Comparison of three remifentanil dose-finding regimens for coronary artery surgery

OBJECTIVES: To identify the remifentanil dosing regimen providing safe and optimal anesthetic conditions during coronary artery bypass graft surgery and to evaluate postoperative recovery characteristics. DESIGN: Open-label, randomized, parallel group. SETTING: Three centers in the United States. PARTICIPANTS: Seventy-two patients with left ventricular stroke volumes >or=50 mL. INTERVENTIONS: Patients were randomized to remifentanil doses of 1 microg/kg/min (group 1, n = 23); 2 microg/kg/min (group 2, n = 24), or 3 microg/kg/min (group 3, n = 25). Somatic, sympathetic, and hemodynamic responses indicating inadequate anesthesia were treated with bolus doses of remifentanil, 1 to 2 microg/kg, and infusion rate increases, and, if necessary, isoflurane 0.5% to 1.0% was added as a rescue anesthetic. In the intensive care unit, the remifentanil infusion was reset to 1 microg/kg/min, with midazolam administered for supplemental sedation and morphine for analgesia. MEASUREMENTS AND MAIN RESULTS: The durations of anesthesia, surgery, and cardiopulmonary bypass were similar for the 3 study groups. In addition, dose of lorazepam premedication, time to loss of consciousness, preoperative left ventricular ejection fraction, age, weight, and sex were similar for the 3 study groups. Remifentanil alone (infusion and boluses) prevented and controlled all responses to stimulation in 44% of group 3, 37% of group 2 and 9% of group 1 patients intraoperatively. Isoflurane (0.5%-1% inspired) rescue was successful in the remaining patients in each group. Hypotension indicating discontinuation of isoflurane and reductions of remifentanil infusion rates occurred in 64% to 75% of all patients. The optimal range of remifentanil infusion was 2 to 4 microg/kg/min with isoflurane to supplement the opioid. Fifty-one patients (71%) met the criteria for extubation within 6 hours postoperatively; because of surgical practice differences, only 30 patients (59%) were actually extubated. CONCLUSIONS: After lorazepam premedication, remifentanil infusion (2-4 microg/kg/min) supplemented intermittently with low inspired concentrations of isoflurane provided an effective anesthetic regimen for coronary artery bypass graft surgery. Early extubation times were feasible after remifentanil continuous infusions (1-5 microg/kg/min) used as the primary anesthetic component intraoperatively and for analgesia (相似文献   

Comparison of patient and doctor responses to a total hip arthroplasty clinical evaluation questionnaire

BACKGROUND: Surgeons traditionally undertake a prospective evaluation of patients undergoing total hip arthroplasty in order to determine outcomes. The validity of doctor-derived data is questionable because of the potential for interobserver error, reporting bias, and differences between the perceptions of doctors and patients. Also, the use of doctor-derived data necessitates the use of costly outpatient services. Consequently, there are likely to be benefits associated with the use of patient-derived clinical evaluation data. However, few studies have focused on whether data obtained from the patient and doctor differ. METHODS: The agreement between patient and doctor responses on a sixteen-item total hip arthroplasty clinical evaluation questionnaire completed at more than 2900 clinical assessments was determined. Data from repeated assessments performed preoperatively and postoperatively enabled stratified analyses that were used to examine reasons for disagreement and factors influencing agreement. Agreement was measured with use of the kappa coefficient. RESULTS: For twelve of the sixteen items, the patient responses had acceptable agreement with the doctor responses. Some important differences between patient-derived and doctor-derived data were found. If the patient had other joint or health problems, had a revision total hip arthroplasty, or reported mild or moderate pain, there was a greater chance of reduced agreement on the pain items. Younger patients demonstrated better agreement with doctors than older patients did. CONCLUSIONS: Patients' perceptions of symptoms and outcomes after total hip arthroplasty are relatively similar to those of their doctor. There is minimum risk of misinterpreting outcomes data by replacing doctor-completed questionnaires with patient-completed questionnaires in uncomplicated total hip arthroplasty cases. For patients with comorbid joint problems or other health problems, and for those reporting substantial pain, direct physician involvement in the evaluation of pain is recommended. The selective use of patient-completed questionnaires has the potential to substantially reduce the costs of outcomes evaluation programs by minimizing doctor input. Pending revision of some of the items, the use of this patient-completed questionnaire is advocated.     

