PubMed Health⌕ Search

Biomedical subjects

F Dapper

Publications and source records attributed to F Dapper.

71 records · Page 4Linked to original sources
PubMed1990

Effects of nitrous oxide on endocrine stress response and haemodynamic parameters during coronary artery surgery.

To compare simultaneously the influence of nitrous oxide on haemodynamic parameters and on surgical stress response, 20 patients scheduled for coronary artery bypass graft were investigated during standardized modified neurolept anaesthesia. Before onset of cardiopulmonary bypass, one group received nitrous oxide and oxygen (2:1), whereas in the other group air with oxygen (F10(2) 0.33) was used. Increases in adrenaline, noradrenaline, ADH, and cortisol were slightly less and mean arterial pressure and cardiac output reached markedly lower levels in the nitrous oxide group. When nitrous oxide is not acceptable for a cardiac surgery patient during modified neurolept anaesthesia due to haemodynamic side effects enhancing intravenous application of anaesthetics to compensate the analgetic properties of the substance should be considered.

Adrenocorticotropic Hormone↗
PubMed1990

Haemodynamic effects of the phosphodiesterase inhibitor enoximone in comparison with dobutamine in esmolol-treated cardiac surgery patients.

In a randomized study, the haemodynamic effects of the new phosphodiesterase-III-inhibitor, enoximone, were compared with dobutamine in acutely beta-adrenoceptor blocked patients. Twenty patients scheduled for aorto-coronary bypass grafting suffering from tachycardia (heart rate (HR) greater than 100 beat min-1) were treated by infusion of esmolol, an ultra-short acting, selective beta 1-blocker. Twenty minutes after the start of esmolol, either enoximone 0.5 mg kg-1 as a bolus (n = 10) or dobutamine 5 micrograms kg-1 min-1 was administered. Haemodynamic effects were monitored for 40 min, including measurement of left ventricular haemodynamics. Esmolol reduced HR (-27%) and dP/dtmax (-38%) significantly in both groups. Cardiac index (CI) was decreased also. Enoximone increased Cl (+35%) and dP/dtmax (+39%) significantly, while no change in dobutamine-treated patients was observed. Systemic vascular resistance increased only in the dobutamine group (+44%).

Adrenergic beta-Antagonists↗
PubMed1990

Volume therapy with hypertonic saline hydroxyethyl starch solution in cardiac surgery.

The ideal solution for volume therapy remains controversial. In cardiac surgery, haemodynamic efficacy as well as the influence of extracorporeal oxygenation are of major interest when administering volume. The present study examines the effects of a new hypertonic saline hydroxyethyl starch solution in comparison to a 6% hydroxyethyl starch solution on haemodynamics and laboratory variables. Patients scheduled for elective aortocoronary bypass grafting received hypertonic saline hydroxyethyl starch (n = 10) or hydroxyethyl starch (n = 10) after induction of anaesthesia in order to double baseline pulmonary capillary wedge pressure. Ten patients without volume therapy served as a control group. Significantly less hypertonic solution than standard solution was effective in doubling pulmonary capillary wedge pressure. Fluid requirements in the patients who received the hypertonic solution were significantly less during, as well as after, cardiopulmonary bypas in comparison to those in the other groups. Cardiac index increased most in the patients who received the hypertonic solution (+34.8%), as did right ventricular end-diastolic volume. Patients in that group showed the highest decrease in total systemic resistance (-29.8%), whereas arterial pressure and right ventricular ejection fraction remained almost unchanged in all groups. No negative alteration in coagulation or organ function was demonstrated within the investigation period. It can be concluded that hypertonic saline hydroxyethyl starch solution seems to be a valuable alternative to conventional volume therapy in cardiac surgery.

Blood Volume↗
PubMed1990

RETRACTED: Efficacy of the phosphodiesterase inhibitor enoximone in complicated cardiac surgery.

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.

Aged↗
PubMed1990

[The hemodynamic effects of various hydroxyethyl starch solutions in heart surgery patients].

