[Nursing Activity Score (NAS). Our experience with a nursing load calculation system based on times]

The load calculation systems of nursing work in the ICU has not had the same success in its introduction as the prognostic survival estimation systems. It causes may be: a medical design not oriented towards nursing (Therapeutic Intervention Scoring System--TISS in all its versions), lack of adaptation to the calculating of staff (Nursing Manpower Use Score--NEMS, care levels) and demand for permanent technological up-dating. In 2003, NAS was published in an attempt to obviate all the problems expressed. Its result expresses the percentage of nursing work time required for attention to each patient. Our objective has been to apply the method in our ICU and evaluate its results.

During the last quarter of 2004, NAS was systematically applied to all the patients admitted to our ICU, regardless of the reason for admission and stay time in the Unit. The analysis of this application was done by SPSS/PC 11.

NAS calculations of 350 patients, which represents 1880 total registers, were collected during the mentioned period. The NAS result of the first day was analyzed, 40.8 +/- 14.1, comparing it with its evolution during all the stay days of each patient, until reaching the ICU discharge date (39.3 +/- 12.7). The mean stay of our series has been 4.3 +/- 5.4 days during this period and the total accumulated NAS per patient was 196.2 +/- 279.8. There was no good correlation (R2: 0.273) between the NAS score on the first day of stay in the ICU but there was between total NAS and total stay of each case (R2: 0.958). Translated into times, this implies that one nurse can care for (by shift and average) 2.5 patients in our ICU.

This system adapts, without demands of periodic up-dating, to the real nursing work in the ICU. Its design is oriented to nursing work, regardless of the disease that justifies admission to the ICU. It is useful to adequately evaluate the nursing staff in the conventional ICU.