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Biomedical subjects

D Kling

Publications and source records attributed to D Kling.

At least 55 records · Page 3Linked to original sources
PubMed1989

Blood conservation in cardiac operations. Cell separation versus hemofiltration.

The effects of hemoconcentration performed during and after extracorporeal circulation by either centrifugation (cell separation group, n = 20) or hemofiltration (n = 20) were investigated in 40 patients undergoing elective aorta-coronary bypass grafting. Interest was focused on the quality of the blood concentrated from the blood remaining in the extracorporeal circuit and on the reaction of the patients after retransfusion of the concentrated products. Hemofiltration was easy to perform and produced whole blood quicker than the cell separation technique. Coagulation studies revealed no significant differences in heparin concentration, levels of fibrinogen and antithrombin III, or platelet counts. Various coagulation parameters tended to normalize completely and more quickly after hemofiltration than after centrifugation. None of the patients had severe bleeding postoperatively. Free hemoglobin levels were not affected by hemofiltration; elastase concentration was higher only immediately after retransfusion of the concentrated blood, with no effect on organ function. We conclude that both methods were effective means of hemoconcentration during extracorporeal circulation and in salvaging the diluted pump blood after extracorporeal circulation. Loss of plasma fraction is an important disadvantage in the centrifugation technique, which can be avoided by hemofiltration; derangement in colloid osmotic pressure and coagulation parameters was less pronounced after hemofiltration. Costs were lower, as well. Therefore, when a high volume of cardioplegic solution and two-stage cannulation are used, hemofiltration seems to be the method of choice for blood conservation during cardiac operations.

Aged↗
PubMed1988

The effect of pentoxifylline on endothelial permeability of rabbit carotid artery wall.

Weak electrical stimulation of the rabbit carotid artery wall with direct current impulses over a period of 45 min increased the endothelial permeability for horseradish peroxidase (HRP), molecular weight 40,000 Da, beneath the anode region of the electrodes. The stimuli caused a massive accumulation of the reaction products of peroxidase in the subendothelial space. With a microdensitometric technique, it was possible to quantify the amount of the peroxidase reaction products in the subendothelium, and to compare the amounts in the non-stimulated regions with those in the stimulated regions. Intravenous administration of pentoxifylline before stimulation inhibited the transendothelial transport of peroxidase. Inhibition was pronounced in the stimulated regions, whereas the uptake of HRP in the non-stimulated regions was only slightly lower than that in non-treated animals. It was demonstrated that the extent of inhibition was dose-dependent (3, 10 and 30 mg pentoxifylline/kg). Electron microscopic examination showed that the main route of permeation of HRP was through the interendothelial clefts. However, electrical stimulation also caused an increase in the vesicular uptake of HRP into endothelial cells. Both pathways seem to be influenced by pentoxifylline.

Animals↗
PubMed1988

Influence of acute preoperative hemodilution on right ventricular function.

In a randomized study, the effects of acute, preoperative hemodilution (HD) (12 mL/kg) on right ventricular function were investigated in coronary artery surgery patients with reduced left ventricular function (ejection fraction < 50%) and significant stenosis of the right coronary artery (RCA). Blood was replaced either by hydroxyethyl starch (HES) solution (ratio 1:1; HD-HES; n = 15) or by Ringer's lactate, (RL) (ratio 2.5:1; HD-RL; n = 15). Fifteen comparable patients without HD served as a control group. Besides commonly measured pressure parameters, right ventricular end-diastolic volume (RVEDV), right ventricular end-systolic volume (RVESV), and right ventricular ejection fraction (RVEF) were measured using a computerized thermodilution technique before and after HD, as well as after extracorporeal circulation (ECC). Right ventricular systolic function, expressed as RVEF, was not changed significantly by HD in any group. Furthermore, right ventricular function of the hemodiluted patients was not impaired by the subsequent ECC procedure. None of the traditionally measured parameters could be correlated significantly to the right ventricular thermodilution variables. It is concluded that moderate HD does not change right ventricular function even when the RCA is significantly stenosed.

Aged↗
PubMed1988

Revascularization of the right coronary artery: influence on thermodilution right ventricular ejection fraction.

