Lactic Acidosis after Cardiac Surgery Is Associated with Adverse Outcome
DOI:
https://doi.org/10.1532/HSF98.20041002Abstract
Background: The accurate identification of patients who have the potential to further deteriorate after cardiac surgery is difficult. Elevated serum lactate level after cardiac surgery is an indicator of systemic hypoperfusion and tissue hypoxia. The aim of this study was to investigate the effect of increased serum lactate on outcome after on-pump coronary artery bypass grafting.
Methods: Serum lactate level was measured in 776 patients within half an hour after surgery. Lactate level was less than or equal to 2 mmol/L in 534 patients (low lactate group) and more than 2 mmol/L in 242 patients (high lactate group). Continuous variables were analyzed with the Student t test. The ?2 test and Fisher exact test were used to compare categorical variables.
Results: Demographic characteristics and details of surgery were similar in both groups. Increased cross-clamp and cardiopulmonary bypass times and highly positive fluid balance at the end of surgery were associated with a significant rise in postoperative lactate levels, which leads to increased need for intraaortic balloon pump support (odds ration [OR], 5.9, P = .006), increased likelihood of >24 h intensive care unit stay (OR, 3.4, P = .0001), greater need for red blood cell transfusion (OR, 1.6, P = .002), increased length of hospital stay, and higher mortality rates (OR, 5.6, P = .04).
Conclusions: This study has demonstrated that elevated blood lactate level is associated with adverse outcome, and monitoring the blood lactate level during and after cardiac surgery is a valuable tool in identifying the patients who have the potential to deteriorate.
References
Ariza M, Gothard JWW, Macnaughton P. 1991. Blood lactate and mixed venous-arterial pCO2 gradient as indices of poor peripheral perfusion following cardiopulmonary bypass surgery. Intensive Care Med 17:320-4.nBakker J, Coffernils M, Leon M, Gris P, Vincent JL. 1991. Blood lactate levels are superior to oxygen-derived variables in predicting outcome in human septic shock. Chest 99:956-62.nBernardin G, Pradier C, Tiger F, Deloffre P, Mattei M. 1996. Blood pressure and arterial lactate level are early indicators of short-term survival in human septic shock. Intensive Care Med 22:17-25.nBitek V, Cowley RA. 1971. Blood lactate in prognosis of various forms of shock. Ann Surg 173:308-13.nBroder G, Weil MH. 1964. Excess lactate: an index of reversibility of shock in human patients. Science 143:1457-9.nClowes GH, Neville MW, Sahaga G, Shibota Y. 1958. The relationship of oxygen consumption, perfusion rate and temperature to the acidosis associated with cardiopulmonary circulatory bypass. Surgery 44:220-39.nDavis JW. 1994. The relationship of base deficit to lactate in porcine hemorrhagic shock and resuscitation. J Trauma 36:168-72.nDoglio GR, Pusajo JF, Egurrola MA, et al. 1991. Gastric mucosal pH as a prognostic index of mortality in critically ill patients. Crit Care Med 19:1037-40.nFiaccadori E, Vezzani A, Coffrini E, et al. 1989. Cell metabolism in patients undergoing major valvular heart surgery: relationship with intraand postoperative hemodynamics, oxygen transport and oxygen utilization patterns. Crit Care Med 17:1286-92.nFriedman G, Berlot G, Kahn RJ, Vincent JL. 1995. Combined measurement of blood lactate concentrations and gastric intramucosal pH in patients with severe sepsis. Crit Care Med 23:1184-93.nHarris EA, Seelye ER, Barratt-Botes BG. 1970. Respiratory and metabolic acid-base changes during cardiopulmonary bypass in man. Br J Anaesth 42:912-21.nHiggins TL, Estafanous FG, Loop FD, et al. 1997. ICU admission score for predicting morbidity and mortality risk after coronary artery bypass grafting. Ann Thorac Surg 64:1050-8.nJoynt G, Lipman J, Gomersall C, Tan I, Scribante J. 1997. Gastric intramucosal pH and blood lactate in severe sepsis. Anaesthesia 52:726-32.nKirklin JK, Blackstone EH, Kirklin JW. 1981. Intracardiac surgery in infants under age 3 months: incremental risk factors for hospital mortality. Am J Cardiol 48:500-6.nKirklin JK, Westaby S, Blackstone EH. 1983. Complement and the damaging effects of cardiopulmonary bypass. J Thorac Cardiovasc Surg 86:845-57.nKnaus WA, Zimmerman JE, Wagner DP, Draper EA, Lawrence DE. 1981. APACHE-acute physiology and chronic health evaluation: a physiologically based classification system. Crit Care Med 9:591-7.nLandow L, Phillips DA, Heard SO, Prevost D, Vandersalm TJ, Fink MP. 1991. Gastric tonometry and venous oximetry in cardiac surgery patients. Crit Care Med 19:1226-33.nLitwin MS, Panico FG, Rubini C. 1959. Acidosis and lactic acidemia in extracorporeal circulation: the significance of perfusion flow rate and the relation to preperfusion respiratory alkalosis. Ann Surg 149:188-97.nMaillet JM, Le Besnerais P, Cantoni M, et al. 2003. Frequency, risk factors, and outcome of hyperlactatemia after cardiac surgery. Chest 123:1361-6.nMarik PE. 1993. Gastric intramucosal pH. A better predictor of multiorgan dysfunction syndrome and death than oxygen-derived variables in patients with sepsis. Chest 104:225-9.nMcGiffin DC, Kirklin JK. 1994. Cardiopulmonary bypass, deep hypothermia and total circulatory arrest. In: Maroudis EC, Backer CL, editors. Pediatric cardiac surgery. St. Louis: Mosby. p 115-29.nMizock BA, Falk JL. 1992. Lactic acidosis in critical illness. Crit Care Med 20:80-93.nParker MM, Shelhamer JH, Natanson C, Alling DW, Parrillo JE. 1987. Serial cardiovascular variables in survivors and nonsurvivors of human septic shock: heart rate as an early predictor of prognosis. Crit Care Med 15:923-9.nSchiavello R, Cavalire F, Sollazzi L. 1984. Changes of serum pyruvate and lactate in open-heart surgery. Resuscitation 11:35-45.nSeghaye MC, Duchateau J, Grabitz RG. 1993. Complement activation during cardiopulmonary bypass in infants and children. J Thorac Cardiovasc Surg 106:978-87.nShepard RB, Kirklin JW. 1969. Relationship of pulsatile flow to oxygen consumption and other variables during cardiopulmonary bypass. J Thorac Cardiovasc Surg 58:694-2.nSiegel LB, Dalton HJ, Hertzog JH, Hopkins RA, Hannan RL, Hauser GJ. 1996. Initial postoperative serum lactate levels predict survival in children after open heart surgery. Intensive Care Med 22:1418-23.nWaxman K, Lorene S, Nolan RN, Shoemaker W. 1982. Sequential perioperative lactate determination: physiological and clinical implications. Crit Care Med 10:96-9.nWeil MH, Afifi AA. 1970. Experimental and clinical studies on circulatory failure. Circulation 41:989-1001.n
