Peri-op diabetes

Elective peri-op management of diabetes:

• Simple things:
  • First on list
  • Don't drive themselves to hospital (hypoglycaemia)
  • Clear apple juice if hypo pre-op
  • Consider pre and post op admission
• Referral to endocrinology:
  • All type 1 diabetics
  • All patients on subcut pump
• T1DM:
  • Do not withhold basal insulin
  • BSL hourly
  • Check ketones if BSL > 15
  • Use insulin infusion with 5% dextrose at q18h
  • Do not stop insulin infusion unless already given insulin 2 hours previously
• SGLT2 (flozins):
  • Cease 3/7 pre-op and only restart when patient is eating and drinking normally
  • Day cases - withhold on day of procedure only
• Aim 6.1-10 mmol/L
• T2DM Oral
  • Continue orals and non-insulin injectables until morning of surgery, then withhold day of surgery
  • Restart when eating, except metformin, which should be withhold until renal function back to normal
• T1DM/T2DM insulin-controlled
  • Short procedures (2 hours) can continue subcut insulin
    • If breakfast is likely to be only delayed, not missed, then can continue usual basal regime.
    • Morning procedures causing missed meals, or afternoon procedures:
      • Withhold short-acting while fasting
      • Give half usual morning dose of long-acting
      • Insulin pumps can continue at their usual basal rate
      • Run slow IV dextrose while fasting
      • T1DM - can reduce previous night's dose of long-acting by 20%. Not necessary in T2DM.
  • Longer/complex procedures
    • Should be on insulin infusion started with enough time to bring sugars under control

Acute management of T2DM in emergency patients

• Avoid sliding scale alone - usually inadequate
• Ideally should have a basal-bolus regime which is frequently adjusted

SGLT-2 inhibitors in emergency cases - euDKA

• Epidemiology
  • The overall risk of this happening is doubled compared to placebo but still really low - about 0.5% of patients per year
• Risk factors
  • Lean patients
  • Low-carbohydrate diet
  • Hypovolaemic
  • Low reserve of insulin-secreting cells (long-term insulin use, T1DM)
  • Sudden reduction in insulin dose
  • Increased requirement for insulin (acutely unwell, surgery, alcohol abuse)
  • Hidden diagnosis of latent autoimmune diabetes of adulthood (LADA)
• Pathophysiology
  • Urinary glucose excretion is independent of circulating insulin level
  • Inhibition of SGLT2 may lead to increased glucagon and consequently liver production of glucose and ketones
  • There is also a linked renal cotransporter, normally responsible for excreting lactate and ketones, that may be inhibited by SGLT-2 inhibitors
  • Euglycaemic (meaning BSL<13.9) DKA can occur during illness or when ongoing glucosuria masks stress-induced requirements for insulin. DKA might be present due to lack of/resistance to insulin, but the BSL is not elevated due to ongoing urinary losses.
  • Often a hyper-chloraemic metabolic acidosis complicates recovery from DKA
• Prevention
  • Withhold SGLT-2 inhibitors three days prior
  • Prevent hypovolaemia
• Diagnosis
  • Check serum ketones in any patient fasting or with nausea/vomiting/anorexia who has had SGLT-2 inhibitors within past 3 days
  • My plan: BD BSL and ketone checks, and daily VBG, until either the patient is eating again, or it's been 3/7 since SGLT-2 inhibitor
• Management
  • Stop the SGLT-2 inhibitor
  • Generally, both insulin and glucose are required to correct the problem
    • First, ensure K+ > 3.3 and volume resuscitate with 0.9% normal saline
    • Start insulin infusion as per protocol (generally 0.1IU/kg bolus followed by continuous infusion, although can just start with continuous infusion; replace 0.9% saline with 5% Dextrose with BSL<11.1)
      • Some say just start directly on Dextrose 5% infusion
    • Give bicarbonate if pH < 6.9, which may require additional administration of calcium
    • Once acid-base balance is restored, switch to subcutaneous insulin in an intensive regimen, such as 0.5-0.8IU/kg short-acting with meals and a long-acting insulin at night
  • Talk to endocrinology before reinstating the SGLT-2 inhibitor
  • See 'DKA' page

<<Peri-Op Guidelines for Patients with Type1 and Type2 Diabetes.pdf>>