Official reprint from UpToDate®
www.uptodate.com ©2017 UpToDate®

Weaning from cardiopulmonary bypass (CPB)

Michael G Fitzsimons, MD
Section Editor
Jonathan B Mark, MD
Deputy Editor
Nancy A Nussmeier, MD, FAHA


Cardiopulmonary bypass (CPB) is a form of extracorporeal circulation in which the patient's blood is diverted from the heart and lungs and rerouted outside of the body. The normal physiological functions of the heart and lungs, including circulation of blood, oxygenation, and ventilation, are temporarily assumed by surrogate technology. This allows a surgeon to operate on a non-beating heart in a field largely devoid of blood while maintaining complete control of tissue oxygenation and perfusion.

This topic will discuss the general principles and physiology of CPB, preparations for weaning from CPB, the process of weaning, problems that may be encountered during and after the weaning process, and management of failure to wean.


Components of the cardiopulmonary bypass (CPB) machine include pumps, tubing, artificial organs, and monitoring systems (figure 1A). Modern CPB circuits are also equipped with several safety features, including continuous vascular pressure monitoring; blood gas, hemoglobin, and electrolyte monitoring; air detection systems; and blood filters.

Physiology — During CPB, venous blood is intercepted as it returns to the right atrium and is diverted through the venous line of the CPB circuit to a venous reservoir (figure 1A-B). The arterial pump functions as an artificial heart by withdrawing blood from this reservoir and propelling it through an artificial lung (oxygenator or gas exchanger), a heat exchanger, and finally an arterial line filter. The blood then returns to the patient's arterial system through an arterial line positioned in the ascending aorta or other major artery. Additional CPB circuit components and pumps are employed as needed to remove fluid (hemoconcentration), suction blood from the surgical field, deliver cardioplegia solution to produce cardiac electromechanical silence, and decompress the heart (venting). The functions of the heart, lungs, and, to a lesser extent, the kidneys are temporarily replaced.

CPB is associated with an intense inflammatory response that is primarily induced by contact of blood with non-endothelial extracorporeal surfaces [1]. This results in platelet activation, initiation of the coagulation cascade, and decreased levels of coagulation factors. Endothelial cells and leukocytes are activated, releasing more mediators and resulting in capillary leakage and tissue edema. Many of the challenges encountered during weaning from CPB and the postbypass period (eg, myocardial dysfunction, vasodilation, and bleeding) are thought to be consequences of this inflammatory sequence [2-4].


