Incidence and Risk Factors of PostopeRativE Delirium in ICU in China

Delirium is an acute and fluctuating alteration of mental state characterized by a disturbance in attention, level of consciousness and cognition. Postoperative delirium (POD) is a common postoperative complication that can occur in patients of any age, from children to elderly. POD was proved to be associated with several worse outcome, including increased mechanically ventilated duration, hospital length of stay (LOS) and cost. Moreover, the each day with delirium is independently associated with an increased hazard of death by 10%. Although studies on delirium substantially increased in the past decade, many research gaps still exist in this area due to the heterogeneity of their results. First, the incidence varies broad range because the targeted population are different. In China, up to now, no large sample studies to investigate the incidence and risk factors of POD in ICU. Moreover, although there have been numerous studies exploring the potential risk factors of POD, most of them are still with inconclusive evidence. The Benzodiazepine use and blood transfusion administration are the only two modifiable factors with strong evidence. Hence, still needs further studies to focus on etiology of POD to find out modifiable and non-modifiable factors to verify the presumed factors. Since there is lack of effective treatments for POD, prevention remains the best strategy to cope with delirium. Predictive models that include delirium risk factors can guide us to early prevention of high risk patients. There were two high-quality studies on prediction models for ICU delirium, named PRE-DELIRIC model and E-PRE-DELIRIC model. However, both of the models are conducted in general ICU, did not fully consider the factors of surgery.

The PREDICt study aims to find out risk factors, especially any are modifiable, and any have value for developing prediction model. Our primary aim is to determine the incidence and severity of Post-Operative Delirium (POD) in ICU after surgery, and identify the associated outcomes and burdens of POD in ICU by evaluating the impact on postoperative outcome, ICU and hospital length of stay, medical expenses. Our secondary aim is to investigate the modifiable and non-modifiable risk factors for the occurrence of POD during ICU stay and develop delirium prediction model for ICU patients. Our final aim is to comprehensively and deeply explore the etiology of POD to guide prevention of delirium among postoperative patients.