ICU delirium:what is different between the type of diseases?

Background: Delirium is an acute neurological disorder that is quite common complication in intensive care unit (ICU) patients. However, there are no studies to focus on risk factors vary from disease to disease. The purpose of our study was to identify the risk factors and prognosis of delirium in patients with different disease types. Method: We conducted an observed study of consecutive patients from September to November 2016, who underwent surgical operation or with poor conservative treatment were admitted to the ICU. The patients were screened for delirium by using the diagnostic tools of Richmond Agitation Sedation Scale (RASS score) and the Confusion Assessment Method ICU (CAM-ICU). Results: A total of 406 patients met the inclusion criteria in our study. The overall incidence of ICU delirium was 45.8% (186/406), the delirium was highest in patients with brain disease (68%), followed by pulmonary disease (63%) and sepsis/shock (49%). The risk factors are different for different types of disease, for heart and vascular disease subgroup, only sleep quality (OR=0.236, p＜0.001) was independent risk factor for delirium. For abdominal disease subgroup, age (OR=2.514, p=0.002), vasoactive drugs (OR=13.799, p=0.002), and sleep quality (OR=0.114, p＜0.001) were risk factors for the delirium. And for sepsis and septic shock subgroup, age(OR=1.100, p=0.022), APACHE II scores(OR=1.255, p＜0.001) and sleep quality (OR=0.090, p=0.034) were risk factors for the delirium. ICU delirium is associated with worse outcomes including ICU stays(P<0.001) and 28-day mortality(P=0.001). The difference of ICU stays between delirium and non-delirium groups in the subgroup of heart and vascular disease(P<0.001), pulmonary disease(P=0.011), sepsis/septic shock(P<0.001) and cerebral disease(P=0.011) were consistent with the general population. But subgroup of sepsis/septic shock was the only one whom has the significant difference in the 28-day mortality (P=0.006) between delirium and non-delirium groups. Conclusion: The incidence and risk factors of delirium varied greatly with the type of disease. Age and sleep quality were independent risk factors for the development of delirium in most subgroup diseases. The prognosis of delirium was different in different disease types, among them, patients with sepsis/septic shock associated delirium have the worst prognosis.