Effects of critical care nurses' work hours on vigilance and patients' safety.

BACKGROUND: To minimize the occurrence of adverse events among patients, critical care nurses must be alert to subtle changes in patients' conditions, perform accurate clinical assessments, and respond expediently. However, little is known about the effects of the nurses' work hours on vigilance and patients' safety.

OBJECTIVES: To describe the work patterns of critical care nurses, determine if an association exists between the occurrence of errors and the hours worked by the nurses, and explore whether these work hours have adverse effects on the nurses' vigilance.

METHODS: Data were obtained from a random sample of critical care nurses in the United States. Nurses eligible for the study were mailed two 14-day logbooks to fill out. Information collected included the hours worked, the time of day worked, overtime hours, days off, and sleep-wake patterns. On days worked, the respondents completed all work-related questions and questions about difficulties in remaining awake while on duty. Space was provided for descriptions of any errors or near errors that might have occurred. On days off, the nurses completed only those questions about sleep-wake patterns, mood, and caffeine intake.

RESULTS: The 502 respondents consistently worked longer than scheduled and for extended periods. Longer work duration increased the risk of errors and near errors and decreased nurses' vigilance.

CONCLUSIONS: The findings support the Institute of Medicine recommendations to minimize the use of 12-hour shifts and to limit nurses' work hours to no more than 12 consecutive hours during a 24-hour period.