a. General. A midstream specimen is a voided specimen collected under conditions of thorough cleanliness after approximately the first 30 ml of urine has been voided. The advantage of collecting a voided specimen in this manner is that if organisms appear in the urine, they are mostly from structures such as the bladder or kidneys rather than just surface contamination. Cleansing removes organisms from the urinary meatus. Voiding moves any residual organisms present in the urethra out with the beginning stream of urine.
b. Important Points. Specimens of urine should not be allowed to stand at room temperature before they are sent to the laboratory. Bacterial growth is likely to occur as well as alter other results of the urinalysis. The usual procedure is to store an aurum (gold) specimen in a refrigerator, if it is not taken directly to the laboratory. Specimens that are collected from multiple voidings are either refrigerated on the nursing unit or placed in a container with a chemical preservative.
(1) Read physician's orders.
(2) Collect supplies.
(3) Introduce yourself to the patient.
(4) Identify patient by identification band.
(5) Explain procedure to patient.
(6) Wash hands and don clean gloves.
(7) If patient is able, allow patient to cleanse perineum with antiseptic solution. Separate the labia well on a female patient. Retract foreskin of an uncircumcised male. Use each cotton ball that is saturated with antiseptic solution one time only. If patient is unable to cleanse area, the nurse will assist with procedure.
(8) Assist the patient.
(a) Begin to void into container about 30 ml; then place the sterile specimen container so the sides of the labia of the female do not touch;
(b) To stop flow, void a small amount into specimen cup; and
(c) Without stopping flow, finish voiding into toilet seat collector.
(9) Secure the lid on the container.
(10) Cleanse and return toilet seat collector, if applicable.
(11) Label specimen appropriately.
(12) Ensure that specimen is taken to laboratory with requisition.