This study was designed in order to evaluate the influence of right coronary artery (RCA) disease and its revascularization on right heart performance monitored by measuring thermodilution right ventricular ejection fraction (RVEF). Forty patients undergoing elective aortocoronary bypass surgery were divided into two groups: group 1, with RCA revascularization, n=20; and group 2, without RCA disease or revascularization, n=20. RVEF was measured using a pulmonary arterial catheter mounted with a fast-response thermistor and a bedside microprocessor ejection fraction computer. The major finding of the study was that myocardial revascularization with extracorporeal circulation was followed by a decrease in RVEF which was significantly more pronounced in group 1 (-13.1%) in comparison to group 2 (-5.0%). RVEF gradually increased after bypass, but did not reach baseline values. By the first postoperative day, RVEF had reached baseline values again in group 1 and had increased beyond baseline values in group 2. Traditionally measured hemodynamic parameters could not be correlated with the course of RVEF, except for cardiac index. The present study further suggests that right-sided events may have clinical effects on left-sided function. Inadequate protection of the right heart, especially in patients with RCA stenosis, may result in depression of right ventricular myocardial performance, which can be monitored serially by measuring RVEF.

Blood Pressure↗
PubMed1988

Resection of a heart tumor using autotransplantation.

A 38 year old male patient presented with a cardiac tumor. Echocardiography and visualization of the left atrium revealed a large myxoma. Surgical resection of the tumor was performed with the aid of cardiopulmonary bypass. The extensive size of the tumor base and its localisation at the posterior left atrial wall made a conventional approach impossible. Therefore radical resection of the tumor was undertaken using autotransplantation. After a routine postoperative course, the patient was discharged on the twenty seventh hospital day.

Adult↗
PubMed1988

Influence of acute normovolemic hemodilution on extravascular lung water in cardiac surgery.

Preoperative hemodilution (HD) is an established blood-saving method. With HD, however, a concomitant increase in extracellular and interstitial water has been reported. This randomized study was undertaken to compare the effects of acute normovolemic HD (10 ml/kg; n = 15) using hydroxyethyl starch solution (HES) on extravascular lung water (EVLW) with those of an untreated control group (n = 15) of cardiac surgery patients submitted to extracorporeal circulation (ECC). A thermal-dye technique was used to measure EVLW. There was no significant change in EVLW due to preoperative HD (5.55 +/- 0.51 vs. 5.71 +/- 0.59 ml/kg). After ECC, a transient increase in both groups could be demonstrated because of a possible change in pulmonary capillary permeability (maximal increase in the HD group: +1.30 ml/kg and in the nonHD group: +1.02 ml/kg). Five hours after ECC, no differences could be seen between the groups. Pulmonary gas exchange was not significantly affected (PaO2 in the HD group: -20 torr). Hemodynamic and laboratory variables indicated the typical changes during HD (cardiac index increases while albumin concentration decreases); circulatory stability was maintained during the entire study. We conclude that preoperative normovolemic HD did not increase lung water content significantly nor compromise pulmonary function even in cardiac surgery patients. Although ECC provides an additional HD (crystalloid priming of the heart-lung bypass machine) and possibly damage of capillary integrity, the two groups did not differ.

Body Water↗
PubMed1988

RETRACTED: Influence of PEEP ventilation immediately after cardiopulmonary bypass on right ventricular function.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the request of the editor. In 2018, CHEST published a notice1 that all articles authored by Joachim Boldt be read with caution due to expressions of concern about falsified data. In 2020, CHEST received additional evidence of research misconduct and breaches of scientific integrity that were discovered following an investigation by the author's former institution, the University of Giessen2. In light of this new evidence, this article has been retracted by CHEST. 1. Irwin, R.S., MD, Master FCCP. Notice From the Editor in Chief. CHEST 153(3), p. 767. 2. Mukherjee, J. Statement on the scientific credibility of articles published by Joachim Boldt, formerly professor at Justus Liebig University (JLU), Giessen, Germany. https://ars.els-cdn.com/content/image/1-s2.0-S000709122030163X-mmc3.pdf.

Cardiac Output↗
PubMed1988

[Enoximone, a new phosphodiesterase inhibitor: the spectrum of applications during heart surgery--a comparison with dobutamine].

