Neurocognitive Function in Patients Undergoing Coronary Artery Bypass Graft Surgery With Cardiopulmonary Bypass: The Effect of Two Different Rewarming Strategies

Published:September 25, 2008DOI:


      Hypothermia followed by rewarming during cardiopulmonary bypass can lead to cerebral hyperthermia, which has been implicated as 1 of the causes for postoperative deterioration in neurocognitive function in patients undergoing coronary revascularization. Hence, the authors studied the effects of 2 different rewarming strategies on postoperative neurocognitive function in adult patients undergoing coronary artery bypass graft surgery with the aid of cardiopulmonary bypass.


      This was a randomized clinical trial.


      A cardiothoracic center of a tertiary level referral, teaching hospital.


      A total of 80 adult patients aged 45 to 70 years undergoing elective primary isolated coronary artery bypass graft surgery with cardiopulmonary bypass under moderate hypothermia at 30°C were included in this study.


      The patients were randomly allocated into 2 groups of 40 each. In group A, patients were rewarmed to a nasopharyngeal temperature of 37°C; whereas, in group B, patients were rewarmed to a nasopharyngeal temperature of 33°C before weaning off bypass. The anesthetic and bypass management were standardized for both groups.


      All patients were assessed for neurocognitive function preoperatively and on the fifth postoperative day using the Post Graduate Institute Memory Scale. The amount of blood loss and need for blood and blood product transfusion postoperatively, the need for pacing, increased inotrope or vasodilator use, and time to extubation were also noted. Serum S100β levels were measured after anesthetic induction and at 24 hours postoperatively. The jugular venous oxygen saturation and oxygen tension were noted at 30°C and at the end of full rewarming (ie, at 37°C or 33°C, respectively, in the 2 groups).


      There was a significant deterioration in neurocognitive function postoperatively as compared with preoperative function in patients of group A (37°C). This was associated with higher S100β levels 24 hours postoperatively in group A (37°C) compared with group B (33°C) patients. Also, there was a significant decrease in jugular venous oxygen saturation in group A (37°C) as compared with group B (33°C) at the end of rewarming. The time to extubation was longer in group B (33°C). No significant differences were noted in the amount of postoperative blood loss, blood and blood product use, inotrope or vasodilator use, and the need for pacing.


      Weaning from CPB at 33°C may be a simple and useful strategy to lower the postoperative impairment of neurocognitive function and may be used as a tool to decrease morbidity after coronary revascularization.

