ATS Pulmonary Function Laboratory Manual

ATS Pulmonary Function Laboratory Management & Procedure Manual | 3rd Edition

Test Procedure for Capillary Sampling

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Step Action 3. The heel should be punctured with a sterile lancet, or with an automated lancet device to a depth of approximately 2 mm. 4. The specimen should be collected in a heparinized capillary tube and must not contain air bubbles. Exposure of blood to air even for short periods can result in significant changes. Thus, the specimen is to be kept anaerobic (i.e., capillary ends sealed) at all times. 5. After collecting a specimen in the capillary tube, seal one end immediately with a cap or putty. Place a small magnetic stirring bar (also called “flea”) into the tube and seal the other end. With the stirring bar in the tube, the blood can be mixed by moving the magnet back and forth along the entire length of the outside of the tube. 6. Apply mild pressure to the site using dry gauze, until hemostasis occurs. Initial Handling • Properly identify and label the specimen according to institutional procedures. If the specimen is to be immersed in coolant, the label must remain legible after immersion. • Specimens obtained in plastic syringes for blood gas measurements should be stored at room temperature. If analysis is anticipated to be delayed by more than 30 minutes, the blood should be collected in a glass syringe and placed in an ice water bath (1, 2). • Coolant: if it necessary to cool the specimen, a container with a mixture of crushed ice and water or other coolant, large enough to permit immersion of the entire barrel of the syringe or collection device, should be prepared before the specimen is obtained. Immerse the specimen in the coolant immediately after it has been securely closed and labeled. 2. Samples for blood gas and pH analysis: • If prompt analysis occurs within 30 minutes of collection, the use of a plastic syringe is recommended, and specimen does not need cooling. • If analysis is delayed (i.e., >30 minutes after collection), the specimen should be immersed in coolant as soon as possible after collection. 3. Transportation to laboratory: • The entire container (including coolant, if used) and the specimen should be taken to the laboratory and analyzed as soon as possible. • A requisition or test-request form must accompany the specimen and include a unique specimen identification, date and time of specimen collection, and additional information as referred to in Patient Preparation section. Post Collection Procedure Step Action 1.

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