[Confusion Assessment Method for the Intensive Care Unit (CAM-ICU): diagnosis of postoperative delirium in cardiac surgery]

Abstract

Objective: Since 2001 the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU), a method for the diagnosis of delirium, has been available for the Anglo American area which can also be applied to mechanically ventilated patients. This study was conducted to answer the following questions: 1. Can a German version of the CAM-ICU be applied to patients after cardiac surgery? 2. What is the prevalence rate of postoperative delirium after cardiac surgery diagnosed by the CAM-ICU? 3. Do patients with and without the diagnosis delirium differ in the clinical variables usually associated with this disorder in cardiac surgery?

Methods: A total of 194 patients undergoing cardiac surgery served as the analysis sample (85.5% of the total group). The CAM-ICU was carried out every day for 5 days after the operation. Sociodemographic and clinical variables were collected to examine the validity of CAM-ICU. Postoperative complaints were assessed by the Anaesthesiological Questionnaire for Patients (ANP).

Results: Postoperatively, the CAM-ICU could be applied to almost all patients without any problems. The prevalence rate of delirium was 28.4% and 85.5% of the delirium diagnosed was a hypoactive subtype when diagnosed for the first time. Patients with delirium diagnosed by CAM-ICU were older (p<0.001), had a lower educational level (p<0.05), longer anaesthesia time and operation time (p<0.05), a longer postoperative ICU stay (p<0.001), were mechanically ventilated for a longer time postoperatively (p<0.001), more often reintubated (p<0.01) and had higher leucocytes postoperatively (p<0.10). More patients with delirium had the lowest postoperatively measured oxygen saturation below 95% (p<0.01).

Conclusion: The CAM-ICU is an economic method for the assessment of delirium which can easily be learned. It can be applied to patients after cardiac surgery without any problems.