PERIOPERATIVE ANESTHESIA
From the 15th Annual Current Topics in Anesthesia, presented by Mayo Clinic College of Medicine, February 23-26, 2005
| THE IMPLICATIONS OF SMOKING ON PERIOPERATIVE OUTCOME —David O. Warner, MD, Professor of Anesthesiology, Mayo Clinic College of Medicine, Rochester, Minnesota |
| Incidence: ≈1 of 5 adult patients for anesthesia and surgery current cigarette smokers; some adolescents also current cigarette smokers (“although they won’t tell you that”); patients may behave badly around time of surgery, but already know dangers of smoking |
| Benefits of intervention in surgical patient |
 | Tobacco cessation improves surgical outcome: decreased risk for cardiovascular and respiratory complications; reduced wound-related complications |
| Cardiovascular effects of smoking: promotion of atherosclerosis; acute effects detrimental to cardiac function (eg, hypercoagulable state; causes catecholamine release, increasing myocardial work; reduces capacity of blood to carry O2 ); role of nicotine, carbon monoxide (CO), and other components |
| Short-term cardiovascular benefits of smoking cessation: nicotine half-life ≈1 hr; decreases in heart rate and systolic blood pressure (BP) within 12 hr; CO half-life ≈4 hr; carboxyhemoglobin level near normal at 12 hr; net effect is improvement in exercise capacity within 12 hr of cessation |
| Respiratory effects of smoking: primary risk factor for chronic obstructive pulmonary disease (COPD); decreased mucociliary transport; airway hyperreactivity; impaired pulmonary immune function; Kotani study of smokers and nonsmokers undergoing prolonged propofol/fentanyl anesthetic showed that in both groups, progressive decrease in macrophage function noted; but decrease exaggerated in patients who smoke (ability to resist lung infection significantly decreased); unlike cardiovascular risk, smoking cessation required for longer period of time to have significant benefit to pulmonary system; acute smoking cessation does not increase risk for pulmonary complications |
| Effects of smoking on wound and bone healing: decreased tissue perfusion, leading to decreased tissue oxygenation; decreased immune function (inflammatory response to speed wound healing); possible effects on fibroblast and osteoblast function; studies show smoking cessation reduces postoperative complications and wound infections |
| Surgery may promote tobacco cessation: opportunity to intervene (contact with healthcare system; forced abstinence); major medical interventions improve quit rates (occurs even in absence of tobacco interventions; also may improve efficacy of tobacco interventions); maintaining abstinence for 1 yr—≈10% of self-help population (better than 3-4% spontaneous quitting rate in unmotivated smokers); 20% in outpatient cessation program; ≈20% undergoing major noncardiac surgery; ≈50% undergoing coronary artery bypass grafting (CABG) surgery; 80% undergoing lung cancer surgery; speaker’s study found that intensity of surgery affects perioperative cessation rates |
| Nicotine-replacement therapy (NRT): doubles odds of quitting smoking; side effects include sleep disturbances and nausea; studies looked at possible adverse effects postoperatively (including cardiovascular side effects and problems with wound healing) and found NRT caused decrease in perfusion defect size, despite increase in plasma nicotine; other studies show NRT, in usual dosages, safe for wound healing (rate of complications with use of nicotine patch dramatically lower than if smoking continued) |
| Stress and nicotine withdrawal: speaker’s study on smokers and nonsmokers undergoing surgery found that smokers, under baseline conditions, report increases in perceived stress and nicotine withdrawal; but when looking at changes over course of hospitalization, at time of abstinence, no difference in reported stress; suggests that withdrawal from nicotine not clinical concern for most patients over perioperative period |
| Helping smokers who need surgery: ask—assess tobacco use; advise—strongly urge all tobacco users to quit; assess—determine willingness to make quit attempt; assist—aid patient in quitting; arrange—schedule follow-up contact |
| Interventions by surgical specialists: survey responses indicate anesthesiologists and surgeons ask regularly about tobacco use, but anesthesiologists do not advise well (only 30% reported telling patient to quit); anesthesiologists also reported not ever assisting patient to quit |
| Strategies tailored to surgical patient |
| Ask: scheduling of surgery represents opportunity to intervene; systems need to be implemented to assess tobacco use |
| Advise: good data available indicating improved outcome; if permanent cessation impossible, consider temporary abstinence around time of surgery (12 hr before and 1 wk after surgery) |
| Assess: determine whether patient willing to extend perioperative abstinence |
