Point of care testing
Outside the laboratory
Table 4.1 shows what can be commonly measured in a blood sample outside the normal laboratory setting. The most common blood test outside the laboratory is the determination of glucose concentration, in a finger stab sample, at home or in the clinic. Diabetic patients who need to monitor their blood glucose on a regular basis can do so at home or at work using one of many commercially available pocket-sized instruments.
Table 4.1
Common tests on blood performed away from the laboratory
| Analyte | Used when investigating |
| Blood gases | Acid–base status |
| Glucose | Diabetes mellitus |
| Urea | Renal disease |
| Creatinine | Renal disease |
| Bilirubin | Neonatal jaundice |
| Therapeutic drugs | Compliance or toxicity |
| Salicylate | Detection of poisoning |
| Paracetamol | Detection of poisoning |
| Cholesterol | Coronary heart disease risk |
| Alcohol | Fitness to drive/confusion, coma |
Figure 4.1 shows a portable bench analyser. These analysers may be used to monitor various analytes in blood and urine and are often used in outpatient clinics.
Table 4.2 lists urine constituents that can be commonly measured away from the laboratory. Many are conveniently measured, semi-quantitatively, using test strips which are dipped briefly into a fresh urine sample. Any excess urine is removed, and the result assessed after a specified time by comparing a colour change with a code on the side of the test strip container. The information obtained from such tests is of variable value to the tester, whether patient or clinician.
Table 4.2
Tests on urine performed away from the laboratory
| Analyte | Used when investigating |
| Ketones | Diabetic ketoacidosis |
| Protein | Renal disease |
| Red cells/haemoglobin |
