Phosphate(phosphorus) in urine (P)
(PHOS)

Sample type

24-hour urine

Random urine

Uses

1-Evaluation of calcium to phosphorus balance

2-Evaluation of nephrolithiasis

Precautions

make sure that a 24-hour urine sample has been collected

24-hour urine sample collection instructions

On day 1, urinate into the toilet when you get up in the morning.
Afterward, collect all urine in a special container for the next 24 hours.
On day 2, urinate into the container when you get up in the morning.
Cap the container. Keep it in the refrigerator or a cool place during the collection period.
Label the container with your name, the date, the time of completion, and return it as instructed.

Interfering factors

Laxatives with sodium phosphate or lots of vitamin D
During the last trimester of pregnancy, there is a sixfold increase in calcium and phosphorus accumulation
Increasing dietary intake of potassium has been reported to increase serum phosphate

Pre-analytical errors

1-If the sample was not collected with the correct instructions , or you received unlabeled sample .it will affect the result

2-The patient’s history has not been taken carefully and therefore there is information that needs to know and is not available.

The corrective actions

1-The sample should be rejected and another sample requested.

2-You must communicate with the patient ,and know all the informations you need especially ask about if he taking any laxitives containing sodium or any vitamin or drugs that can affect the result and If the patient is a woman, you should ask her if she is pregnant and at what stage of pregnancy. And in the next time the history of the patient should be taken carefully.

Post-analytical errors

1-Writing a wrong result or wrong name in the report

2- If the patient’s gender is written wrong in the report, the reference range was written incorrectly

3-report were sent to incorrect patient

The corrective actions

1- If the report is not delivered to the patient and this error is discovered, the correct result or the correct name must be written, but if the report is delivered to the patient, you must communicate with the patient, apologise to him, and tell him that an error has occurred and replace it with the correct report.

2-If the report is not delivered to the patient and this error is discovered, fix it, but if the report is delivered to the patient, apologise to him, tell him that an error has occurred, and replace it with the correct report. And next time, Be careful when you write down the gender and reference range.

3-Communicate with patient ,apologizing for the error, and providing him with the correct report

Reference range

24-hour urine

Adults : 0.4-1.3 g/day

Random urine:

Male:

Less than 40 years: 36–1,770 mg/g creatinine

Greater than 40 years: 54–860 mg/g creatinine

Female:

Less than 40 years: 111–927 mg/g creatinine

Greater than 40 years: 105–1,081 mg/g creatinine