Subscribers log in here

To continue reading this article, you must log in with your personal, hospital, or group practice subscription. For more information or to purchase a personal subscription, click below on the option that best describes you:
Literature review current through: Jan 2017. | This topic last updated: Tue Nov 29 00:00:00 GMT+00:00 2016.
The content on the UpToDate website is not intended nor recommended as a substitute for medical advice, diagnosis, or treatment. Always seek the advice of your own physician or other qualified health care professional regarding any medical questions or conditions. The use of this website is governed by the UpToDate Terms of Use ©2017 UpToDate, Inc.
  1. Warren OJ, Smith AJ, Alexiou C, et al. The inflammatory response to cardiopulmonary bypass: part 1--mechanisms of pathogenesis. J Cardiothorac Vasc Anesth 2009; 23:223.
  2. Wan S, LeClerc JL, Vincent JL. Inflammatory response to cardiopulmonary bypass: mechanisms involved and possible therapeutic strategies. Chest 1997; 112:676.
  3. Day JR, Taylor KM. The systemic inflammatory response syndrome and cardiopulmonary bypass. Int J Surg 2005; 3:129.
  4. Warren OJ, Watret AL, de Wit KL, et al. The inflammatory response to cardiopulmonary bypass: part 2--anti-inflammatory therapeutic strategies. J Cardiothorac Vasc Anesth 2009; 23:384.
  5. Murphy GS, Hessel EA 2nd, Groom RC. Optimal perfusion during cardiopulmonary bypass: an evidence-based approach. Anesth Analg 2009; 108:1394.
  6. Hogue CW Jr, Palin CA, Arrowsmith JE. Cardiopulmonary bypass management and neurologic outcomes: an evidence-based appraisal of current practices. Anesth Analg 2006; 103:21.
  7. Joshi B, Ono M, Brown C, et al. Predicting the limits of cerebral autoregulation during cardiopulmonary bypass. Anesth Analg 2012; 114:503.
  8. Murkin JM, Martzke JS, Buchan AM, et al. A randomized study of the influence of perfusion technique and pH management strategy in 316 patients undergoing coronary artery bypass surgery. II. Neurologic and cognitive outcomes. J Thorac Cardiovasc Surg 1995; 110:349.
  9. Svenmarker S, Häggmark S, Östman M, et al. Central venous oxygen saturation during cardiopulmonary bypass predicts 3-year survival. Interact Cardiovasc Thorac Surg 2013; 16:21.
  10. Salis S, Mazzanti VV, Merli G, et al. Cardiopulmonary bypass duration is an independent predictor of morbidity and mortality after cardiac surgery. J Cardiothorac Vasc Anesth 2008; 22:814.
  11. Licker M, Diaper J, Cartier V, et al. Clinical review: management of weaning from cardiopulmonary bypass after cardiac surgery. Ann Card Anaesth 2012; 15:206.
  12. Wahr JA, Prager RL, Abernathy JH 3rd, et al. Patient safety in the cardiac operating room: human factors and teamwork: a scientific statement from the American Heart Association. Circulation 2013; 128:1139.
  13. Gawande AA. The Checklist Manifesto: How to Get Things Right, Metropolitan Books, New York, New York 2010.
  14. Grigore AM, Murray CF, Ramakrishna H, Djaiani G. A core review of temperature regimens and neuroprotection during cardiopulmonary bypass: does rewarming rate matter? Anesth Analg 2009; 109:1741.
  15. Engelman R, Baker RA, Likosky DS, et al. The Society of Thoracic Surgeons, The Society of Cardiovascular Anesthesiologists, and The American Society of ExtraCorporeal Technology: Clinical Practice Guidelines for Cardiopulmonary Bypass--Temperature Management During Cardiopulmonary Bypass. J Cardiothorac Vasc Anesth 2015; 29:1104.
  16. Engelman R, Baker RA, Likosky DS, et al. The Society of Thoracic Surgeons, The Society of Cardiovascular Anesthesiologists, and The American Society of ExtraCorporeal Technology: Clinical Practice Guidelines for Cardiopulmonary Bypass--Temperature Management During Cardiopulmonary Bypass. Ann Thorac Surg 2015; 100:748.
  17. Barry AE, Chaney MA, London MJ. Anesthetic management during cardiopulmonary bypass: a systematic review. Anesth Analg 2015; 120:749.
