Comparison of hydromorphone and fentanyl administered by lumbar epidural as patient-controlled analgesia after total knee arthroplasty

ABSTRACT

BACKGROUND:Hydromorphone is a semi-synthetic opioid that has recently been used for the control of acute and chronic pain.It has been reported that epidural infusion of hydromorphone provides rapid onset of analgesia and a lower incidence of side effects than morphine.However, comparative studies of hydromorphone and lipophilic opioids such as fentanyl are rare.Therefore, we compared the analgesic effects and side effects of hydromorphone infused epidurally with fentanyl in patients who underwent total knee arthroplasty. METHODS:In a randomized, double-blind manner, 79 patients (ASA I-III, aged 60?75) underwent total knee arthroplasty and were provided with patient-controlled epidural analgesia (PCEA) using a lumbar spinal/epidural-combined technique. Group HR (n = 39) received epidurally administered hydromorphone (4microg/ml) with 0.1% ropivacaine, while group FR (n = 40) received epidural fentanyl (2microg/ml) with 0.1% ropivacaine for 24 h after surgery at a rate of 5 ml/h. The visual analogue scale (VAS) was used to evaluate pain and the incidence of side effects such as nausea/vomiting, pruritis, dizziness, and respiratory depression were recorded at 4, 8, 12, 24 h after surgery. RESULTS:Group HR showed a lower VAS than group FR at 4, 12 and 24 h after surgery, but a higher incidence of nausea and vomiting at 8 h after surgery, and a higher incidence of pruritis at 8 and 12 h after surgery. None of the patients showed respiratory depression. CONCLUSIONS:Lumbar epidural infusion of hydromorphone more effectively controlled acute pain after total knee arthroplasty when compared with fentanyl, but some adverse effects such as nausea and vomiting appeared to occur more frequently.