| Assist: indicate importance of cessation (eg, decreases chances of problems during surgery; reduces healing time after surgery; helps prevent complications); indicate what patient can do (eg, set quit date; stop smoking ≥12 hr before surgery; use nicotine gum instead of smoking on morning of surgery; stay smoke free for ≥1 wk after surgery); surgery great time to quit smoking (cannot smoke in surgical facility; most patients free of cravings right after surgery; patient may be more motivated to change lifestyle); getting help (make telephone call to state Quit Line; tobacco-control specialists may be available within healthcare system) |
| Arrange: almost every patient has automatic follow-up visit |
| HYPERGLYCEMIA DURING THE PERIOPERATIVE PERIOD —Daniel R. Brown, MD, PhD, Chair, Division of Critical Care, Mayo Clinic—Rochester, and Assistant Professor of Anesthesiology, Mayo Clinic College of Medicine, Rochester, Minnesota |
| Case: patient scheduled for carotid endarterectomy; general anesthesia indicated (systolic BP at ≈150 mm Hg); obtain hemoglobin and blood glucose levels as part of routine laboratory set ordered during care; majority start treatment with insulin drip when blood glucose levels reach ≈200 mg/dL |
| Contemporary anesthesia practice: associated with low perioperative morbidity and mortality; research in genomics and human error reduction promises to improve patient care; role of perioperative care and effect on long- term outcomes means by which anesthesia care team affects patients; Mangano study of patients with coronary artery disease undergoing noncardiac surgery showed beneficial cardiac effects with use of perioperative β-blockers even ≤2 yr later; recent studies in intensive care unit (ICU) patients suggest transfusion practice and ventilator management likely to affect long-term patient outcome |
| Glycemic control: data support association between hyperglycemia and increased morbidity and mortality; hyperglycemia independent risk factor for adverse outcomes; increases rate and duration of hospitalization; perioperative metabolic state difficult to predict; surgery and general anesthesia tend to cause state of relative insulin hyposecretion and insulin resistance; type of anesthesia also affects glucose metabolism |
| Hyperglycemia: associated with increased infection rate, impaired wound healing, osmotic diuresis, and electrolyte and acid-base abnormalities; older studies looking at relationship between insulin, glucose, and infections concluded that insulin therapy may reduce mortality; insulin also inhibits lipolysis, stimulates endothelial nitric oxide synthetase, and appears to inhibit proinflammatory cytokines and acute-phase protein |
| Patient outcome: retrospective review of >2000 adult patients (hyperglycemia defined as >126 mg/dL); newly discovered hyperglycemia associated with highest mortality (16%), as compared to diabetic patients (3%) and normoglycemic patients (1.7%); systematic review of 26 studies on adult stroke patients concluded that hyperglycemia (>144 mg/dL on admission) associated with increased risk for in-hospital and 30-day mortality and greater risk for poor functional recovery in survivors; Malmberg study looked at 620 diabetic patients admitted with acute myocardial infarction (MI) and randomly assigned to either insulin therapy with intravenous (IV) insulin or routine antidiabetic therapy (subcutaneous insulin); mortality predicted by age, previous heart failure, and severity of hyperglycemia on admission; IV insulin therapy associated with decreased mortality (≈3.4 yr average length of follow-up); study of >3500 diabetic patients undergoing CABG surgery from 1987 to 2001; initially (1987 to 1991), subcutaneous insulin administered, followed by insulin infusions (from 1992 to 2001); showed reduction in absolute and risk-adjusted mortality of 57% and 50% respectively; van den Berghe study looked at 1500 patients admitted to ICU; randomized either to intensive insulin therapy (with goal glucose level of 80 to 110 mg/dL) or to conventional therapy (treat for glucose level >215 mg/dL; goal glucose level of 180 to 200 mg/dL); 90% of patients postsurgical and 60% of those postcardiac surgery; found reduction in ICU mortality (from 8% to 4.6%) and in-hospital mortality; benefit seen predominantly in patients in ICU >5 days; greatest reduction in mortality involved patients with multiorgan failure and proven focus of infection (blood stream infection rate decreased by ≈50%); Krinsley reported data in adult ICU with medical and surgical populations; found mortality directly related to mean and maximum blood glucose values; subsequent study reported effect of instituting intensive glucose management protocol; idea to keep blood glucose level <140 mg/dL and start insulin drip if 2 blood glucose measurements >200 mg/dL; institution of protocol significantly decreased blood glucose; no change in hypoglycemic episodes; significant decreases in hospital mortality and ICU length of stay; however, recent study concluded that control of glucose, rather than absolute levels of exogenous insulin, account for mortality benefit associated with intensive insulin therapy |
