PROLONGED CARDIORESPIRATORY MONITORING OF CHILDREN MORE THAN 12 MONTHS OF AGE - CHARACTERIZATION OF EVENTS AND APPROACH TO DISCONTINUATION

We assessed children referred to our apnea program who wee greater tha n or equal to 12 months:of age, beyond the at-risk period for sudden i nfant death syndrome (SIDS), but for whom home cardiorespiratory monit oring had continued. Our objectives were to (1) determine reasons for initiation and continuation of monitoring, (2) apply documented monito ring, of transthoracic impedance, electrocardiographic signals, and, i n a subset of patients, pulse oximetry, to determine the types of card iorespiratory 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 intra uterine drug exp osure in 4.4%. Continuation of monitoring had been based on continued alarms and, in 31% of patients, documented apnea, bradycardia, or hemo globin desaturation. In 40 of 45 patients, 2292 episodes of apnea (17. 5% of all events) were recorded (range, 16 to 31 seconds). Five patien ts 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 t hese alarms were for apnea and 2.2% were for bradycardia. Of 19 patien ts studied with pulse oximetry, 18 had 663 episodes of hemoglobin desa turation <90%. All children were thriving at the time of referral. Dis continuation of monitoring was based on a child's ability to resume br eathing spontaneously or on normalization of heart rate or hemoglobin saturation before the audible alarm sounded, for a minimum of 2 to 3 m onths. By extension of the audible apnea alarm to 25 or 30 seconds, lo wering of the cutoff point for bradycardia alarm, or lowering of the c utoff point for the oximetry alarm, a recommendation to discontinue mo nitoring could be made for 41 patients. Of these, no child had a recur rence of cardiorespiratory events or died of SIDS. Documented monitori ng proved to be a useful clinical tool for investigation of the clinic al and physiologic importance of these cardiorespiratory events in chi ldren beyond the at-risk period for SIDS; recommendations about discon tinuation of monitoring could be made knowledgeably and safely.