Screening for delirium after surgery: validation of the 4 A's test (4AT) in the post‐anaesthesia care unit

The purpose of this guideline is to present evidence-based and consensus-based recommendations for the prevention and treatment of postoperative delirium. The cornerstones of the guideline are the preoperative identification and handling of patients at risk, adequate intraoperative care, postoperative detection of delirium and management of delirious patients. The scope of this guideline is not to cover ICU delirium. Considering that many medical disciplines are involved in the treatment of surgical patients, a team-based approach should be implemented into daily practice. This guideline is aimed to promote knowledge and education in the preoperative, intraoperative and postoperative setting not only among anaesthesiologists but also among all other healthcare professionals involved in the care of surgical patients.

Because no rigorously validated, simple yet accurate continuous delirium assessment instrument exists, we developed the Nursing Delirium Screening Scale (Nu-DESC). The Nu-DESC is an observational five-item scale that can be completed quickly. To test the validity of the Nu-DESC, 146 consecutive hospitalized patients from a prospective cohort study were continuously assessed for delirium symptoms by bedside nurses using the Nu-DESC. Psychometric properties of Nu-DESC screening were established using 59 blinded Confusion Assessment Method (CAM) ratings made by research nurses and psychiatrists. DSM-IV criteria and the Memorial Delirium Assessment Scale (MDAS) were rated along with CAM assessments. Analysis of these data showed that the Nu-DESC is psychometrically valid and has a sensitivity and specificity of 85.7% and 86.8%, respectively. These values are comparable to those of the MDAS, a longer instrument. Nu-DESC and DSM-IV sensitivities were similar. The Nu-DESC appears to be well-suited for widespread clinical use in busy oncology inpatient settings and shows promise as a research instrument.