ABSTRACT
INTRODUCTION: Bradycardia is a known side effect of dexmedetomidine. Reports of sinus pauses or asystole, however, are rare. We present 2 cases of pediatric patients who developed asystole on a dexmedetomidine infusion. SUMMARY OF CASES: An 8-week-old male with RSV bronchiolitis and acute hypoxemic respiratory failure was started on dexmedetomidine for sedation at 0.2 mcg/kg/h with a maximum dose of 0.7mcg/kg/h. On Hospital day (HD) 4, on dexmedetomidine at 0.7 mcg/kg/h, he developed intermittent episodes of bradycardia with heart rates in the 60 s. Echocardiogram on HD 6 showed normal function. On HD 7, he began having periods of asystole lasting up to 6 seconds. Dexmedetomidine was discontinued, with the resolution of episodes of asystole after 6 hours. A 27-month-old male with a congenital left diaphragmatic hernia and pulmonary hypertension who had been weaned off sildenafil 6 months earlier underwent re-repair of left diaphragmatic hernia. Postoperatively he remained intubated and paralyzed. Dexmedetomidine was started at 0.3 mcg/kg/h for sedation, with a maximum dose of 1.2 mcg/kg/h. An echocardiogram on HD 3 showed good function with mild to moderate pulmonary hypertension. That evening, with dexmedetomidine at 1.1 mcg/kg/h, he developed a 15 second period of asystole requiring CPR. Dexmedetomidine was discontinued, and he was started on a midazolam infusion with no further episodes. DISCUSSION: Both cases occurred in patients without cardiac conduction defects or on negative chronotropic or sympatholytic medications that have been associated with dexmedetomidine-induced asystole. We hypothesize that both episodes of asystole were due to increased patient-related vagal tone exacerbated by dexmedetomidine.
Subject(s)
Dexmedetomidine , Heart Arrest , Hernia, Diaphragmatic , Hypertension, Pulmonary , Humans , Child , Male , Infant , Dexmedetomidine/adverse effects , Bradycardia/chemically induced , Hypertension, Pulmonary/drug therapy , Heart Arrest/chemically induced , Heart Arrest/drug therapy , Hernia, Diaphragmatic/chemically induced , Hernia, Diaphragmatic/drug therapy , Hypnotics and Sedatives/adverse effectsABSTRACT
OBJECTIVE: Determine if a standardized methadone and lorazepam weaning protocol that is based on dose and duration of exposure can reduce the length of opioid and benzodiazepine weaning and shorten hospital stay. METHODS: Retrospective cohort study performed in a 24-bed medical/surgical PICU. A total of 177 patients on opioid and/or benzodiazepine infusions for >3 days were included; 75 patients pre protocol (June 2012- June 2013) were compared with 102 patients post implementation of a standardized weaning protocol of methadone and lorazepam (March 2014-March 2015). The recommended wean was based on duration of infusions of >3 days up to 5 days (no wean), 5 to 13 days (short wean), and ≥14 days (long wean). RESULTS: Median number of days on methadone for patients on opioid infusions for 5 to 13 days was reduced from 8.5 to 5.7 days (p = 0.001; n = 45 [pre], n = 68 [post]) and for patients on opioid infusions for ≥14 days, from 29.7 to 11.5 days (p = 0.003; n = 9 [pre], n = 9 [post]) after protocol implementation. The median number of days on lorazepam for patients on benzodiazepine infusions for 5 to 13 days was reduced from 8.1 to 5.2 days (p = 0.020; n = 43 [pre], n = 55 [post]) and for patients on benzodiazepine infusions for ≥14 days, from 27.4 to 9.3 days (p = 0.011; n = 9 [pre], n = 8 [post]). There was no difference in methadone or lorazepam wean length for patients on 3 to 5 days of infusions. There was no difference in adverse events or hospital length of stay. CONCLUSIONS: A methadone and lorazepam weaning protocol based on patient's exposure to opioids and benzodiazepines (dose and duration) reduces weaning length.
