The relationship between low intraoperative hematocrit levels during cardiopulmonary bypass and postoperative neurological events.

OBJECTIVE The objective of our study is to analyze whether low intraoperative hematocrit levels have an effect upon postoperative neurological events. METHODS Our study included 140 patients who underwent isolated coronary bypass under cardiopulmonary bypass between 2009 and 2012. The main group of the study was 70 patients with intraoperative hematocrit levels lower than 22%. These patients' 30-day postoperative neurological (particularly stroke) follow up was registered as the main data of the study. Another group of 70 patients possessing the same demographic features who underwent open heart surgery with hematocrit levels remaining above 22% were registered as the control group for perioperative neurological data. RESULTS The average age of the patients with hematocrit levels below and above 22% was 56.8 ± 5.8 years and 54.1 ± 7.3 years, respectively. The mean follow-up period of the patients was 37.2 ± 8.6 days. None of the patients had any neurological postoperative sequalae. No mortalities occurred. One patient who had mild paresthesia and motor weakness of the left hand had no pathological finding on computed tomography and was diagnosed with peripheral neuropathy due to intraoperative sternal retraction. CONCLUSION Because our study revealed no cerebrovascular events, coronary bypass surgery under cardiopulmonary bypass may be safely conducted even in patients with hematocrit levels lower than 22%.