Several organizations including the Environmental Protection Agency, World Health Organization and American Academy of Pediatrics recommend that hospital sound levels not exceed 45 decibels. Yet, several studies across multiple age groups have observed higher than recommended levels in the intensive care setting. Elevated sound levels in hospitals have been associated with disturbances in sleep, patient discomfort, delayed recovery, and delirium.

We measured sound levels in a pediatric cardiac intensive care unit and collected vital signs data, sedation dosing and delirium scores. During a 5-week study period, sound levels for 68 patients in 22 private and 4 semi-private rooms were monitored.

Sound levels were consistently above stated recommendations with an average daytime level of 50.6 decibels (maximum, 76.9 decibels) and an average nighttime level of 49.5 decibels (maximum, 69.6 decibels). An increase in average and maximum sound levels increased the probability of sedation administration the following hour (p-value < 0.001 and 0.01, respectively) and was predictive of an increase in heart rate and blood pressure (p-value < 0.001).

Sound levels in the CICU were consistently higher than recommended. An increase in heart rate, blood pressure and sedation utilization may suggest a stress response to persistent and sudden loud sounds. Given known negative impacts of excessive noise on stress, sleep, and brain development, as well as the similar adverse effects from the related use of sedative medications, reducing excessive and sudden noise may provide an opportunity to improve short- and long-term hemodynamic and neurodevelopmental outcomes in the pediatric cardiac intensive care unit.