Greater Glasgow and Clyde Medicines

Safe use of insulin for adults admitted to hospital - Prescribing

Part 2 – Safe inpatient prescribing

This blog is the second in a series outlining risks relating to insulin prescribing and administration for adults in hospital, and at discharge and aims to provide good practice points to minimise these risks.

Key messages

• Errors involving insulin can cause serious harm to patients. Accurate prescribing is essential to maintain patient safety.

• For general advice on insulin, clinical staff are advised to follow the NHSGGC ‘Key Insulin Safety Tips’ which can be accessed via Diabetes, Inpatient Prescribing FAQs for Junior Doctors.

• Follow the advice below on where, how and what to prescribe.

1. Where to Prescribe

   • All subcutaneous (SC) insulin MUST be prescribed by brand on both HEPMA AND the paper Insulin Prescribing and Administration Record (IPAR) which is usually kept in the patient’s bedside folder.

   • Intravenous (IV) insulin should be prescribed on HEPMA AND an accompanying IV insulin protocol e.g. Diabetic Ketoacidosis (DKA) pathway 1 or 2, Hyperosmolar Hyperglycaemic Syndrome (HHS) pathway or Variable Rate Intravenous Insulin Infusion (VRIII) chart. Paper copies are available in relevant ward areas and guidance can be found online via the clinical guidelines directory: NHSGGC Clinical Guideline Platform

2. How to Prescribe

   • Always prescribe insulin with units written in full. NEVER abbreviate “units” to “U” or “IU” as this can be misinterpreted as a zero and lead to an unintentional ten-fold increase in dosing.

   Subcutaneous (SC) Insulin

   • Regular doses of insulin must be prescribed as a “regular” prescription on HEPMA ‘as per paper chart’ (see screenshots below).

   • Due to variability in dosing, the HEPMA prescription will only indicate the frequency and will refer to use of the IPAR for individual doses.

   • Ensure the timing on HEMPA corresponds with the regular times the patient usually takes their insulin(s) as this alerts nursing staff that a dose is due.

   • Each individual dose of insulin should be prescribed on the IPAR. The IPAR should be reviewed daily and it is good practice to prescribe insulin doses for the next 24 hours, where possible, to prevent delays.

   • Always continue long acting SC insulin in patients on IV insulin infusions but note, mixed insulins (e.g. Humalog Mix 25®) should be withheld. Do not attempt to convert a mixed insulin into its long acting component.

   Examples of SC insulin prescribing on HEPMA:

   (use zoom function to enlarge images and if using a mobile device, switch to landscape)

   Rapid Acting insulin

   
   

   Long Acting insulin

   
   

   Mixed Insulin

   

   • All changes to the insulin regime e.g. brand of insulin or frequency must be reflected with prescriptions on both IPAR and HEPMA. If HEPMA and IPAR do not match it can lead to ambiguous prescribing or incorrect information on discharge.

   Correction Doses (PRN insulin)

   • Correction doses of rapid acting insulin are used in patients with very high blood glucose or signs of ketosis to gain rapid control of glycaemia and prevent development of metabolic decompensation e.g. DKA.

   • See Diabetes, Inpatient Prescribing FAQs for Junior Doctors for details on how to calculate correction doses.

   • The following is an example of how to prescribe correction doses on HEPMA (they must also be prescribed on the IPAR).

     

   • Correction insulin should not be prescribed on discharge unless discussed with the diabetes team and a clear plan is in place.

   IV Insulin Prescribing

   • Actrapid® is the most commonly used insulin for IV administration in NHSGGC.

   • As an additional infusion chart is used for IV insulin, the HEPMA prescription will default to "PRN" use and refer to use of the paper chart (see below). No dose or frequency need to be specified on HEPMA. See example below.
     
     

     

   • The appropriate sections of the supplemental paper charts should be completed and signed. Refer to individual charts for details.

3. What to prescribe

   • Ensure the correct brand of insulin is prescribed. Many insulins have similar names and errors in drug selection can lead to avoidable complications such as hypoglycaemia or acute diabetic decompensation e.g. DKA. For example, Humulin S (short acting), Humulin I (Intermediate acting) and Humulin M3 (mixed biphasic) while sounding similar, ARE NOT INTERCHANGABLE. Refer to Safe use of insulin for adults admitted to hospital - Medicines Reconciliation.

   • The insulin prescribed on the IPAR should match the insulin prescribed on HEPMA.

   • SC insulin should always be prescribed as pre-filled pens or cartridges for inpatient use. Ensure the correct device is selected on HEPMA and endorse the insulin chart to avoid:

     • A delay in supply, with subsequent delayed or missed doses.

     • An incorrect device being ordered/supplied, causing confusion for the patient and unnecessary costs if it cannot be used.

     Ensure the device is reviewed at discharge to ensure it is appropriate for use at home.

   • High Concentration Insulin: If a high concentration preparation is indicated, ensure this product is selected on HEPMA and documented on the IPAR. Highlight the prescription to nursing staff: this should minimise confusion and ensure that the correct concentration is selected for administration. Refer to Safe use of insulin for adults admitted to hospital - Medicines Reconciliation.

   • The IPAR is for prescription of SC INSULIN only. Injectable GLP-1 receptor agonists, e.g. liraglutide, dulaglutide, semaglutide, can be prescribed on HEPMA only.              

Refer to other blogs in the insulin safety series:

Safe Use of Insulin for Adults Admitted to Hospital – Summary of Blog Series
Safe use of insulin for adults admitted to hospital - Medicines Reconciliation

Safe use of insulin for adults admitted to hospital - Administration

Safe use of insulin for adults admitted to hospital - Discharge

Published 28/03/2023. Link to guideline updated 08/09/23. Medicines Update blogs are correct at the time of publication.

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