Blood conservation is gaining more and more interest because of the increasing risks involved in homologous blood transfusions. Acute normovolemic hemodilution (ANH) is becoming an established technique even in cardiac surgery patients. The "optimal" kind of volume replacement, however, is still controversial. Thus, this study was carried out to investigate the hemodynamic response of 6 different hydroxyethyl starch (HES) solutions as volume replacement. METHODS. In 60 patients undergoing elective aortocoronary bypass surgery, acute, preoperative hemodilution was performed (10 ml/kg) and HES with different concentrations, molecular weight, and substitution was infused according to a randomized sequence: 1. 6% HES 450,000/0.7; 2. 10% HES 200,000/0.5; 3. 3% HES 200,000/0.5%; 4. 6% HES 40,000/0.5; 5. 6% HES 200,000/0.5; 6. 6% HES 200,000/0.62. All patients were monitored using a new pulmonary artery catheter that allows measurement of the right ventricular ejection fraction (RVEF), right ventricular enddiastolic volume (RVEDV), and right ventricular end systolic volume (RVESV) in addition to standard hemodynamic parameters. RESULTS. Immediately after finishing ANH the typical hemodynamic changes of hemodilution (HD) were apparent (decrease in peripheral resistance and increase in cardiac index (CI]. All 6 solutions investigated were effective in hemodynamic stabilization (no changes in mean arterial pressure (MAP), filling pressures (PCP, RAP), or heart rate (HR]. Forty min after ANH, however (before beginning extracorporeal circulation (ECC], there were significant differences between the groups: in groups 3 and 4 the increase in CI had already disappeared, and SVI in group 3 was even lower than the baseline values (-8%). In the other groups, a higher CI level remained even 40 min after ANH, which was most pronounced in groups 2 (+40%) and 5 (+43%). Right ventricular performance was not changed by ANH (RVEF unchanged in all groups). Forty min after hemodilution RVEDVI (-8%) and RVESVI (-16%) decreased significantly only in group 4, whereas in the other groups these parameters were still elevated. The most pronounced positive fluid balance after the end of ECC was found in group 4 (+850 ml); in these patients paO2 decreased significantly (-150 mmHg). CONCLUSIONS. The guarantee of stable hemodynamic conditions is a prerequisite when performing ANH in coronary surgery patients. The different physiochemical attributes of various HES solutions seem to be important, thus influencing their hemodynamic response. In this study, low-concentration (3% HES 200/0.5) and low-molecular (6% HES 40/0.5) HES solutions were less effective in stabilizing hemodynamics until the beginning of ECC. Additionally, their negative influence on fluid balance during ECC, followed by a deterioration in pulmonary function led to the conclusion that other solutions are preferable; in particular, 10% HES seems to be of advantage in these situations.

Coronary Artery Bypass↗
PubMed1990

[Hyperosmolar volume replacement in heart surgery].

The ideal solution for use in volume therapy is still a matter of debate. Hypertonic sodium (HS) solutions have been advocated for resuscitation from hemorrhagic shock (small volume resuscitation). As hypertonic fluids may also be of interest in cardiac surgery, the effects of a new HS solution were studied. METHODS. In 90 patients undergoing aorto-coronary bypass grafting studies were performed at three different periods: I (n = 30) after induction of anesthesia (before onset of the operation); II (n = 30) during cardiopulmonary bypass (CPB); III (n = 30) after termination of bypass. During these periods the patients were randomly allocated to one of three groups with 10 patients in each group: group 1 received a new hypertonic solution prepared in hydroxyethyl starch (HES) solution (72 g/l NaCl, 60 g/l HES, 2400 mosmol/l; HS-HES patients), group 2 received a 6% HES solution (200/0.5; HES patients), and group 3 received no volume infusion and served as controls. RESULTS. After the induction of anesthesia, significantly less HS-HES solution (4.5 +/- 0.5 ml/kg) than 6% HES solution (10.1 +/- 1.4 ml/kg) was necessary to double the baseline PCWP. The fluid balance during CPB was negative in the patients who had received HS-HES preoperatively (-0.03 +/- 0.01 ml/kg.min CPB), whereas 6% HES (+0.06 +/- 0.02 ml/kg.min CPB) and control patients (+0.13 +/- 0.03 ml/kg.min CPB) had a positive fluid balance. Both after the induction of anesthesia and after termination of bypass, CI increased more in the HS-HES group than in the HES patients, and it even decreased in the control group. SVR decreased in the HS-HES patients, whereas it increased in the control group. Rapid infusion of HS-HES during CPB was followed by a significant, but short-lasting decrease in MAP (-40 mmHg) and an increase in the oxygenator volume. Pulmonary gas exchange (= paO2) was least compromised in the HS-HES patients; the sodium concentration increased only in the HS-HES patients, but never exceeded 150 mmol/l. DISCUSSION. Cardiac surgery procedures offer a special situation for volume therapy as there is a possibility of deterioration in the macro- and microcirculation before, after, and during the period of CPB. Hemodynamic effects of the new HS-HES solution included an increase in CI and a decrease in SVR, which were not merely transient as has been reported which hypertonic saline solution used alone. It was also observed that HS-HES patients required significantly smaller volumes of fluids, both during CPB and during the early postoperative period. This effect seems to be due to a redistribution of interstitial fluid to the intravascular space, possibly decreasing tissue edema. CONCLUSION. The hypertonic saline HES solution adds a new dimension to volume therapy for cardiac surgery patients. The improvement in hemodynamics was effective and not only transient. Fluid requirements were significantly reduced during as well as after CPB, and pulmonary gas exchange was least compromised in these patients.

