Approach to Peri-operative Diabetes Management

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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

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Physiology

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

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Why worry?

• Dehydration
• Infection
• Wound Healing
• DKA/NKHC
• Hypoglycemia
• Other complications
• CV
• gt Hospital stay

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EvidenceCV ICU - Intensive Insulin
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Evidence

• CV Surgery patients even without DM
• n1548
• 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

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Intensive Insulin in Critically Ill PatientsNEJM
2001 345 1359-67
Risk Reduction 42 (unadj) 32 (adj) p lt
0.04 Subgroup Largest effect in hospital due to
? deaths from sepsis (MOSF)
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Medical ICU
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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 gt 6.1
• target CBG 4.4-6.1
• Then conventional insulin when d/c ICU
• Randomly Assigned, non-blinded RNs
• C Conventional Insulin infusion
• When CBG gt 12.0 (target 10.0-11.1)

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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 p0.02

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Intensive Insulin in Medical ICUNEJM 2006 354
449-61
Secondary All patients (stat
significant) Subgroup analysis gt 3 days (stat
significant)
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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 lt 0.05
• Less bacteremia
• stat NS

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Intensive Insulin in Medical ICUNEJM 2006 354
449-61

• Unanswered question
• Does insulin therapy actually cause HARM if lt3
  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

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Types of Insulin
Insulin 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
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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 gt10
• Minor
• Frequent monitoring BS q1-2h
• call MD if BS outside of 5-10mM
• tighter if CV Sx post-op

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General Principles

• Insulin for
• BS gt 10
• Type 1
• all Major OR
• iv Insulin if BS gt 15 or Major OR
• Hypoglycemia a no-no!
• NO sliding scales!

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Goals of Glycemia

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

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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

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Other Investigations

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

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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 11 if volume an issue
• talk to nurse re pump capabilities

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iv Insulin

• all Major surgery
• all BS gt 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
• gt18 Lispro/Aspart sc 3U inc iv Insulin by
  0.5-1.0U/hr if BS still increasing
• ? OR if persistent BS gt 15mM

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sc Insulin

• Minor only
• BS lt 15
• lt8 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)

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What if the morning BS is low?

• never want to go into OR hypoglycemic
• lt 5mM iv D50W 1/2-1 amp q20min till BS gt 6mM
• Decrease iv rate by 0.5U/hr and hold for
  1h if necessary
• BS monitor q30-60min
• Ensure iv D5W running

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Post-Op

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

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Post-op

• Major
• switch to usual once eating well stable
• may need gt 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

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Dont Forget

• Cardiopulmonary evaluation and mgmt
• Opportunity for DM education by team
• Follow-up
• Lipids, ASA, ACEI, BP
• ? Beta-blockers
• Medic-Alert, Vaccines
• Glucagon prn

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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

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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.

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Thank You