Prolonged cardiorespiratory monitoring of children more than twelve months of age: characterization of events and approach to discontinuation.

We assessed children referred to our apnea program who were > or = 12 months of age, beyond the at-risk period for sudden infant death syndrome (SIDS), but for whom home cardiorespiratory monitoring had continued. Our objectives were to (1) determine reasons for initiation and continuation of monitoring, (2) apply documented monitoring of transthoracic impedance, electrocardiographic signals, and, in a subset of patients, pulse oximetry, to determine the types of cardiorespiratory events that these children experienced, and (3) describe how documented monitoring was applied for eventual discontinuation of monitoring. Among 45 patients (median age, 22 months), 263 disks were collected, representing 2982 monitor days. Indications for initiation of monitoring included an apparent life-threatening event in 51.1% of patients, apnea of prematurity in 35.5%, history of SIDS or apparent life-threatening event in a relative in 9%, and intrauterine drug exposure in 4.4%. Continuation of monitoring had been based on continued alarms and, in 31% of patients, documented apnea, bradycardia, or hemoglobin desaturation. In 40 of 45 patients, 2292 episodes of apnea (17.5% of all events) were recorded (range, 16 to 31 seconds). Five patients had 223 episodes of bradycardia (1.7% of all events). Of all 13,075 recorded events, 76.8% resulted in audible alarms, but only 3.9% of these alarms were for apnea and 2.2% were for bradycardia. Of 19 patients studied with pulse oximetry, 18 had 663 episodes of hemoglobin desaturation <90%. All children were thriving at the time of referral. Discontinuation of monitoring was based on a child's ability to resume breathing spontaneously or on normalization of heart rate or hemoglobin saturation before the audible alarm sounded, for a minimum of 2 to 3 months. By extension of the audible apnea alarm to 25 or 30 seconds, lowering of the cutoff point for bradycardia alarm, or lowering of the cutoff point for the oximetry alarm, a recommendation to discontinue monitoring could be made for 41 patients. Of these, no child had a recurrence of cardiorespiratory events or died of SIDS. Documented monitoring proved to be a useful clinical tool for investigation of the clinical and physiologic importance of these cardiorespiratory events in children beyond the at-risk period for SIDS; recommendations about discontinuation of monitoring could be made knowledgeably and safely.