  18. Morris BN, Romanoff ME, Royster RL. The Postcardiopulmonary Bypass Period: Weaning to ICU Transport. In: Cardiac Anesthesia, Hensley FA, Martin DE, Gravlee GP. (Eds), Lippincott Williams & Wilkins, Philadelphia 2013. Vol Fifth, p.238.
  19. Society of Thoracic Surgeons Blood Conservation Guideline Task Force, Ferraris VA, Brown JR, et al. 2011 update to the Society of Thoracic Surgeons and the Society of Cardiovascular Anesthesiologists blood conservation clinical practice guidelines. Ann Thorac Surg 2011; 91:944.
  20. Ogden SR, Culp WC Jr, Villamaria FJ, Ball TR. Developing a Checklist: Consensus Via a Modified Delphi Technique. J Cardiothorac Vasc Anesth 2016; 30:855.
  21. Murphy GJ, Pike K, Rogers CA, et al. Liberal or restrictive transfusion after cardiac surgery. N Engl J Med 2015; 372:997.
  22. Cui WW, Ramsay JG. Pharmacologic approaches to weaning from cardiopulmonary bypass and extracorporeal membrane oxygenation. Best Pract Res Clin Anaesthesiol 2015; 29:257.
  23. Mebazaa A, Pitsis AA, Rudiger A, et al. Clinical review: practical recommendations on the management of perioperative heart failure in cardiac surgery. Crit Care 2010; 14:201.
  24. Gillies M, Bellomo R, Doolan L, Buxton B. Bench-to-bedside review: Inotropic drug therapy after adult cardiac surgery -- a systematic literature review. Crit Care 2005; 9:266.
  25. Parissis JT, Rafouli-Stergiou P, Stasinos V, et al. Inotropes in cardiac patients: update 2011. Curr Opin Crit Care 2010; 16:432.
  26. Nielsen DV, Hansen MK, Johnsen SP, et al. Health outcomes with and without use of inotropic therapy in cardiac surgery: results of a propensity score-matched analysis. Anesthesiology 2014; 120:1098.
  27. Allen LA, Fonarow GC, Grau-Sepulveda MV, et al. Hospital variation in intravenous inotrope use for patients hospitalized with heart failure: insights from Get With The Guidelines. Circ Heart Fail 2014; 7:251.
  28. Williams JB, Hernandez AF, Li S, et al. Postoperative inotrope and vasopressor use following CABG: outcome data from the CAPS-care study. J Card Surg 2011; 26:572.
  29. Nielsen DV, Johnsen SP, Madsen M, Jakobsen CJ. Variation in use of peroperative inotropic support therapy in cardiac surgery: time for reflection? Acta Anaesthesiol Scand 2011; 55:352.
  30. Hernandez AF, Li S, Dokholyan RS, et al. Variation in perioperative vasoactive therapy in cardiovascular surgical care: data from the Society of Thoracic Surgeons. Am Heart J 2009; 158:47.
  31. Vakamudi M. Weaning from cardiopulmonary bypass: problems and remedies. Ann Card Anaesth 2004; 7:178.
  32. Levy JH, Bailey JM, Deeb GM. Intravenous milrinone in cardiac surgery. Ann Thorac Surg 2002; 73:325.
  33. Yamada T, Takeda J, Katori N, et al. Hemodynamic effects of milrinone during weaning from cardiopulmonary bypass: comparison of patients with a low and high prebypass cardiac index. J Cardiothorac Vasc Anesth 2000; 14:367.
  34. Maharaj R, Metaxa V. Levosimendan and mortality after coronary revascularisation: a meta-analysis of randomised controlled trials. Crit Care 2011; 15:R140.
  35. Shahin J, DeVarennes B, Tse CW, et al. The relationship between inotrope exposure, six-hour postoperative physiological variables, hospital mortality and renal dysfunction in patients undergoing cardiac surgery. Crit Care 2011; 15:R162.
  36. Fellahi JL, Parienti JJ, Hanouz JL, et al. Perioperative use of dobutamine in cardiac surgery and adverse cardiac outcome: propensity-adjusted analyses. Anesthesiology 2008; 108:979.
  37. Bernard F, Denault A, Babin D, et al. Diastolic dysfunction is predictive of difficult weaning from cardiopulmonary bypass. Anesth Analg 2001; 92:291.
  38. Buckley MS, Feldman JP. Inhaled epoprostenol for the treatment of pulmonary arterial hypertension in critically ill adults. Pharmacotherapy 2010; 30:728.
  39. Mekontso-Dessap A, Houël R, Soustelle C, et al. Risk factors for post-cardiopulmonary bypass vasoplegia in patients with preserved left ventricular function. Ann Thorac Surg 2001; 71:1428.
