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Biomedical subjects

O Elert

Publications and source records attributed to O Elert.

At least 19 recordsLinked to original sources
PubMed2006

[Development of cardiovascular risk factors in patients after coronary artery bypass grafting with an in-hospital rehabilitation programme (WHO Stage I of Rehabilitation): 1-year follow-up].

BACKGROUND: The purpose of this study was to evaluate the influence of an in-hospital (stage I of rehabilitation) individualized motivation programme for life-style change on the cardiovascular risk factors of patients after coronary artery bypass grafting (CABG). METHODS: 142 consecutive patients undergoing CABG because of coronary heart disease were divided into two groups. Group I received the usual care; Group II received the intervention (individual motivation programme). Medical variables concerning all cardiovascular risk factors and the current medication plan were evaluated on admission and one year after surgery. RESULTS: After 12 months significant reductions in systolic blood pressure (p = 0.002), LDL-cholesterol (p = 0.023) and triglyceride (p = 0.046) were found in the intervention group on comparison of the two groups. The HDL cholesterol improved in the intervention group and decreased slightly in the control group. Both groups showed an improvement in diastolic blood pressure, Body Mass Index, blood cholesterol and blood glucose values. The intervention did not show a significant influence on smoking and medication habits. CONCLUSION: An individualized motivation programme starting in the acute hospital may positively influence cardiovascular risk factors with ongoing success.

Aged↗
PubMed2006

Primary closure of median sternotomy: a survey of all German surgical heart centers and a review of the literature concerning sternal closure technique.

BACKGROUND: Sternal instability and mediastinitis are rare but serious complications following cardiac surgery with median sternotomy. METHODS: This study presents the results of a questionnaire, which was sent to all 79 German surgical heart centers. The conventional sternal closure technique, the parameters considered to be risk factors for sternal instability, and the surgical strategy in the presence of risk factors were determined. In addition, a literature research with the key words "sternal closure technique" and "sternal dehiscence" was performed. RESULTS: Conventional closure of primary sternotomy is done using many different methods, most often with surgical steel sutures (87 %) passed trans/peristernally (64 %). An osteoporotic or fractured sternum (70 x), and obesity (31 x) were the most frequently cited risk factors. The preferred osteosynthetic procedure for patients with an increased risk for sternal instability was the method of Robicsek (48 x). CONCLUSION: There is no uniform osteosynthetic method for primary sternal closure and there is substantial variation in the perception of risk factors for sternal instability and possible surgical consequences among the surgical heart centers in Germany.

Biomechanical Phenomena↗
PubMed1999

Influence of different autotransfusion devices on the quality of salvaged blood.

BACKGROUND: Cardiopulmonary bypass causes a systemic inflammatory response and impaired hemostasis. We investigated whether intraoperative blood salvage with the cardiotomy suction contributes to these alterations. Furthermore, an alternative autotransfusion device (Haemonetics cell-saving device) was examined. METHODS: In 10 patients, interleukin-6, interleukin-8, tumor necrosis factor-alpha, thrombin-antithrombin complex, plasmin-antiplasmin complex, free hemoglobin, and the percentage of CD62+ thrombocytes were determined in the systemic circulation during cardiopulmonary bypass, in the cardiotomy suction tube, and in the blood from the cell-saving device. Additionally, bacterial contamination was examined. RESULTS: Median levels of interleukin-6 (52 versus 10 microg/L; p = 0.005), interleukin-8 (26 versus 20 microg/L; p = 0.017), tumor necrosis factor-alpha (24 versus 1 microg/L; p = 0.005), thrombin-antithrombin complex (113 versus 43 microg/L; p = 0.005), plasmin-antiplasmin complex (566 versus 489 microg/L; p = 0.022), and free hemoglobin (61 versus 30 mg/dL; p = 0.005) were higher in the cardiotomy suction tube compared with the systemic circulation. After processing the blood from the cell-saving device, interleukin-8, thrombin-antithrombin complex, and free hemoglobin remained above reference range, and in 90% of the cases bacterial contamination was observed. CONCLUSIONS: Cardiotomy suction additionally contributes to the release of proinflammatory cytokines, activation of coagulation, and hemolysis. Because blood salvage with a Haemonetics cell-saving device led to normalization of some, but not all, parameters and bacterial contamination was common, the alternative use seems at least questionable.

