The Effect of Nursing Workload on the Length of Hospital Stay and the Mortality of Patients after Coronary Artery Bypass Surgery

Τhe high cost of care for patients undergoing coronary artery by-pass grafting, (CABG), in conjunction with the necessity for high quality nursing care dictate the monitoring of the nursing workload (NWL) and its correlation with outcomes, such as in-hospital mortality and length of hospital stay (LOS). Aim: The aim of this study was to test the hypothesis that the NWL during the first two postoperative days of patients undergoing CABG hospitalization can predict their hospital LOS and mortality. Method: The study sample consisted of 140 consecutive patients who were admitted to the cardiac surgery intensive care unit (ICU) of one general hospital in the Attica region from November 2007 to December 2008, after CABG. Data collection was performed by the use of two instruments: a) The Nursing Activities Score (NAS) for measuring NWL, and b) the logistic EuroScore for predicting the perioperative mortality. In addition each patient’s demographic and clinical data were recorded. The correlation of hospital LOS and mortality with NWL and other preoperative and intraoperative variables was studied. Statistical analysis was performed with SPSS version 14.0, using univariate or multivariate linear and logistic regression. The P-value of ≤ 0.05 was considered statistically significant. Results: The mean NAS (±S D) of the study patients’ two first days of hospitalization in the cardiac surgery ICU was 57.1% (±5) and their mean hospital LOS was 11.5 days (±15). The in-hospital mortality was 10.7%. The exposure of patients to high NWL levels during the first two days of hospitalization in the cardiac surgery ICU was associated with a statistically significant increase of both hospital LOS (p=0.001) and mortality (p<0.001). In-hospital mortality was positively associated with High EuroScore values (p=0.01) and increase of hospital LOS (p=0.05). Conclusions: The NAS used during the first two days in the cardiac surgery ICU as an instrument for measurement of NWL appears to be an independent nursing predictor of LOS and in-hospital mortality of patients undergoing CABG. The multiplicity of different methods for estimating of NWL reported in the international literature, along with the increased severity of cardiac ICU patients and the shortage of studies about NWL in the population of cardiac surgery patients indicate the need for further research.