Aged↗
PubMed1990

[The hemodynamic effects of a treatment with beta-receptor blockers during coronary surgery. A comparison between acebutolol and esmolol].

UNLABELLED: Patients undergoing coronary artery bypass grafting are at risk for perioperative myocardial ischemia. Most such ischemic episodes occur without obvious hemodynamic changes. Tachycardia as a predictor for increased myocardial oxygen consumption doubles the incidence of myocardial ischemia when heart rate increases to over 110 beats/min. During the operative procedure for coronary revascularization, some maneuvers, e.g. intubation, sternotomy and mediastinal preparation, may be associated with tachycardia and increases in blood pressure despite an adequate level of anesthesia, so that the administration of beta-receptor blocking agents seems to be indicated. METHODS: The study included 20 patients undergoing elective aortocoronary bypass grafting. All patients developed tachycardia (heart rate greater than 100 beats/min) before the start of extracorporeal circulation. The hemodynamic effects of 0.1 mg/kg acebutolol given i.v. as a bolus over 30 s and hemodynamic effects of the ultrashort-acting esmolol by continuous infusion (loading dose 500 micrograms/kg over 1 min followed by a dose of 100 micrograms/kg per min) were randomly investigated. Anesthesia was maintained with fentanyl, midazolam and pancuronium bromide. All patients were invasively monitored by means of a pulmonary artery catheter. In addition, left ventricular pressure (LVP), left ventricular end diastolic pressure (LVEDP) and dp/dtmax were measured. RESULTS: Both acebutolol and esmolol, decreased the heart rate significantly (-24%, -27.5%), while the mean arterial pressure remained nearly unchanged. The cardiac index was diminished following acebutolol (-15.4%) and esmolol (-27.4%), while no significant change in stroke volume index was observed; systemic vascular resistance rose in all patients. Pulmonary artery pressure, PCP, PRA, LVP and LVEDP were unchanged, whereas dp/dtmax decreased both with acebutolol (-23.5%) and with esmolol (-36.5%). CONCLUSION: Both beta-receptor blockers--acebutolol and the ultrashort-acting esmolol--diminish heart rate sufficiently when tachycardia occurs during coronary artery bypass grafting. Reduction of heart rate is associated with a decrease of cardiac output and an impairment of myocardial contractility. From the hemodynamic point of view there is no major difference between the two beta-receptor blockers investigated, but esmolol may have an advantage over acebutolol because of its short elimination half-life.

Acebutolol↗
PubMed1990

[Heart injuries: diagnosis and therapy].

The clinical manifestation of wounds of the heart is determined by the mode, site and size of the injury as well as the structure of the pericardial and myocardial lesion. Diagnosis can be confirmed by ECG and echocardiography. Only 20% of the patients with penetrating wounds of the heart live for more than 30 minutes. Pericardio-centesis should be used only to gain time for a safe sternotomy, cardiac decompression and suture of the wound of the heart. An aggressive surgical approach is mandatory. Cardiopulmonary bypass is necessary only to correct of concomitant lesions.

Cardiac Tamponade↗
PubMed1990

[Detection of cerebral microembolisms during extracorporeal circulation with pulsatile flow using transcranial Doppler monitoring].

The incidence of focal neurological deficits and diffuse neuropsychiatric disorders in patients undergoing open-heart surgery still remains unacceptably high. The consensus is increasing that diffuse microembolism is the most important cause. Changes in blood flow velocity in the middle cerebral artery were investigated by transcranial Doppler sonography in 26 patients regarding the effect of continuous and pulsatile perfusion during extracorporeal circulation. The quotient of systolic and diastolic flow velocity was significantly increased in patients with pulsatile perfusion. Abnormal high-frequent Doppler-signals were registered in 8 patients using pulsatile perfusion without diastolic basic flow. All the other patients in whom continuous pump flow was applied (13) did not reveal any signs of hemodynamic disturbances. In the group treated with pulsatile perfusion the systolic pressures before and behind the oxygenator were significantly increased in patients with high-frequent Doppler-signals which are likely to be caused by gaseous microemboli. Investigating one type of four different oxygenators no cerebral hemodynamic alterations were recorded even during pulsatile perfusion. The use of membrane oxygenators and arterial filters during pulsatile perfusion cannot completely prevent the occurrence of gaseous microemboli; their principle causes are supposed to be the level of perfusion pressure, the flow velocity and the design of oxygenator.

