While attempting to draw blood from an indwelling arterial catheter, the respiratory therapist no-tices a dampened waveform and has difficulty withdrawing blood for sampling. What should the respiratory therapist's immediate action be?

a. Flush the catheter.
b. Remove the catheter.
c. Reposition the catheter.
d. Recalibrate the transducer.

ANS: B
The presence of both a persistently dampened waveform and difficulty withdrawing blood indi-cates that there is a clot. To avoid any adverse effects the catheter should be removed. Flushing the catheter could cause the blood clot to move into the patient's circulation and has the potential to cause an infarction in the brain, heart, or lungs. Repositioning the catheter will not remove the clot. Recalibrating the transducer will not remove the clot.