Adult↗
PubMed1999

Effects of the propofol combination anesthesia on the intrinsic blood-clotting system.

Fat emulsions can cause changes in blood-clotting and fibrinolysis. The aim of this study was to examine the relation between the use of the short-acting hypnotic propofol and alteration of the blood clotting system. In a double-blind randomized study, 36 patients with an aortocoronary bypass operation were given either midazolam/fentanyl or propofol/alfentanil. Eleven blood samples were taken at fixed times pre-, intra- and postoperatively to determine changes caused by the anesthetic agents on the hemostaseologic parameters during the whole operation. Perioperative blood pressures of both groups were measured at seven fixed points. From the beginning of the extracorporeal circulation (ECC) to the end of the operation, the measured values of the factor XIIa- and kallikrein-like activity in the propofol group were significantly higher than those of the midazolam group. Also the values of the kallikrein inhibition capacity and the indicators of fibrinolysis (t-PA and D-dimers) suggest a stronger activation of the contact phase at the start of the recirculation and as a result of it a stronger fibrinolysis within the propofol group. Besides, the hypotensive side-effect in the propofol group was evident in contrast to the midazolam group. With this investigation, a correlation between the application of propofol/alfentanil, contact phase activation with activation of the kallikrein-kinin-bradykinin system and the observed hypotension can be set up.

Adult↗
PubMed1999

Intraoperative embolus formation during cardiopulmonary bypass affects the release of S100B.

BACKGROUND: Intraoperative thromboembolism and the systemic inflammatory reaction are thought to play a role in causing cerebral dysfunction following cardiopulmonary bypass (CPB). Increased levels of S100B, an astroglial protein, have been linked to neuropsychological deficits after CPB. The present study investigated whether S100B release correlates with intraoperative embolus formation, thrombin formation, or the release of inflammatory parameters. METHODS: 40 patients undergoing coronary artery bypass grafting were included. Blood samples were taken before, during, and after CPB, and levels of S100B, thrombin-antithrombin complex (TAT), complement C5a, and interleukin 8 were analysed. Embolus formation was assessed by Doppler ultrasound at the arterial line of CPB. RESULTS: The release of S100B correlated with embolus count (r = 0.42; p = 0.009) and TAT formation (r = 0.71; p = 0.0001). The correlation of S100B with interleukin 8 (r = 0.58; p = 0.0001) was due to the dependence of both parameters on bypass time (r = 0.29; p = 0.075, partial correlation). A correlation of S100B with C5a formation could not be observed. CONCLUSIONS: S100B release is related to embolus and thrombin formation during CPB, indicating that thrombofibrinous embolism is involved in perioperative brain damage. Inflammatory parameters (i.e. interleukin 8 and C5a) seem to have no influence on S100B release.

Brain Damage, Chronic↗
PubMed1999

Ultrastructural investigations for reducing endothelial cell damage of vein grafts during CABG-operation and practical consequences.

BACKGROUND: In the present study the influence of different storage solutions on endothelial integrity or damage was investigated with direct methods particularly with transmission electron microscopy (TEM), scanning electron microscopy (SEM) and immunohistochemistry. METHODS: Saphenous vein segments of 10 cm in length were taken surgically from 6 male CABG-patients (aged 60-70) under standardized conditions. Each vein segment was cut into rings, which were incubated at room temperature for 45 minutes in different storage solutions, particularly in 0.9% sodium chloride solution and in buffered solution (M 199) with 5% human serum albumin respectively. Then, the vein segments were fixed in 3.5% glutaraldehyde and prepared for scanning and transmission electron microscopy to evaluate the endothelial damage. In addition, immunohistochemical staining (CD34, PECAM and Factor VIII) was performed. RESULTS: When using 0.9% sodium chloride solution, the SEM-examination revealed that 55% of the cell population was destroyed. In comparison to these findings only 26% of the endothelial cell population was damaged when the venous segment was stored in buffered solution with 5% albumin (p<0.01). In immunohistochemistry (CD34, PECAM, Factor VIII) these findings were supported. CONCLUSIONS: This study demonstrates the importance of storage solutions in regard to endothelial integrity. For best preservation of endothelium it is necessary to modify conventional storage methods. So, storage in buffered solution with albumin has shown much better endothelial cell preservation compared with physiological saline which might reduce the obliteration rate of CABG in future.

