Why should you avoid having a patient pump their fist before an i-STAT blood draw?

Pumping the fist before an i-STAT blood draw can lead to excessive muscle activity, which may affect the blood sample and overall procedure. When a patient pumps their fist, it causes contraction of the forearm muscles, which can release additional metabolites and alter the composition of the blood sample. This can lead to inaccurate results as the sample may reflect changes specific to muscle activity rather than the true state of the blood. Proper blood sampling requires minimizing external influences on the blood composition to ensure the results are reliable and accurate.

The other options generally pertain to different aspects or considerations related to blood draws—such as concerns for vein integrity, contamination, or physical complications—that are not the primary reason for avoiding fist pumping specifically before an i-STAT blood draw. Understanding the importance of minimizing muscle activity ensures that the test results are reliable.