Of course, this kind of result requires investigation into the default hypothesis: ICU delirium is a symptom of a kind of brain failure, sedative use, etc., and that very brain failure, sedative use, etc., is responsible also for the subsequent cognitive impairment. That is, ICU delirium and post-ICU cognitive impairment selleckchem have a common cause, the precise nature of which has yet to be discovered.The heretical alternative hypothesis I want to put forward is that rather than the delirium and the impairment having a common cause, the experience of delirium might in some instances be responsible for the low neuropsychological test scores seen in post-ICU patients. Notice that both of the hypotheses could well be true, as long as they are not taken to be universal generalizations; in some instances there may be a common cause and in some instances delirium may be a confounding factor in testing for cognitive impairment.

The argument for the heretical hypothesis is as follows.Depression and anxiety are known to exacerbate the findings of neurological impairment [17]. Indeed, studies of cognitive impairment screen for patients with these identifiable prior psychological problems [18]. However, surely it is not only pre-existing psychological problems that are potentially confounding factors. We need also to consider psychological and emotional problems that have come into existence during and after ICU admission. My suggestion is that, at least sometimes, what one may be seeing when one sees cognitive dysfunction in patients discharged from the ICU may in part be a lingering effect of devastating ICU delirium and the struggle to cope with it.

This thought gets some support from Rothenhausler and coworkers [18], who found their ‘most interesting result’ to be that post-ARDS cognitive impairments involve attention deficits and that other research suggests that this kind of impairment ‘may be related to “psychological distress” or emotional problems.’ That is, patients who become depressed or otherwise distressed in the ICU can display the very kind of cognitive impairment most associated with ARDS, and distressed and depressed ex-ICU patients are thick on the ground. Kapfhammer and colleagues [11] found ‘long-lasting emotional sequelae for most patients’ after ARDS and ‘pronounced impairments in psychosocial dimensions of health-related quality of life’.

At 8 years, almost 24% were still suffering from ‘full-blown PTSD [post-traumatic stress disorder]‘ and 17% from ‘sub-PTSD’. Hopkins and coworkers [19] found 23% of patients to have moderate to severe symptoms of depression and anxiety 2 years after discharge.In my own case I had a whiff of this, and that was bad enough. For a long time after my release, every time I saw or heard an ambulance GSK-3 I was hit by a sinking feeling and by the thought that there would now be all that effort to save one measly life.