Aged↗
PubMed1999

[Prophylaxis and therapy of infectious complications of lung surgery].

Postoperative infections are a dreaded complication in pulmonal surgery. Besides the optimal preparation of the patients and careful operative technique, perioperative antibiotic prophylaxis represents an important factor in avoiding infectious consequences. Owing particularly to the high proportion of patients with malignant, consumptious illnesses in thorax surgery, immune deficiencies must be reckoned with in this group of patients. The spectrum of germs to be expected within the framework of pulmonal surgery determines to some extent which antibiotic shall be used. We have investigated the efficacy of a standardized antibiotic prophylaxis using cefotaxime (Claforan) in 200 pulmonal patients. Pleural empyema is a rare, but nonetheless important infectious illness, as a consequence of pulmonal operations, or also following pneumonia. Whilst the early stages of an empyema can often be successfully treated using only drainage treatment, chronic empyema usually requires a thoracotomy with empyema dissection and excortication, as well as subsequent irrigation-suction drainage treatment. In spite of specific surgical sanitation and irrigation-suction drainage treatment, therapy is often complicated by persistent germs in the thoracic cavity. Instillation therapy with taurolidine can lead to faster healing of the infection in such cases. Purulent mediastinitis is an extremely rare illness, but dreaded owing to its high mortality. The causes of the illness lie in injuries of the trachea, of the bronchial tubes, and of the oesophagus. With the introduction of medial sternotomy as operative entry, mediastinitis as a postoperative complication has increased noticeably in frequency. Mediastinitis occurs as a descending infection as a consequence of odontogenic affections. Owing to frequently late diagnosis, infection is usually advanced, so that simple drainage treatment of the mediastinum no longer suffices in many cases. We introduce our concept of treatment using our own patient collective.

Anti-Bacterial Agents↗
PubMed1998

Reduced release of tissue factor by application of a centrifugal pump during cardiopulmonary bypass.

The application of a centrifugal pump might lead to a reduced release of tissue factor (TF) due to less blood cell damage. This could result in a decrease in activation of the extrinsic pathway of coagulation and embolus formation. In the present study, 60 patients undergoing coronary artery bypass grafting were randomly assigned to a centrifugal or a roller pump. Plasma concentrations of TF, thrombin-antithrombin complex (TAT), and prothrombin fragments F1 + 2 were investigated before, during, and after cardiopulmonary bypass (CPB). Embolus detection was performed at the arterial line of CPB and transcranially by Doppler ultrasound. The centrifugal pump group revealed a lower TF release (area under the curve during CPB) when compared with the roller pump group [5661 (696-10359) vs 12681 (6383-17538) microg x min/l; median (lower - upper quartiles); P = 0.009]. In contrast, TAT and F1 + 2 formation did not differ between the groups, and neither did the total embolus count of both Doppler systems. Embolus counts did not correlate with TAT or F1 + 2 formation. In conclusion, the reduction in TF release by the application of a centrifugal pump seems to have little consequence on total thrombin formation. Since the applied Doppler systems seem to detect mainly microbubbles, conclusions regarding differences between the two pumps in the formation of thrombofibrinous clots cannot be drawn.

Cardiopulmonary Bypass↗
PubMed1998

Aprotinin counterbalances an increased risk of peri-operative hemorrhage in CABG patients pre-treated with Aspirin.

