Perioperative Decision Making The decision has been made to proceed with operative management timing and site of surgery the type of anesthesia preope

Transcription

1 Preoperative Evaluation In Endocrine Disorders Dr Nahid Zirak 2012

2 Perioperative Decision Making The decision has been made to proceed with operative management timing and site of surgery the type of anesthesia preoperative preparation necessary to understand the patient's risk and optimize the outcome.

3 Clinical Predictors of Increased Perioperative Cardiovascular Risk MAJOR Unstable coronary syndromes Acute (<7d) or recent MI (<1mo) with evidence of ischemic risk Unstable or severe angina Decompensated heart failure Significant arrhythmias High-grade grade AV block Symptomatic ventricular arrhythmia SVT uncontrolled rate Severe valvular disease

4 Clinical Predictors of Increased Perioperative Cardiovascular Risk INTERMEDIATE Mild angina pectoris Previous myocardial infarction (>1mo) by history of pathological Q waves Compensated or prior heart failure Diabetes mellitus (particularly insulin dependent) Renal insufficiency (creatinine >2.0)

5 Clinical Predictors of Increased Perioperative Cardiovascular Risk MINOR Advanced age Abnormal ECG (LVH, LBBB, ST-T abnormalities) Rhythm other than sinus (e.g. a fib) Low functional capacity (e.g. inability to climb one flight of stairs with a bag of groceries) History of stroke Uncontrolled systemic hypertension

6 evidence of poor control of an underlying disease process, consultation with an internist or medical subspecialist is essential

7 The preoperative evaluation identifies the type and degree of endocrine dysfunction to permit preoperative optimization.

8 Diabetes Mellitus Type 1,at risk for ketoacidosis, at increased risk for premature vascular disease, especially myocardial ischemia, even in the second decade of life. Type 2, found in older, overweight adults.

9 Diabetes Mellitus Heart failure is twice as common in men and five times as common in women with diabetes as in those without diabetes. Diabetics are at increased risk for renal failure perioperatively and for postoperative infections.

10 Diabetes Mellitus The combination of hypertension, diabetes, and age older than 55 years accounts for more than 90% of patients with renal insufficiency. Screening for kidney disease is accepted practice in patients with diabetes.

11 Diabetes Mellitus A preoperative ECG plus determination of electrolytes, BUN, creatinine, and blood glucose is recommended for all diabetic patients

12 Diabetes Mellitus The goals of perioperative diabetic management include avoidance of hypoglycemia and marked hyperglycemia.

13 Diabetes Mellitus Multiorgan dysfunction Delayed gastric emptying, retinopathy, and reduced joint mobility Diabetes is considered a CAD equivalent and an intermediate risk factor for perioperative cardiac complications, on a par with angina or a previous MI

14 Diabetes Mellitus Diabetic patients without known coronary stenosis or angina have the same risk of myocardial ischemia or cardiac death as a nondiabetic with a previous MI

15 Diabetes Mellitus Autonomic neuropathy is the best predictor of silent ischemia.

16 Diabetes Mellitus Simplified cardiac evaluation for noncardiac surgery ACC/AHA 2007 guidelines on perioperative cardiovascular evaluation and care for noncardiac surgery. J Am Coll Cardiol 50:e159-e241, Available at

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18 Diabetes Mellitus The evaluation of a diabetic patient for surgery assesses the adequacy of glycemic control and identifies the presence of diabetic complications, which may have an impact on the patient's perioperative course.

19 Preoperative testing fasting and postprandial glucose hemoglobin A1c levels Serum electrolyte blood urea nitrogen, and creatinine Urinalysis may reveal proteinuria as evidence of diabetic nephropathy.

20 Metabolic Equivalents of Functional Capacity MET Functional Levels of Exercise 1 Eating, working at a computer, dressing 2 Walking down stairs or in your house, cooking 3 Walking 1-2 blocks 4 Raking leaves, gardening 5 Climbing 1 flight of stairs, dancing, bicycling 6 Playing golf, carrying clubs 7 Playing singles tennis 8 Rapidly climbing stairs, jogging slowly 9 Jumping rope slowly, moderate cycling 10 Swimming quickly, running or jogging briskly 11 Skiing cross country, playing full-court basketball 12 Running rapidly for moderate to long distances

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22 Diabetes Mellitus ECG in patients with long-standing disease. cardiac autonomic neuropathy, increases the risk for cardiorespiratory instability in the perioperative period.

23 optimize glycemic control perioperatively. discontinue long-acting sulfonylureas a shorter-acting agent or sliding-scale scale insulin coverage may be substituted in this period.

24 The use of metformin is stopped preoperatively An insulin-dependent diabetic is told to withhold long-acting insulin,lower dosages of intermediate-acting acting insulin

25 scheduled for early morning surgery, During surgery, a standard 5% or 10% dextrose infusion is used with short- acting insulin or an insulin drip

26 Diabetes Mellitus well controlled Poor controlled taking insulin

27 Diabetes Mellitus maintain the perioperative glucose level between 80 and 150 mg/dl Adequate hydration

28 Diabetes Mellitus Adequate prophylaxis for deep venous thrombosis (DVT) is essential because of the increased risk for thrombosis.

29 Thyroid Disease Significant hyperthyroidism or hypothyroidism appears to increase perioperative risk.

30 Thyroid Disease Determination of medical therapy Patients with a history of chronic thyroid disease need thyroid function tests before surgery. If symptomatology and therapy have not changed, tests within the 6 month before surgery are generally adequate

31 Thyroid Disease Preoperative consultation with an endocrinologist should be considered if surgery is urgent in patients with clinical thyroid dysfunction

32 Thyroid Disease Large mass may distort airway: chest x- ray include neck or CT Medication continue

33 Thyroid Disease patient with known or suspected thyroid disease is evaluated with a thyroid function panel. Evidence of hyperthyroidism is addressed preoperatively and surgery deferred until a euthyroid state is achieved, when feasible

34 Thyroid Disease electrolyte levels ECG If the physical examination suggests signs of airway compromise, further imaging may be warranted

35 Thyroid Disease hyperthyroidism, antithyroid medication such as propylthiouracil or methimazole is instructed to continue this regimen on the day of surgery

36 Thyroid Disease The patient's usual doses of β-blockers or digoxin are also continued. In the event of urgent surgery in a thyrotoxic patient at risk for thyroid storm, a combination of adrenergic blockers and glucocorticoids may be required and are administered in consultation with an endocrinologist

37 Thyroid Disease Patients with newly diagnosed hypothyroidism generally do not require preoperative treatment, although they may be subject to increased sensitivity to medications, including anesthetic agents and narcotics

38 Thyroid Disease Severe hypothyroidism can be associated with myocardial dysfunction, coagulation abnormality, and electrolyte imbalance, notably hypoglycemia. Severe hypothyroidism needs to be corrected before elective operations