During cardiac surgery treatment of deterioration of myocardial function is usually based on catecholamines. Development of selective phosphodiesterase-(PDE-)III-inhibitors seems to be a new aspect in treating myocardial dysfunction. Therefore the hemodynamic effects of the new PDE-inhibitor enoximone were investigated in 20 coronary surgery patients unable to be weaned from extracorporeal circulation (ECC) without pharmacological intervention (MAP less than 60 mmHg, CI less than 2.00 l/min.m2, PCP greater than 15 mmHg). After controlled reperfusion with 2.4 1/min.m2 two groups were separated in a random sequence receiving either 0.5 mg/kg enoximone as a bolus (n = 10), or dobutamine (n = 10, 5 micrograms/kg.min) as perfusion. In the dobutamine-group MAP and CI (-14%) were decreased, while HR was increased significantly (+30%). Application of enoximone was followed by a slight increase in CI (+5%), a significant decrease in TSR while HR remained almost unchanged. PCP, too, differed significantly between the groups (enoximone: -38%; dobutamine: -10%). Ten minutes after weaning from ECC additional pharmacologic therapy (calcium, vasodilators, epinephrine) was necessary in eight dobutamine treated patients in contrast to four patients in the enoximone group (calcium, epinephrine). In patients with impaired myocardial performance during weaning from ECC enoximone seems to be an alternative therapy and is judged to be of some advantage compared to dobutamine application in this situation. The mechanism for improvement appears to be enhanced contractility owing to its positive inotropic effects, as well as a decrease in left ventricular outflow resistance resulting from peripheral vasodilation.

Aged↗
PubMed1988

[Hemodynamics in donor plasmapheresis].

Several studies have demonstrated that preoperative withdrawal and storage of autologous plasma as fresh frozen plasma is effective in blood conservation. For that purpose patients with elective surgery (orthopaedic surgery, open heart surgery, neurosurgery and others) have to undergo donor plasmapheresis without staying in the hospital. Depending upon the need the procedure can be performed several times preoperatively, taking about 900 ml in a normal weighting subject at once. The collection of autologous plasma should be finished at least 14 days before surgery. In order to investigate the haemodynamic effects of donor plasmapheresis 30 patients scheduled for coronary bypass surgery were devided into two groups. 15 patients underwent plasmapheresis (10 ml plasma/kgbw) by one-needle-technique using a Haemonetics seperator (PCS) after premedication but before onset of anaesthesia. Blood withdrawal was performed with 0.5 ml/kgbw x min. Another 15 patients, serving as control had no plasma withdrawal and were measured at identical times as the other group. Both groups had an identical fluid replacement with 500 ml Ringer's solution during the investigation period. Plasma withdrawn was not substituted by colloidal solution (simulating the situation when plasmapheresis is performed at the outpatient). Haemodynamic measurements (both groups) included heart rate, arterial blood pressure, right- and left-atrial pressure, systemic- and pulmonary-vascular resistance and cardiac output. There were no relevant effects of plasmapheresis on haemodynamic function during and after the investigation period in that patients: neither heart rate, blood pressure or vascular resistance changed significantly nor did pre- and afterload or cardiac index. No differences to the group without plasmapheresis could be observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Transfusion, Autologous↗
PubMed1988

[Experiences with parenteral administration of diltiazem in coronary surgery patients].

Diltiazem is a calcium channel blocker whose effects lie between those of the two other important calcium antagonists nifedipine and verapamil. In addition to vasodilation, it has a negative dromotropic effect with prolongation of the A-V interval. In animal experiments and human investigations, diltiazem improves the function of ischemic myocardium due to a direct dilating effect on coronary vessels. The purpose of the present study was to investigate the hemodynamic effects of diltiazem in patients before and during coronary revascularization. METHODS. The study included 60 consenting male patients with coronary heart disease. Twenty premedicated patients randomly received 0.3 mg/kg diltiazem or placebo within 3 min before induction of anesthesia. Hemodynamic measurements (arterial pressure, heart rate, mean pulmonary arterial pressure, pulmonary capillary pressure, right atrial pressure and cardiac output) were taken during the following 21 min. Before cannulation of the great vessels for institution of extracorporeal circulation (ECC), 20 other patients received 0.014 mg diltiazem or placebo/kg per min over 20 min. In addition to the above mentioned hemodynamic measurements, left ventricular parameters (LVP, LVEDP, dp/dt) were directly registered, and 5 min after the end of ECC the measurements were repeated with the same preload as before the ECC. Twenty additional patients received 0.014 mg diltiazem or placebo/kg per min within 21 min during ECC observing arterial perfusion pressure and oxygenator volume. RESULTS. Pre- and intraoperatively diltiazem caused a decrease in mean arterial pressure; cardiac index increased only during the preoperative investigation period (Tables 1, 2), whereas stroke volume index increased pre- and intraoperatively; heart rate decreased in all patients as well as dp/dt (Fig. 1).(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, General↗
PubMed1988

[Resuscitation and extravascular lung fluid in cardiac surgery].