OBJECTIVE: As Aspirin (ASA) has proven efficacy in preventing patients with CAD from complications related to cardiovascular diseases, most patients scheduled for CABG are treated with ASA therapy. Consequently, impaired hemostasis is a problem in the management of CABG patients. Clinical studies have shown that Aprotinin can reduce bleeding and the use of blood products by 50% in patients both with and without pre-operative ASA therapy. Concerning the combined effect of peri-operative low-dose ASA therapy and intra-operative high-dose Aprotinin therapy, the gathering of additional and prospective data seemed to be necessary. METHODS: We conducted a double-blind two-centre randomised three-arm study in patients with elective primary CABG surgery. Three groups have been tested, comprising 119 patients in total (group A: ASA + Aprotinin, group B: placebo + Aprotinin, group C: placebo + placebo) to investigate a possible reduction of bleeding in Aprotinin treated patients. For all patients, thromboxane levels were used to identify ASA or placebo treatment. RESULTS: The post-operative blood loss is significantly reduced by 21% after Trasylol administration (B vs. C; P = 0.009). The unexpected result of this study has been that the pre-treatment with ASA led to a further reduction of 18% (A vs. C; P < 0.0001). The difference between the two Aprotinin groups (A and B) is significant (P = 0. 01) in favour of ASA pre-treatment. Myocardial infarction (MI) had been diagnosed at levels of 1.8% in total (2/113), 2.6% (1/38) in group B and 3.2% (1/31 ) in group C. An additional blinded evaluation of ECG, enzyme levels and clinical status revealed 'definite, probable and possible' MIs of 5% in group A, compared to 16% in group B and 13% in group C, thus providing no evidence for a higher risk of infarction by Aprotinin treatment. When comparing the ASA group to non-ASA pre-treatment, a strong trend towards a reduction in MI rate becomes obvious, from 15% to 5% in favour of the ASA pre-treatment (P = 0.08). Concerning other peri-operative complications, no statistical difference between the groups could be detected. CONCLUSIONS: A reduction in post-operative blood loss in primary elective CABG surgery with intra-operative Aprotinin treatment could be confirmed. A low-dose ASA treatment combined with a high-dose aprotinin administration during surgery not only neutralized a potentially higher risk of bleeding, but did in fact reduce the post-operative blood loss. The protective effect of ASA on peri-operative MI has been evident through a reduction of MI rate in ASA treated patients.

Aprotinin↗
PubMed1997

Response of the cellular immune system to cardiopulmonary bypass in vivo.

Cardiopulmonary bypass (CPB) is known to induce an inflammatory response. Previous studies reported an impairment of the cellular immune response with activation of neutrophils and changes in lymphocyte subpopulations. The objective of the present study was to investigate the effect of CPB on leukocyte activation in vivo. In 27 patients undergoing coronary artery bypass grafting, the quantitative and the qualitative response of leukocyte populations to CPB was analysed pre-, intra-, and postoperatively using flow cytometry. A significant increase in leukocyte counts was detected during CPB, resulting in a marked leukocytosis postoperatively. The total number of lymphocytes peaked in the early phase of CPB, followed by a significant decrease, mainly due to a loss in B and cytotoxic T lymphocytes. In contrast, the lymphocytopenia observed 8 h after protamin administration was mainly caused by a drop in the population of helper T lymphocytes. Activation of distinct cell populations could be detected during and following CPB. The results indicate an influence of CPB on the cellular immune system, however an immuno-suppression was detectable only transiently.

Aged↗
PubMed1997

[Coincidence of pulmonary cryptococcoma in an immunocompetent patients with a chondrohamartoma and chronic tuberculoma--differential diagnostic considerations concerining pulmonary coin lesions].

Of primary importance in the differential diagnosis of multiple circular foci in the lungs are the lung metastases. This study involves a patient with three circular foci, each of which could have been metastases. They proved, however, to be a rare coincidence of three benign lung affections, namely, an old tuberculoma, a chondrohamartoma, and a seldom encountered pulmonary cryptococcoma. Computerized tomography utilizing the spiral technique was valuable diagnostically, as it led to the discovery of the smallest of the three circular foci in the basodorsal left lower lobe. The form of the cryptococcosis among immunocompetent patients--only rarely localized in our experience--must be included in the differential diagnostical considerations of a circular focus in the lungs. In the event there are multiple circular foci with an unknown primary tumor, surgical intervention with a pathohistological clarification regarding a possible malignancy is absolutely necessary.

