Intravenous methohexital for brief sedation of pediatric oncology outpatients: physiologic and behavioral responses

Abstract

Objective: In this successor to a preliminary retrospective study, we sought to confirm the apparent safety and efficacy of intravenous methohexital (MHX) for brief, unconscious sedation of pediatric hematology/oncology outpatients undergoing painful, invasive procedures.

Methods: This prospective study was conducted in a children's hospital-based hematology/oncology clinic. Following published monitoring guidelines for deep pediatric sedation, MHX (1.0 mg/kg) was administered immediately before each procedure, 1% xylocaine was given locally, and additional MHX was titrated to maintain minimal response to pain during the procedure. For each patient, the procedural and physiologic response data reported below were recorded from the onset of sedation through recovery. Behavioral distress responses were measured using a standardized pediatric observational tool (Procedure Behavioral Checklist).

Results: Two hundred and thirty-three procedures were carried out in 76 patients ranging .1 to 19.6 years of age. The mean cumulative MHX dose/procedure was 4.6 +/- 2.9 mg/kg. The mean lengths of time from initiation of sedation until completion of the invasive procedure, attainment of patient arousability, discontinuation of monitoring, and attainment of patient alertness were 8 +/- 5, 19 +/- 8, 19 +/- 9, and 22 +/- 9 minutes, respectively. Relative to presedation values, mean arterial pressure (MAP), heart rate, and respiratory rate showed maximum mean percent changes of -16.6, +17.8, and +13.4, respectively (all clinically insignificant). Complications among procedures were transient and included hiccoughs and myoclonus (each 10%); oropharyngeal secretions (6%); and pain at the injection site, emergence phenomena, and mild stridor (each </=3%). Of two procedures (.9%) affected by transient upper airway obstruction associated with emesis or secretions, only one briefly needed mask ventilation. No procedures required intubation or early termination. In 49 additional procedures assessed for patient distress, observed pain responses were absent to mild in 45 (92%) and moderate in 4.

Conclusion: MHX appropriately administered provides sedation which is effective, safe, well tolerated, and of short duration, making MHX attractive for use in pediatric oncology outpatients and other populations with similar sedation needs.