Cardiovascular arrest may be followed by severe respiratory insufficiency due to an increase in the pressure in the pulmonary vascular system, an alteration in capillary permeability, or both. Extracorporeal circulation (ECC), on the other hand, can lead to a change in capillary integrity ('capillary leakage') caused by the unphysiologic perfusion patterns and/or activation of various mediator systems. Pulmonary hyperhydration (increased extravascular lung water [EVLW]) seems to be the most important factor limiting pulmonary function in this situation. This retrospective study was designed to investigate the influence of resuscitation in the period before ECC on pulmonary EVLW thereafter. Eight coronary surgery patients who had to be resuscitated in the period before the start of ECC due to cardiocirculatory arrest were compared to 8 patients without resuscitation selected randomly (control group). There were no differences between the two groups with regard to age, catheterization data, and ECC conditions. All patients underwent identical monitoring, including estimation of EVLW. Lung water measurement was performed by the thermal dye technique with indocyanine green (= non-diffusible indicator) dissolved in ice-cold dextrose (= diffusible indicator) and a bedside microprocessor before resusciation and after ECC (15 min, 45 min, 5h). Simultaneously, hemodynamics and parameters of pulmonary gas exchange were monitored. Baseline values of EVLW were comparable in both groups. After ECC a transient increase in EVLW could be demonstrated in the controls, indicating an altered fluid flux even in 'uncomplicated' courses; 5 h after ECC lung water content had again reached baseline values. In contrast, there was a significant increase in EVLW in the 'complicated group' immediately after ECC (+2.60 ml/kg) and 5 h after ECC (+1.38 ml/kg); in consequence, the paO2 was significantly decreased (-180 mmHg) while Qs/Qt was increased (+6.79%). It is concluded that the combination of two factors that potentially damage pulmonary tissue and increase lung water content (reanimation due to circulatory arrest and extracorporeal circulation) lead to a significant increase in extravascular lung water combined with a deterioration of pulmonary function, resulting in severe respiratory failure.

Capillary Permeability↗
PubMed1988

[Non-invasive versus invasive cardiovascular monitoring. Determination of stroke volume and pulmonary hydration using a new bioimpedance monitor].

Measurement of hemodynamic parameters by noninvasive techniques is gaining more and more popularity in the face of severe complications associated with invasive methods. Thoracic electrical bioimpedance is a noninvasive means of estimating cardiac output (CO) and pulmonary edema formation. The validity of this method, however, has been controversial. In the present study a new bioimpedance monitoring system (NCCOM 3) was used in 10 intensive care patients undergoing mechanical hemofiltration (group I) and in 20 cardiac surgery patients undergoing either aortic valve replacement (AVR, group IIa, n = 10) or aorto-coronary bypass grafting (CABG, group IIb, n = 10). In cardiac surgery patients the measurements were performed before as well as after extracorporeal circulation (ECC). CO measured by the impedance monitor was compared to the standard thermodilution method; pulmonary fluids were estimated by a thermo-dye technique and by measurement of total electrical impedance (base impedance), expressed as the thoracic fluid index (TFI). The principal finding of the study was that CO as measured by the two techniques differed significantly in all groups with regard to absolute values. The relative changes in CO, however, were comparable in both intensive care patients and CABG patients. In patients with special thoracic blood flow conditions (regurgitation in aortic insufficiency patients), no corresponding course of CO could be found.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Kidney Injury↗
PubMed1988

[Heparin elimination and free hemoglobin following cell separation and washing of autologous blood with Cell Saver 4].

Haemoseparation is used for recovery of autologous blood following cardiac surgery protecting patients from various hazards accompanying homologous blood transfusion. Former studies demonstrated that autotransfusion did not increase blood loss after cardiac surgery despite reduced plasma and platelets following centrifugation and washing of oxygenator content. The purpose of our study was to determine the content of heparin and unbound haemoglobin in autologous packed red cells. METHODS. 10 consenting patients undergoing cardiac surgery (table 1) were investigated. Immediately after termination of bypass blood samples were collected from the oxygenator and from autologous blood following concentration and washing with saline solution in the Haemonetics Cell-Saver 4. Contents of haemoglobin, haematocrit, heparin - with and without addition of antithrombine III - and unbound haemoglobin were analysed. RESULTS. Mean duration of extracorporeal circulation was 100.4 minutes. The oxygenators' volume averaged 2089.9 ml blood with a haemoglobin content of 6.7 g/dl and a haematocrit of 20.4%. This was reduced to 660.8 ml autologous blood with a haemoglobin content of 17.9 g/dl and a haematocrit of 57.2% (table 2). The heparin content of the oxygenator blood was 0.47 U/ml without AT III, and with AT III 0.87 U/ml. Autologous blood contained 0.009 U/ml without AT III; with AT III we measured 0.41 U/ml heparin. Unbound haemoglobin content amounted to 11.4 mg/dl in the oxygenator blood and 71.8 mg/dl in the autologous blood (table 3). CONCLUSIONS. Our results demonstrate that autologous blood following concentration and washing of the oxygenator blood with a Haemonetics Cell-Saver 4 contains heparin, but the amount of heparin is not enough to provoke bleeding after retransfusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Component Removal↗
PubMed1988

