Approach to Peri-operative Diabetes Management

Ally P.H. PrebtaniAssociate Professor of Medicine

Internal Medicine, Endocrinology & Metabolism

McMaster University

Disclosure

SpeakerAd Board

Novo Nordisk Eli Lilly Sanofi Aventis

Objectives

PhysiologyWhy worry?New evidenceKey questions in managementGeneral principles of therapy and goalsDiabetes education & long-term issuesCases

Physiology

Insulin Resistance Catacholamines, cortisol, GH, glucagon Drugs

InsulinopeniaFluid shifts/Hemodynamics

Insulin absorptionFood intake

HypoglycemiaDecreased LOC

Gastroparesis

Why worry?

DehydrationInfectionWound HealingDKA/NKHCHypoglycemiaOther complications

CV > Hospital stay

EvidenceCV ICU - Intensive Insulin

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

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)

Medical ICU

Intensive Insulin in Medical ICUNEJM 2006; 354: 449-61

Prospective RCT, Single centren= 1200 Medical ICU, requiring ≥ 3 days

DM ~ 16% I: “Intensive glycemic control”

Insulin infusion when CBG > 6.1target 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)

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

Intensive Insulin in Medical ICUNEJM 2006; 354: 449-61

Secondary:

All patients

(stat significant)

Subgroup analysis > 3 days

(stat significant)

Intensive Insulin in Medical ICUNEJM 2006; 354: 449-61

Other Results: Hypoglycemia:

More often intensive groupMore in those with CRI, liver failure & longer

stayAn independent risk factor for death

Less renal insufficiencyp < 0.05

Less bacteremiastat NS

Intensive Insulin in Medical ICUNEJM 2006; 354: 449-61

Unanswered question… Does insulin therapy actually cause

HARM if <3 daysAuthor 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

Types of InsulinInsulin Type Onset Peak Duration

Rapid-Acting(Lispro/Aspart)

10-15 min 60-90 min 4-5 h

Fast-Acting(Humlin R / Toronto)

0.5-1.0 h 2-4 h 5-8 h

Intermediate-Acting(N/NPH/Lente)

1-3 h 5-8 h Up to 18h

Long-Acting(Ultralente)

3-4 h 8-15 h 22-26 h

Extended Long-Acting(Glargine, Detemir)

90 min None 24 h

Premixed eg. 30 / 70(fast / intermediate)

Variable Variable Variable

General Principles

Morning OR if possibleHold own OHA & Insulin in am

decrease intermediate hs if Hx lows amConsider 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

General Principles

Insulin for BS > 10 Type 1Type 1 all Major OR

iv Insulin if BS > 15 or Major ORHypoglycemia a no-no!NO sliding scales!

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

Key Questions

1. Type of DM, Control & Complications

2. Treatment 3. Type & Length of OR and Type

of Anesthesia4. Expected time of NPO5. Morning BS

Other Investigations

CBC, Lytes, Renal, CoagsFBG, HbA1cECGCXR

(Lipids, Microalbumin, Liver, TSH)

IV Insulin Initiation

sc TDD/24/2 = iv U/hr to startTDD = 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

iv Insulin

all Major surgeryall BS > 15mM

5-10 iv Insulin as calculated rate per hr10-14 increase iv Insulin by 0.5U/hr15-18 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

sc Insulin

Minor onlyBS < 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)

What if the morning BS is low?

never want to go into OR hypoglycemic

< 5mM iv D50W 1/2-1 amp q20min till BS > 6mMDecrease iv rate by 0.5U/hr and hold for 1h if necessaryBS monitor q30-60minEnsure iv D5W running

Post-Op

Minor resume usual Tx if eating well may need short-acting insulin prn if

not given

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

Don’t Forget

Cardiopulmonary evaluation and mgmtOpportunity for DM education by teamFollow-up

Lipids, ASA, ACEI, BP ? Beta-blockers Medic-Alert, Vaccines Glucagon prn

Bottom Line

Pretty simpleAsk Key questionsDecreased ComplicationsMonitor BS frequentlyLow threshold InsulinAvoid HypoglycemiaAvoid sliding scalesDM education & Long-term Managment

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.

Thank You