Biomedical subjects

G Ekbäck

Publications and source records attributed to G Ekbäck.

7 recordsLinked to original sources

PubMed2005

Postoperative extradural analgesia with morphine and ropivacaine. A double-blind comparison between placebo and ropivacaine 10 mg/h or 16 mg/h.

BACKGROUND: Some controversy exists in the literature on the benefit of epidurals compared to patient-controlled intravenous analgesia (PCA). Also, the dose of ropivacaine for epidural analgesia when combined with morphine remains uncertain. The aim of this study was to compare the epidural vs. PCA technique and high-dose vs. low-dose ropivacaine combined with morphine during knee replacement surgery. METHODS: In this prospective, randomized, double-blind study, postoperative pain relief with a combination of epidural ropivacaine (Group L: 10 mg h-1, Group H: 16 mg h-1) and morphine (0.16 mg h-1) was evaluated in 30 patients. A placebo group (Group PL) of 15 patients having PCA morphine served as the control. Visual analog pain (VAS), morphine consumption, sensory and motor block and side-effects were recorded during 48 h. RESULTS: VAS scores at rest were significantly lower in Groups L and H compared to Group PL. On movement, Group H had lower VAS scores than Group PL during 3-27 h (P<0.05) and Group L during 4-9 h (P<0.05), while Group L had lower a VAS than Group PL during 9-18 h (P<0.05). Morphine consumption after 48 h was greater in Group PL (64.6+/-36.3 mg) vs. Group L (23.3+/-33.9 mg) (P<0.001) and Group H (4.3+/-9.6 mg) (P<0.0001). Mild motor block was seen in Group H in 20% and 14% patients at 24 h and 48 h, respectively, but time to mobilization was similar between the groups. Pruritus was more common in the ropivacaine groups (P<0.05). CONCLUSION: Lumbar epidural analgesia using a combination of ropivacaine (16 mg h-1) and morphine (0.16 mg h-1) provides superior analgesia compared to the PCA technique or ropivacaine (10 mg h-1) and morphine (0.16 mg h-1). Although this resulted in a mild motor block during the first 12 h, patient mobilization was similar in all groups.

Aged↗

PubMed2003

Patient-controlled regional analgesia (PCRA) with ropivacaine after arthroscopic subacromial decompression.

BACKGROUND: The aim of the study was to evaluate postoperative analgesia and safety of wound instillation of ropivacaine either by a single dose or a patient-controlled regional anaesthesia (PCRA) technique. METHODS: In 40 patients undergoing arthroscopic subacromial decompression the surgeon placed a catheter into the subacromial space at the end of the operation. In Phase I (10 patients), ropivacaine 250 mg was injected twice within 1 h. In Phase II, 30 patients were randomised into three groups: group prilocaine-ropivacaine (PR) = 20 ml of 1% prilocaine-epinephrine injected preoperatively into the subacromial bursa + 20 ml of 0.5% ropivacaine infused in the catheter postoperatively; group saline-ropivacaine (SR) = saline-epinephrine (20 ml) preoperatively + 0.5% ropivacaine as in group PR; group saline-saline (SS) = saline-epinephrine (20 ml) preoperatively + saline postoperatively. The PCRA pump was filled with local anaesthetic or saline to allow boluses of 10-ml each, maximum one bolus/h, via the catheter. Pain relief, side-effects and venous plasma concentration of ropivacaine were evaluated during a 24-h-test period. RESULTS: The free plasma concentration of ropivacaine was 0.12 + 0.041 mg l-1 in Phase I. No adverse effects were seen. In Phase II pain at rest and on movement was lower in group PR than in group SS during the first 30 min postoperatively (P < 0.05). Group PR had the lowest morphine consumption (P < 0.05). Five to seven boluses were administered via the PCRA-pump, and 20 min after administration of the study solution, pain was lower in groups PR and SR compared with group SS (P < 0.001). CONCLUSIONS: Preoperative intrabursal prilocaine with epinephrine + postoperative subacromial administration of ropivacaine by PCRA-technique provided the most effective analgesia with no major side-effects. The free plasma concentrations of ropivacaine were far below toxic concentrations.

Adult↗

PubMed2002

The effects of platelet apheresis in total hip replacement surgery on platelet activation.

BACKGROUND: Autologous platelet rich plasma (PRP) harvest with autotransfusion devices has been used for 10 years in cardiac surgery and recently in orthopedics as a blood saving method. The quality of the harvested platelets has not been adequately examined, in part because of methodological difficulties in studying platelet function during surgery. METHODS: Twenty patients undergoing primary total hip replacement (THR) were studied. Ten patients underwent an immediate preoperative platelet apheresis to obtain concentrated platelet rich plasma (c-PRP). The other 10 patients not undergoing apheresis were allocated to a control group. Platelet activation was evaluated as the population expressing P-selectin on the surface of platelets in the c-PRP and in blood samples collected pre-, per- and postoperatively. The method used was flow cytometry. RESULTS AND CONCLUSIONS: A minor population of activated platelets was found to be circulating in the patients' blood, with a highly significant difference between patients (P = 0.005), and with a range of 1-23% in peroperative activation. PRP harvest did not significantly alter platelet activity. The platelet apheresis procedure did not inhibit platelet function in the c-PRP, as judged by a high proportion of platelets that could be activated in ADP stimulation experiments (mean value +/- SD 86% +/- 7.5%).

Adenosine Diphosphate↗

PubMed2000

Preoperative platelet-rich plasmapheresis and hemodilution with an autotransfusion device in total hip replacement surgery.

