SURGICAL CHALLENGES IN DIABETIC PATIENTS

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SURGICAL CHALLENGES IN DIABETIC PATIENTS

• Mark Shapiro, MD
• Mount Sinai Medical Center
• July 22, 2005

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Classification

• Type 1
• Type 1A Immune-mediated
• Type 1B Idiopathic
• Type 2
• Other causes
• Diseases of exocrine pancreas (cystic fibrosis,
  neoplasia)
• Endocrinopathies (glucagonoma, acromegaly,
  pheochromocytoma, Cushings, etc.)
• Drug induced

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Criteria for Diabetes Mellitus
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Epidemiology

• Sixth most common cause of death
• Diabetics have increased incidence of
• cardiac complications (leading cause of death)
• cerebrovascular pathology (third leading cause of
  death)

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Diabetics

• Undergo various procedures and surgeries more
  commonly than their nondiabetic counterparts
• Have increased morbidity and mortality rates when
  acutely compromised or ill
• At least a third of perioperative diabetics are
  unrecognized or untreated before surgery
• the physician must be vigilant in the
  identification of diabetes

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Cardiac Consequences

• Cardiac compromise must be identified before
  major surgery and during critical illness
• High prevalence of silent ischemia warrants
  cardiac testing preoperatively
• Acute glycemic control results in marked
  improvement in cardiac survival in diabetics with
  ACS, MI, and after recent cardiac surgery

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Renal Consequences

• Diabetes is the leading cause of end-stage renal
  disease
• Leads to hypertension, dyslipidemias, and anemia
• Developing acute renal failure after CABG
  increases mortality rate from 1-2 to 20 with
  moderate acute renal failure and 60 for patients
  who require dialysis
• Mangano CM, et al. Renal dysfunction after
  myocardial revascularization Risk factors,
  adverse outcomes, and hospital resource
  utilization. Ann Inter Med 1998 128194-203

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Goals of Critical Care

• To avoid acute renal failure, leading to dialysis
• Limiting hypovolemia
• Avoiding nephrotoxins
• Judicious use of contrast-based radiographic
  procedures
• To decrease significant risk of aspiration (from
  autonomic neuropathy, gastroparesis)
• Appropriate patient positioning
• Use of gastric acid secretion suppressants

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Glycemic Control

• Multiple recent studies suggest that aggressive
  glucose control may benefit diabetic pts who are
  critically ill
• Insulin infusions are recommended as a way of
  glycemic control

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Glycemic Control of Diabetic Patient in ICU

• Intensive Insulin Therapy in Critically Ill
  Patients
• Greet Van den Berghe, et al. NEJM 2001
  3451359-67

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Glycemic Control of Diabetic Patient in ICU

• Prospective, randomized, controlled study
• Population adult diabetic pts admitted to ICU
• Conventional-Treatment group (N783) received
  continuous infusion of insulin if the blood
  glucose level exceeded 215mg/dl, with the target
  value between 180 and 200
• Intensive-Treatment group (N765) received
  continuous infusion of insulin if the blood
  glucose level exceeded 110mg/dl, with the target
  value between 80 to 110

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Glycemic Control of Diabetic Patient in ICU

• Blood glucose level was measured at one- to
  four-hour intervals
• Adjustments of the insulin dose were based on
  measured blood glucose level
• Hypoglycemia (blood glucose level lt40mg)
• 39 pts in the intensive-treatment group
• 6 pts in the conventional-treatment group
• There were no instances of hemodynamic
  deterioration or convulsions

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Glycemic Control of Diabetic Patient in ICU

• The benefit of intensive insulin therapy was
  attributable to pts who remained in the intensive
  care unit greater than 5 days
• Mortality in ICU intensive-treatment vs.
  conventional-treatment 4.6 vs. 8.0 (p.lt0.04)
• The greatest reduction in mortality involved
  deaths due to multiple-organ failure

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Glycemic Control of Diabetic Patient in ICU

• Blood stream infections were reduced by 46
  (p.003)
• Decreased number of pts requiring Abx treatment
  gt10 days (plt.001) due to lower rate of bacteremia
• Acute renal failure requiring dialysis was
  decreased by 41 (p.007)
• The median number of blood transfusions by 50
  (p.001)
• Criticalillness polyneuropathy by 44 (plt.001)
• Decreased duration of mechanical ventilation
• Decreased duration of intensive care days

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Glycemic Control of Diabetic Patient in ICU

• CONCLUSION The use of intensive insulin therapy
  to maintain blood glucose at a level that did not
  exceed 110 mg/dl substantially reduced mortality
  in the ICU and morbidity among critically ill
  patients admitted to ICU

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Continuous Insulin Infusion Effect on Wound
Infections

