ADVERSE ENVIRONMENTAL-CONDITIONS IN THE RESPIRATORY AND MEDICAL ICU SETTINGS

Sleep deprivation and fragmentation occurring in the hospital setting may have a negative impact on the respiratory system by decreasing res piratory muscle function and ventilatory response to CO2. Sleep depriv ation in a patient with respiratory failure may, therefore, impair rec overy and weaning from mechanical ventilation. We postulate that light , sound, and interruption levels in a weaning unit are major factors r esulting in sleep disorders and possibly circadian rhythm disruption. As an initial test of this hypothesis, we sampled interruption levels and continuously monitored light and sound levels for a minimum of sev en consecutive days in a medical ICU, a multiple bed respiratory care unit (RCU) room, a single-bed RCU room, and a private room. Light leve ls in all areas maintained a day-night rhythm, with peak levels depend ent on window orientation and shading. Peak sound levels were extremel y high in all areas representing values significantly higher than thos e recommended by the Environmental Protection Agency as acceptable for a hospital environment. The number of sound peaks greater than 80 dec ibels, which may result in sleep arousals, was especially high in the intensive and respiratory care areas, but did show a day-night rhythm in all settings. Patient interruptions tended to be erratic, leaving l ittle time for condensed sleep. We conclude that the potential for env ironmentally induced sleep disruption is high in all areas, but especi ally high in intensive and respiratory care areas where the negative c onsequences may be the most severe.