Effectiveness of acute postoperative pain management: I. Evidence from published data

Background. This review examines the evidence from published data concerning the incidence of moderate-severe and of severe pain after major surgery, with three analgesic techniques; intramuscular (i.m.) analgesia, patient controlled analgesia (PCA), and epidural analgesia. Methods. A MEDLINE search of the literature was conducted for publications concerned with the management of postoperative pain. Over 800 original papers and reviews were identified. Of these 212 papers fulfilled the inclusion criteria but only 165 provided usable data on pain intensity and pain relief. Pooled data on pain scores obtained from these studies, which represent the experience of a total of nearly 20 000 patients, form the basis of this review. Results. Different pain measurement tools provided comparable data. When considering a mixture of three analgesic techniques, the overall mean (95% CI) incidence of moderate-severe pain and of severe pain was 29.7 (26.4-33.0)% and 10.9 (8.4-13.4)%, respectively. The overall mean (95% CI) incidence of poor pain relief and of fair-to-poor pain relief was 3.5 (2.4-4.6)% and 19.4 (16.4-22.3)%, respectively. For i.m. analgesia the incidence of moderate-severe pain was 67.2 (58.1-76.2)% and that of severe pain was 29.1 (18.8-39.4)%. For PCA, the incidence of moderate-severe pain was 35.8 (31.4-40.2)% and that of severe pain was 10.4 (8.0-12.8)%. For epidural analgesia the incidence of moderate-severe pain was 20.9 (17.8-24.0)% and that of severe pain was 7.8 (6.1-9.5)%. The incidence of premature catheter dislodgement was 5.7 (4.0-7.4)%. Over the period 1973-1999 there has been a highly significant (P<0.0001) reduction in the incidence of moderate-severe pain of 1.9 (1.1-2.7)% per year. Conclusions. These results suggest that the UK Audit Commission (1997) proposed standards of care might be unachievable using current analgesic techniques. The data may be useful in setting standards of care for Acute Pain Services.