Description of an Association Between Leukocytosis and Clinical Outcomes in Large Hemispheric Infarctions.

Background: Large hemispheric infarctions (LHI) are associated with significant morbidity and mortality. Leukocytosis has been observed to directly correlate with stroke severity but has not been specifically described in the LHI population. We hypothesized that patients with LHI and leukocytosis on admission have worse clinical outcomes.

Methods: Retrospective study of patients admitted to the neurosciences intensive care unit at a tertiary care center with the diagnosis of acute ischemic stroke from Jan 2012 to Dec 2018. Inclusion criteria included admission imaging with stroke size greater than two-thirds of the middle cerebral artery territory, with or without other vascular territory involvement. Patients were excluded if antibiotics were started on admission for presumed infection. White blood cell count was recorded at admission, along with Modified Rankin Scale on admission and discharge, need for mechanical ventilation, tracheostomy, and discharge disposition. Logistic regression was used for association measures.

Results: Of the 2,318 patients that were screened, 360 met inclusion criteria. Mean age was 64, median was 63; 51.7% were female. Mean and median NIHSS were 21. Leukocytosis on admission was seen in 139 patients (38.6%), and it was associated with need for mechanical ventilation (p<0.0001, OR 2.54, [1.64-3.95]) and mortality during hospitalization (p<0.0003, OR 2.66, [1.56-4.55]). Results persisted after correction for age and sex in a logistic regression model.

Conclusions: Leukocytosis on admission in patients with LHI significantly correlated with mortality and need for mechanical ventilation. There was a trend towards association with poor outcome at discharge, although not statistically significant. Further research may identify how leukocytosis and other SIRS markers may be used to prognosticate outcomes in this challenging patient population.