Cryptococcosis↗
PubMed1996

Changes in coagulation and fibrinolytic parameters caused by extracorporeal circulation.

During cardiopulmonary bypass (CPB) mechanical stress and the contact of blood with artificial surfaces lead to the activation of pro- and anticoagulant systems and the complement cascade, and to changes in cellular components. This phenomenon causes the "postperfusion-syndrome", with leukocytosis, increased capillary permeability, accumulation of interstitial fluid, and organ dysfunction. In this study, we focused on the influence of the extracorporeal circulation, sternotomy, and heparin administration on the activation of coagulation and fibrinolysis. In 15 patients we investigated coagulation parameters before, during and post CPB, i.e., fibrinogen, antithrombin (AT) III, thrombin-antithrombin complex (TAT), prothrombin fragments F1 + 2 (F1 + 2), factor (F) XIIa, tissue factor (TF), and parameters of the fibrinolytic system, i.e., plasmin-antiplasmin-complex (PAP), D-dimer, tissue-plasminogen-activator (tPA), urokinase-type plasminogen activator (uPA), and plasminogen-activator inhibitor type 1 (PAI 1). The results demonstrate distinct alterations in the above mentioned parameters. Despite administration of a high dose of heparin (activated clotting time [ACT] > 450s) combined with a low dose of aprotinin, activation of the coagulation and fibrinolytic pathways was observed. We found this activation was mainly caused by CPB and not by sternotomy. The activation of coagulation was due to foreign surface contact (F XII => F XIIa) as well as to an effect of tissue factor release in the late phase of CPB. The enhanced fibrinolytic activity during CPB was, at least in part, caused by tPA and was followed by PAI 1 release.

Anticoagulants↗
PubMed1996

Efficacy and safety of low-dose propranolol versus diltiazem in the prophylaxis of supraventricular tachyarrhythmia after coronary artery bypass grafting.

OBJECTIVE: Supraventricular tachyarrhythmias (SVT) complicate postoperative management after coronary bypass surgery in about 30% of all patients. Though a prophylactic treatment both with beta-adrenergic blocking agents and the calcium antagonist diltiazem has been used for the prevention of post-operative SVT, no study yet has performed a prospective comparison of the efficacy of these therapies. METHODS: To investigate the prophylactic effect of either a calcium antagonist (diltiazem, 0.1 mg/kg per h i.v.) or a beta-adrenergic blocking agent (propranolol, 10 mg every 6 h postoperatively), we randomized prospectively 103 consecutive patients into three groups, the third one serving as a control group. Anti-arrhythmic medication was started with the procedure and was continued until the 3rd postoperative day. RESULTS: Preoperative conditions were the same for the three groups concerning age, extent of coronary heart disease, ventricular function and heart-related medication. There were no differences in intraoperative parameters or postoperative enzyme patterns. Diltiazem was ineffective in preventing SVT, the incidence being exactly the same as in the control group (35%). Propranolol reduced the occurrence of SVT significantly (7%, P < 0.05). Furthermore, patients treated with diltiazem needed positive inotropic support more often in the first hours after surgery than patients of the control group (30% vs 5%, P < 0.01). CONCLUSIONS: The perioperative administration of low-dose propranolol is considered a safe and effective drug prophylaxis to avoid the occurrence of SVT after bypass surgery.

Adult↗
PubMed1995

Concentrations of catecholamines in transplanted hearts after extracorporeal perfusion and cold storage.

