Sleep and adverse environmental factors in sedated mechanically ventilated pediatric intensive care patients

Objective To document the quantity and architecture of sleep using objective electrophysiologic assessment in sedated mechanically ventilated pediatric intensive care unit patients over a 24-hr period and to investigate the effect of noise and staff interventions on sleep pattern in these subjects. Design Prospective observational study. Setting Pediatric intensive care unit at a university hospital. Patients A total of 11 patients studied between September 2000 and June 2001, with ages ranging from 3 to 21 months. All patients were intubated, mechanically ventilated, and sedated with morphine and midazolam infusions. Interventions Limited sleep polysomnograph, staff interventions, and noise levels were continuously monitored during a 24-hr period. Measurements and main results Noise levels were consistently >48 dB(A); the highest night peak reached 103 dB(A). Staff interventions lasted for a mean of 240 (SD 90) mins in a 24-hr period. There was no significant difference in the number of interventions between day and night. Severe alterations to sleep architecture were found throughout the 24 hrs, with no diurnal variations. Active sleep was severely reduced to a mean of 3% (SD 4%; range, 0-11%) of total sleep time. There was severe sleep fragmentation as reflected by the high number (mean, 40 [SD 20]) of wake episodes. Conclusion The above findings suggest a significant electrophysiologic abnormality of sleep in the pediatric intensive care unit patients. Our pediatric intensive care unit environment is characterized by both, high noise levels and frequent staff interventions. This study has several limitations and future studies are needed, with larger sample size and an attempt to manipulate the environmental factors to minimize their negative effects on sleep.