Blood Flow Velocity↗
PubMed1990

Myocardial temperature during cardiac operations: influence on right ventricular function.

Maintenance of right heart integrity is frequently neglected during coronary operations. Right ventricular dysfunction sometimes limits the success of the surgical procedure, however. In addition to the use of cardioplegic solutions, myocardial hypothermia during ischemic cardiac arrest seems to be an important factor for guaranteeing right ventricular performance thereafter. This study was designed to measure myocardial temperature in patients with coronary artery disease who have significant stenosis of the right coronary artery in comparison with those who do not have stenosis of the right coronary artery and to evaluate the influence of myocardial temperature on right ventricular hemodynamics after cardiopulmonary bypass. Right ventricular function was assessed by thermodilution technique, which allows measurement of right ventricular ejection fraction, right ventricular end-diastolic volume, and right ventricular end-systolic volume. Right ventricular temperature differed significantly between the two groups, with the lowest value of 15.1 degrees +/- 1.8 degrees C in the group without stenosis of the right coronary artery and a value of 22.2 degrees +/- 2.1 degrees C in the group with stenosis of the right coronary artery. Left ventricular and septal temperatures were without group differences within the investigation period. Right ventricular hemodynamics were impaired only in the group with stenosis of the right coronary artery with a decrease in right ventricular ejection fraction from 44.2% to 34.1% immediately after termination of bypass and an increase in right ventricular end-diastolic volume index (+38%) and right ventricular end-systolic volume index (+70%). Cardiac index decreased only in this group, too (-22.5%). Analysis of covariance revealed a significant correlation only between changes in right ventricular ejection fraction, right ventricular end-diastolic volume, and right ventricular end-systolic volume and the course of right myocardial temperature. It is concluded that right ventricular hypothermia is more difficult to achieve in patients with a diseased right coronary artery. Constant myocardial hypothermia, however, seems to be important in guaranteeing right ventricular function, which easily can be evaluated by the thermodilution technique.

Body Temperature↗
PubMed1990

[Effect of the duration of reperfusion on metabolic recovery during unloading of the hypertrophic heart following induced heart arrest].

The methods of cardioplegia used today are not always able to sufficiently protect the hypertrophied heart. The present study investigated if a recovery period of 30 min before the end of ECC improves metabolic recovery of the heart in comparison to a recovery period of 15 min before terminating extracorporeal circulation. A clinical study was performed of patients undergoing aortic valve replacement. In one group reperfusion was performed for 15 min and in the second group for 30 min before the conclusion of extracorporeal circulation. The concentration of high energy phosphates in the left ventricle was determined at the end of the ischemic period, after 15 min and after 30 min of reperfusion. The behavior of the myocardial metabolites of the two groups showed no differences. Creatinephosphate increased continuously in both groups, while adenosine triphosphate and the adenonucleotide pool did not change during the reperfusion period. From our results we conclude that under the conditions given in our study a recovery period of 15 min is sufficient for metabolic recovery and prolongation of reperfusion before termination of extracorporeal circulation do not improve metabolic recovery.

Adenosine Triphosphate↗
PubMed1989

[Hemodynamic effects of the new phosphodiesterase inhibitor enoximone in heart surgery patients].

