- Overview
- Triage
- Causes
- Diagnosis
- Clinical features
- Investigations
- Management - Mild to Moderate Hyperglycaemia
- Initial Management of Moderate Hyperglycaemia
- Ongoing Management of Hyperglycaemia
- Starting Insulin
- Patients with Primarily Pre-breakfast (Fasting) Hyperglycaemia
- Patients with Primarily Pre-lunch Hyperglycaemia
- Patients with Primarily Pre-dinner Hyperglycaemia
- Patients with Primarily Pre-bed Hyperglycaemia
- Patients with Day Time Hyperglycaemia
- Patients with Hyperglycaemia Secondary to Prednisolone
- Patients with Hyperglycaemia Secondary to Dexamethasone
- Patients with Hyperglycaemia Secondary to TPN/EN
- Titrating Insulin
- Converting from Mixed Insulin to Basal Bolus Regime
- When to Contact Endocrinology
- Starting Insulin
- References
Overview #
Inpatient hyperglycaemia is defined by a random blood glucose level above the patient’s individualised target range. This is >10.0 mmol/L in most patients, although a target of 8.0-15.0 may be in place for elderly patients or those with several comorbidities.
Triage #
If either DKA or HHS is suspected (e.g. altered conscious state, signs of dehydration), the patient requires immediate attention (refer to the separate DKA and HHS protocol).
Pending the severity and chronicity of hyperglycaemia, some patients may require attention within the hour or within several hours if mild.
- Aim to see a patient with BG >20 within the hour, however, treatment can often be commenced immediately through communication with nursing staff prior to your review of the patient.
- BG between 10-20 can be managed within several hours
Causes #
Patients with known diabetes (Type 1 or Type 2) #
- Change in insulin or oral hypoglycaemic agents
- Inadequate regimen of diabetic medications
- Non-adherence
- Change in diet/exercise
- Stress hyperglycaemia
- Trauma, surgery
- Acute myocardial infarction, stroke
- Sepsis
- Medications (1)
- Glucocorticoids
- Immunosuppressants
- Cytotoxic drugs
- Antidepressants
Patients without diabetes* #
- New-onset diabetes
- Gestational diabetes
- Medications
- Glucocorticoids
- Immunosuppressants
- Cytotoxic drugs
- Antidepressants
- TPN/Enteral nutrition
- Endocrine causes
- Cushing syndrome
- Acromegaly
- Phaeochromocytoma/paraganglioma
- Pancreatic injury
- Acute or chronic pancreatitis
- Pancreatic adenocarcinoma
- Factitious e.g. broken glucometer, finger with sugar on it
*Some of these causes can also cause hyperglycaemia in known diabetic patients.
Diagnosis #
A diagnosis of diabetes can be made when two of the following criteria are met:
- HbA1c ≥6.5% (48 mmol/mol)
- Fasting glucose ≥7.0 mmol/L
- Random glucose ≥11.1 mmol/L (2)
This diagnosis can be made either from two different diagnostic tests or the same test on two different occasions.
Note: A diagnosis of diabetes should be made cautiously in hospital due to hyperglycaemia secondary to intercurrent illness. As such, diabetes is generally diagnosed in an outpatient setting.
For diagnostic criteria of DKA and HHS, please refer to the separate DKA/HHS protocol.
Clinical features #
Symptoms
- Usually asymptomatic
- Polyuria, polydipsia, polyphagia
- Difficulty thinking
- Visual changes e.g. blurry vision
Signs
- Often nil signs
Investigations #
Initial investigations #
Investigation | Significance |
Fingerprick BG | |
Fingerprick ketones | If greater than 0.6, patient is at risk of DKA |
Further investigations #
Investigation | Indication |
General Tests | |
VBG | If ketones elevated, BGs i.e. >15.0 mmol/L or any other reason to suspect DKA/HHS – looking for acidosis/bicarb/electrolyte derangements |
HbA1C | To assess glycaemic control over the past 3 months. Only if nil HbA1C reading available in the previous 3 months. |
Fasting serum BG | To aid in diagnosis of diabetes if nil previous history |
Septic Screen (for callout box) | |
Urine MCS | If urine infection is suspected to be precipitating stress hyperglycaemia |
FBE | For leukocytosis if infection is suspected to be precipitating stress hyperglycaemia |
CRP | If infection is suspected to be precipitating stress hyperglycaemia |
Blood cultures | If infection is suspected to be precipitating stress hyperglycaemia |
CXR | If chest infection is suspected to be precipitating stress hyperglycaemia |
Other Causes of Stress Hyperglycaemia | |
ECG | If cardiac pathology is suspected to be precipitating stress hyperglycaemia. |
LFT | If pancreatitis is suspected |
Lipase | If pancreatitis is suspected |
Late night salivary cortisol x2, 24 hr urinary free cortisol or low dose dexamethasone suppression test | If Cushing syndrome is suspected. |
Management – Mild to Moderate Hyperglycaemia #
For management of DKA/HHS, please refer to the separate DKA/HHS protocol. {hyperlink to DKA/HHS protocol}
For management of blood glucose levels in the perioperative period, please refer to the Perioperative glycaemic control protocol {hyperlink to Perioperative glycaemic control protocol}
Management principles of mild to moderate hyperglycaemia involve making adjustments to the patient’s usual insulin and/or oral hypoglycaemic agents, with BG targets generally sitting between 5.0 and 10.0mmol/L.
