Satoko Asano, Yasuto Kunii, Hiroshi Hoshino, Yusuke Osakabe, Tetsuya Shiga, Shuntaro Itagaki, Itaru Miura, Hirooki Yabe

Delirium is commonly encountered in daily clinical practice. To identify predictors influencing outcomes, we retrospectively examined the characteristics of inpatients with delirium who required psychiatric medication during hospitalization. We extracted all new inpatients (n=523) consulted for psychiatric symptoms at Fukushima Medical University Hospital between October 2011 and September 2013. We selected 203 inpatients with delirium diagnosed by psychiatrists. We analyzed data from 177 inpatients with delirium who received psychiatric medication. We defined an "early improvement group" in which delirium resolved in ≤3 days after starting psychiatric medication, and a "prolonged group" with delirium lasting for >3 days. Among the 83 inpatients with renal dysfunction (estimated glomerular filtration rate <60 mL/min/1.73 m2), we defined an "early improvement group with renal dysfunction" in which delirium resolved in ≤3 days after starting psychiatric medication and a "prolonged group with renal dysfunction" with delirium lasting for >3 days. We then examined differences between groups for different categorical variables. Dose of antipsychotic medication at end point was significantly lower in the prolonged group with renal dysfunction than in the early improvement group with renal dysfunction. The results suggest that maintaining a sufficient dose of antipsychotics from an early stage may prevent prolongation of delirium even in inpatients with renal dysfunction.