Patients' vs nurses' assessments of postoperative pain and anxiety during patient- or nurse-controlled analgesia

We have compared patients' and nurses' assessments of postoperative pain and anxiety after different analgesic treatments. Sixty orthopaedic patients were allocated randomly to receive i.v. piritramide (either nurse-controlled or patient-controlled) or subarachnoid bupivacaine (nurse-controlled or patient-controlled). Patients and nurses assessed pain and anxiety using a visual analogue scale (VAS; 1-100 mm). Pain and anxiety ratings of patients and nurses were significantly correlated (Spearman's r > or = 0.69; P < 0.001). In general, patients' pain scores were higher than nurses' scores (patients' median VAS = 34 (range 1-76) mm; nurses VAS 21 (1-59) mm) and for all groups except the patient-controlled subarachnoid bupivacaine group, where they were significantly higher (P < 0.01). Discrepancy in pain estimates between patients and nurses increased with the level of pain. The relationship between patients' and nurses' anxiety scores was less clearly defined and did not depend on the level of anxiety.