Metabolic
Glucose
Glucose is the principal circulating sugar and the body's main short-term energy substrate, tightly regulated by insulin and counter-regulatory hormones. At the point of care it is one of the most frequently measured analytes, used to detect and monitor hyperglycaemia and hypoglycaemia within seconds from a small blood sample.
Why it is measured
Rapid bedside glucose supports immediate decisions in suspected hypoglycaemia, diabetic emergencies, acute illness and perioperative care, where waiting for a central laboratory result could delay treatment. It also underpins routine diabetes screening and monitoring close to the patient.
| Typical range | Indicative adult fasting plasma-equivalent reference: approximately 3.9 to 5.5 mmol/L (about 70 to 99 mg/dL). Many POCT meters report plasma-calibrated values; capillary, venous and arterial samples and different methods can shift results, so ranges and clinical cut-offs vary by method and sample type and should follow local and manufacturer guidance. |
|---|---|
| Sample | Capillary whole blood from a fingerstick is most common; venous or arterial whole blood is also used on some analysers. Most modern meters report plasma-equivalent glucose. Avoid squeezing the fingertip excessively and observe device-specific limits on haematocrit, oxygen tension and interfering substances. |
| Turnaround | Seconds to about one minute from sample application to result on a handheld meter or benchtop POCT analyser. |
Point of care devices that report it
- Nova Biomedical StatStrip Glucose
- Roche Accu-Chek Inform II
- Abbott i-STAT (e.g. CHEM8+ or CG8+ cartridges)
- HemoCue Glucose 201
Questions, answered
Why can a fingerstick POCT glucose differ from the laboratory result?
Differences are expected and usually reflect sample type and method. Capillary blood, the timing relative to a meal, haematocrit, poor perfusion, and substances that interfere with the meter chemistry can all shift a reading compared with a venous laboratory plasma measurement. POCT meters are designed for monitoring and rapid triage; when a result is unexpected or clinically critical, confirming with a laboratory sample is good practice. This is general operational guidance, not advice for an individual case.
Does a POCT meter report whole blood or plasma glucose?
Most current hospital and professional meters apply a calibration factor and report plasma-equivalent glucose, which is typically around 11 percent higher than whole-blood values, so results align better with laboratory plasma assays. The exact behaviour depends on the device, so always check the specific analyser's documentation and the units it reports.
How is POCT glucose quality assured?
Operators run manufacturer liquid quality-control material at defined intervals and after events such as new strip lots, alongside competency assessment, lot checks and periodic comparison against the central laboratory. Connectivity through a POCT data manager helps lock out untrained users and capture QC compliance. This describes general quality processes rather than any clinical interpretation.