Objective: To assess temporal changes in patient characteristics, nursing workload and outcome of the patients and to compare the actual amount of available nursing staff with the estimated needs in a medical-surgical ICU.
Design: Retrospective analysis of prospectively collected data.
Setting: A medical-surgical adult intensive care unit (ICU) in a Swiss university hospital.
Patients: Data of all patients staying in the ICU between January 1980 and December 1995 were included.
Measurements and results: The estimated number of nurses needed was defined according to the Swiss Society of Intensive Care Medicine (SGI) grading system: category I = one nurse/patient/shift (= 8 h), category II = one nurse/two patients/shift, category III = one nurse/three patients/shift. An intervention score (IS) was obtained, based on a number of specific activities in the ICU. There was a total of 35,327 patients (32% medical and 68% postoperative/trauma patients). Over time, the number of patients per year increased (1980/1995: 1,825/2,305, p < 0.001) and the length of ICU stay (LOS) decreased (4.1/3.8 days, p < 0.013). There was an increase in the number of patients aged > 70 years (19%/28%, p < 0.001), and a decrease in the number of patients < 60 years (58%/41%, p < 0.001). During the same time period, the IS increased two-fold. Measurement of nursing workload showed an increase over time. The number of nursing days per year increased (1980/1995: 7454/8681, p < 0.019), as did the relative amount of patients in category I (49%/71%, p < 0.001), whereas the portion of patients in category II (41%/28%, p < 0.019) and category III (10%/0%) decreased. During the same time period, mortality at ICU discharge decreased (9.0%/7.0%, p < 0.002).
Conclusions: During the last 16 years, there has been a marked increase in workload at this medical-surgical ICU. Despite an increase in the number of severely sick patients (as defined by the nursing grading system) and patient age, ICU mortality and LOS declined from 1980 to 1995. This may be ascribed to improved patient treatment or care. Whether an increasingly liberal discharge policy (transfer to newly opened intermediate care units, transfer of patients expected to die to the ward) or a more rigorous triage (denying admission to patients with a very poor prognosis) are confounding factors cannot be answered by this investigation. The present data provide support for the tenet that there is a trend toward more complex therapies in increasingly older patients in tertiary care ICUs. Calculations for the number or nurses needed in an ICU should take into acount the increased turnover of patients and the changing patient characteristics.