Patient-controlled postoperative analgesia: comparison of efficacy, side-effects and safety of various regimens

Contents 6 7 This dissertation is based on the following original publications, which will be referred to in the text by their Roman numerals I-V. Comparison of analgesic efficacy of oxycodone and morphine in postoperative intravenous patient-controlled analgesia. Efficacy and side effects of tramadol versus oxycodone for patient-controlled analgesia after maxillofacial surgery. Comparison of intravenous patient-controlled analgesia with tramadol versus morphine after microvascular breast reconstruction. Continuous epidural analgesia with bupivacaine-fentanyl versus patient-controlled analgesia with i.v. morphine for postoperative pain relief after knee ligament surgery. Patient-controlled epidural analgesia versus continuous epidural analgesia after total knee arthroplasty. The articles are reproduced in this dissertation with the kind permission of the publishers. ABBREVIATIONS ASA the classification of physical status (I-V) according to the American Society of Anesthesiologists (American Society of Anesthesiologists 1963; Schneider 1983) DSST Digit Symbol Substitution Test ECG electrocardiogram EPI continuous epidural infusion (Study V) F5 continuous epidural infusion with bupivacaine 1 mg/ml and fentanyl 5 µg/ml (Study IV) F10 continuous epidural infusion with bupivacaine 1 mg/ml and fentanyl 10 µg/ml (Study IV) G Gauge (international calibre unit) 5-HT 5-hydroxytryptamine, serotonin i.m. intramuscular(ly) i.v. intravenous(ly) ME(A)C minimum effective (analgesic) concentration NSAID non-steroidal anti-inflammatory drug PCA patient-controlled analgesia PCEA patient-controlled epidural analgesia p.o. peroral(ly) PONV postoperative nausea and vomiting S continuous epidural infusion with saline (Study IV) s.c. subcutaneus(ly) SD standard deviation VAS visual analogue scale VRS verbal rating scale Abbreviations 9 1. ABSTRACT Patient-controlled analgesia (PCA) has been used for the past 30 years as an alternative method to administer postoperative analgesia. PCA allows patients to self-administer small boluses of opioids, providing better dose titration and regulation. The quantity of analgesic available to the patient is limited by the prescribed PCA variables; demand dose size, lockout period and hourly or 4-hourly limits. The aim of the present series of studies was to examine which analgesic: oxycodone, morphine or tramadol, would be the best alternative in PCA after orthopaedic, maxillofacial or plastic surgery. In addition, a comparison was made of epidural bupivacaine-fentanyl infusion along with i.v. PCA, and along with patient-controlled epidural analgesia (PCEA). A total of 274 patients were assigned to receive opioids by either i.v. patient-controlled analgesia (220 patients), epidural infusion (64) or patient-controlled epidural analgesia (27). In patients undergoing a plastic reconstruction of the breast or a major operation on the vertebral column, the hypothesis was tested that the efficacy of oxycodone differs from that of morphine in postoperative …