If predialysis BUN is lower than postdialysis BUN, the technician should ask:

If predialysis BUN is lower than postdialysis BUN, the technician should ask:

• A. Was the post dialysis sample drawn correctly
• B. Was the pre-dialysis sample labeled properly
• C. Was the dialysis session stopped early
• D. Was the patient hydrated

Answer: (C)

The key idea is that BUN should decrease during a proper dialysis session. If the predialysis BUN ends up lower than the postdialysis BUN, something prevented the expected clearance from happening. The most direct explanation to investigate is whether the dialysis session was stopped early. If the session ended before enough time and dialysis flow were allowed to run, there wouldn’t be adequate removal of urea, so the postdialysis BUN could remain high or even be higher than the predialysis level. While other issues like sampling timing, labeling, or hydration status could contribute to discrepancies, stopping the session early best explains a reversal in the expected trend and should be checked first.

The key idea is that BUN should decrease during a proper dialysis session. If the predialysis BUN ends up lower than the postdialysis BUN, something prevented the expected clearance from happening. The most direct explanation to investigate is whether the dialysis session was stopped early. If the session ended before enough time and dialysis flow were allowed to run, there wouldn’t be adequate removal of urea, so the postdialysis BUN could remain high or even be higher than the predialysis level.

While other issues like sampling timing, labeling, or hydration status could contribute to discrepancies, stopping the session early best explains a reversal in the expected trend and should be checked first.