A postoperative patient is using patient-controlled analgesia (PCA) pump. You will evaluate the effectiveness of the medication when

The correct answer is D because comparing assessed pain with baseline pain provides an objective measure of the effectiveness of the medication. This method allows for a direct comparison of the patient's current pain level to their pre-treatment pain level, giving a clear indication of the medication's efficacy. Family members' reports (A) may be subjective and not necessarily reflective of the patient's actual pain level. Vital signs (B) returning to baseline may indicate physiological stability but not necessarily pain relief. Body language incongruent with pain relief reports (C) could be due to various factors and may not accurately reflect pain relief. Therefore, the most reliable method to evaluate the medication's effectiveness is to compare the assessed pain with the baseline pain level.