ANESTHESIA AND PEDIATRIC EXTERNAL BEAM RADIATION THERAPY-A REVIEW OF 512 PATIENTS

Abstract

S296 INTRODUCTION: The use of general anesthesia to produce immobility and to reduce emotional stress in pediatric patients undergoing external beam radiation therapy (EBRT) has been gaining in popularity over the past decade. We review our experience with a large series of pediatric patients undergoing multiple anesthetics for EBRT. METHODS: 512 children <or=to 16 yrs old received EBRT at Duke from 1/83 to 2/96. The charts of children anesthetized for EBRT during this period were reviewed. Patient demographics, diagnosis, anesthesia techniques, and complications were recorded. RESULTS: Of the 512 children, 123 (24%) required anesthesia for 141 courses of EBRT. These patients ranged in age from 20 days to 11 years, and consisted of 71 males (58%) and 52 females (42%). Among the patients were 95 Caucasians (77%), 26 African-Americans (21%), and 2 Native Americans (2%). Children under three were the most likely to require anesthesia for EBRT - 90% vs 28% of children from 3-7 yrs of age vs 0.7% over age 7. The most common diagnoses were: primary CNS tumor (28%), retinoblastoma (26%), and neuroblastoma (18%). The mean number of treatments per child was 22 +/- 16 with a median of 24, and a range of 1 to 65. 78% of the treatments were Q.D. and 22% were B.I.D. Treatment position was supine for 114 courses (81%), prone for 23 (16%), and combined for 4 (3%). In 88 of the courses (62%), the child had a prior or simultaneous exposure to cytotoxic/immunosuppressive chemotherapy. The most commonly used chemotherapeutic agents were vincristine, cyclophosphamide, VP16, cisplatin, adriamycin, and prednisone or dexamethasone. Anesthesia techniques consisted of ketamine alone (19%), propofol infusion (12%), halogenated inhalation agent alone (20%), intravenous induction (ketamine, barbiturate, or propofol) + halogenated inhalation maintenance (43%), midazolam alone (2%), and other (4%). The airway was maintained with either a standard mask (82%), a laryngeal mask (4%), or with intubation (14%). Intubation was typically used only at the time of radiation simulation. Complications included laryngeal spasm or airway obstruction occurring at least once during a course of EBRT (13%), and infected central venous line (occurring in 11 of the 74 children with a central line for an incidence of 15%). In ten of the children with CVP line sepsis, the line had been accessed for anesthesia use, utilizing propofol in 6 patients and barbiturate in 4. No child experienced signs or symptoms of aspiration, or clinically detectable hepatic dysfunction. CONCLUSIONS: Over a 13 yr period 123 children were anesthetized multiple times over a short time period for EBRT. Satisfactory conditions for EBRT were achieved with a variety of anesthetic techniques. The incidence of adverse events was low. Mask or laryngeal mask airway was adequate in the vast majority of patients. Despite the multiple exposures to anesthetic agents, including halogenated anesthetics, and hepatotoxic chemotherapeutic agents, no child developed hepatic dysfunction severe enough to be clinically detectable. The most common complications were airway obstruction and CVP line sepsis. The incidence of CVP line sepsis appears to be unrelated to to the anesthetic agent used and emphasizes the need to follow strict sterile protocols in accessing these lines. (Table 1)Table 1: Types of Anesthesia Used in 141 Courses of Pediatric EBRT