Neuropsychological follow-up of isoflurane sedated intensive care patients: a substudy of a randomized trial.

Abstract

Inhaled sedation of intensive care unit (ICU) patients ventilated >24 hours may have long term effects. We hypothesized that isoflurane has a better neuropsychological outcome in a one-year follow-up compared to propofol sedation. All 66 patients included by the coordinating center of the ISOCONDA study (EudraCT#: 2016-004551-67) took part in this substudy (DRKS00020240). A delirium test (CAM-ICU) was performed 24 hours after end of sedation. Sedation-, ventilator-, ICU- and delirium-free days within 30 days were calculated. Patients were sent five questionnaires one, three and twelve months after ICU discharge: ICU-Memory-tool (ICU-MT), Short-Form-36-Health-survey (SF-36), Posttraumatic-Stress-Scale-14 (PTSS-14), WHO-Five-Well-Being-Index (WHO-5) and Hospital-Anxiety-Depression-Scale (HADS). CAM-ICU was positive in 17% of patients, however 68% showed signs of delirium during the ICU stay (no group differences). Mortality was lower after isoflurane (30-days: 1/33 versus 7/33, P=0.024; One-year: 9/33 versus 14/33, P=0.156). Isoflurane led to significantly more sedation- (median [IQR]: 28[25-29] versus 24[21-29], P=0.016), ventilator- (28[24-29] versus 22[4-28], P=0.011), ICU- (23[13-26] versus 11[0-25], P=0.044) and delirium-free days (25[21-29] versus 20[12-28], P=0.031). Return rate of questionnaires was high (87/128). In the ICU-MT, isoflurane patients recalled significantly more factual memories after one year. Generally, the psychological tests suggested a poor quality of life (SF-36), high rates of post-traumatic-stress-disorder (PTSS-14: 38%) and depression (WHO-5: 54%, HADS: 43%), without significant group differences. Isoflurane sedation leads to more delirium free days during the ICU treatment and more factual memories of the ICU stay one year after the ICU stay. However long-term outcome of ventilated ICU patients is poor, and there were no differences between isoflurane and propofol sedation.