Anesthetic management for pediatric strabismus surgery: Continuing Professional Development

Abstract

Purpose Strabismus surgery is one of the most common pediatric ophthalmic procedures. The purpose of this continuing professional development module is to update physicians on the anesthetic considerations of pediatric patients undergoing strabismus surgery. Principal findings The preoperative assessment is important, as patients undergoing strabismus surgery may have an associated neuromuscular disorder, congenital syndrome, or cardiac disease. Malignant hyperthermia is no longer considered as being an issue associated with strabismus. The laryngeal mask airway is used frequently and has been shown as being associated with a low incidence of complications in strabismus surgery. The anesthesia technique can be adapted to decrease the incidence of the oculocardiac reflex and the oculorespiratory reflex, and the use of anticholinergic prophylaxis remains debatable. Since patients are at high risk for postoperative nausea and vomiting (PONV), combination anti-emetic therapy is recommended using dexamethasone and ondansetron. Metoclopramide was not found to provide additional benefit when combined with other anti-emetics. Droperidol is effective, but there remains a black box warning for dysrhythmias. Effective analgesics in this patient population include acetaminophen, nonsteroidal anti-inflammatory drugs, peribulbar blocks, and subtenon blocks. Topical tetracaine drops have demonstrated mixed results, and topical nonsteroidal anti-inflammatory drops were found not to be effective. The use of opioids should be minimized due to the increased incidence of PONV. Conclusions To provide optimal care for the pediatric patient undergoing strabismus surgery, it is important to understand the unique anesthetic considerations for strabismus surgery and to appreciate how each decision regarding the anesthetic technique can alter these considerations. Objectives of this continuing professional development (CPD) moduleUpon completion of this CPD module, the reader will be able to:1 Perform a thorough preoperative assessment with an emphasis on the co-existing diseases and syndromes with ocular manifestations; 2. Evaluate the possibility of an increased incidence of masseter muscle spasm or malignant hyperthermia in this patient group; 3. Detail an anesthetic plan for strabismus surgery, including airway management and choice of anesthetic agents; 4. Understand the mechanism of the oculocardiac and the oculorespiratory reflex and recognize the associated risk factors and treatment; 5. Determine the analgesia options for strabismus surgery; and 6. Plan evidence-based anti-emetic prophylaxis for strabismus surgery. Summary reviewStrabismus surgery is the most common pediatric ophthalmic procedure. 1,2 The purpose of this continuing professional development module is to review the unique anesthetic issues facing a patient presenting for strabismus surgery. It is important to be aware of specific issues, such as the association with specific syndromes and diseases, the occurrence of the oculocardiac reflex, and the increas...

The effect of anesthesia depth on the oculocardiac reflex in strabismus surgery

“…However, many factors affect the incidence of OCR. The OCR is much more likely to occur in children than in adults during strabismus surgery [1]. Hypercarbia and hypoxemia are important adjuvant factors of the OCR [8].…”

“…The vagal stimulation leads to decreases in both heart rate and contractility of the heart. The incidence of the OCR decreases with age and tends to be more pronounced in young, healthy patients, which is clinically significant for pediatric anesthesiologists [1]. Sinus bradycardia is the most common manifestation of OCR, however, atrioventricular block, ventricular fibrillation, and even asystole may occur.…”

“…Sevoflurane and desflurane have similar effects on ORC incidence and can be used with a low OCR incidence rate during pediatric strabismus surgery [3,4]. To date, the only successful way to interrupt an OCR is to stop the EOM traction, and then proceed with caution as the surgery is continued [1]. The depth of anesthesia is another presumed factor having an impact on OCR incidence [5,6].…”

Effect of ketamine and midazolam on oculocardiac reflex in pediatric strabismus surgery

“…Major risk factors of PONV are the type of surgery including strabismus surgery, age more than 3 years old, duration of anesthesia more than 30 minutes, and a personal or family history of PONV or motion sickness [21]. Since strabismus surgery is an independent risk factor for PONV, use of anti-emetics such as ondansetron in high risk group of children is highly efficient and cost-effective [1-3]. Other strategies to minimize PONV include gentle surgical stimulation, an anesthetic plan with propofol rather than inhalation agents [18], a peribulbar block with bupivacaine, and an eye dropping of 2% lidocaine [9].…”

“…In general OCR is defined as a decrease in heart rate more than 20% from baseline heart rate after pressing globe [3,4]. Other definitions, such as a decrease in heart rate more than 10%, an increase in heart rate more than specific value, and occurrence of any type of dysrhythmia after manipulating of orbital structure are also used [5].…”