Prevalence and independent predictors of in-hospital stroke among patients who developed acute alteration of consciousness in the medical intensive care unit: A retrospective case-control study.

Background: In-hospital stroke is a serious event, associated with poor outcomes and high mortality. However, identifying signs of stroke may be more difficult in critically ill patients.

Objectives: This study investigated the prevalence and independent predictors of in-hospital stroke among patients with acute alteration of consciousness in the medical intensive care unit (MICU) who underwent subsequent brain computed tomography (CT).

Methods: This retrospective study enrolled eligible patients during the period 2007 - 2017. The alterations researched were radiologically confirmed acute ischaemic stroke (AIS) and intracerebral haemorrhage (ICH).

Results: Of 4 360 patients, 113 underwent brain CT. Among these, 31% had AIS, while 15% had ICH. They had higher diastolic blood pressures and arterial pH than non-stroke patients. ICH patients had higher mean (standard deviation (SD) systolic blood pressures (152 (48) v. 129 (25) mmHg; p=0.01), lower mean (SD) Glasgow Coma Scale scores (4 (3) v. 7 (4); p=0.004), and more pupillary abnormalities (75% v. 9%; p<0.001) than AIS patients. AIS patients were older (65 (18) v. 57 (18) years; p=0.03), had more hypertension (60% v. 39%; p=0.04), and more commonly presented with the Babinski sign (26% v. 9%; p=0.04). Multivariate analysis found that pupillary abnormalities independently predicted ICH (adjusted odds ratio (aOR) 26.9; 95% CI 3.7 - 196.3; p=0.001). The Babinski sign (aOR 5.1; 95% CI 1.1 - 23.5; p=0.04) and alkalaemia (arterial pH >7.4; aOR 3.6; 95% CI 1.0 - 12.3; p=0.05) independently predicted AIS.

Conclusion: Forty-six percent of the cohort had ICH or AIS. Both conditions had high mortality. The presence of pupillary abnormalities predicts ICH, whereas the Babinski sign and alkalaemia predict AIS.

Contributions of the study: The present study reports that almost half (46%) of critically ill patients with alterations of consciousness had an acute stroke. Of these, two-thirds had an acute ischaemic stroke (AIS), and one-third had an intracranial haemorrhage (ICH). Multivariate analysis revealed that a pupillary abnormality was a predictor for ICH and the Babinski sign was identified as a predictor of AIS.