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Q-bank · regional →
Regional · 7 min
Regional anesthesia — last-night quick guide
Spinal, epidural, peripheral nerve blocks, complications.
Spinal — common doses
| Drug | Dose | Duration |
|---|---|---|
| Bupivacaine 0.5% hyperbaric | 9–15 mg + fentanyl 10–25 mcg + morphine 0.1–0.2 mg | 90–120 min |
| Lidocaine 2% (rare now — TNS risk) | 60–80 mg | 60–90 min |
Rule
Spinal hypotension
Sympathectomy below block + venous pooling. Phenylephrine 50–100 mcg first-line (preserves placental flow in OB). Add ephedrine 5–10 mg if bradycardic. Co-load 250–500 mL crystalloid. Block above T4 → Bezold-Jarisch → bradycardia.
Mnemonic missing: spinal-hypotension-pearl
Brachial plexus blocks
- Interscalene — shoulder/upper arm. Spares ulnar (C8/T1).
- Supraclavicular — 'spinal of the arm', whole BP at trunks. Pneumothorax risk.
- Infraclavicular — entire arm below shoulder. Cords level.
- Axillary — forearm/hand, requires separate musculocutaneous block.
Common LE blocks
- Femoral — anterior thigh, knee. Combine with sciatic for full leg.
- Adductor canal — knee analgesia, preserves quadriceps strength (vs femoral).
- Popliteal sciatic — foot/ankle.
- Saphenous — medial leg/foot (post-op TKA).
Watch out
Hematoma risk + anticoagulation
ASRA guidelines: hold ASA only if combined with thromboprophylaxis; clopidogrel 7d; DOACs 48–72h depending on agent + renal function; warfarin INR <1.5. Neuraxial > deep PNB > superficial PNB risk.