Approach to Peri-operative Diabetes Management

1. Approach to Peri-operative Diabetes Management Ally P.H. Prebtani Associate Professor of Medicine Internal Medicine, Endocrinology & Metabolism McMaster University

2. Disclosure • Speaker • Ad Board • Novo Nordisk • Eli Lilly • Sanofi Aventis

3. Objectives • Physiology • Why worry? • New evidence • Key questions in management • General principles of therapy and goals • Diabetes education & long-term issues • Cases

4. Physiology • Insulin Resistance • Catacholamines, cortisol, GH, glucagon • Drugs • Insulinopenia • Fluid shifts/Hemodynamics • Insulin absorption • Food intake • Hypoglycemia • Decreased LOC • Gastroparesis

5. Why worry? • Dehydration • Infection • Wound Healing • DKA/NKHC • Hypoglycemia • Other complications • CV • > Hospital stay

6. EvidenceCV ICU - Intensive Insulin

7. Evidence • CV Surgery patients even without DM • n=1548 • 12 mos • iv Insulin • Tight control BS 4.4-6.1 post-op vs 10-11.1mM • Significant decrease • Infection • Mortality • 8.0% vs 4.6% • Ventilator • Renal failure • PRBC • Critical polyneuropathy • Increased Hypoglycemia

8. Intensive Insulin in Critically Ill PatientsNEJM 2001; 345: 1359-67 Risk Reduction 42% (unadj) 32% (adj) p < 0.04 Subgroup: Largest effect in hospital due to ↓ deaths from sepsis (MOSF)

9. Medical ICU

10. Intensive Insulin in Medical ICUNEJM 2006; 354: 449-61 • Prospective RCT, Single centre • n= 1200 Medical ICU, requiring ≥ 3 days • DM ~ 16% • I: “Intensive glycemic control” • Insulin infusion when CBG > 6.1 • target CBG 4.4-6.1 • Then conventional insulin when d/c ICU • Randomly Assigned, non-blinded RN’s • C: Conventional Insulin infusion • When CBG > 12.0 (target 10.0-11.1)

11. Intensive Insulin in Medical ICUNEJM 2006; 354: 449-61 • Primary • Survival • A: All pts • by day 3, possible increase mortality • stat NS • ICU: 2.8% vs 3.9% p= 0.3 • Hosp: 3.6% vs 4.0% p= 0.7 • B: ≥ 3 days • Hosp: 52.5% vs 43.0% p=0.02

12. Intensive Insulin in Medical ICUNEJM 2006; 354: 449-61 Secondary: All patients (stat significant) Subgroup analysis > 3 days (stat significant)

13. Intensive Insulin in Medical ICUNEJM 2006; 354: 449-61 • Other Results: • Hypoglycemia: • More often intensive group • More in those with CRI, liver failure & longer stay • An independent risk factor for death • Less renal insufficiency • p < 0.05 • Less bacteremia • stat NS

14. Intensive Insulin in Medical ICUNEJM 2006; 354: 449-61 • Unanswered question… • Does insulin therapy actually cause HARM if <3 days • Author explanations: • More sick patients • More withdrawal of care (futility) • Why would 48 hours of insulin be harmful whereas sustained insulin beneficial • Benefit require more time to realization • Prevention of complications

15. Types of Insulin

16. General Principles • Morning OR if possible • Hold own OHA & Insulin in am • decrease intermediate hs if Hx lows am • Consider iv D5W infusion 75-100g/hr • unless BS >10 • Minor • Frequent monitoring BS q1-2h • call MD if BS outside of 5-10mM • tighter if CV Sx post-op

17. General Principles • Insulin for • BS > 10 • Type 1 • all Major OR • iv Insulin if BS > 15 or Major OR • Hypoglycemia a no-no! • NO sliding scales!

18. Goals of Glycemia • aim 5-10mM in General • limited evidence • small human and animal studies • benefit > harm • 4.5-6.0mM post-op CV Surgery/? other Major • good evidence

19. Key Questions 1. Type of DM, Control & Complications 2. Treatment 3. Type & Length of OR and Type of Anesthesia 4. Expected time of NPO 5. Morning BS

20. Other Investigations • CBC, Lytes, Renal, Coags • FBG, HbA1c • ECG • CXR • (Lipids, Microalbumin, Liver, TSH)

21. IV Insulin Initiation • sc TDD/24/2 = iv U/hr to start • TDD = 0.5-1.0U/kg if not on sc insulin • BMI, Type DM, Drugs • mix 50U Regular insulin in 250-500cc NS/D5W • may concentrate 1:1 if volume an issue • talk to nurse re: pump capabilities

22. iv Insulin • all Major surgery • all BS > 15mM 5-10 iv Insulin as calculated rate per hr 10-14 increase iv Insulin by 0.5U/hr 15-18 Lispro/Aspart sc 2U & inc iv Insulin by 0.5U/hr if BS still increasing >18 Lispro/Aspart sc 3U & inc iv Insulin by 0.5-1.0U/hr if BS still increasing ? OR if persistent BS > 15mM

23. sc Insulin • Minor only • BS < 15 <8 1/2 of am intermediate sc Insulin (1/4 calculated TDD if new) 8-14 2/3 of am intermediate sc Insulin + Lispro/Aspart sc 2-3U (1/3 calculated TDD if new)

24. What if the morning BS is low? • never want to go into OR hypoglycemic < 5mM iv D50W 1/2-1 amp q20min till BS > 6mM Decrease iv rate by 0.5U/hr and hold for 1h if necessary BS monitor q30-60min Ensure iv D5W running

25. Post-Op • Minor • resume usual Tx if eating well • may need short-acting insulin prn if not given

26. Post-op • Major • switch to usual once eating well & stable • may need > sc insulin if on ++ iv Insulin (look at amount iv needed) • slowly increase sulfonylureas • Renal/liver fxn, po status • no metformin if contraindications • NO sliding scales/supplements based on TDD

27. Don’t Forget • Cardiopulmonary evaluation and mgmt • Opportunity for DM education by team • Follow-up • Lipids, ASA, ACEI, BP • ? Beta-blockers • Medic-Alert, Vaccines • Glucagon prn

28. Bottom Line • Pretty simple • Ask Key questions • Decreased Complications • Monitor BS frequently • Low threshold Insulin • Avoid Hypoglycemia • Avoid sliding scales • DM education & Long-term Managment

29. Cases 1. 65yo man Type 2 DM going for CABG on insulin. 2. 17yo woman Type 1 DM for carpal tunnel release on Insulin. 3. 50yo woman Type 2 DM for cholycystectomy on Metformin.

30. Thank You