Oral Hypoglycaemic Agents
Note: the majority of these agents are renally excreted and will require dose reduction or cessation at certain renal thresholds
Class | Drug examples | Considerations |
Biguanide | Metformin(Diabex/ Diaformin) | Risk of lactic acidosis (withhold/cease in patients with eGFR <30. Dose reduce when eGFR <45) |
Sulfonylurea | Gliclazide (Glyade)Glimepiride (Amaryl) | Risk of hypoglycaemia |
GLP-1 Receptor Agonist | Exenatide (Byetta/ Bydureon)Dulaglutide (Trulicity)Semaglutide (Ozempic) | Risk of pancreatitis |
DPP4 Inhibitor | Sitagliptin (Januvia)Linagliptin (Trajenta) | Risk of pancreatitis |
Thiazolidinedione | Pioglitazone (Actos)Rosiglitazone(Avandia) | HepatotoxicFluid retention |
SGLT2 Inhibitor | Dapagliflozin (Forxiga)Empagliflozin (Jardiance) | Risk of UTIsRisk of euglycaemic ketoacidosis, especially in the perioperative period |
Insulins
Insulin | Onset (min) | Peak (hrs) | Duration (hrs) | When to administer |
Ultra-Rapid Acting | ||||
Fiasp | 2 | 0.5-1 | 3-5 | 15 min before meals |
Rapid Acting | ||||
Apidra | 15 | 1 | 4 | 15 min before meals |
Humalog | 15 | 1 | 4 | 15 min before meals |
Novorapid | 10-20 | 1-3 | 3-5 | 15 min before meals |
Short Acting | ||||
Actrapid | 30 | 2.5-5 | 8 | 30 min before meals |
Humulin R | 30 | 2-4 | 6-8 | 30 min before meals |
Intermediate Acting | ||||
Humulin NPH | 60 | 4-10 | 16-18 | Same time every day |
Protaphane | 90 | 4-12 | Up to 24 | Same time every day |
Long Acting | ||||
Levemir | 180-240 | 3-14 | Up to 24 | Same time every day |
Optisulin | 180-240 | No peak | 24 | Same time every day |
Toujeo | 60-120 | No peak | 24-36 | Same time every day |
Pre-mixed Insulins (Biphasic) – Intermediate + Short/Rapid Acting | ||||
Humulin 30/70 | 30 | 2-12 | 16-18 | 30 min before meals |
Humalog Mix 25 | 15 | 2 | Up to 20-22 | 15 min before meals |
Humalog Mix 50 | 15 | 2 | Up to 20-22 | 15 min before meals |
Mixtard 30/70 | 30 | 2-12 | Up to 24 | 30 min before meals |
Mixtard 50/50 | 30 | 4-8 | Up to 24 | 30 min before meals |
Novomix 30 | 10-20 | 1-4 | 24 | 15 min before meals |
Pre-mixed Insulins (Biphasic) – Ultra-long Acting + Rapid Acting | ||||
Ryzodeg 70/30 | 10-20 | 1-3 | 26-48 | 15 min before meals |
Insulin Regimens
- Basal Insulin only – normally long acting insulins used in Type 2 diabetes in conjunction with OHGs
- Basal Bolus – Long acting insulin + ultra-rapid/rapid/short acting insulin with meals. Gives more tight control over BGs
- Pre-mixed insulin – mixed insulins normally taken pre-breakfast and pre-dinner. Can be more difficult to obtain good control of BGs when patients have variable nutritional intake throughout the day, but is preferred by some patients as it is more simple and requires less finger prick testing.
Initial Management of Moderate Hyperglycaemia #
- Review the patient’s recent BG control over the past few days, in particular the timing of hyperglycaemia. For example, a patient on basal bolus insulin with hyperglycaemia pre-lunch may need a higher bolus dose of insulin with breakfast, whereas a patient with global hyperglycaemia may need a higher basal insulin dose.
- Try to identify a cause for the patient’s hyperglycaemia e.g. withheld insulin/oral hypoglycaemic agents, new corticosteroid, dextrose infusion etc.
- A supplemental short/rapid acting insulin sliding scale can be utilised with meals to improve glycaemic control and assist with insulin titration whilst patients are in hospital. An initial stat dose of insulin can also be given for moderate hyperglycaemia e.g. BG >16 as per the table below.
Suggested Initial Stat and Supplemental Rapid/Short Acting Insulin Doses (4)
Previously on insulin: Determine using previous total daily dose | Less than 25 units | 25-49 units | 50-80 units | More than 80 units | |
Not previously on insulin:Determine using the patient’s actual weight | Less than or equal to 50kg | 50.1-75kg | 75.1-100kg | More than 100kg | |
BG (mmol/L) with suggested insulin doses | Greater than 20 | 4 units | 6 units | 8 units | 12 units |
16.1-20 | 3 units | 4 units | 6 units | 9 units | |
12.1-16 | 2 units | 3 units | 4 units | 6 units | |
8.1-12 | 1 unit | 1 unit | 2 units | 3 units |
Ongoing Management of Hyperglycaemia #
For patients with ongoing hyperglycaemia, an increase to the patient’s regular oral hyperglycaemic agents or insulin should be considered.
