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Biomedical subjects

E Fosse

Publications and source records attributed to E Fosse.

At least 37 records · Page 2Linked to original sources

Viral safety of solvent/detergent-treated plasma.

BACKGROUND: Pooling of plasma donations increases the risk for blood-borne infections. In solvent/detergent (SD)-treated plasma, lipid-enveloped viruses are efficiently inactivated. This method, however, does not affect non-lipid-enveloped viruses. The current study investigated the viral safety of SD-treated plasma (Octaplas) and paid particular attention to the transmission of non-lipid-enveloped viruses. STUDY DESIGN AND METHODS: The study comprised 343 adults undergoing cardiac surgery. Follow-up was performed 6 to 12 months and 2 years after operation. The sera were tested for hepatitis B surface antigen and specific antibodies against hepatitis A, B, and C; cyto-megalovirus; HIV, human T-lymphotropic virus types I and II; and human parvovirus B19 (B19). A total of 25 batches of SD-treated plasma prepared from Norwegian plasma were used. All batches were tested for hepatitis A virus and B19 by nucleic acid amplification testing and investigated for neutralizing antibodies directed against these viruses. RESULTS: In patients who received SD-treated plasma, B19 seroconversion occurred at a rate similar to that in nontransfused patients. No other seroconversions could be ascribed to the transfusion of SD-treated plasma. All 25 SD-treated plasma batches contained neutralizing antibodies against hepatitis A virus and B19. In nucleic amplification testing, all SD-treated plasma batches tested positive for B19, while five demonstrated borderline reactions for hepatitis A virus. CONCLUSION: Transfusion of SD-treated plasma was found to be safe with regard to lipid-enveloped viruses. Immune antibodies neutralize viral particles in plasma and are of importance in avoiding clinical disease with the non-lipid-enveloped hepatitis A virus and B19.

Adolescent↗

A magnetic resonance imaging study of modifications to the infraclavicular brachial plexus block.

A previously described infraclavicular brachial plexus block may be modified by using a more lateral needle insertion point, while the patient abducts the arm 45 degrees or 90 degrees. In performing the modified block on patients abducting 45 degrees, we often had problems finding the cords of the brachial plexus. Therefore, we designed an anatomic study to describe the ability of the recommended needle direction to consistently reach the cords. Additionally, we assessed the risk of penetrating the pleura by the needle. Magnetic resonance images were obtained in 10 volunteers. From these images, a virtual reality model of each volunteer was created, allowing precise positioning of a simulated needle according to the modified block, without exposing the volunteers to actual needle placement. In both arm positions, the recommended needle angle of 45 degrees to the skin was too shallow to reach a defined target on the cords. Comparing the two arm positions, target precision and risk of contacting the pleura were more favorable with the greater arm abduction. We conclude that when the arm is abducted to 90 degrees, a 65 degrees -needle angle to the skin appears optimal for contacting the cords, still with a minimal risk of penetrating the pleura. However, this needs to be confirmed by a clinical study.

Adult↗

Plasma endotoxin concentrations during cardiac surgery may be related to atherosclerosis.

Systemic endotoxemia develops during cardiopulmonary bypass, probably due to intestinal ischaemia. Differences in endotoxaemia among various cardiac operations and the relationship between endotoxemia and postoperative complications were studied in high-risk patients. Blood samples were obtained at termination of bypass in 136 adults undergoing elective cardiac surgery. Postoperative complications were registered prospectively. Plasma endotoxin was quantified by a kinetic limulus amebocyte lysate assay. Mean endotoxin concentrations were significantly lower in patients undergoing isolated valve replacement (89 ng/l) than in patients undergoing coronary artery bypass grafting alone (234 ng/l), or combined with valve replacement (278 ng/l) or carotid artery surgery (321 ng/l) (p < 0.05). In multivariate linear regression, only the number of grafts (0, 1-3, 4-5) was significantly correlated to endotoxin concentrations (p < 0.0005). Endotoxin concentrations were related to development of gastrointestinal dysfunction (p = 0.03), but not to mortality (p = 0.24) or other complications (p = 0.62).

Aged↗

Vascular complications of the intraaortic balloon pump in patients undergoing open heart operations: 15-year experience.

