Introduction

This section provides guidance and information on capillary blood glucose monitoring, optimal glycaemic control and the management of hyperglycaemia for inpatients with diabetes.  

NOTE: management of hypoglycaemia is covered in a separate chapter here


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Basics of good diabetes care

All patients known to have diabetes should have a venous plasma glucose measurement and HbA1c (unless there is a result on record within previous 2 months). Test for ketones (urine or blood) on arrival to hospital in any patient with diabetes who is unwell, has newly diagnosed diabetes or known to have type 1 diabetes. Their diabetes medication should be prescribed promptly and correctly.

For all patients you need to ensure that you:

  • Check the DIABETES CHART daily (see link to diabetes checklist document)

  • Check patients FEET and heels daily for pressure damage or ulceration

  • Take ACTION when necessary

  • Use insulin SAFELY

  • TALK to patients, family and carers and staff about INSULIN

  • SPEAK UP if there is a problem


 Bedside Monitoring of Capillary Blood Glucose (CBG)

All patients with diabetes require daily capillary blood glucose checks. For the majority CBG will be measured before each meal and before bed (4 tests). If all results in the first 24 hours are in the acceptable range (CBG 6-10mmol/l ideal, 4–12mmol/l acceptable), and the patient’s condition is considered to be stable, the test frequency could be reduced according to the type of treatment the patient is taking for diabetes as shown below.

Guidelines

  • Metformin or diet alone - 1 or more/day

  • Other tablet treatments and/ or non-insulin injectable treatment - 2 or more/day

  • Insulin treatment, unwell or unstable diabetes ( on any diabetes treatment) - 4 or more/day

Several studies looking at glycaemic control in hospitalised medical patients point to a strong association between hyperglycaemia and poor clinical outcomes, including prolonged hospital stay, infection, disability after discharge from the hospital and death.

Target blood glucose levels have not been established in trials but there is consensus for an ideal range between 6-10 mmol/l (4-12mmol/l being acceptable).  

CAUTION: Target for elderly/frail patient is 7.8-10mmol/l. For patients with moderate/severe frailty or end of life the recommendation is to individualise the target to avoid hypoglycaemia (range 7.8-15mmol/l).

 This range aims to avoid the risks associated with both hyperglycaemia and hypoglycaemia. 


Hyperglycaemia

Several factors (e.g. sepsis, stress, steroids) can temporarily increase the blood glucose levels and hence the doses of oral hypoglycaemic agents/ insulin need to be reviewed and titrated accordingly. If the blood glucose is above 12mmol/l, follow the guidance below and wherever possible, consult the patient about their diabetes management. 

 Is the patient obstetric?

 

Is the patient unwell?

  • If YES, check for blood or urinary ketones

  • If blood ketones > 3 mmol/L or urine ketones ketones +++ or more check pH and bicarbonate. 

    • If pH <7.3 or bicarbonate < 15mmol/L  – Treat according to DKA guidelines

    • If pH > 7.3 and bicarbonate > 15 mmol/L exclude HHS in Type 2 diabetes and start variable rate intravenous insulin infusion (see VRIII guidelines) for those who are unwell and/or unable to eat and drink. 

 

Is the patient stable, systemically well and eating?

  • If YES – was the blood glucose measured BEFORE a meal? If NO, repeat before next meal and review again

  • If YES – discuss management with patient where possible. If a stable/well patient on insulin or tablets has hyperglycaemia during his/her inpatient stay aim to titrate the regular dose of diabetes medication where possible.  

  • PRN doses of insulin may be required in the management of hyperglycaemia. 

  • The sections below discuss insulin dose titration and use of PRN insulin in more detail.

Adult UHL Hyperglycaemia Decision Support tool


Insulin Dose Titration

  • Review trends in capillary blood glucose (CBG) readings rather than individual/random results. Review the readings from preceding 48- 72 hours.

  • View the blood glucose results in relation to the type of insulin and timing of injections. Generally when titrating usual insulin treatment, increases are made in 10% increments. 