The effectiveness of both preoperative autologous donation (PAD) and intraoperative autotransfusion (IAT) with an autotransfusion device has recently been questioned. Preoperative apheresis, with separation of concentrated platelet rich-plasma (c-PRP) and erythrocyte concentrate (ERC), represents an aggressive use of the autotransfusion device. Can such a procedure replace PAD in total hip replacement surgery (THR)? Eighty patients undergoing THR were investigated in a prospective and randomized study. Forty patients underwent PAD, and 2 units of ERC + plasma were retrieved within 4 weeks preoperatively. Another 40 patients underwent an immediately preoperative apheresis with a concomitant hemodilution with 4% albumin, retrieving c-PRP (30% of the platelet pool) and 2 units of ERC. Both groups used IAT up to 2 hours postoperatively, with 3% dextran-60 as a plasma substitute according to our standard of care. There were no differences in blood loss, B-hemoglobin or allogeneic transfusions between the groups: 85% of the patients did not receive allogeneic blood. Both apheresis and reinfusion of c-PRP had minor impact on the coagulation parameters. Platelet count increased slightly but significantly (P<0.05) from 154 to 179 x 10(9)/L after the c-PRP at wound closure. Preoperative apheresis with an autotransfusion device, separating platelet-rich plasma and erythrocyte concentrate, is a useful alternative for patients who are unable to utilize the PAD technique for either religious or practical reasons.

Aged↗

PubMed2000

Tranexamic acid reduces blood loss in total hip replacement surgery.

UNLABELLED: Intraoperatively administered, tranexamic acid (TA) does not reduce bleeding in total hip replacement (THR). Therefore, its prophylactic use was attempted in the present study because this has been shown to be more effective in cardiac surgery. We investigated 40 patients undergoing THR in a prospective, randomized, double-blinded study. Twenty patients received TA given in two bolus doses of 10 mg/kg each, the first just before surgical incision and the second 3 h later. In addition, a continuous infusion of TA, 1.0 mg. kg(-1). h(-1) for 10 h, was given after the first bolus dose. The remaining 20 patients formed a control group. Both groups used preoperative autologous blood donation and intraoperative autotransfusion. Intraoperative bleeding was significantly less (P: = 0.001) in the TA group compared with the control group (630 +/- 220 mL vs 850 +/- 260 mL). Postoperative drainage bleeding was correspondingly less (P: = 0.001) (520 +/- 280 vs 920 +/- 410 mL). Up to 10 h postoperatively, plasma D-dimer concentration was halved in the TA group compared with the control group. One patient in each group had an ultrasound-verified late deep vein thrombosis. In conclusion, we found TA, administrated before surgical incision, to be efficient in reducing bleeding during THR. IMPLICATIONS: In a prospective, double-blinded study of 40 patients undergoing total hip replacement, the preoperative administration of tranexamic acid reduced bleeding by 35%, probably by decreasing induced fibrinolysis. Whether tranexamic acid therapy can replace predonation of autologous blood or intraoperative autotransfusion requires further study.

Aged↗

PubMed1999

Sonoclot coagulation analysis: a study of test variability.

OBJECTIVE: To test the reproducibility of Sonoclot coagulation analysis (SCA; Sienco Inc, Morrison, CO). The authors wished to determine if the mix/release of the preloaded celite activator in standard Sono-cuvettes could be responsible for the high variation coefficients for SCA parameters with citrated whole blood and if citrated whole blood is optimal for SCA. DESIGN: A prospective trial. SETTING: A large academic teaching medical center. PARTICIPANTS: Eight healthy volunteers. INTERVENTIONS: Repeated blood sampling was performed through indwelling radial artery catheters. Seven different Sonoclot analyzers were used to test seven different types of analysis procedures in the volunteers, involving activators of different types and amounts and in different forms, and the use of citrated or native whole blood. MEASUREMENTS AND MAIN RESULTS: Two-way and one-way ANOVA, variance, variance analysis, and Tukey's test were used to evaluate differences in SCA methods and volunteer influence. A high variance, with SDs up to 200% of the median values of the SCA parameters with recalcified citrated blood and the standard Sono-cuvette, was confirmed. SCA with native blood and/or the use of other types of preloaded activators, ie, kaolin, significantly (p < 0.05) reduced this variance. Repeated SCAs further reduced the variance to 10% to 35% of the variance for a single analysis (standard cuvette and native blood). CONCLUSION: Improvement of the activator in the Sonocuvette, use of native whole blood, and repeated Sonoclot analyses reduced the previously reported high variability of this instrument.

Adult↗

PubMed1995

Perioperative autotransfusion and functional coagulation analysis in total hip replacement.

Functional coagulation analyses like Sonoclot and thromboelastography have not been evaluated during perioperative autotransfusion. We have prospectively studied three different transfusion regimes in 45 patients undergoing total hip arthroplasty. Blood losses were replaced either with heterologous erythrocyte concentrate (group I), intra- and postoperative autotransfusion of blood salvaged with cellsaver technique (group II) or predonated autologous erythrocyte concentrates together with salvaged blood (group III). Routine and functional coagulation analyses with a Sonoclot were performed preoperatively, 6 hours postoperatively (6 h), day 1-5 and 10. An early postoperative hypo- and late postoperative hypercoagulative phase could be detected with Sonoclot signs of platelet function and fibrin deposition in all groups. Sonoclot coagulation analyses better correlated to both blood loss and dextran dosage than APTT and platelet count in the routine coagulation analyses. Functional coagulation analysis has a potential use in individualizing plasmasubstitution and thromboprophylaxis regimes during autotransfusion in THR.

Blood Coagulation↗