Elevated hemoglobin is associated with poor prognosis in Tibetans with poor-grade aneurysmal subarachnoid hemorrhage after clipping: A Retrospective Case-Control Study

Abstract

ObjectivesHigh hemoglobin (HGB) concentration is frequently seen in Tibetans in clinical practice; however, the impact on postsurgical prognosis in patients with poor-grade aneurysmal subarachnoid hemorrhage (aSAH) is not precisely known. Thus, we sought to understand the association between high HGB level and postoperative outcome in Tibetans with poor-grade aSAH. Patients and methodsResults of clipping in consecutive Tibetan patients with poor-grade aSAH were analyzed retrospectively for the period January 2012 to January 2017. Based on the upper limit (160g/L) of normal hemoglobin levels, patients were divided to a high (HHC) and a normal (NHC) HGB-level cohort according to the first routine blood result on admission. Propensity score matching was used for baseline matching in the 2 cohorts. Postoperative complications in the 2 groups were compared. Prognosis after ictus, including 6-month neurological functional status and mortality at 30 days and 6 months were also assessed. ResultsRisk of ischemia, pulmonary embolism and lower-limb deep venous thrombosis (DVT) was higher in HHC than NHC (62.88% vs. 21.64%; P<0.001; 10.30% vs. 1.31%, P<0.005; 24.74% vs. 7.21%, P<0.001, respectively). Hospital stay also differed significantly (15.82±3.86 vs. 10.37±4.80 days; P<0.001). Out of the 194 patients, 150 survived at 6 months. At 6-month neurological functional follow-up, 8 NHC patients had favorable modified Rankin scale (mRS) scores ≤2 at discharge, versus only 1 HHC patient, showing better outcome in NHC than HHC (8.25% vs. 1.03%; P=0.035). In-hospital mortality was significantly greater in HHC than NHC (17.52% vs. 7.22%; P=0.029). 30-day post-ictus mortality was 30.93% in HHC versus 14.43% in NHC (P<0.006). There was also a significant difference in mortality at 6 months post-ictus (47.42% vs. 18.56%; P<0.001). ConclusionHigh HGB level was associated with increased risk of postsurgical cerebral ischemia, pulmonary embolism and lower-limb DVT and poor prognosis in poor-grade aSAH patients. Preoperative hemodilution therapy might be beneficial in reducing operative complications, reducing hospital stay and improving short-term prognosis for neurological functional recovery in aSAH patients with high HGB concentration, but further detailed research is needed.