  40. Denault AY, Tardif JC, Mazer CD, et al. Difficult and complex separation from cardiopulmonary bypass in high-risk cardiac surgical patients: a multicenter study. J Cardiothorac Vasc Anesth 2012; 26:608.
  41. Baraka A, Kawkabani N, Dabbous A, Nawfal M. Lidocaine for prevention of reperfusion ventricular fibrillation after release of aortic cross-clamping. J Cardiothorac Vasc Anesth 2000; 14:531.
  42. Dias RR, Stolf NA, Dalva M, et al. Inclusion of lidocaine in cardioplegic solutions provides additional myocardial protection. J Cardiovasc Surg (Torino) 2004; 45:551.
  43. Praeger PI, Kay RH, Moggio R, et al. Prevention of ventricular fibrillation after aortic declamping during cardiac surgery. Tex Heart Inst J 1988; 15:98.
  44. Rho RW. The management of atrial fibrillation after cardiac surgery. Heart 2009; 95:422.
  45. Maron MS, Olivotto I, Harrigan C, et al. Mitral valve abnormalities identified by cardiovascular magnetic resonance represent a primary phenotypic expression of hypertrophic cardiomyopathy. Circulation 2011; 124:40.
  46. Karhunen JP, Sihvo EI, Suojaranta-Ylinen RT, et al. Predictive factors of hemodynamic collapse after coronary artery bypass grafting: a case-control study. J Cardiothorac Vasc Anesth 2006; 20:143.
  47. Anthi A, Tzelepis GE, Alivizatos P, et al. Unexpected cardiac arrest after cardiac surgery: incidence, predisposing causes, and outcome of open chest cardiopulmonary resuscitation. Chest 1998; 113:15.
  48. Ecoff SA, Miyahara C, Steward DJ. Severe bronchospasm during cardiopulmonary bypass. Can J Anaesth 1996; 43:1244.
  49. Westhorpe RN, Ludbrook GL, Helps SC. Crisis management during anaesthesia: bronchospasm. Qual Saf Health Care 2005; 14:e7.
  50. Apostolakis E, Filos KS, Koletsis E, Dougenis D. Lung dysfunction following cardiopulmonary bypass. J Card Surg 2010; 25:47.
  51. Hajjar LA, Vincent JL, Galas FR, et al. Transfusion requirements after cardiac surgery: the TRACS randomized controlled trial. JAMA 2010; 304:1559.
  52. Society of Thoracic Surgeons Blood Conservation Guideline Task Force, Ferraris VA, Ferraris SP, et al. Perioperative blood transfusion and blood conservation in cardiac surgery: the Society of Thoracic Surgeons and The Society of Cardiovascular Anesthesiologists clinical practice guideline. Ann Thorac Surg 2007; 83:S27.
  53. Pleym H, Wahba A, Videm V, et al. Increased fibrinolysis and platelet activation in elderly patients undergoing coronary bypass surgery. Anesth Analg 2006; 102:660.
  54. Nuttall GA, Oliver WC, Santrach PJ, et al. Efficacy of a simple intraoperative transfusion algorithm for nonerythrocyte component utilization after cardiopulmonary bypass. Anesthesiology 2001; 94:773.
  55. Avidan MS, Alcock EL, Da Fonseca J, et al. Comparison of structured use of routine laboratory tests or near-patient assessment with clinical judgement in the management of bleeding after cardiac surgery. Br J Anaesth 2004; 92:178.
  56. McCormack PL. Tranexamic acid: a review of its use in the treatment of hyperfibrinolysis. Drugs 2012; 72:585.
  57. Falana O, Patel G. Efficacy and safety of tranexamic acid versus ϵ-aminocaproic acid in cardiovascular surgery. Ann Pharmacother 2014; 48:1563.
  58. Karkouti K, Beattie WS, Arellano R, et al. Comprehensive Canadian review of the off-label use of recombinant activated factor VII in cardiac surgery. Circulation 2008; 118:331.
  59. American Society of Anesthesiologists Task Force on Perioperative Blood Transfusion and Adjuvant Therapies. Practice guidelines for perioperative blood transfusion and adjuvant therapies: an updated report by the American Society of Anesthesiologists Task Force on Perioperative Blood Transfusion and Adjuvant Therapies. Anesthesiology 2006; 105:198.
  60. Opie L. Myocardial stunning: a role for calcium antagonists during reperfusion? Cardiovasc Res 1992; 26:20.