• Continuous Intravenous Insulin Infusion Reduces
  the Incidence of Deep Sternal Wound Infection in
  Diabetic patients After Cardiac Surgical
  Procedures
• Furnary AP, et al. Ann Thorac Surg 1999 67352-62

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Continuous Insulin Infusion Effect on Wound
Infections

• Prospective, controlled study, not randomized
• Population diabetic pts who underwent open
  heart surgical procedures (1987-1997)
• Control group (N968) treated with
  sliding-scale-guided intermittent SQ insulin
  injections (SQI) every 4 hrs, with a target level
  at or below 200
• Admission dates 01/87-09/91
• Study group (N1499) treated with a continuous
  intravenous insulin infusion (CII) with target
  glucose level between 150 and 200 mg/dl
• Admission dates 09/91-11/97

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Continuous Insulin Infusion Effect on Wound
Infections

• Blood glucose levels were monitored
  intraoperatively and postoperatively every 1-2
  hrs
• Infection prophylaxis remained constant through
  the entire study period
• All procedures were performed by the same
  surgical team

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Continuous Insulin Infusion Effect on Wound
Infections

• Mean blood glucose levels on the operative day
  and first three PODs were significantly lower
  within the CII group than in the SQI control
  group (199 vs. 241, 176 vs. 206, 181 vs. 195)
  plt0.0001
• Aggressive CII approach resulted in overall
  tighter glucose control

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Continuous Insulin Infusion Effect on Wound
Infections

• Use of CII protocol resulted in a 2.5-fold
  decreased in the rate of deep sternal wound
  infections (DSWI) 0.8 vs. 1.9 (p0.011)
• Results suggest that hyperglycemia in the first 2
  PODs is significantly associated with DSWI
• Frequency of leg wound problems in only 1 of pts

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Hyperglycemia as a Risk Factor for Wound
Infections

• Hyperglycemia impedes the normal physiologic
  responses to infections
• Periods of hyperglycemia are associated with
  accelerated nonenzymatic glycosylation of body
  proteins
• C3 component of complement is inactivated and
  unable to bind to the surface of invading
  bacteria
• Glycosylation of newly synthesized collagen in
  hyperglycemic animals is associated with
  increased collagenase activity and decreased
  wound collagen content
• Hennessey PJ, et al. Nonenzymatic glycosylation
  of immunoglobulin G impairs complement fixation.
  J Parenter Enter Nutr 1991 1560-4

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Hyperglycemia as a Risk Factor for Wound
Infections

• Impaired phagocytosis, delayed chemotaxis, and
  depressed bacteriocidal capacity
• The degree of hyperglycemia that has been shown
  to impair phagocytic function is as low as 200
  mg/dl
• Wound healing impairment improves dramatically
  with control of glucose concentrations
• McMahon MM, et al. Host defenses and
  susceptibility to infection in patients with
  diabetes melitus. Infect Dis Clin North Am 1995
  91-9.

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Diabetes and Surgery

• Surgery leads to increased secretion of stress
  hormones (cortisol, catecholamines)
• Insulin sensitivity is reduced
• Sympathetic activity increased
• Reduced insulin secretion
• Secretions of glucagon and GH also increased
• All this leads to a marked catabolic response
• State of hyperglycemia and ketosis

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Diabetes and Surgery

• Glycemic control should be monitored before
  admission (target HbA1c lt 7)
• Preoperatively U/A, Chem7, EKG, Echocardiogram
  should be obtained
• Pt should be assessed for signs of gastroparesis
• Increased risk of regurgitation and aspiration on
  induction of anesthesia

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Diabetes and Surgery

• 12-hour fast is recommended before surgery
• Undiagnosed gastroparesis may prolong retention
  of food in the stomach
• Fasting blood glucose should be measured on the
  day of operation
• Intraoperative measurements should be made if the
  operation is long
• Post. surgery FS 2 hrs after, and then Q4H

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Type 2 Diabetics Not on Insulin

• Oral agents administered on the day before
  surgery
• Withheld on the day of surgery
• If surgery is minor need observation only
• In all other cases use GIK (glucose-insulin-K)
• Continue GIK until pts are ready to eat
• Then revert to oral drugs with the 1st meal

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Standard GIK

• 500 ml 10 dextrose solution
• 15 Units of short-acting insulin
• 10 mmol KCl
• Infuse at 100 ml/hr

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Insulin Treated Diabetics

• Long-acting insulin should be stopped several
  days before operation and be replaced with
• intermediate-acting insulin
• or with multiple injections of short-acting
  insulin through the day with an
  intermediate-acting preparation at night

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Insulin Treated Diabetics

• GIK should be started on the morning of operation
  and continued until pt is ready to eat
• Then give 1 dose of SQ insulin before 1st meal
  and discontinue GIK in 2-3 hours