BACKGROUND: The beneficial effects of the intraaortic balloon pump (IABP) in providing circulatory support must be weighed against its complications, particularly its vascular trauma. METHODS: Five hundred nine patients who underwent open heart operations at our institution and who were treated with the IABP from January 1980 through December 1994 were studied retrospectively to assess IABP-related vascular complications and their independent preoperative predictors and the implications of IABP-related vascular complications on the patients' mortality, morbidity (clinical sepsis and organ failure), and long-term survival. RESULTS: Early vascular complications occurred in 56 patients (11%) and major complications occurred in 41 patients (8%). The latter consisted of aortic perforation in 1 patient, aortoiliac dissection in 2 patients, and limb ischemia in 38 patients. Logistic regression analysis identified concomitant peripheral vascular disease (p<0.001), elevated preoperative end-diastolic pressure, small body surface area, and large catheter size (p<0.05) as independent risk factors for IABP-related major vascular complications in patients who survived the day of operation. Late IABP-related sequelae occurred in 10 patients, 9 of whom had had early vascular complications. The presence of vascular complications per se was not a significant independent factor among other risk factors for mortality, morbidity, or long-term survival. CONCLUSIONS: Careful clinical assessment of the aortofemoral vascular tree is a cornerstone of early diagnosis and early intervention and usually prevents limb loss. The significant decrease in major vascular complications that has occurred over the last 5 years can be explained by the increased use of catheters with smaller diameters. The timing of IABP insertion in relation to operation and the duration of IABP use were the only device-related risk factors identified for morbidity and survival.

Adolescent↗

Heparin-coated cardiopulmonary bypass equipment. I. Biocompatibility markers and development of complications in a high-risk population.

OBJECTIVES: 1. To study possible clinical benefits of heparin-coated cardiopulmonary bypass in patients with a broad range of preoperative risk factors. 2. To evaluate the correlation between the terminal complement complex and clinical outcome. 3. To identify clinical predictors of complement activation and correlates of granulocyte activation during cardiac surgery. METHODS: Blood samples from adults undergoing elective cardiac surgery with Duraflo II heparin-coated (n = 81) or uncoated (n = 75) cardiopulmonary bypass sets (Duraflo coating surface; Baxter International, Inc, Deerfield, Ill) were analyzed for activation of complement (C3 activation products, terminal complement complex), granulocytes (myeloperoxidase, lactoferrin), and platelets (beta-thromboglobulin) by enzyme immunoassays. Preoperative risk was assessed by means of the "Higgins' score." Complications (cardiac, renal, pulmonary, gastrointestinal, and central nervous system dysfunction, infections, death) were registered prospectively. Data were analyzed by analysis of variance, logistic regression, and linear regression. RESULTS AND CONCLUSIONS: Sixty-seven percent of the patients had predefined risk factors. Complications developed in 53 patients (34%), equivalently with and without heparin-coated bypass sets (P =. 44-.82), despite a significant reduction in complement and granulocyte activation by heparin coating. No clear-cut relationship between the terminal complement complex and outcome was found, even if it was significant in the models for renal and central nervous system dysfunction and infections (P =.006). The Higgins' score was significantly related to complement activation (P <.05). Approximately 50% of the variation in granulocyte activation was explained by complement (P </=.01) and platelet activation (P <.05), heparin/protamine dose ratio (P =.02), duration of cardiopulmonary bypass (P <.01), and gender (P <.05). Therefore measures reducing complement activation alone will not necessarily reduce granulocyte activation sufficiently for clinical significance.

Aged↗

Heparin-coated cardiopulmonary bypass equipment. II. Mechanisms for reduced complement activation in vivo.

