Postoperative delirium assessed by post anesthesia care unit staff utilizing the Nursing Delirium Screening Scale: a prospective observational study of 1000 patients in a single Swiss institution

BACKGROUND: Delirium has become better studied, but is still only partially understood and significantly underestimated. There are some well-known risk factors, but little is known about the incidence of delirium in the diverse patient population of a post anesthesia care unit (PACU). The aim of this study was to investigate the presence of delirium using the Nursing Delirium Screening Scale (NU-DESC). METHODS: 1000 consecutive patients in the PACU were prospectively evaluated at the point when being ready to be transferred to the normal ward by the registered nurses of the PACU. RESULTS: The data of 1,000 patients was recorded. 242 of the patients (24.2 %) were preoperatively classified as ASA I physical status, 664 patients (66.4 %) as ASA II. A total of 43 patients (4.3 %) presented with a delirium at the time point where they would have been transferred to the normal ward (138.4 ± 55.2 min after arrival in the PACU). 287 patients (28.7 %) of the entire group were over the age of 70 years. Considering only this subgroup, delirium was diagnosed in 30 individuals (10.5 %). CONCLUSIONS: Delirium screening with the NU-DESC, collected by nursing staff of a PACU is easily feasible and demonstrated a low incidence of delirium in the presented setting. TRIAL REGISTRATION: German Clinical Trials Register (Deutsches Register Klinischer Studien, www.drks.de; DRKS 000005426; date of registration 4th December 2013).