Hyperglycaemia

Initial assessment

• Ask about osmotic symptoms
• If CBG > 18, check ketones and pH (manage as DKA if required)
• If CBG > 25, check VBG and calculate effective osmolality (2 Na + glucose) and initiate HHS pathway if > 310 (don’t include urea as this takes too long to come back)
• Consider underlying cause
  • • New onset DM
    • Drugs – steroids, danazol, diuretics, growth hormone, levothyroxine, oral contraceptive, sympathomimetics
    • Infection (always check the feet)
    • Pregnancy
    • Missed doses/medications – ask the patient about adherence, check the drug chart if admitted
    • High sugar intake – ask about their diet, check the food chart
    • Inadequate usual prescription – especially if recurrent hyperglycaemia
    • Reactive hyperglycaemia (non-diabetic) – hyperglycaemia can simply relate to ‘stress’ and not signify DM but they should have a yearly fasting glucose or HbA1C because they are at greater risk
• Make a plan for ongoing monitoring
  • • If CBG > 12, usually worth monitoring initially to check their CBG pattern before initiating/changing treatment
    • Usually check CBGs hourly, unless eating and drinking and normal HbA1C, then can check 4 hourly

---

How to manage hyperglycaemia due to missed medications

• Missed long acting insulin
  • • If within 6 hours, give normal dose of long acting
    • If 6-12 hours late, give 50% of the normal dose
    • If > 12 hours late, consider omitting dose and monitoring CBGs
• Missed a dose of twice daily premixed insulin
  • • If within 2 hours, reduce dose by 10%
    • If 2-6 hours late, reduce dose by 50% and give at the next meal
    • If > 6 hours late, omit dose and monitor
• Missed a dose of metformin or gliclazide – take missed dose if within one hour of a meal, otherwise omit
• Missed a dose of a -gliptin – take dose as soon as remembered, unless nearly time for the next
• Missed a dose of a -gliflozin – take missed dose if within 12 hours, if not, skip missed dose

---

Tips for adjusting insulin regimes and adding insulin

• Always carefully review the CBG pattern
• If CBG high pre-breakfast
  • • Can adjust evening long-acting or intermediate acting insulin. Then adjust the short acting depending on CBGs
    • You can however get rebound with a glucose of say 5 at bedtime, and 9 in the morning. This is because the liver kicks in during the night and releases glucose.
    • Don’t increase insulin in this scenario as the CBG could have been low at 1am. Consider checking a midnight to 3am CBG and giving a snack before bed
• If high pre-lunch
  • • Adjust morning intermediate acting, or breakfast short acting
• If high in the evenings
  • • Adjust lunch short acting or morning intermediate acting
• If high at bedtime
  • • Check no previous morning hypos. If not, adjust evening long or intermediate acting (consider taking a night time CBG to ensure no night time hypos)
• Stat novorapid 2-6 units (ie a correction dose)
  • • Some clinicians give stat insulin if CBG >18, but always review their usual regime
    • Others tend to avoid stat short acting insulin altogether
    • Roughly speaking, one unit of novorapid will reduce CBG by 3, but there is lots of variability so this can’t be safely relied on
    • If giving a correction dose – recheck CBG at least every 2 hours. If CBG >18 at 4 hours, can consider another correction dose. If remains high – consider a sliding scale
• In type 1 DM
  • • Ask patient about their usual correction doses
    • T1 diabetics should be encouraged to calculate insulin required as usual using DAFNE
    • Often a patient will know the ratio: eg how many units of long acting are required to correct a CBG by 3.
• Tips
  • • Usually best to adjust one insulin at a time
    • Try to adjust short-acting insulin by 2 units at a time for safety (and generally no more than 4u daily)
    • Can increase background insulin by 2-4 units depending upon time of day hyperglycaemic, although some advocate never adjust long acting by 2 units, always at least 4
    • Usually best not to increase background insulin again for another 3 days after an increase
    • Patients can sometimes adjust own insulin in hospital if that’s their preference (and no risk of self-harm, not confused and admission not due to poor glycaemic control)
    • Poor renal function will delay insulin clearance… bear this in mind
    • The heavier the patient, the more insulin required
    • If patient not eating or drinking, or if CBGs persistently over 18 – put them on a sliding scale and aim CBG 6-10

---

Managing hyperglycaemia in patients not on insulin

• Send up to date HbA1c
• Check adherence
• Consider whether oral medications can be added if adherent – see diabetes medications and glycaemic control
• If starting insulin – can initiate intermediate acting insulin at 0.3 units per kg, divided into twice daily dose (Eg for a 60kg patient: Prescribe Humulin I or Insulatard 9 units BD)
• Metformin – can increase dose by 50% if eGFR > 50 and normal LFTs (don’t change dose if eGFR < 50). Max dose 1g BD
• Gliclazide – can increase dose by 50% if LFTs ok. Do not prescribe stat doses. Take with meals. The risk of hypoglycaemia is increased in the elderly, and those with liver and kidney disease. Max dose 160mg BD