[Reaction of the sympathetic nervous system, cardiovascular parameters and endocrine stress response in disobliterating interventions of the carotid arteries. A comparison of isoflurane anesthesia and modified neurolepto-anesthesia].

In order to investigate whether the increases in mean arterial pressure (MAP) and HR during carotid endarterectomy are due to a systemic, sympathicotonic stress response and to compare two anesthetic regimens for this operation, 20 patients were randomly allocated to the following groups: (1) modified neuroleptanesthesia with midazolam, fentanyl, and vecuronium: and (2) isoflurane anesthesia with vecuronium relaxation. Premedication (pethidine, promethazine) and induction of anesthesia were similar in both groups. The plasma levels of epinephrine and norepinephrine (by HPLC/ECD), ADH, ACTH, and cortisol (by RIA), glucose, lactate, and free glycerol were determined before and after induction of anesthesia, 7 times during the operation, and 30 min after extubation. MAP and HR were measured continuously. Statistical evaluation was undertaken by analysis of variance with repeated measures on 1 factor, considering P values of less than 0.05 as significant. The endocrine parameters failed to show any remarkable increase during the entire operation period. After the end of the operation all hormones rose significantly (P less than 0.001). No correlation was found between plasma catecholamines and increases in MAP and HR. Group levels of norepinephrine and ADH were higher in the isoflurane group (P less than 0.04). It is concluded that cardiovascular reactions during carotid endarterectomy are not caused by systemic stress. Neuroleptanesthesia leads to better stress protection in the postoperative period, while isoflurane anesthesia has some advantages for the intraoperative control of arterial pressure.

Adult↗
PubMed1987

[Combination autotransfusion in heart surgery. Use of acute normovolemic hemodilution in coronary heart disease].

Normovolemic hemodilution (15 mg/kg body-weight: group I) was undertaken in 100 patients immediately before the start of coronary-artery surgery. In addition, a Cell-Saver (Haemonetics, Munich) was used for intra-operative autotransfusion. Another group of 100 patients (group II) was similarly operated on without autotransfusion (the study was conducted on 200 consecutive patients undergoing aorto-coronary bypass). Before blood (autologous or homologous) was administered a reduction of hemoglobin to 9 g/100 ml and hematocrit to 0.28 was well tolerated (during extracorporeal circulation: 6.5 g/100 ml and 0.16, respectively). Due to intra- and postoperative complications, such as infarct bleeding (including reoperation) or septicemia, the number of patients placed in group I fell to 94, that in group II to 90. Acute normovolemic hemodilution increased cardiac output and oxygen transport capacity, while other hemodynamic parameters remained unchanged, and there was no effect on extravascular lung water. Autotransfusion reduced the need for homologous blood derivatives by 71% (fresh blood, fresh plasma, RBC concentrates). No clinically significant disadvantages occurred.

Adult↗
PubMed1987

Influence of cardiac output on thermal-dye extravascular lung water (EVLW) in cardiac patients.

The influence of varying cardiac output (CO) on thermal-dye extravascular lung water (EVLW) was investigated in a total of 40 cardiac surgery patients before the onset of the operation. EVLW was measured by means of the double indicator dilution technique with indocyanine green as the non-diffusible indicator and a microprocessed lung water computer 15 min and 30 min after change of CO. CO was varied from -45% to +70% of the baseline value by nifedipine infusion (CO increases, n = 20) or halothane application (CO decreases, n = 20), respectively. CO was measured from the femoral artery instream thermistor tipped lung water catheter and, simultaneously, from the pulmonary artery. In spite of a highly significant decrease (-45%) and increase (+70%) in CO no change in EVLW could be observed. CO estimation was comparable for both methods used. Regression analysis revealed no relationship between CO and EVLW as well as between EVLW and various hemodynamic parameters. We conclude that thermal-dye technique for estimation of EVLW may be accurate in spite of changing cardiac output over a wide range.

Cardiac Output↗