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GMC #08/Diagnostic procedures taught Y1 & Y2

Capillary blood glucose

Measure the concentration of glucose in the blood at the bedside; record and interpret the result.

Target · Perform independently0% ready

Do it yourself on a patient, with support available if you need it — the GMC’s highest new-grad level (“indirect supervision”).

Overview

A near-patient test that must be part of the workup of every reduced-consciousness or acutely unwell patient — “don’t ever forget glucose”.

Key numbers

  • Hypoglycaemia = blood glucose <4.0 mmol/L (“four is the floor”)JBDS
  • Conscious/able to swallow: 15–20 g fast-acting carbohydrate, recheck at 15 min; if unable: IM glucagon or IV 10% glucoseJBDS hypoglycaemia

Indications

  • Diabetes monitoring
  • Reduced consciousness / collapse / seizure
  • Any acutely unwell patient

Equipment

Glucometer + in-date, calibrated test stripsSingle-use lancetAlcohol wipe/gauze, sharps bin

Step by step

Prepare
  1. 1Check the meter is calibrated and the strips are in date
  2. 2Wash the patient’s hands (warm water improves flow); do not use alcohol on the sample finger (falsely alters result)
Measure
  1. 1Lance the side of a fingertip (less painful, more capillaries)
  2. 2Apply a hanging drop to the strip; read the value
  3. 3Dispose of the lancet in the sharps bin
Interpret
  1. 1Hypoglycaemia <4.0 mmol/L (“four is the floor”) → treat immediately
  2. 2Confirm with a lab glucose if the result doesn’t fit the picture

Complications

  • Infection, inaccurate reading (wet/contaminated finger, out-of-date strips)

OSCE tips

  • Check strips in date & calibrated — an easy safety mark.
  • Side of the finger, not the pulp.
  • Know hypo management (“15 g fast carbs, recheck at 15 min”; IV glucose/IM glucagon if unable to swallow).

Watch

Read

Sources & credits

Authored to UK finals standard and verified against UK guidance (JBDS · JBDS hypoglycaemia) and Geeky Medics OSCE guides . Southampton teaching materials © University of Southampton. Always follow current local policy.