  • Consider which insulin dose/s requires titration. For instance, for patients on biphasic/mixed insulin, morning dose of insulin is titrated against pre-lunch and pre-evening meal blood glucose tests (suggest 2 unit increments or 10% increase to aim for target blood glucose levels). Similarly evening dose is titrated against pre-bed and pre- breakfast test to aim for target results at these times.  

  • For patients on basal only insulin regimen, aim to achieve target fasting glucose levels by increasing the dose of basal insulin (E.g., Lantus or Levemir) by 2 units or 10% every 3 days until agreed targets are reached. 

  • Watch carefully for the risk of nocturnal hypoglycaemia.

  • Avoid readings ≤ 4mmol/l. Prevention of hypoglycaemia takes precedence and if hypoglycaemia occurs and no obvious cause can be found (e.g., missed meal) a 20% reduction in insulin dose is required with careful monitoring. For the management of hypoglycaemia, see here.

  • Deterioration in renal function may lead to a risk of hypoglycaemia in insulin users so doses need regular monitoring and titration where renal function is impaired.

  • Consider referral to diabetes team/ DSNs if appropriate. The referral criteria are found here.

The Insulin Dose Titration Decision support tool provides guidance on insulin titration with various regimens: 

  •  Always consider if patient is well or unwell, has type 1 diabetes or type 2 diabetes and reasons why patient has become hyperglycaemic when assessing raised CBG levels and deciding on management.



 Use of PRN insulin

The Hyperglycaemia Decision Support tool provides guidance on the management of hyperglycaemia in inpatients. PRN doses of insulin are usually required for the management of hyperglycaemia in the following scenarios:

  • Well patients with Type 1 diabetes who are eating and drinking and who are hyperglycaemic (DKA excluded) Note; always consult with patient regarding diabetes management in this scenario.  

  • For well patients with Type 2 diabetes who are eating and drinking and who are found to be hyperglycaemic aim to manage hyperglycaemia by titrating usual medication in first instance.

  • Symptomatic or systemically unwell patients (Type 1 and Type 2 diabetes) who are able to eat and drink and where HHS / DKA excluded it is reasonable to use PRN insulin for rapid control of CBG if patient is hyperglycaemic. If 2 consecutive doses of PRN insulin are required consider VRIII.  Note: patients who are systemically unwell or unable to eat or drink will require VRIII.

  • In any patient with diabetes who is well and eating and drinking however there is a clinical requirement to gain rapid control of CBG and manipulation of usual regime is not possible, eg, pre-operatively.

 If PRN insulin required:

  • Use rapid-acting insulin analogue, eg Novorapid

  • For individuals with Type 1 diabetes, 1 unit of rapid-acting insulin lowers CBG by approx. 3mmol/l and CBG should be checked at 2 and 4 hours 

CAUTION: Some patients are very sensitive to insulin and will require a reduced PRN dose.  This includes some patients who are newly diagnosed with type 1 diabetes, slim / low BMI, patients with secondary diabetes due to pancreatitis or pancreatic surgery and patients who are on small daily doses of insulin.

  • For individuals with Type 2 diabetes who are insulin resistant and on large doses of insulin an increased PRN insulin dose may be required.  If dose suggested in the Hyperglycaemia Decision support tool is ineffective and patient is well but remains hyperglycaemic then consider increasing the PRN insulin dose by 2 – 4 units.  The maximum PRN dose for a patient with Type 2 diabetes should not exceed 0.1 units/kg rapid acting insulin analogue, eg, NovoRapid and check blood glucose at 2 and 4 hours

  • When making any decision to titrate insulin doses / use of PRN insulin doses always clearly document reasons for changes made and new dose / regime in the patient’s notes.  Ensure the change in prescription is clear also.  If you decide that a change in treatment or PRN insulin dose is not appropriate (eg, in patient who is in final days of life and asymptomatic) you should also clearly document in notes reason why treatment not altered.

Adult UHL Hyperglycaemia Decision Support tool

 

ITS ANIMATION: INSULIN TITRATION