Using different perfusion regimes and orthograde implantation, some investigators have found sufficient heart function after extracorporeal perfusion of hearts for 24 and even 72 h. However, we found no significant improvement of perfused hearts compared to cold stored hearts after a 9-h extracorporeal period. A possible explanation for this finding could be the excessive liberation of catecholamines during ischemia, as has been demonstrated in isolated perfused hearts. Therefore, the aim of this study was to investigate whether concentrations of noradrenaline and dihydroxyphenylglycol (DOPEG)--a noradrenaline metabolite-increased pathologically during continuous extracorporeal heart perfusion for 5 h in pigs, in comparison to hearts stored at 4 degrees C. The venoarterial differences in noradrenaline and DOPEG were not significantly different in the two groups. Concentrations of lactate and pyruvate decreased substantially after 3-h hypothermic perfusion. The lactate/pyruvate ratio remained at a value of 25-35. Only after the end of the extracorporeal circulation did this ratio reach a value of 40-65. In our model, these findings demonstrate that the excessive liberation of catecholamines is not a reason for heart failure after cold storage or perfusion.

Animals↗
PubMed1995

Centrifugal and roller pumps--are there differences in coagulation and fibrinolysis during and after cardiopulmonary bypass?

A number of hemostatic parameters reflecting the activation of coagulation and fibrinolysis were investigated in a prospective study of 24 patients undergoing cardiopulmonary bypass (CPB) during heart surgery. The patients were randomized to a group in which either a roller (group 1) or a centrifugal pump (group 2) was used. Blood samples were taken preoperatively, at the onset of and every 20 min during CPB, after the administration of protamine, and 4, 20, 44, and 68 h postoperatively. The groups did not differ significantly in hematocrit, fibrinogen, factor XIII, and antithrombin III. Significant differences in favor of group 2 during and after CPB were found in prothrombin fragment F1 + 2, plasmin-antiplasmin complex (PAP), thrombin-antithrombin complex (TAT), and D-dimer (F1 + 2 P < 0.01 after 80-min CPB, PAP P < 0.005 after 40-min CPB, TAT and D-dimer P < 0.05 after 100-min CPB, D-dimer and PAP P < 0.05 after protamine administration, TAT and F1 + 2 4 h after CPB). These findings indicate the activation of fibrinolysis preceding thrombin generation during cardiopulmonary bypass. In addition, we conclude that centrifugal blood pumping is beneficial in avoiding excessive activation of both coagulation and fibrinolysis.

Aged↗
PubMed1995

Aortic bioprosthesis without early anticoagulation--risk of thromboembolism.

Anticoagulation after implantation of a bioprosthetic heart valve has been suggested during a high-risk period of 3 months following surgery. There is little information available concerning the risk of thromboembolism during this period if anticoagulation is not carried out. However, this is of interest since 60-80% of all bleeding complications due to anticoagulation occur during the first year of treatment. Between 1983 and 1993, 57 of our patients did not receive oral anticoagulation after implantation of a bioprothesis in the aortic position (49 Hancock, 7 Mitroflow and one Edwards stentless). All patients were investigated retrospectively. A risk for thromboembolic complications of 1.75% is calculated for the first six months following surgery, being 3.5 per 100 patients/year. There seems to be no advantage in standard anticoagulation (INR 2.5-4) with its risk of serious bleeding complications of about 4% during this period of treatment. Low-dose anticoagulation (INR 2.0-2.3), however, preferably in combination with prothrombin estimation by the patients, seems to offer a relatively safe treatment for these patients.

Administration, Oral↗
PubMed1995

Early and late prognosis following valve replacement for bacterial endocarditis of the native valve.

Between 1983 and 1922 70 patients of the author's institution underwent valve replacement for bacterial endocarditis of native valves. In 22 cases the source of infection could be identified. Among them the most frequent source of infection was dental manipulation (7 patients). The predominating causative microorganism was Streptococcus viridans followed by Staphylococcus aureus. Preoperative complications, the intraoperative finding of extensive destructions, and the histological finding of acute changes influenced significantly the occurrence of perioperative complications. 20 patients died (28.6% overall mortality), there were 9 perioperative deaths (perioperative survival 87.1%). The one-year survival was 73.8% the five-year survival 61.5%. Significant risk factors for the prognosis were preoperative complications, positive bacteriological result of the analyzed resected valves, perioperative complications, duration of the postoperative antibiotic treatment, and the postoperative NYHA functional class. Therefore one should intervene surgically before preoperative complications appear. Perioperative complications must by treated immediately, and an adequate postoperative antibiotic therapy must be guaranteed.

Adolescent↗