In Reply: White Blood Cell Count Improves Prediction of Delayed Cerebral Ischemia Following Aneurysmal Subarachnoid Hemorrhage
To the Editor:
We are thankful to the authors1 for their excitement and questions regarding our study on early white blood cell (WBC) count elevations and delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (aSAH).2 Our objective in evaluating the association of early WBC count on DCI was to facilitate triaging and intensive care unit (ICU) care planning for aSAH patients. Therefore, it was crucial to statistically account for factors that occur in the first 72 h that may be associated with early WBC count elevations, such as clinical grade, thick SAH blood, and surgical clipping of the aneurysm. As reported, even after controlling for these factors patients with elevated WBC count were more likely to experience DCI. Early elevated WBC count is most likely an indicator of a strong inflammatory response to the ictal event that may later develop into systemic inflammatory response syndrome and DCI. Our intention was to also suggest that good-grade patients who have an uncomplicated clinical course and remain in intensive care primarily for DCI surveillance may be safe to downgrade care intensity if their WBC count was not elevated in the first 72 h. As it was pointed out in the letter to the editor, some good-grade patients do have complicated courses that include significant pneumonia and pulmonary edema; however, these patients are not typically candidates for early ICU discharge. Secondary complications like pneumonia could develop in high-functioning patients after early discharged from the ICU, but it is unlikely to evade detection even with reduced care intensity and may not require ICU readmission to treat. In practice the biggest risk of early ICU discharge for uncomplicated high-functioning aSAH patients is later undetected DCI that leads to cerebral infarction. Our data suggest that this risk is significantly less for patients who do not have early elevations in WBC count. Prospective studies that evaluate the cost savings of early downgrading of care intensity against the proportion of good-grade uncomplicated patients that go on to develop DCI, and other secondary complications, are still needed.
The authors have no personal, financial, or institutional interest in any of the drugs, materials, or devices described in this article.
1. He Q, Yu Z, You C. Letter: white blood cell count improves prediction of delayed cerebral ischemia following aneurysmal subarachnoid hemorrhage. Neurosurgery. 2020;87(3):E417.
Copyright © 2020 by the Congress of Neurological Surgeons
2. Al-Mufti F, Misiolek KA, Roh D, et al. White blood cell count improves prediction of delayed cerebral ischemia following aneurysmal subarachnoid hemorrhage. Neurosurgery. 2019;84(2):397-403.