OBJECTIVE: Our objective was to study mechanisms for reduced complement activation by heparin coating of cardiopulmonary bypass equipment in clinical heart surgery. METHODS: Adults undergoing elective coronary artery bypass grafting were randomized to cardiopulmonary bypass with Duraflo II heparin-coated (n = 15) or uncoated (n = 14) sets (Duraflo coating surface; Baxter International, Inc, Deerfield, Ill). Blood samples were analyzed with the use of enzyme immunoassays for C1rs-C1 inhibitor complexes and the activation products Bb, C4bc, C3bc, C5a-desArg, and the terminal complement complex. Data were compared by repeated-measures analysis of variance. RESULTS: C1 was activated during bypass, and increases in C1rs-C1 inhibitor complexes were larger with heparin coating (P =.03). C4bc increased after administration of protamine, without intergroup differences (P =.69). Bb (P =.22) and C5a-desArg (P =.13) tended to increase less with heparin coating. Formation of C3bc (P =.03) and the terminal complement complex (P <.01) was significantly reduced with heparin coating. C5a-desArg increased 2-fold during bypass, whereas the terminal complement complex increased 10- to 20-fold. Maximal terminal complement complex concentrations were significantly correlated to maximal Bb and C3bc (R = 0.6, P <.001), but not to C1rs-C1 inhibitor complexes or C4bc (R < 0.05, P >.8). CONCLUSIONS: C1 activation during bypass was increased by heparin coating, but further classical pathway activation was held in check until administration of protamine. Heparin coating significantly inhibited C3bc and terminal complement complex formation. Terminal complement complex concentrations were related to alternative pathway activation and may be useful for evaluation of differences in bypass circuitry. Increases and intergroup differences in terminal complement complex concentrations were much larger than those in C5a-desArg.

Anticoagulants↗

Magnetic resonance imaging demonstrates lack of precision in needle placement by the infraclavicular brachial plexus block described by Raj et al.

UNLABELLED: The infraclavicular brachial plexus block first described by Raj et al. was supposed to anesthetize all the main peripheral nerves of the brachial plexus without the risk of pneumothorax. However, in performing the block, we have had difficulties finding the nerves at the cord level. Therefore, we questioned whether the recommended needle direction (the "Raj line") guides the needle close enough to the cords. We therefore designed an anatomic study to answer this question and to assess the risks of entering the pleura and axillary vein. Ten volunteers were examined noninvasively in an open model magnetic resonance scanner. The Raj line deviated greatly from a defined location on the cords by a mean of 26 (range 14-39) mm, always caudad, and posterior to the target in nine cases. Further, the needle trajectory's shortest distance to the pleura was only 10 (0-27) mm, and in one case, it hit the pleura. Finally, the Raj line's distance to the axillary vein was also short, 11 (0-18) mm. We conclude that a modification of the method is necessary to guide the needle closer to the cords and further away from the pleura and the axillary vein. A more lateral needle insertion seems beneficial. IMPLICATIONS: Using a magnetic resonance scanner, the anatomical basis of Raj's infraclavicular method for brachial plexus blockade was examined in volunteers. The results show that the method should be modified to make it more precise and to provide less risk of complications.

Adult↗

In vitro evaluation of new surface coatings for extracorporeal circulation.

Cardiopulmonary bypass (CPB) exposes blood to large, foreign surfaces. This exposure may activate the cellular and humoral inflammatory systems, resulting in inflammatory reactions and organ dysfunction. Coating the inner surfaces of the bypass circuit may help alleviate these side-effects. The objective of this study was to determine the influence of two new surface treatments on blood cell and complement activation. Oxygenator and tubing sets coated with synthetic polymers (n = 7) or heparin (n = 7) were compared to uncoated sets (n = 7) in an in vitro model of CPB. The circuits were run at 4 l/min and recirculated for 120 min. The inflammatory response was assessed at regular intervals by platelet counts, and activation of complement, leucocytes and platelets. We found that the median platelet counts decreased from 127 to 122 x 10(9)/l (not significant, NS) in the synthetic polymer sets, from 96 to 88 x 10(9)/l (NS) in the heparin-coated sets, and from 93 to 54 x 10(9)/l (p < 0.01) in the uncoated sets after 2 h of recirculation. There were significant differences in platelet counts between the coated sets and the uncoated set at end of experiments (p < 0.05). Beta-thromboglobulin (BTG) concentrations increased in the synthetic polymer sets from 166 to 352 ng/ml (p < 0.01), in the heparin coated sets from 336 to 1168 ng/ml (p < 0.01), and in the uncoated sets from 301 to 3149 ng/ml (p < 0.01) after 2 h of recirculation. The differences in BTG at termination of the experiments were significant among all three sets (p < 0.05). Myeloperoxidase (MPO) concentrations in the synthetic polymer sets increased from 63 to 86 micrograms/l (p < 0.01), in the heparin-coated sets from 90 to 208 micrograms/l (p < 0.01), and in the uncoated sets from 122 to 513 micrograms/l (p < 0.01) after 2 h of recirculation. The differences in MPO at termination of the experiments were significant among all three groups (p < 0.01). There were no significant differences at termination of the experiments among the three sets regarding complement activation as measured by C3 activation products and the terminal complement complex. We conclude that in the current in vitro model of a CPB circuit, the synthetic polymer coating and the heparin coating caused significantly less platelet loss and granulocyte and platelet activation than the uncoated surface (p < 0.05). The synthetic polymer coating caused significantly less granulocyte and platelet activation than the heparin coating (p < 0.05). There was moderate complement activation within each group, but no significant differences among the three groups.

