Documented monitoring: an alarming turn of events.

Event recording of transthoracic impedance and electrocardiogram (documented monitoring) has recently become available to the clinician. Through its use, investigators have documented a remarkably low incidence of true alarms for apnea and bradycardia among monitored infants and children and an even lower incidence of clinically significant alarms. This technique has allowed clinicians to improve monitor management and to discontinue monitoring sooner. Coupled with recording of hemoglobin saturation and pulse waveform, this technology will serve to enhance our understanding of the pathophysiology of events that accompany apparent life-threatening events and that precede sudden infant death syndrome.