      Key Words

      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to Journal of Cardiothoracic and Vascular Anesthesia
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Grocott H.P.
        • Mackensen G.B.
        • Grigore A.M.
        • et al.
        Postoperative hyperthermia is associated with cognitive dysfunction after coronary artery bypass graft surgery.
        Stroke. 2002; 33: 537-541
        • Mclean R.F.
        • Wong M.D.
        • Naylor C.D.
        • et al.
        Cardiopulmonary bypass, temperature and central nervous system dysfunction.
        Circulation. 1994; 90 (II-250-II-55)
        • Croughwell N.D.
        • Frasco P.
        • Blumenthal J.A.
        • et al.
        Warming during cardiopulmonary bypass is associated with jugular bulb desaturation.
        Ann Thorac Surg. 1992; 53: 827-832
        • Nakajima T.
        • Kuro M.
        • Hayashi Y.
        • et al.
        Clinical evaluation of cerebral oxygen balance during cardiopulmonary bypass: Online continuous monitoring of jugular venous oxygen saturation.
        Anesth Analg. 1992; 74: 630-635
        • Westaby S.
        • Andrew J.P.
        • Blomquist S.
        • et al.
        Serum s100β protein: A potential marker for cerebral events during CPB.
        Ann Thorac Surg. 1996; 6: 88-92
        • Fletcher J.M.
        • Levin H.S.
        • Satz P.
        Neuropsychological and intellectual assessment in children.
        in: Kaplan H.I. Sadock B.I. Comprehensive Textbook of Psychiatry. (ed 5). Williams and Wilkins, Baltimore, MD1989: 513-525
        • Kohli A.
        • Manreet K.
        • Manju M.
        • et al.
        Neuropsychological functioning in specific learning disorders—Reading, writing and mixed groups.
        J Indian Assoc Child Adolesc Ment Health. 2006; 2: 112-115
        • Clark J.A.
        • Bar-Yosef S.
        • Anderson A.
        • et al.
        Postoperative hyperthermia following off-pump versus on-pump coronary artery bypass surgery.
        J Cardiothorac Vasc Anesth. 2005; 19: 426-429
        • Cook D.J.
        • Orszulak T.A.
        • Daly R.C.
        • et al.
        Cerebral hyperthermia during cardiopulmonary bypass in adults.
        J Thorac Cardiovasc Surg. 1996; 111: 268-269
        • Stone J.G.
        • Young W.L.
        • Smith C.R.
        • et al.
        Do standard monitoring sites reflect the true brain temperature when profound hypothermia is rapidly induced and reversed?.
        Anesthesiology. 1995; 82: 344-351
        • Arrowsmith J.E.
        • Grocott H.P.
        • Reves J.G.
        • et al.
        Central nervous system complications of cardiac surgery.
        Br J Anaesth. 2000; 84: 378-393
        • Cheng W.P.
        • Marino M.R.
        • Romanogli A.
        • et al.
        Temperature measurement during CPB.
        Anesthesiology. 2000; 93: A384
        • Nussmeier N.A.
        • Li S.
        • Strickler A.G.
        • et al.
        Temperature measurement during CPB.
        Anesth Analg. 2002; 93: SCA35
        • Grocott H.P.
        • Newman M.F.
        • Croughwell N.A.
        • et al.
        Continuous jugular venous versus nasopharyngeal temperature monitoring during hypothermic CPB for cardiac surgery.
        J Clin Anesth. 1997; 9: 312-316
        • Busto R.
        • Dietrich W.
        • Globus M.T.
        • et al.
        The importance of brain temperature in cerebral ischemic injury.
        Stroke. 1989; 20: 1113-1114
        • Dietrich W.D.
        • Busto R.
        • Valdes I.
        • et al.
        Effect of normothermic vs mild hypothermic forebrain ischemia in rats.
        Stroke. 1990; 21: 1318-1325
        • Reith J.
        • Jorgensen H.
        • Pedersen P.
        • et al.
        Body temperature in acute stroke: Relation to stroke severity, infarct size, mortality and outcome.
        Lancet. 1996; 347: 422-425
        • Sternau L.
        • Globus M.T.
        • Dietrich W.
        Ischemia-induced neurotransmitter release: effects of mild intraischemic hyperthermia.
        in: Globus M.T. Dietrich W. The Role of Neurotransmitter in Brain Injury. Plenum Press, New York, NY1992: 33-38
        • Globus M.
        • Busto R.
        • Lin B.
        • et al.
        Detection of free radical activity during transient global ischemia and recirculation: Effects of intraischemic brain temperature modulation.
        J Neurochem. 1995; 65: 1250-1256
        • Dietrich W.
        • Halley M.
        • Valdes I.
        • et al.
        Interrelationship between increased vascular permeability and acute neuronal damage following temperature-controlled brain ischemia in rats.
        Acta Neuropathol. 1991; 81: 615-625
        • Chopp M.
        • Welch K.M.
        • Tidwell C.D.
        • et al.
        Effect of mild hyperthermia on recovery of metabolic function after global cerebral ischemia in rats.
        Stroke. 1998; 19: 1521-1525
        • Grigore A.M.
        • Grocott H.P.
        • Mathew J.P.
        • et al.
        The rewarming rate and increased peak temperature alter neurocognitive outcome after cardiac surgery.
        Anesth Analg. 2002; 94: 4-10
        • Mora C.T.
        • Henson M.B.
        • Weintraub W.S.
        • et al.
        Effect of temperature management during cardiopulmonary bypass on neurologic and neuropsychological outcome in patients undergoing coronary revascularisation.
        J Thorac Cardiovasc Surg. 1996; 112: 514-522
        • Nathan J.H.
        • Wells G.A.
        • Munson J.L.
        • et al.
        Neuroprotective effects of mild hypothermia in patients undergoing coronary artery surgery with cardiopulmonary bypass.
        Circulation. 2001; 104: I-85-I-91
        • Nathan H.J.
        • Rodriguez R.
        • Wozny D.
        • et al.
        Neuroprotective effect of mild hypothermia in patients undergoing coronary artery surgery with cardiopulmonary bypass: Five-year follow-up of a randomized trial.
        J Thorac Cardiovasc Surg. 2007; 133: 1206-1211
        • Boodhwani M.
        • Rubens F.
        • Wozny D.
        • et al.
        Effects of sustained mild hypothermia on neurocognitive function after coronary artery bypass surgery: A randomized, double- blind study.
        J Thorac Cardiovasc Surg. 2007; 134: 1443-1452
        • Plourde G.
        • Leduc A.S.
        • Morin J.E.
        • et al.
        Temperature during cardiopulmonary bypass for coronary artery operations does not influence postoperative cognitive function: A prospective, randomized trial.
        J Thorac Cardiovasc Surg. 1997; 114: 123-128
        • Engelman R.M.
        • Pleet A.B.
        • Rousou J.A.
        • et al.
        Influence of cardiopulmonary bypass perfusion temperature on neurologic and hematologic function after coronary artery bypass grafting.
        Ann Thorac Surg. 1999; 67: 1547-1556
        • Chen C.S.
        • Len B.K.
        • Liu K.
        Detection of cerebral desaturation during CPB by cerebral oximetry.
        Acta Anaesthesiol Sin. 1996; 34: 173-178
        • Van Knobelsdorff G.
        • Tonner P.H.
        • Havel F.
        • et al.
        Prolonged rewarming after hypothermic cardiopulmonary bypass does not attenuate reduction of jugular bulb oxygen saturation.
        J Cardiothorac Vasc Anesth. 1997; 11: 689-693
        • Von Knobelsdorff G.
        • Hanel F.
        • Werner C.
        • et al.
        Jugular bulb oxygen saturation and middle cerebral blood flow velocity during cardiopulmonary bypass.
        J Neurosurg Anesthesiol. 1997; 9: 128-133
        • Van der Linden J.
        • Ekroth R.
        • Linole C.
        • et al.
        Is cerebral blood flow metabolic mismatch during rewarming a risk factor after profound hypothermic procedure in small children?.
        Eur J Cardiothorac Surg. 1989; 3: 209-215
        • Croughwell N.
        • Smith L.R.
        • Quill T.
        • et al.
        The effect of temperature on cerebral metabolism and blood flow in adults during cardiopulmonary bypass.
        J Thorac Cardiovasc Surg. 1992; 103: 549-554
        • Croughwell N.D.
        • Newman M.F.
        • Blumenthal J.A.
        • et al.
        Jugular bulb saturation and cognitive dysfunction after cardiopulmonary bypass.
        Ann Thorac Surg. 1994; 58: 1702-1708
        • Jonsson H.
        • Blomquist S.
        • Westaby S.
        • et al.
        Significance of serum s100β release after coronary artery bypass grafting.
        Ann Thorac Surg. 1998; 65: 1639-1644
        • Shaaban M.A.
        • Harmer M.
        • Vaughan R.
        Serum s100 protein as a marker of cerebral damage during cardiac surgery.
        Br J Anaesth. 2000; 85: 287-298
        • Fazio V.
        • Bhudia S.K.
        • Maricha N.
        • et al.
        Peripheral detection of s100β during cardiothoracic surgery: What are we really measuring?.
        Ann Thorac Surg. 2004; 78: 46-53

