Most ophthalmic procedures in adults can be performed with either local or general anesthesia. Data have failed to demonstrate a difference in complications between local and general anesthesia for cataract surgery (Table 48-3: Factors that Influence Choice of Anesthesia).
- Retrobulbar and Peribulbar Blocks. Retrobulbar block may be associated with significant complications, emphasizing that local anesthesia does not necessarily involve less physiologic trespass than general anesthesia (Table 48-4: Complications of Needle-Based Ophthalmic Anesthesia and Fig. 48-2: Path that local anesthetic might follow if accidently injected into the subarachnoid space during performance of a retrobulbar or peribulbar block).
- Topical analgesia can be achieved with local anesthetic drops or gels.
- Choice of Local Anesthetics, Block Adjuvants, and Adjuncts Anesthetics for ocular surgery are selected based on the onset and duration needed. (Local anesthetics should be mixed to obtain the desired onset and duration.) Osmotic agents (mannitol, glycerin, carbonic anhydrase) may be administered IV to reduce vitreous volume and IOP.
- General Principles of Monitored Anesthesia Care (Table 48-5: General Principles of Monitored Anesthesia Care). Cataract surgery (number one Medicare expenditure) is most commonly performed with the patient under some form of regional anesthesia plus monitoring equipment and often the presence of an anesthesiologist (MAC).
- Exogenous (supplemental) oxygen using an open delivery system (nasal cannula) can contribute to surgical fire risk, especially if drapes promote accumulation of oxygen.
- Injuries during facial surgery with supplemental oxygen account for nearly 20% of MAC closed claims.