Cataract Extraction (MAC + topical)
Patient phenotype
Elderly (70-90), often multiple comorbidities (CAD, COPD, dementia, deafness). Outpatient. Simple anesthetic but tricky population — patient needs to stay still + cooperative for ~15 min.
Procedure
Phacoemulsification of lens through 2-3 mm corneal incision; insertion of intraocular lens. Surgeon uses topical anesthetic + minimal IV sedation. Patient awake throughout. ~15-30 min.
Anesthetic plan
MAC with minimal sedation. Ophthalmologist administers topical anesthetic + sometimes peribulbar block. Goal: calm, still, cooperative patient. Avoid oversedation (apnea, movement on emergence).
Setup
- ·Standard ASA monitors
- ·PIV (small gauge — 22 or 24g acceptable)
- ·Nasal cannula + ETCO₂ monitoring
- ·Light sedation: midaz 0.5-1 mg + fentanyl 25-50 mcg
- ·Pillow under knees, head taped to bed rail (gentle restraint)
- ·Reverse Trendelenburg slight if reflux history
Biggest concerns by phase
Patient cooperation + comorbidity assessment
Patient must lie flat + still for 15-30 min. Screen for: dementia (may need GA conversion), tremor (Parkinson), inability to follow commands, severe back pain, claustrophobia, deafness (need pre-procedure communication strategy).
Don't oversedate — movement during phaco is catastrophic
Patient moving during phaco → corneal/iris/capsule damage. But oversedation → confusion + sudden movement on emergence. Goal: anxiolysis only. Midaz 0.5-1 mg + fentanyl 25 mcg single dose. AVOID propofol bolus (apnea).
Oculocardiac reflex — bradycardia from eye traction
Trigeminal-vagal reflex. Pressure on globe → bradycardia, nausea, sometimes asystole. Glycopyrrolate 0.2 mg IV pretreatment if known sensitivity. If happens: tell surgeon to release traction, atropine 0.4-0.6 mg if persistent.
Retrobulbar block complications (if used)
Some surgeons request retrobulbar/peribulbar block. Risks: globe perforation (rare), retrobulbar hemorrhage (acute proptosis), brainstem anesthesia (seizure, apnea, bradycardia from systemic spread). Have intubation kit ready.
Air under drape + claustrophobia
Surgical drape covers face. Claustrophobia common. Use surgical 'tent' with O₂ at 4 L NC + suction tube near mouth. Some patients need fan or verbal reassurance.
Quick discharge but watch for retrobulbar hemorrhage
Most patients home in 30-60 min. If retrobulbar block was used and there's pain or proptosis, urgent ophtho re-eval. Most patients see surgeon next day.
Mock-defense scenarios
Practice answering these out loud. The probes show what an examiner is listening for.
Mid-cataract surgery, awake patient on 1 mg midaz + 25 mcg fentanyl. Surgeon says 'this is going to be tight, can you make sure he doesn't move?' Patient asks 'why is everyone sounding worried?' What do you do?
What an examiner probes for
- ▹Avoid bolus propofol — risk of sudden apnea + movement
- ▹Verbal reassurance, light additional fentanyl 25 mcg if needed
- ▹Verify patient comfort + position
- ▹Communicate with surgeon — avoid escalating sedation as primary tool
Sources
- Miller's Ch 56 (ophthalmic)
- ASA Practice Advisory: MAC
Anatomy reference
Sourced reference images. 4 matches for "eye orbital ophthalmic".