The new phosphodiesterase-III inhibitor (PDI) enoximone is a non-catecholamine, non-glycoside cardiotonic agent with concomitant vasodilating properties. It has proved beneficial in patients with severe chronic heart failure. The influence of enoximone i.v. on hemodynamics was investigated during cardiac surgery under various conditions. METHODS. A randomized series of 60 patients undergoing elective aorto-coronary bypass grafting were studied. The hemodynamic effects of 0.5 mg/kg enoximone given i.v. as a bolus (30 s) were investigated before anesthesia (n = 10), during anesthesia (n = 10), and during extracorporeal circulation (ECC, n = 10) and compared with those observed in corresponding control groups (n = 10 in each control) of patients who had received saline solution as placebo. Anesthesia was maintained with weight-dependent dosages of fentanyl, midazolam and pancuronium bromide. All patients were invasively monitored by means of a pulmonary artery catheter. Additionally, left ventricular pressure (LVP), left ventricular end-diastolic pressure (LVEDP) and dp/dtmax were measured before the initiation of ECC. During ECC direct vascular effects were investigated with measurement of perfusion pressure and the volume of the oxygenator. RESULTS. Before the induction of anesthesia no significant change in MAP and HR could be observed, whereas CI increased (+20%) and TSR decreased (-24%) significantly. During anesthesia, the injection of enoximone was followed by a significant decrease in MAP only in the 1st min (-17%); baseline level was reached again after 6 min; and HR was slightly increased (+8%). TSR (-31%) and LVEDP (-38%) decreased, whereas CI (+17%) and dp/dtmax (+45%) were increased significantly. During ECC perfusion pressure (-37%) and the volume of the oxygenator (-17%) were significantly decreased, demonstrating direct vasodilating effects on both the arteries and the vein. CONCLUSION. Arterial and venous vasodilation with an increase in myocardial performance (dp/dtmax) resulting in an increase in CI were the predominant hemodynamic effects of enoximone i.v. No arrhythmogenic effects or interactions with the anesthetics used were observed in this study.

Anesthesia↗
PubMed1988

Primary cardiac tumors--clinical experiences and late results in 48 patients.

Between 1971 and 1987 48 patients (35 female and 13 male) underwent operations at the Department of Cardiovascular Surgery, Justus-Liebig-University Giessen, for primary cardiac tumors. The age of the patients ranged from 21 to 71 years. Clinical symptoms were congestive heart failure, cardiac murmurs and findings similar to mitral stenosis, chest pain, arrhythmias, arterial embolism, myocardial infarction and pericarditis. 39 of the tumors were benign and 9 were malignant. Diagnosis was confirmed by echocardiography and/or cineangiocardiography. The left atrium was most commonly involved, followed by the right atrium. Surgery was performed in all cases using cardiopulmonary bypass. Benign tumors were totally removed, including attachment to the atrial septum or the free wall. In one case the tumor resection was carried out by autotransplantation of the heart. During the perioperative period we lost one of the 39 patients with benign tumors due to low cardiac output. Observing a mean follow up period of 48 months, no recurrence of tumors was noted and all patients are doing well now. The malignant neoplasms could not be removed completely, and in 4 cases only a reduction of the tumor mass was possible. Three of the 9 patients died during the postoperative period. Only one patient survived longer than 48 months. Whereas surgical therapy of malignant cardiac tumors is still a matter of discussion based upon these discouraging results, benign or semimalignant cardiac neoplasms have a very favourable prognosis when the surgical intervention can be performed prior to the occurrence of severe complications, such as congestive heart failure and arterial embolism.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

[Use of the mammary artery in coronary revascularization].

From August 1983 through December 1985 1088 patients underwent coronary surgery. 406 (37%) received a single or bilateral internal mammary artery (IMA) graft with single or sequential anastomoses. The youngest patient was 6 years old, the oldest 75, with a mean age of 55.7 years. A total of 672 IMA anastomoses was constructed. In addition 348 patients received 610 saphenous vein grafts. 83% of the IMA were anastomosed to the LAD and its branches, 12% to the circumflex and 5% to the right coronary artery. 4 patients (0.98%) died postoperatively, 402 survived and are free of angina. In our experience the IMA can be used routinely with low operative risk and good results.

Adolescent↗
PubMedDate not supplied

Perioperative myocardial injury in patients undergoing aortic valve replacement.

In cases of myocardial hypertrophy myocardial protection may be insufficient. In order to determine the factors responsible for myocardial injury we assessed myocardial injury in 54 patients undergoing isolated aortic valve replacement. In all cases hypothermic cardioplegic arrest was induced. At 13 different times we measured the serum level of creatine-kinase (CK), myocardial bound creatine-kinase (CKmb), lactic dehydrogenase (LDH), alpha-hydroxybutyrate dehydrogenase (alpha-HBDH), glutamic oxaloacetic transferase (GOT) and myoglobin. The mean duration of ischemia was 52.6 +/- 16.2 minutes and the mean time of extracorporeal circulation was 85.85 +/- 20.25 minutes. By performance of a multiple regression analysis a significant correlation between ischemia and LDH and alpha-HBDH was found; CK, GOT, LDH and alpha-HBDH correlated with duration of extracorporeal circulation. In none of the patients was a low cardiac output syndrome observed. From our results we conclude that in our study myocardial protection was sufficient and therefore the detrimental effects of extracorporeal circulation were the determining factors of enzyme release.

Adult↗