| Position statement from American Association of Clinical Endocrinologists: indications for IV insulin therapy include critical illness, perioperative period, labor and delivery, and after high-dose glucocorticoid therapy |
| Goals: in ICU, glucose <110 mg/dL; outside ICU, 110 mg/dL preprandial, 180 mg/dL maximum; for labor and delivery, <100 mg/dL; more aggressive metabolic control appears to be beneficial (but patient and procedure factors must be considered); speaker unsure whether to intervene more aggressively based on preoperative testing (also may have implications for anesthetic plan) |
Educational Objectives
| The goal of this program is to educate the listener about perioperative issues in anesthesia care. After hearing and assimilating this program, the participant will be better able to: |
| 1. Describe the benefits of smoking intervention in the surgical patient. |
| 2. Discuss the benefits and concerns associated with nicotine-replacement therapy. |
| 3. Review the strategies for smoking cessation tailored to the surgical patient. |
| 4. Explain glycemic control in the critically ill patient. |
| 5. Examine the association between hyperglycemia and outcomes in the critically ill patient. |
Discussed on This Program
Fentanyl [Sublimaze] Insulin injection, regular (several trade names) Propofol [Diprivan]
Suggested Reading
Capes SE et al: Stress hyperglycaemia and increased risk of death after myocardial infarction in patients with and without diabetes: a systematic overview. Lancet 355:773, 2000; Capes SE et al: Stress hyperglycemia and prognosis of stroke in nondiabetic and diabetic patients: a systematic overview. Stroke 32:2426, 2001; Hebert PC et al: A multicenter, randomized, controlled clinical trial of transfusion requirements in critical care. Transfusion Requirements in Critical Care Investigators, Canadian Critical Care Trials Group. N Engl J Med 340:409, 1999; Joseph AM et al: The safety of transdermal nicotine as an aid to smoking cessation in patients with cardiac disease. N Engl J Med 335:1792, 1996; Kotani N et al: Smoking decreases alveolar macrophage function during anesthesia and surgery. Anesthesiology 92:1268, 2000; Krinsley JS: Association between hyperglycemia and increased hospital mortality in a heterogeneous population of critically ill patients. Mayo Clin Proc 78:1471, 2003; Krinsley JS: Effect of an intensive glucose management protocol on the mortality of critically ill adult patients. Mayo Clin Proc 79:992, 2004; Mahmarian JJ et al: Nicotine patch therapy in smoking cessation reduces the extent of exercise-induced myocardial ischemia. J Am Coll Cardiol 30:125, 1997; Malmberg K et al: Glycometabolic state at admission: important risk marker of mortality in conventionally treated patients with diabetes mellitus and acute myocardial infarction: long-term results from the Diabetes and Insulin-Glucose Infusion in Acute Myocardial Infarction (DIGAMI) study. Circulation 99:2626, 1999; Mangano DT et al: Effect of atenolol on mortality and cardiovascular morbidity after noncardiac surgery. Multicenter Study of Perioperative Ischemia Research Group. N Engl J Med 335:1713, 1996; Moller AM et al: Effect of preoperative smoking intervention on postoperative complications: a randomised clinical trial. Lancet 359:114, 2002; Sorensen LT et al: Abstinence from smoking reduces incisional wound infection: a randomized controlled trial. Ann Surg 238:1, 2003; Umpierrez GE et al: Hyperglycemia: an independent marker of in-hospital mortality in patients with undiagnosed diabetes. J Clin Endocrinol Metab 87:978, 2002; van den Berghe G et al: Intensive insulin therapy in the critically ill patients. N Engl J Med 345:1359, 2001; Warner DO et al: Anesthesiologists, general surgeons, and tobacco interventions in the perioperative period. Anesth Analg 99:1766, 2004; Warner DO et al: Smoking behavior and perceived stress in cigarette smokers undergoing elective surgery. Anesthesiology 100:1125, 2004; Warner MA et al: Role of preoperative cessation of smoking and other factors in postoperative pulmonary complications: a blinded prospective study of coronary artery bypass patients. Mayo Clin Proc 64:609, 1989.
Faculty Disclosure
In adherence to ACCME guidelines, the Audio-Digest Foundation requests all lecturers to disclose any significant financial relationship with the manufacturer or provider of any commercial product or service discussed. For this issue, the faculty reported nothing to disclose.
Drs. Warner and Brown spoke in Scottsdale, Arizona at the 15th Annual Current Topics in Anesthesia, held February 23-26, 2005, and sponsored by the Mayo Clinic College of Medicine. The Audio-Digest Foundation thanks the speakers and the Mayo Clinic College of Medicine for their cooperation in the production of this program.
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