Starting Insulin #
For patients who have exhausted their oral hyperglycaemic agents or with difficult to control BGs, it is reasonable to consider starting the patient on insulin. In general, basal-plus (call out box – basal insulin and sliding scale) or basal-bolus insulin is commenced in inpatients. Pre-mixed insulins should be avoided in inpatients who often have variable oral intake whilst in hospital.
There are two main considerations used to decide on an insulin regime: timing of hyperglycaemia and cause of hyperglycaemia.
Patients with Primarily Pre-breakfast (Fasting) Hyperglycaemia #
Long acting insulin (e.g. Optisulin) at 0.1-0.15 units/kg/day and titrate according to BGs |
Patients with Primarily Pre-lunch Hyperglycaemia #
Rapid acting insulin (e.g. Novorapid) with breakfast using the sliding scale table above as a guide. Titrate according to BGs |
Patients with Primarily Pre-dinner Hyperglycaemia #
Rapid acting insulin (e.g. Novorapid) with lunch using the sliding scale table above as a guide. Titrate according to BGs |
Patients with Primarily Pre-bed Hyperglycaemia #
Rapid acting insulin (e.g. Novorapid) with dinner using the sliding scale table above as a guide. Titrate according to BGs |
Patients with Day Time Hyperglycaemia #
Basal bolus insulin: Once daily long acting insulin (e.g. Optisulin) AND rapid acting (e.g. Novorapid) three times a day with meals.Calculate total daily initial dose at 0.2-0.3 units/kg/dayGive 1/2 of this dose as the intermediate/long acting insulin at bedtimeGive the remainder insulin as three equal divided doses of rapid/short acting insulinOnly give the rapid/short acting insulin if patients have eaten >50% of their mealTitrate insulin doses according to BGs |
Patients with Hyperglycaemia Secondary to Prednisolone #
Intermediate acting insulin (e.g. Protaphane) at 0.3-0.4 units/kg/day at time of prednisolone administrationAdjust – If eGFR <45ml/min reduce to 0.15-0.2 units/kg/day |
Patients with Hyperglycaemia Secondary to Dexamethasone #
Long acting insulin (e.g. Optisulin) at 0.3-0.4 units/kg/day at time of prednisolone administrationAdjust – If eGFR <45ml/min reduce to 0.15-0.2 units/kg/day |
Patients with Hyperglycaemia Secondary to TPN/EN #
Can be a complex topic and management differs if the patient has nocte bolus feeds vs continuous feeds, delirious or post stroke. Suggest contacting the local endocrinology team for advice. |
Titrating Insulin #
Chart insulin sliding scaleCalculate the total amount of supplemental insulin used in the previous 24 hoursAdd the supplemental insulin to the patient’s usual insulin regimen, aiming for the above ratios pending their insulin regimenConsider converting to a basal bolus regime for patients with poorly controlled BGs on pre-mixed insulin |
Converting from Mixed Insulin to Basal Bolus Regime #
Calculate the total daily amount of mixed insulin usedGive 1/2 of this dose as the intermediate/long acting insulin at bedtimeGive the remainder insulin as three equal divided doses of rapid/short acting insulinOnly give the rapid/short acting insulin if patients have eaten >50% of their mealTitrate insulin doses according to BGs |
When to Contact Endocrinology #
- All patients with Type 1 Diabetes should be referred to endocrinology
- Patients with newly diagnosed diabetes
- Poorly controlled BGs despite following the above measures
- Patients with DKA or HHS
- Any other concerns
References #
- eTG complete [internet]. Melbourne (Vic): Therapeutic Guidelines Ltd; 2019. Drug-induced hyperglycaemia [cited 2021 Aug 25]. Available from: https://tgldcdp.tg.org.au.acs.hcn.com.au/viewTopic?topicfile=drug-induced-hyperglycaemia&guidelineName=Diabetes&topicNavigation=navigateTopic#MPS_d1e331
- Australian Diabetes Society. Latest Updates & News on Current Position Statements & Guidelines [Internet]. Australian Diabetes Society; 2014 [updated 2014; cited 2021 Sep 27]. Available from: https://diabetessociety.com.au/position-statements.asp
- Kitabchi A, Umpierrez G, Miles J, Fisher J. Hyperglycemic Crises in Adult Patients With Diabetes. Diabetes Care 2009; 32(7): 1335-1343. Table 1, Diagnostic criteria for DKA and HHS; p.1336.
- Hyperglycaemia – General Wards and CCU (Adult). Monash Health Prompt. 2013 October 24 (updated 2019 April 30) p.2
Contributors
Reviewing Consultant/Senior Registrar
Dr Bill Chow
Dr Rahul Barmanray