Early changes in scores of chronic damage on transplant kidney protocol biopsies reflect donor characteristics,but not future graft function

The amount of irreversible injury on renal allograft biopsy predicts function, but little is known about the early evolution of this damage. In a single‐center cohort, we examined the relationship between donor‐, recipient‐, and transplantation‐associated factors and change in a morphometric index of chronic damage (ICD) between protocol biopsies performed at implantation and at 2–3 months. We then investigated whether early delta ICD predicted subsequent biochemical outcomes. We found little evidence to support differences between the study group, who had undergone serial biopsies, and a contemporaneous control group, who had not. In allografts with serial biopsies (n = 162), there was an increase in ICD between implantation (median: 2%, IQR:0–8) and 2–3 months post‐transplant (median 8% IQR:4–15; p < 0.0001). Donation from younger or live donors was independently associated with smaller early post‐transplant increases in ICD. There was no evidence for a difference in delta ICD between donation after cardiac death vs. donation after brain death, nor association with length of cold ischemia. After adjustment for GFR at the time of the second biopsy, delta ICD after three months did not predict allograft function at one yr. These findings suggest that graft damage develops shortly after transplantation and reflects donor factors, but does not predict future biochemical outcomes.     

The synovial response to intraarticular cobalt-chrome wear particles

The intraarticular effects of alloy wear particles similar in size to those present in the tissues around loose total joint prostheses were studied in rat knee joints injected with laboratory-prepared particulate cobalt-chrome. The particles induced rapid proliferation of macrophages and focal degeneration of synovial tissues similar to the response seen in the articular tissues around loose total joint prostheses in humans. Bacteriologic tests excluded infection as a factor. Wear particles may contribute to the changes in the tissues around total joint prostheses and may contribute to bone resorption resulting in prosthetic loosening. Experiments on animals provide useful information about the biocompatibility of materials used in the manufacture of total joint prostheses.     

Single-item satisfaction scores mask large variations in pain,function and joint awareness in patients following total joint arthroplasty

European Journal of Orthopaedic Surgery & Traumatology - Single-item questions assessing patient satisfaction following total hip or knee arthroplasty (THA/TKA) provide immediate and...     

Accuracy of EBRA-cup measurements after reconstruction of severe acetabular defects at revision THR

Radiostereometric analysis (RSA) is the most accurate method of measuring component migration using radiographs but is restricted to use in prospective studies. Ein-Bild-Roentgen-analyze (EBRA)-Cup can be used retrospectively, but its accuracy to measure component migration following revision is unknown. This study aimed to determine the accuracy of EBRA-Cup measurements of uncemented acetabular component migration after revision total hip replacement (THR). The secondary aim was to compare the number of cases identified using EBRA-Cup and RSA as having proximally migrated above and below 1 mm at 2 years postoperatively. EBRA-Cup measurements were performed on plain antero-posterior pelvic radiographs taken at the same time as RSA radiographs in a prospective cohort of 53 hips undergoing acetabular revision. At 2 years, the mean difference between the RSA and EBRA-Cup measurements for 17 components used to treat pelvic discontinuity was 0.90 mm, significantly greater than the mean difference of 0.28 mm for 36 components without discontinuity (P = .0001). The mean difference between the RSA and EBRA-Cup measurements at 2 years for hips that were reconstructed with an acetabular component alone, 0.28 mm, was significantly lower than hips that were reconstructed with an acetabular component in combination with an augment and/or cage, 0.74 mm (P = .0005). In conclusion, EBRA-Cup can accurately measure migration of uncemented acetabular components used at revision THR. The presence of pelvic discontinuity, and addition of augments and cages, significantly influenced the accuracy of EBRA-Cup measurements. EBRA-Cup and RSA had good agreement on classification of components that migrated proximally above or below 1 mm at 2 years, with 100% sensitivity, and 87% specificity.