PURPOSE: This study was undertaken to evaluate the factors affecting the unused remaining volume of intravenous patient-controlled analgesia (IV PCA) in patients who had undergone laparoscopic gynecologic surgery. METHODS: We retrospectively collected patient records from pre-existing PCA log sheets from 98 patients. Surgical factors and IV PCA-related data including remaining volume, administration duration, early discontinuation (yes or no), and adverse reactions were recorded. Chi-square test, one-way analysis of variance, and multiple linear regression were applied for data analysis. RESULTS: The average age of the 98 patients was 40.0 +/- 8.24 years. The incidence of postoperative nausea and vomiting (PONV) and early discontinuation were not statistically significant among the different surgical groups (p = .540 and p = .338, respectively). Twenty-eight patients wanted discontinuation of IV PCA and the remaining volume was 33.6 +/- 7.8 mL (range 20-55 mL). The significant determinants of remaining volume were whether IV PCA was discontinued due to PONV and duration of surgery (p < .001). The surgical duration was inversely correlated with the remaining volume. CONCLUSION: Early discontinuation of IV PCA due to PONV is a major contributing factor to wastage of medicine. Prevention and treatment of PONV is needed to encourage patients to maintain PCA use for pain control.
Administration, Intravenous/*adverse effects/utilization ; Adult ; Analgesia, Patient-Controlled/*adverse effects/utilization ; Female ; Gynecologic Surgical Procedures/*adverse effects ; Humans ; Laparoscopy/*adverse effects ; Middle Aged ; Pain Management/*adverse effects/utilization ; Pain, Postoperative/drug therapy ; Postoperative Nausea and Vomiting/*chemically induced ; Retrospective Studies ; Young Adult

OBJECTIVE: There have been many cases of spontaneous adverse drug reactions to fentanyl at a regional pharmacovigilance center in the hospital. To assess the factors causing the adverse drug reactions reported in patients receiving fentanyl patient-controlled analgesia (PCA) monotherapy or in combination with fentanyl transdermal therapeutic system (TTS) for acute post-operative pain management. METHODS: We conducted a retrospective cohort study with all patients prescribed fentanyl PCA for pain management after orthopedic surgery at a single university hospital from June 2012 to May 2013. We analysed the factors causing adverse drug reactions reported by a spontaneous reporting system in patients receiving fentanyl PCA monotherapy and those receiving fentanyl TTS in combination with fentanyl PCA. RESULTS: Based on the spontaneous adverse drug reaction reporting, the risk ratio for the incidence rate of adverse drug reaction in the fentanyl TTS combination therapy group was 3.04 (95 % CI: 2.4-4.00, P < 0.0001), which was approximately 3-fold higher than that reported for fentanyl PCA monotherapy. Only 60 % of the adverse drug reactions were reported. CONCLUSION: It is inappropriate to add fentanyl TTS to fentanyl PCA to manage post-operative acute pain. There is a need to improve adverse drug reaction reporting. We expect that regular analysis of adverse drug reactions reported at regional pharmacovigilance centre would aid in appropriate drug utilization by patients.
Acute Pain ; Analgesia, Patient-Controlled ; Cohort Studies ; Drug Utilization ; Drug-Related Side Effects and Adverse Reactions* ; Fentanyl* ; Humans ; Incidence ; Odds Ratio ; Orthopedics ; Pain Management* ; Passive Cutaneous Anaphylaxis* ; Pharmacovigilance ; Retrospective Studies