      Linked Article

      • Temperature Management During Cardiopulmonary Bypass
        Journal of Cardiothoracic and Vascular AnesthesiaVol. 24Issue 2
        • Preview
          The recent article by Sahu et al1 assessed 2 temperature management strategies and neurocognitive function in 80 adult coronary artery bypass patients undergoing moderately hypothermic (30°C) cardiopulmonary bypass (CPB). Forty patients in 1 group were rewarmed to a nasopharyngeal (NP) temperature of 37°C before weaning from CPB, and 40 in a second group were rewarmed to 33°C. The authors hypothesized that the risk of cerebral hyperthermia would be reduced or avoided in patients in the second group weaned from CPB at the lower target NP temperature.
        • Full-Text
        • PDF
      • Assessment of Neurocognitive Function and Neuroprotective Strategies in Cardiac Surgery
        Journal of Cardiothoracic and Vascular AnesthesiaVol. 24Issue 3
        • Preview
          We read with interest the article published by Sahu et al1 in which the authors report the findings of 2 different rewarming strategies in patients undergoing coronary artery bypass graft (CABG) surgery with cardiopulmonary bypass (CPB). The authors conclude that weaning from CPB at a nasopharyngeal temperature of 33°C (v 37°C) followed by passive rewarming in the intensive care unit (ICU) may be a useful strategy to lower postoperative neurocognitive dysfunction and to decrease morbidity.
        • Full-Text
        • PDF