What is the recommended premedication and anesthesia technique to reduce anxiety, risk of laryngospasm, and increase in intraocular pressure (IOP) during elective bilateral strabismus surgery in a child?

Premedication and Anesthesia for Pediatric Strabismus Surgery

For elective bilateral strabismus surgery in children, preoperative facility tours can reduce anxiety without requiring sedative premedication, general anesthesia with sevoflurane or desflurane does not increase intraocular pressure (IOP), and ketamine should be avoided as it increases the risk of laryngospasm while providing no benefit in reducing the oculocardiac reflex. 1

Premedication for Anxiety Reduction

Non-pharmacologic approaches are preferred over sedative premedication in pediatric strabismus surgery. The American Academy of Ophthalmology guidelines specifically recommend that a tour of the surgical facility by the patient and family can relieve presurgical anxiety, especially for young children. 1

Why Avoid Routine Sedative Premedication

• Long-acting sedative premedication should be avoided because it impairs immediate postoperative recovery by affecting mobility and oral intake. 1
• Oral anxiolytics can impair psychomotor function up to 4 hours postoperatively, reducing the patient's ability to mobilize, eat, and drink. 1
• Administration of sedatives for anxiolysis is unpredictable and difficult to facilitate for patients being admitted on the day of surgery. 1

When Pharmacologic Anxiolysis Is Necessary

If sedation is required, short-acting intravenous drugs (such as small incremental doses of midazolam) can be titrated carefully by the anesthesiologist under monitoring, with minimal residual effect at the end of surgery. 1

Laryngospasm Risk During Induction

Ketamine carries a significant risk of laryngospasm and should be used with caution in pediatric strabismus surgery. 1

Ketamine-Specific Concerns

• Laryngospasm may occur with ketamine, most often associated with rapid infusion or concomitant upper respiratory infection. 1
• When laryngospasm occurs, it is usually reversible with oxygen administration, repositioning of the airway, and brief positive-pressure ventilation; rarely, treatment with a muscle relaxant may be required. 1
• Glycopyrrolate (0.004 mg/kg IM given 30-60 minutes before anesthesia induction) or atropine can be used to prevent increased salivation associated with ketamine, which may contribute to laryngospasm risk. 1, 2

Optimal Induction Agents

Research comparing ketamine versus midazolam for induction in pediatric strabismus surgery found no advantage of ketamine in reducing the oculocardiac reflex (OCR), with similar incidence rates (10.0% vs. 19.4%, not statistically significant). 3 This negates any theoretical benefit of using ketamine despite its laryngospasm risk.

Intraocular Pressure Considerations

Modern anesthetic techniques for pediatric strabismus surgery do not increase IOP and are safe from an ophthalmologic standpoint. 4

Evidence on IOP During Anesthesia

• Insertion of supraglottic airways (I-gel) with sevoflurane or desflurane inhalation anesthetics does not cause any increase in IOPs in pediatric ophthalmic surgery. 4
• IOP significantly decreased 2 minutes after insertion of supraglottic airway in both sevoflurane and desflurane groups, and remained lower than baseline at 5 minutes. 4
• No significant differences in IOP were found between sevoflurane and desflurane groups. 4

Ketamine and IOP Warning

Ketamine should be avoided in patients with increased IOP or increased intraocular pressure. 1 This is an explicit contraindication listed in pediatric emergency guidelines, making ketamine particularly inappropriate for strabismus surgery where preservation of normal IOP is important.

Recommended Anesthetic Approach

Preoperative Phase

• Arrange a preoperative tour of the surgical facility for the child and family to reduce anxiety. 1
• Avoid routine sedative premedication. 1
• If the patient has significant systemic risk factors, obtain a pre-anesthesia evaluation with the primary care physician or anesthesiology service. 1

Induction and Maintenance

• Use inhalational induction with sevoflurane or desflurane rather than ketamine. 5, 4
• Consider glycopyrrolate premedication (0.004 mg/kg IM 30-60 minutes before induction) to reduce secretions if needed. 2
• General anesthesia is preferable for bilateral and longer surgical procedures. 1
• Supraglottic airways are safe and do not increase IOP. 4

Postoperative Management

• Pain management should be limited to non-narcotic analgesics when possible, as narcotics increase the risk of nausea, vomiting, and dehydration in children. 1
• Anti-emetics such as ondansetron may be used postoperatively to control nausea. 1
• Prophylactic antiemetic combinations (granisetron, ondansetron, or midazolam with dexamethasone) markedly decrease PONV following strabismus surgery. 6

Common Pitfalls to Avoid

• Do not use ketamine as the primary induction agent due to laryngospasm risk and explicit contraindication in patients with increased IOP, with no demonstrated benefit in reducing OCR. 1, 3
• Do not give routine sedative premedication as it delays recovery without providing superior anxiety control compared to facility tours. 1
• Do not use propofol or remifentanil maintenance as these are associated with higher incidence of OCR (54-66%) compared to volatile anesthetics (29-37%). 5