When having trouble visualizing a vein, the best approach is to ask the patient to make a fist but to avoid having them pump the fist because this may result in hemoconcentration and can affect the test results, especially that of potassium. The fist should be released as soon as blood begins to flow into the collection tube. Vigorously massaging the vein or leaving the tourniquet in place for more than 60 seconds can also cause hemoconcentration.

For most point-of-care (POC) pregnancy tests, the earliest time at which the test will be accurate is 1 day after a missed period. If the patient is unsure about when her period is due, then the test can be taken 21 days after unprotected sex Some newer tests are now able to detect pregnancy even before a missed period. However, testing too early can sometimes produce a false negative, so tests taken after a missed period are usually more accurate. Testing is carried out with a urine sample.

When using a bariatric blood pressure cuff instead of a tourniquet for an obese patient, the blood pressure cuff should be inflated to just below the patient's diastolic pressure. The phlebotomist should begin by measuring the patients' blood pressure and then adjusting the pressure. The cuff should not be so tight that it is painful for the patient Whereas most tourniquets are approximately 18 inches in length, bariatric tourniquets are available in longer lengths.

If less than the recommended volume necessary for blood cultures is obtained, the aerobic specimen tube should be filled completely first and then the remainder is placed in the anaerobic tube. The tubes should be inverted gently a few times to prevent clotting. The only anticoagulant that is acceptable for blood cultures is sodium polyanetholesulfonate (SPS), and the blood can be collected directly into tubes with SPS and then transferred to the medium for culture.

Infections that are spread via droplets can travel long distances in the air before dropping to the ground, especially when spread through sneezing and coughing. CDC guidelines recommend that a mask and face shield be donned by all healthcare providers when entering a the room of a patient that is on droplet precautions (for instance, in cases of seasonal influenza or pertussis). When the healthcare provider is at risk for exposure to bodily fluids, such as in the case of phlebotomy practices, gloves and gown are also recommended. N95 respirators are recommended for airborne diseases (e.g„ COVID-19, tuberculosis).