Aim: To investigate patients' psychological distress in relation to memory and stressful experiences in the intensive care unit (ICU), and to identify early predictors for the development of high levels of acute post-traumatic stress disorder (PTSD)-related symptoms.
Methods: A prospective cohort study was performed over 18 months in two general ICUs, including 313 intubated mechanically ventilated adults admitted for more than 24 h, 226 of whom completed the study. Patients were interviewed 5 days and 2 months post-ICU concerning their memories and psychological distress. The instruments used were the ICU Memory Tool, ICU Stressful Experience Questionnaire, Hospital Anxiety and Depression Scale and Impact of Event Scale-Revised (IES-R).
Results: High symptom levels of anxiety, depression and acute PTSD 2 months post-ICU were present in 4.9%, 7.5% and 8.4% of the 226 patients, respectively. Psychological distress 2 months post-ICU was associated with experiences of the ICU rated as extremely stressful and with high levels of anxiety and depression 5 days post-ICU, but not with amnesia or delusional memories without factual recall of the ICU. Female sex, signs of agitation (increasing proportion of Motor Activity Assessment Scale scores of 4-6) and feelings of extreme fear during the ICU stay were significantly and independently associated with IES-R scores of 30 or more.
Conclusions: Extremely stressful experiences of the ICU are associated with subsequent psychological distress. Female sex, agitation and extreme fear during the ICU stay seem to increase the risk of developing high levels of acute PTSD-related symptoms.