Vitrectomy / Retinal Detachment Repair
Patient phenotype
Diabetic retinopathy (vitreous hemorrhage, traction detachment), rhegmatogenous retinal detachment, macular hole. Often diabetic, hypertensive, anticoagulated. Awake/MAC commonly preferred but GA selected for long cases or anxiety.
Procedure
3-port pars plana vitrectomy. Vitreous removed, retina repaired (laser, cryotherapy, scleral buckle). Often gas tamponade (SF6 or C3F8) — patient must avoid air travel + N₂O until gas resolves (weeks).
Anesthetic plan
MAC + retrobulbar/peribulbar block by ophthalmologist + light sedation (midazolam + remifentanil 0.05 mcg/kg/min OR dex 0.4 mcg/kg/h). GA for long cases (> 2h), anxious patients, claustrophobic, or peds.
Setup
- ·Standard monitors
- ·1 PIV
- ·Capnography even with MAC (covered face)
- ·O₂ via nasal cannula under drape (low flow — fire risk if cautery)
- ·Forced air warmer
Biggest concerns by phase
AVOID N₂O ABSOLUTELY
Gas tamponade (SF6, C3F8) expands with N₂O → retinal damage, blindness, severe pain. N₂O contraindicated for 1 week (SF6) to 3 months (C3F8) AFTER surgery. Document allergy/contraindication on chart, alert future anesthesiologists.
Anticoagulation
Warfarin often continued (intraocular bleeding rare). DOACs typically held 24-48h. Aspirin continued. Discuss with retinal surgeon.
Oculocardiac reflex
Traction on extraocular muscles, eye → trigeminal-vagal → bradycardia, asystole, BP swings. Treatment: stop traction, deepen anesthesia, atropine 0.4-0.6 mg if persistent.
Patient must be still
Even small movement = retinal damage. MAC requires cooperative patient + adequate block. Light sedation (remi or dex) preferred over heavy benzo (delirium, movement). GA if cooperation uncertain.
Endotracheal fire risk
Surgical drape covering face + supplemental O₂ + cautery = fire risk. Use lowest FiO₂ tolerated, drape lifting for ventilation, surgeon-anesthesia coordination on cautery start.
Smooth + IOP control
Coughing/bucking → IOP spike → bleed/displacement of gas. Smooth emergence. Position face-down per surgeon (gas tamponade requires specific positioning — confirm orientation).
Mock-defense scenarios
Practice answering these out loud. The probes show what an examiner is listening for.
62-yo with diabetic retinopathy + vitreous hemorrhage requiring vitrectomy + SF6 gas. He needs general anesthesia for an unrelated emergent surgery 2 weeks from now. What do you tell the surgical team?
What an examiner probes for
- ▹Recognizes N₂O absolute contraindication × ~1 week SF6, longer C3F8
- ▹Documents avoidance
- ▹Plans alternative (volatile + opioid, TIVA)
- ▹Considers consultation with retinal surgeon
Sources
- Miller's Ch 65
- AAO Vitreoretinal Surgery Guidelines
Anatomy reference
Sourced reference images. 4 matches for "eye orbital ophthalmic retina".
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