title: Does near-infrared spectroscopy provide an early warning of low haematocrit following the initiation of hypothermic cardiopulmonary bypass in cardiac surgery?
abstract: This study investigated 151 patients undergoing cardiac surgery to determine whether measurement of regional cerebral oxygen saturation (rS(c)O(2)) using near-infrared spectroscopy (NIRS) can indicate a low haematocrit after initiation of hypothermic cardiopulmonary  bypass (CPB). Haematocrit, rS(c)O(2), haemoglobin level, arterial partial pressures of carbon dioxide and oxygen, systemic blood pressure, and nasopharyngeal and rectal temperatures were determined 5 min after the initial administration of heparin for CPB and 90 s  after completion of the first cardioplegic solution injection. Immediately after initiation of hypothermic CPB, rS(c)O(2), haemoglobin and haematocrit values were significantly lower than those before CPB. No significant correlations were found between the change in  haematocrit and changes in left, right and mean rS(c)O(2); thus, changes in rS(c)O(2) before and after initiation of hypothermic CPB did not reflect changes in haematocrit values. This indicates that NIRS cannot provide early warning of a low  haematocrit immediately after initiation of hypothermic CPB in cardiac surgery.
authors: Department of Anaesthesiology and Pain Medicine, Konyang University Hospital, Daejeon, Republic of Korea.
authors: T Y
authors: TY
authors: Sung
authors: W S
authors: WS
authors: Kang
authors: S J
authors: SJ
authors: Han
authors: J S
authors: JS
authors: Kim
authors: H K
authors: HK
authors: Chee
authors: J K
authors: JK
authors: Shin
authors: S H
authors: SH
authors: Kim
mesh_terms: D001794:Blood Pressure; D001831:Body Temperature; D006348:Cardiac Surgical Procedures; D002315:Cardiopulmonary Bypass; D005260:Female; D005500:Follow-Up Studies; D006400:Hematocrit; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D007035:Hypothermia; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D010092:Oximetry; D010100:Oxygen / Q000097:blood; D011379:Prognosis; D012307:Risk Factors; D019265:Spectroscopy, Near-Infrared
chemical_list: D006454:Hemoglobins; D010100:Oxygen