plane block, and PECS II is the combination of interpectoral and pectoserratus plane blocks.2 The examiner may still say "PECS," as the outline does.
- Know the depth by plane — about 1 to 3 cm for the interpectoral plane and 3 to 6 cm for the pectoserratus plane.5
- Name the hazard in each — pneumothorax with PECS,5 kidney injury, bowel injury and unwanted femoral block with QL,6 and toxicity with all of them, because they are volume blocks.
- The bone protects — at the injection point the transverse process sets the depth and stops the needle, and the pleura should not be visible.1
Follow-up question
The examiner freezes your image. You see rounded bright lines with deep shadow, and between them a shimmering bright line that moves with breathing. Where are you, and how do you fix it?
Follow-up answer
HeadlineI am too lateral: the rounded shadows are ribs and the moving bright line between them is pleura.1 I will not inject here.
With no bone below, the needle would be over the pleura. I slide the probe medially in the same parasagittal plane until the shadows become flat and square, the transverse processes, and the pleura disappears behind them.1 If I overshoot medially, the laminae appear as flat lines closer to the midline, so I come back out slightly.1 Then I reconfirm trapezius, rhomboid and erector spinae, point to the plane on top of the transverse process, and ask for the image to be frozen.
Pitfalls that cost points
- Pointing into the erector spinae muscle belly rather than its deep plane.
- Choosing a linear probe for a QL block in an average adult, when a curvilinear probe is usually needed.6
- Running past 2 minutes 30 seconds on one task.4
Rapid-fire
Q: What does PECS I block? A: The medial and lateral pectoral nerves.5
Q: What does the second PECS II injection add? A: The anterior cutaneous branches of intercostal nerves 3 to 6, the intercostobrachial nerves and the long thoracic nerve.5
Q: How do you find the shamrock if it is not obvious? A: Keep the probe just above the iliac crest and slide it to find the tapering abdominal muscles and the transverse process, with the QL at the tip of the shamrock.6
Q: Why go suprainguinal for fascia iliaca? A: Greater cranial spread, with anatomical logic for better coverage.7
Q: Which vessel marks the suprainguinal plane? A: The deep circumflex iliac artery, about 1 cm cranial to the inguinal ligament.7
Numbers to know
| Item | Value |
|---|---|
| ESP probe position | ~2 cm from midline, parasagittal1 |
| ESP test dose, full volume | 1–3 mL, then 20–30 mL1 |
| PECS volume | ~0.2 mL/kg per injection5 |
| QL volume per side | 20 mL6 |
| Fascia iliaca volume | 30–40 mL7 |
| Time per task | ≤2 min 30 s4 |
Links
- The ultrasound application station: format and tasks, TAP, ESP, PECS, QL and fascia iliaca blocks, Transversus abdominis plane, Femoral, adductor canal, popliteal sciatic, Local anesthetic systemic toxicity
- ABA OSCE content outline (2028 nerve-block additions); ASRA-ESRA Delphi consensus on block nomenclature (2021)
Sources
- 1.Erector Spinae Plane Block · NYSORA · nysora.com
- 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.APPLIED Exam Objective Structured Clinical Examination (OSCE) Content Outline · ABA · theaba.orgNerve-block list adds ESP, PECS I and II, fascia iliaca and quadratus lumborum, each 'testing to start 2028'.
- 4.OSCE Example Scenarios (all stations) · ABA, 2023 · theaba.orgNerve block task template: probe orientation, two structures, needle-tip location for local anesthetic.
- 5.Pectoralis Nerve Block · StatPearls, 2023 · statpearls.com
- 6.Quadratus Lumborum Blocks (Anaesthesia Tutorial of the Week 433) · WFSA, 2020 · resources.wfsahq.org
- 7.Fascia Iliaca Compartment Block: An Update (Anaesthesia Tutorial of the Week 489) · WFSA, 2023 · resources.wfsahq.org
Facts on this page were checked against these sources on Oct 16, 2026. Guidelines change; confirm doses against current institutional protocols.