Diabetes Mellitus & Anesthetic Implications, Including Perioperative Glycemic Control

1. Diabetes Mellitus & Anesthetic Implications, Including Perioperative Glycemic Control www.anaesthesia.co.inanaesthesia.co.in@gmail.com

2. outline • Definition, diagnosis & classification • Pre op systematic evaluation • Over view of anesthetic techniques • Pharmacology of insulin &OHA • Peri op glycemic control

3. Definition ( WHO) Diabetes mellitus - A metabolic disorder of multiple etiology characterized by chronic hyperglycemia with disturbances of carbohydrate, fat and protein metabolism resulting from defects in insulin secretion, insulin action or both.

4. Classification, Pathophysiology and Prevalence of DM (WHO / ADA)

5. Revised diagnostic criteria for diabetes mellitus

6. Preoperative evaluation &risk assessment Classical diabetic complications Macroangiopathy - arteriosclerosis Microangiopathy - heart, kidney &retina Autonomic neuropathy - heart,GI &urinary tracts Collagen anomalies - respiratory tract & joints Unifying hypothesis - impaired glycosylation of proteins Systematic search of diabetic complications - key step

7. Cardio vascular risk assessment • Major disturbances Coronary artery disease Arterial HTN Impaired LV function Cardiac dysautonomy Sudden death

8. Diabetic coronary artery disease • Intermediate clinical predictor (ACC/AHA) • Cardiac event rate - 2.5% / year • 2 fold increased in mortality • Silent ischemia • Screening asymptomatic patients ? ? appropriate for high risk patients.

10. Systemic Arterial HTN • Incidence - 29% -54% • Mechanism stage 1 - angiotensin II mediated stage 2 - impaired glycosylation stage 3 - nephropathy • Management - CCB, ACE inhibitors and Alpha adr blocking drugs

11. Cardiac autonomic neuropathy (CAN) • Degeneration of afferent and efferent nerve fibers of SNS&PSNS • Independent of age, duration of diabetes and severity of micro vascular complications • Impaired cardio vascular response to exercise and stress

12. Cardiac autonomic neuropathy (CAN) • Increased cardiac morbidity Hemodynamic instability - impaired baroreflex Painless myocardial ischemia and infarction Dysrhythmias - VF Cardio respiratory arrest BJA 1993; 71: 258 – 261 .Anesthesiology 1994; 80:326 –337 .Anesth analg 1993;88:989 -991

13. Autonomic neuropathy • 20% - 40% of diabetics • Influence anesthetic plan • Clinical predictors Prayer sign Peripheral neuropathy • History loss of sweating early satiety

14. Diabetic dysautonomic neuropathy scoring

15. Diabetic dysautonomic neuropathy scoring

16. Temperature regulation & Visceral neuropathy • Risk of hypothermia - impaired vasoconstriction Anesthesiology 2000;92(5):1311 –8 • Gastro paresis Due to vagal denervation Associated with esophageal dysmotility Reduced LES tone At risk of aspiration Anesth Analg 1994; 79: 943 – 47

17. Neurological risk • Peripheral neuropathy • Mono –poly • 7.5% of type 2 DM • 10%-27%increase in mortality • Risk of nerve compression • Preferable to avoid neural blocks in pre existing neuropathies

18. Respiratory risk • Impaired function even at early stage • Higher plasma HbA1c level correlates significant Impairment • Decrease in the reactivity to cough and ventilatory response to hypoxia and hypercapnia • PFT – reduced TV, FEV and Impaired DLco • Loss of elastic properties and altered transport capacities

19. Difficult intubation risk • 33.2% of long standing type 1 DM • “Stiff joint syndrome” - Rigidity of atlanto occipital joint, tight waxy skin ,non familial short stature and joint rigidity • “Prayer sign” & “Palmer print sign” • Vagus & recurrent laryngeal nerve neuropathy • Difficult in laryngoscopy & intubation combined risk of aspiration Ref : Anesthesiology 1986; 64: 366 – 68 Acta Anesth Scand 1998;42:199 -203

20. Renal risk • Risk of ARF • Major contributing factors • Hemodynamic instability • Decreased renal perfusion • Urosepsis • UTI - Most common post op complication • Renal failure - Most frequent major complication incidence 7% • Microalbiminuria - Predicts general severity of DM Not a marker of renal failure

21. Wound healing and infection • Long known phenomenon • Pre & post operative glycemic control restore healing • Continuous insulin infusion favors healing • Higher rate of wound infection

22. Basic lab investigations • Fasting glucose • Electrolytes • BUN & creatinine • ECG

23. Anesthetic agentsand diabetes • Induction agents Etomidate : Blocks adrenal steroidogenesis BZD : Stimulate GH secretion Propofol : Reduced ability to clear lipids • Inhalation agents Inhibit insulin action on glucose Short lived

24. Regional anesthesia vs GA • Epidural anesthesia blocks catecholamine release • Caution - LA dose & nerve injury • Inhibition of stress by opioid – limited to intraop period • No evidence to support RA over GA • Stable anesthesia - the goal • Quality of anesthesia • Schedule early in the day

25. Out vs. In patient surgery Out patient if Evaluation of history in advance Prehydration Monitoring need No CNS ischemia Pregnancy Glucose monitoring Plan higher admit rate Look for red wound

26. Insulin preparations and guidelines

27. Insulin preparations and guidelines

28. Insulin preparations and guidelines

29. Insulin preparations and guidelines

30. Oral Hypoglycemic Agents

31. Oral Hypoglycemic Agents

32. Oral Hypoglycemic Agents www.anaesthesia.co.inanaesthesia.co.in@gmail.com