A prospective observational cohort study on postoperative intravenous patient-controlled analgesia in surgeries

Lee, Gwan Woo

Abstract

BACKGROUND
An electrical patient-controlled analgesia (PCA) pump enabled us to collect infusion history of opioid analgesic and other efficacy parameters of PCA, including delivery-to-attempt (D/A) ratio. This study evaluated the effectiveness of PCA in a large population of surgical patients using numerical rating scale (NRS) for pain and D/A ratio.
METHODS
A total of 6,847 patients were enrolled in this study. All patients received intravenous bolus of fentanyl (0.2 microg /kg) one hour before the end of the surgery. Basal infusion rate, demand bolus, and lockout time of the PCA pump was set as 1 ml/h, 1 ml, and 15 minutes, respectively. The concentration of fentanyl in the analgesic solution was 15 microg/ml.
RESULTS
NRS scores for pain and D/A ratios for the first 6 hours after operations were as follows (median, 25-75%): open colorectal surgery (NRS: 6.5, 5.0-8.0; D/A: 62.5, 46.2-77.8%), laparoscopic colorectal surgery (NRS: 6.0, 4.5-7.0; D/A: 69.2, 50.0-81.9%), open hepato-biliary-pancreas surgery (NRS: 6.0, 4.5-7.0; D/A: 59.2, 38.7-75.0%), open stomach surgery (NRS: 5.0, 4.0-6.7; D/A: 58.1, 41.2-75.0%), open abdominal vascular surgery (NRS: 5.0, 3.5-6.5; D/A: 58.3, 40.0-81.3%), laparoscopic stomach surgery (NRS: 5.0, 4.0-6.0; D/A: 63.6, 45.5-80.0%), laparoscopic hepato-biliary-pancreas surgery (NRS: 5.0, 4.0-6.0; D/A: 66.7, 50.0-80.8%), vascular bypass surgery (NRS: 4.0, 3.0-6.0; D/A: 64.5, 42.7-84.0%), anal surgery (NRS: 4.0, 3.0-5.8; D/A: 71.4, 60.0-100%), and breast surgery (NRS: 3.0, 3.0-4.0; D/A: 86.6, 67.2-100%).
CONCLUSIONS
Mean D/A ratios for the first 6 hours after all operations except anal and breast surgeries were below 70%, suggesting that a higher amount of fentanyl should be administered during this period.