Urine testing, capillary glucose and diagnostic swabs

Prepare a clean workspace, request, labels, sterile container or validated point-of-care kit, timer, PPE, waste and transport bag. Confirm two identifiers and explain what the sample can and cannot show. Check expiry, storage conditions, quality-control status and manufacturer instructions. Ask about antibiotics, menstruation, hydration, meals, insulin and recent hand contamination because they alter interpretation.

For a clean midstream urine, provide a sterile wide-mouth container and clear instructions. Perform hand hygiene, avoid touching the inside of pot or lid, begin voiding into the toilet, collect the middle stream and complete voiding. Secure the lid, wipe contamination from the outside, label beside the patient with date and time, and send promptly under local preservation rules.

Alternative urine specimens have different techniques. In young children, clean-catch is preferred where achievable; collection bags contaminate easily. Catheter urine for culture is obtained aseptically from the sampling port after preparation, never from the drainage bag. A first-catch urine may be required for some molecular STI tests, so do not substitute an MSU without checking assay instructions.

For dipstick, mix a fresh specimen, remove one strip without touching reagent pads and recap the container. Fully wet all pads briefly, remove excess according to instructions, hold horizontally and use a timer. Read each pad at the manufacturer’s stated time in adequate light or with the validated reader. Record each result, strip lot if required, specimen timing and symptoms.

Interpret urinalysis as pattern and context. Nitrite depends on bacterial nitrate reduction and bladder dwell time; a negative result does not exclude UTI. Leucocyte esterase can reflect inflammation or contamination. Blood requires follow-up when persistent, and myoglobin or haemoglobin can produce a positive pad without intact red cells. Protein is affected by concentration and needs quantitative confirmation when clinically relevant.

Choose the right UTI diagnostic pathway before using a dipstick. Do not use dipsticks to diagnose suspected UTI in catheterised patients or in the older-adult pathway: asymptomatic bacteriuria is common. Assess new symptoms and signs, other causes and indications for culture. UKHSA allows some community women over 65 without the relevant older-adult risk factors to follow its under-65 pathway. These restrictions concern UTI diagnosis, not every other indication for urine testing.

Ketones with hyperglycaemia, vomiting, abdominal pain or rapid breathing raise diabetic ketoacidosis and require urgent blood ketones, venous gas and clinical care; a urine result must not delay treatment. Pregnancy testing also depends on timing and dilution. A negative early sample does not exclude pregnancy when symptoms suggest ectopic pregnancy.

Capillary-glucose equipment includes an approved meter, correct in-date strips, single-use safety lancet, gauze, gloves, sharps bin and cleaning materials. Verify device quality checks and patient-specific restrictions; some meters are inaccurate with shock, severe dehydration, poor perfusion, extreme haematocrit or interfering substances. Use laboratory testing when the device is unsuitable.

Ask the patient to wash hands with soap and water and dry completely; sugary residue can create a false high and wet skin dilutes blood. Warm a cold hand and select the side of a fingertip, avoiding oedema, infection and damaged skin. Insert the strip as instructed, lance once, wipe the first drop only if the device/local protocol requires, and allow a sufficient drop without forceful milking.

Apply blood exactly to the strip’s sample area, wait for the displayed result and check units. Compress the site, discard lancet directly and clean the meter using the product-approved method. Record time, relation to food and treatment, symptoms, device identity and action. Treat the patient, not an isolated number; severe symptoms require ABCDE and confirmatory sampling without delaying glucose treatment.

For an unexpectedly low reading, check symptoms and immediately repeat with a new strip or alternative validated device while giving urgent hypoglycaemia treatment when indicated. For very high glucose, assess ketones, hydration, mental status and acidotic breathing. A “HI,” “LO” or error code is not a numeric result; consult the device instructions and obtain laboratory measurement.

Diagnostic swabs are assay-specific. Read the laboratory directory for swab material, transport medium, site, timing and PPE. A wound sample should target viable infected tissue or fluid after superficial debris is removed, not dry intact skin. Throat swabs sample the tonsillar areas and posterior pharynx while avoiding tongue and cheeks. Viral combined nose/throat techniques follow the named kit and current pathogen guidance.

For a wound, describe site, depth, infection signs, antimicrobial exposure and special exposures. Clean superficial contaminants as local protocol specifies, rotate the swab firmly across the active wound bed to absorb material and return it without touching edges. Pus or tissue may be diagnostically superior to a surface swab; seek laboratory advice for deep, sterile-site or unusual infection.

For a throat swab, use light, tongue depressor and appropriate PPE. Ask the patient to open wide and phonate, swab both tonsillar pillars or inflamed/exudative areas and posterior pharynx, avoiding lips, tongue and teeth, then place in medium. Stop if vomiting, respiratory distress or inability to cooperate makes collection unsafe.

Seal, label and bag every swab at the bedside, including precise site and laterality. Record collection time, clinical syndrome, exposure, antimicrobial use and tests requested. Transport at specified temperature and timeframe; the wrong medium or delay can invalidate molecular and culture tests. Follow isolation and public-health instructions for high-consequence pathogens rather than sampling casually.

Aftercare includes bleeding check after finger prick, hand hygiene, comfort and explanation of when results return. Name who reviews laboratory results and how urgent positives are communicated. Review whether the result fits the syndrome; colonisation or contamination can produce a positive culture, while prior treatment can produce false negatives.