Complement Activation↗

Intraaortic balloon pump in open heart operations: 10-year follow-up with risk analysis.

BACKGROUND: The intraaortic balloon pump (IABP) is the primary mechanical device used for perioperative cardiac failure. METHODS: We analyzed the prognostic predictors and long-term survival of 344 patients undergoing cardiac operations who required the perioperative use of an IABP at our institution from January 1980 to December 1989. Hospital survivors (163 patients) were followed up for a mean of 7.45 years (range, 1 month to 15.3 years); cumulative follow-up included 1,167 patient-years. RESULTS: The early mortality rate was 52.6% (181 patients). From parameters available at the time of IABP insertion, logistic regression analysis identified preoperative serum creatinine level, left ventricular ejection fraction, perioperative myocardial infarction, timing of IABP insertion, and indication for operation as independent predictors of early (30-day) death (p < 0.05). Cox regression analysis of hospital survivors identified timing of IABP insertion, perfusion time, and preoperative serum creatinine level as independent prognostic factors for late death (p < 0.05), whereas patient age was only marginally significant (p < 0.06). There was no association between IABP-related complications and death. Survival analysis demonstrated a 10-year actual survival rate of 22.04% +/- 0.023%, with 57 patients still at risk and significantly improved survival among those who received an IABP before operation (p < 0.02). CONCLUSIONS: The early mortality rate in patients who received an IABP was high. Hospital survivors had a relatively good long-term prognosis. The significantly better short- and long-term survival of patients who received an IABP before operation may justify more liberal preoperative use of the IABP in high-risk patients.

Adolescent↗

Complement activation in injured patients occurs immediately and is dependent on the severity of the trauma.

In order to study the factors related to complement activation, the complement activation products C3bc and TCC were measured in plasma at admittance and during the stay in the intensive care unit in 108 consecutive patients with multiple injuries. These patients were admitted to the surgical department during a 4-month period. Complement activation occurred immediately after the trauma and correlated strongly with the Injury Severity Score and was inversely correlated to the Base Excess. Complement activation also correlated with the number of transfusions. Sepsis caused complement activation later during the stay in hospital. All seven patients developing the adult respiratory distress syndrome (ARDS) had increased complement activation, either on admission or later during the stay in the intensive care unit. Complement activation is known to contribute to organ damage following ischemia and reperfusion. Clinical studies have demonstrated the importance of early restoration of adequate circulation and the present demonstration of a strong negative correlation between complement activation and Base Excess indicates that early restoration of aerobic metabolism may reduce complement activation and the risk for organ dysfunction.

Acid-Base Imbalance↗

Minimally invasive direct coronary artery bypass grafting without cardiopulmonary bypass in combination with intraoperative percutaneous transluminal coronary angioplasty for palliative coronary revascularization in a heart transplant recipient.

The use of minimally invasive direct coronary artery bypass grafting without cardiopulmonary bypass in combination with intraoperative percutaneous transluminal coronary angioplasty for myocardial revascularization in a heart transplant recipient is reported.

Angioplasty, Balloon, Coronary↗

[Catheter treatment of congenital heart defects. Arterial septal defects and open ductus arteriosus].

The results of new methods for catheter treatment of congenital heart defects are presented. Between 1989 and 1996 closure of a patent ductus arteriosus was performed in 66 instances on 63 patients, eight of which were with coils. Three patients were treated twice, one with an additional umbrella, two with coils. The overall complete closure rate for umbrellas was 75%, after two ducts, which were initially totally occluded, recanalized. In six more patients the procedure was either aborted or indication was not present. All six ducts treated with coils as the first procedure were completely closed. One of two patients who had residual leak after previous umbrella treatment achieved complete closure after subsequent coil implantation. Closure of atrial septal defects in the oval fossa was performed using the Amplatzer septal occluder in seven children. Complete closure was achieved in all of them. There have been no complications, in particular there have been no cases of embolization in any of the groups. The results seem to indicate that coil occlusion of a persistently patent duct may be at least as good as the umbrella in terms of complete closure. So far both methods have been safe, but experience with coils is limited. The closure of atrial septal defects shows encouraging results. We will continue to offer this treatment as an alternative to open heart surgery in carefully selected patients.