  61. DiNardo JA. Pro: calcium is routinely indicated during separation from cardiopulmonary bypass. J Cardiothorac Vasc Anesth 1997; 11:905.
  62. DeHert SG, Ten Broecke PW, De Mulder PA, et al. Effects of calcium on left ventricular function early after cardiopulmonary bypass. J Cardiothorac Vasc Anesth 1997; 11:864.
  63. Prielipp R, Butterworth J. Con: calcium is not routinely indicated during separation from cardiopulmonary bypass. J Cardiothorac Vasc Anesth 1997; 11:908.
  64. Janelle GM, Urdaneta F, Martin TD, Lobato EB. Effects of calcium chloride on grafted internal mammary artery flow after cardiopulmonary bypass. J Cardiothorac Vasc Anesth 2000; 14:4.
  65. Booth JV, Phillips-Bute B, McCants CB, et al. Low serum magnesium level predicts major adverse cardiac events after coronary artery bypass graft surgery. Am Heart J 2003; 145:1108.
  66. Lazar HL. How important is glycemic control during coronary artery bypass? Adv Surg 2012; 46:219.
  67. NICE-SUGAR Study Investigators, Finfer S, Chittock DR, et al. Intensive versus conventional glucose control in critically ill patients. N Engl J Med 2009; 360:1283.
  68. Gandhi GY, Nuttall GA, Abel MD, et al. Intensive intraoperative insulin therapy versus conventional glucose management during cardiac surgery: a randomized trial. Ann Intern Med 2007; 146:233.
  69. Lazar HL, McDonnell M, Chipkin SR, et al. The Society of Thoracic Surgeons practice guideline series: Blood glucose management during adult cardiac surgery. Ann Thorac Surg 2009; 87:663.
  70. Sessler DI. Complications and treatment of mild hypothermia. Anesthesiology 2001; 95:531.
  71. Adsumelli RS, Shapiro JR, Shah PM, et al. Hemodynamic effects of chest closure in adult patients undergoing cardiac surgery. J Cardiothorac Vasc Anesth 2001; 15:589.
  72. Cohen M, Urban P, Christenson JT, et al. Intra-aortic balloon counterpulsation in US and non-US centres: results of the Benchmark Registry. Eur Heart J 2003; 24:1763.
  73. Pulido JN, Park SJ, Rihal CS. Percutaneous left ventricular assist devices: clinical uses, future applications, and anesthetic considerations. J Cardiothorac Vasc Anesth 2010; 24:478.
  74. Marelli D, Shemin RJ. Post-cardiac surgery mechanical support: a tool for decision making. Circulation 2007; 116:586.
  75. Hernandez AF, Grab JD, Gammie JS, et al. A decade of short-term outcomes in post cardiac surgery ventricular assist device implantation: data from the Society of Thoracic Surgeons' National Cardiac Database. Circulation 2007; 116:606.
  76. Rossiter-Thornton M, Arun V, Forrest AP, et al. Left ventricular support with the Impella LP 5.0 for cardiogenic shock following cardiac surgery. Heart Lung Circ 2008; 17:243.
  77. Griffith BP, Anderson MB, Samuels LE, et al. The RECOVER I: a multicenter prospective study of Impella 5.0/LD for postcardiotomy circulatory support. J Thorac Cardiovasc Surg 2013; 145:548.
  78. Sidebotham D, McGeorge A, McGuinness S, et al. Extracorporeal membrane oxygenation for treating severe cardiac and respiratory failure in adults: part 2-technical considerations. J Cardiothorac Vasc Anesth 2010; 24:164.
  79. Bakhtiary F, Keller H, Dogan S, et al. Venoarterial extracorporeal membrane oxygenation for treatment of cardiogenic shock: clinical experiences in 45 adult patients. J Thorac Cardiovasc Surg 2008; 135:382.
  80. Elsharkawy HA, Li L, Esa WA, et al. Outcome in patients who require venoarterial extracorporeal membrane oxygenation support after cardiac surgery. J Cardiothorac Vasc Anesth 2010; 24:946.
  81. Slottosch I, Liakopoulos O, Kuhn E, et al. Outcomes after peripheral extracorporeal membrane oxygenation therapy for postcardiotomy cardiogenic shock: a single-center experience. J Surg Res 2013; 181:e47.
  82. Platts DG, Sedgwick JF, Burstow DJ, et al. The role of echocardiography in the management of patients supported by extracorporeal membrane oxygenation. J Am Soc Echocardiogr 2012; 25:131.