**Glycemic Control in Cardiac Surgery**

Martín Martínez Rosas1, Eduardo Wilfrido Goicoechea-Turcott2, Pastor Luna Ortiz3, Alberto Salazar4 and Benito Antón Palma4 *1Physiology Department, National Institute of Cardiology "Ignacio Chavez", Mexico, D.F 2Faculty of Medicine, National Autonomous University of Mexico (UNAM), Mexico, D.F 3Pharmacology Department, National Institute of Cardiology "Ignacio Chavez", Mexico, D.F 4Laboratory of Molecular Neurobiology, National Institute of Psychiatry "Ramón de la Fuente", Mexico, D.F Mexico* 

#### **1. Introduction**

246 Perioperative Considerations in Cardiac Surgery

[118] The ADMIRAL Investigators. Montalescot G, Barragan P, Wittenberg O, Ecollan P,

[119] The ISAR-II Investigators. Schömig A, Kastrati A, Dirschinger J, Mehilli J, Schricke U,

[120] The STOP-AMI Investigators. Schömig A, Kastrati A, Dirschinger J, Mehilli J, Schricke

[121] The ERASER Investigators. Acute platelet inhibition with abciximab does not reduce

in-stent restenosis (ERASER study). Circulation 1999;100:799-806

acute myocardial infarction. N Engl J Med 2000;343:385-391

Med 2001;344:1895-1903

391

Elhadad S, Villain P, Boulenc JM, Morice MC, Maillard L, Pansiéri M, Choussat R, Pinton P;. Abciximab before Direct Angioplasty and Stenting in Myocardial Infarction Regarding Acute and Long-Term Follow-up. Platelet glycoprotein IIb/IIIa inhibition with coronary stenting for acute myocardial infarction. N Engl J

Pache J, Martinoff S, Neumann FJ, Schwaiger M. Coronary stenting plus platelet glycoprotein IIb/IIIa blockade compared with tissue plasminogen activator in

U, Pache J, Martinoff S, Neumann FJ, Schwaiger M. Coronary stenting plus platelet glycoprotein IIb/IIIa blockade compared with tissue plasminogen activator in acute myocardial infarction. Stent versus Thrombolysis for Occluded Coronary Arteries in Patients with Acute Myocardial Infarction. N Engl J Med 2000;343:385-

> In cardiac surgery, hyperglycemia is a common occurrence in patients with and without diabetes (1,2). For many years, stress-induced hyperglycemia was considered an adaptive and beneficial response of the organism. However, both human and animal studies suggest that it is not a benign condition and, in contrast, it is associated with a high risk of morbidity and mortality. Stress hyperglycemia is defined as an elevation of plasma glucose levels (above 126 mg/dl in fasting condition or 200 mg/dl at any time) in critically ill or hospitalized patients, with or without history of diabetes (3). More specifically, elevated values of blood glucose in presence of normal levels of glycosylated hemoglobin (HbA1c), regardless of diabetes status, may be considered a stress response; this kind of hyperglycemia is developed during any physiological reaction to a situation of high metabolic demand or injury, in which diverse mechanisms become active for maintaining homeostasis, for example: major burns, severe trauma, hemorrhage, septicemia, and major surgery, in which it is very common for blood sugar to reach levels up to 370 mg/dl (4). It was the French physiologist Claude Bernard who first described this phenomenon in dogs subjected to hemorrhagic shock in 1885 (5); since then, this finding has been extensively studied, especially in recent decades because of it´s impact on outcomes of critically ill patients.

> Hyperglycemia is a well recognized condition that increases the overall hospital morbidity and mortality of any patient admitted for any reason. In addition, it also increases the rate of complications in diabetic and non-diabetic patients undergoing major surgeries; besides this condition is associated with a longer hospital-stay and higher costs (1). Considering the strong association between hyperglycemia and general morbidity and mortality in surgery, there has been great interest for developing protocols to control blood-glucose levels during the perioperative period in order to prevent hyperglycemia, to achieve euglycemia and to reduce episodes of hypoglycemia, aiming the improvement of patient outcomes. In particular, the glycemic control in cardiac surgery has become a very important matter in

the full standard care as a mean of reducing infections and further complications, and in consequence, the patient's improvement.

This chapter reviews the mechanisms of stress hyperglycemia, the evidence of the association between hyperglycemia and adverse outcomes in surgical patients particularly in cardiac surgery. Besides, it offers a general overview about discordant reports found in the literature on the strict glycemic control during the peri-operative period of a cardiac surgery. In addition to, it also recommends common approaches to control the glycemia in surgical intensive care unit (ICU) and post-surgical cardiovascular patients based on the best performed randomized controlled trials.
