Intravenous patient-controlled analgesia vs nurse administered oral oxycodone after total knee arthroplasty: a retrospective cohort study.

OBJECTIVES: Severe post-operative pain is common after total knee arthroplasty. Patient-controlled analgesia is an alternative method of pain management, whereby a patient administers his or her own pain medication. Patients seem to prefer this method over nurse-administered analgesia. However, it remains unclear whether patients using patient-controlled analgesia devices use higher or lower doses of opioids compared to patients treated with oral opioids. METHODS: This retrospective study examined 164 patients undergoing total knee arthroplasty. Post-operatively, 82 patients received oxycodone via intravenous patient-controlled analgesia devices, while the pain medication for 82 patients in the control group was administered by nurses. The main outcome measure was the consumption of intravenous opioid equivalents within 24 h after surgery. Secondary outcome measures were the use of anti-emetic drugs and the length of stay. Furthermore, we evaluated opioid-related adverse event reports. RESULTS: The consumption of opioids during the first 24 h after surgery and the use of anti-emetic drugs were similar in both groups. The median opioid dose of intravenous morphine equivalents was 41.1 mg (interquartile range (IQR): 29.5-69.1 mg) in the patient-controlled analgesia group and 40.5 mg (IQR: 32.4-48.6 mg) in the control group, respectively. The median length of stay was 2 days (IQR: 2-3 days) in the patient-controlled analgesia group and 3 days (IQR: 2-3 days) in the control group (p=0.02). The use of anti-emetic drugs was similar in both groups. CONCLUSIONS: The administration of oxycodone via intravenous patient-controlled analgesia devices does not lead to increased opioid or anti-emetic consumptions compared to nurse-administered pain medication after total knee arthroplasty. Patient-controlled analgesia might lead to shortened length of stay.

Effects of anaesthesia method and tourniquet use on recovery following total knee arthroplasty: a randomised controlled study.

BACKGROUND: We investigated the effects of spinal and general anaesthesia and surgical tourniquet on acute pain and early recovery after total knee arthroplasty (TKA). METHODS: Patients (n=413) were randomised to four parallel groups: spinal anaesthesia with or without tourniquet, and general anaesthesia with or without tourniquet. The primary outcome was patient-controlled i.v. oxycodone consumption over 24 postoperative hours. RESULTS: Results from 395 subjects were analysed. Median i.v. oxycodone consumption did not differ between the four groups (spinal anaesthesia without [36.6 mg] and with tourniquet [38.0 mg], general anaesthesia without [42.3 mg] and with tourniquet [42.5 mg], P=0.42), between spinal (37.7 mg) and general anaesthesia (42.5 mg) groups (median difference -3.1, 95% confidence interval [CI] -7.4 to 1.2, P=0.15) and between tourniquet and no-tourniquet groups (40.0 vs 40.0 mg, median difference -0.8, CI -5.1 to 3.5, P=0.72). Vomiting incidence was higher with spinal than with general anaesthesia (21% [42/200] vs 13% [25/194], CI 1.05 to 3.1, P=0.034). The mean haemoglobin decrease was greater without than with tourniquet (-3.0 vs -2.5 g dl-1, mean difference -0.48, CI -0.65 to -0.32, P<0.001). No differences were observed in pain, pain management, incidences of blood transfusions, in-hospital complications, or length of hospital stay. CONCLUSIONS: For TKA, spinal and general anaesthesia with or without tourniquet did not differ in 24-h postoperative opioid consumption, pain management, blood transfusions, in-hospital complications, and length of hospital stay. Vomiting incidence was higher in the spinal than in the general anaesthesia group. Tourniquet use caused smaller decreases in haemoglobin levels. CLINICAL TRIAL REGISTRATION: EudraCT 2016-002035-15.