Adolescent↗

[The intervention center at the Rikshospital. Experiences from the first year of activity].

In order to co-ordinate and promote the development of new clinical applications by structuring collaboration and communication across traditional specialty boundaries, a first of its kind hospital department was opened at Rikshospitalet in June 1996. The Interventional Centre is a multidisciplinary centre for research and development, teaching and quality management of imaging-guided minimally invasive therapy, endoscopic surgery and interventional radiology. The department is a full fusion of state-of-the art operating theatre with an advanced radiology department and with fully up-to-date ultrasound and endoscopy facilities for integrated use in the treatment of the patient. The department is cross-disciplinary organised. A small staff of 14 persons are responsible for the day-to-day running of the centre. Specialists from other hospital departments work together with the centre's permanent staff to develop new procedures. During the first year, 19 research projects were started and a total of 510 procedures performed within the fields of Radiology, Neurosurgery, Gastroenterology, Cardiology, Cardiovascular surgery and Paediatric cardiology, and also within the fields of image processing and telecommunication.

Centralized Hospital Services↗

Attenuation of changes in leukocyte surface markers and complement activation with heparin-coated cardiopulmonary bypass.

BACKGROUND: The inflammatory response induced by cardiopulmonary bypass can result in severe organ dysfunction in some patients. This postperfusion response is caused mainly by contact between blood and the foreign surface of the cardiopulmonary bypass equipment and includes adhesion of leukocytes to vascular endothelium, which precedes a series of events that mediate inflammatory damage to tissues. METHODS: Low-risk patients accepted for coronary artery bypass grafting were randomized to operation with the cardiopulmonary bypass surface either completely heparin coated (Duraflo II) or uncoated. There were 12 patients in each group. Blood plasma sampled during cardiopulmonary bypass was analyzed for complement activation (C3bc and terminal SC5b-9 complement complex) and neutrophil activation (lactoferrin and myeloperoxidase). In addition, neutrophils, monocytes, and platelets were counted, and the expression of surface markers on the neutrophils and monocytes (complement receptor [CR] 1, CR3, CR4, and L-selectin) and on the platelets (P-selectin and CD41) was quantified with flow cytometry. RESULTS: Clinical and surgical results were similar in both groups. In the group with the heparin-coated surface, the formation of the terminal SC5b-9 complement complex was significantly reduced, and the counts of circulating leukocytes and platelets were significantly less reduced initially but were higher at the end of cardiopulmonary bypass compared with baseline. Also, the expression of CR1, CR3, and CR4 was significantly less upregulated and the L-selectin, significantly less downregulated on monocytes and neutrophils. CONCLUSIONS: We conclude that heparin coating reduces complement activation and attenuates the leukocyte integrin and selectin response that occurs when uncoated circuits are used.

Antigens, Surface↗

Both plasma- and leukocyte-associated C5a are essential for assessment of C5a generation in vivo.

BACKGROUND: Measurement of C5a in plasma is hampered by the rapid clearance of C5a as a result of cell binding. Therefore, an assessment of whether cell-bound C5a might better reflect C5a generation in vivo is essential. METHODS: We quantified plasma and leukocyte-bound C5a in samples from patients undergoing cardiopulmonary bypass, which is known to be associated with complement activation. C3 activation products and the terminal complement complex were measured as well. RESULTS: Plasma levels of C3 activation products and the terminal complement complex increased rapidly and significantly after the onset of cardiopulmonary bypass until they reached a plateau after 30 minutes. The concentration of plasma C5a increased steadily to twice baseline at the end of bypass. The concentration of leukocyte-associated C5a increased threefold after 10 minutes of cardiopulmonary bypass, when a plateau was reached. A positive correlation was found between levels of plasma C3 activation products or terminal complement complex and plasma C5a plus cell-associated C5a but not between C3 activation products or terminal complement complex and either one of the C5a variables. CONCLUSIONS: We conclude that both plasma C5a and leukocyte-associated C5a are needed for monitoring in vivo C5a generation.

Cardiopulmonary Bypass↗