[Show abstract][Hide abstract] ABSTRACT: Beating heart aortic valve (re)placement without thoracotomy would be a desirable therapeutic strategy. In the present study, the feasibility of an endovascular aortic valve (re)placement was evaluated in an animal model.
A self-expandable stent-valve and two different non-obstructive delivery devices were designed. Initially, the stent-valve was temporarily placed via surgically dissected carotid and subclavian arteries. After retrieval of the stent-valve, an endovascular resection of the native aortic valve was performed, followed by definitive stent-valve implantation. All procedures were performed under echocardiographic guidance.
Non-aortic vascular access was obtained in all animals. Via the carotid artery, the stent-valve was first placed into, and then retrieved from, the subcoronary position. Next, the native aortic valve was resected endovascularly, resulting in at least partial resection in all cases. The final step, definitive stent-valve implantation, was successful in all animals. The biological heart valve became functional after only a partial release of the stent. All animals remained hemodynamically stable after definitive implantation. Correct subcoronary position of the stent-valve was confirmed in a post-mortem examination. There was marked thrombus formation.
The study results proved the feasibility of: (i) reversible stent-valve placement with a nonobstructive technique in the beating heart; and (ii) partial endovascular resection of the aortic valve, with both procedures achieved via non-aortic access.
The Journal of heart valve disease 08/2005; 14(4):546-50. · 0.75 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Surfactant abnormalities have been implicated in reperfusion injury and respiratory failure in lung transplantation.
We investigated the efficacy of bronchoscopic administration of a bovine natural lung surfactant extract (Alveofact) to improve gas exchange and lung mechanics after heterologous left lung transplantation in foxhounds (+4 degrees C ischemia for 24 hours, conservation with Euro-Collins solution). Animals received either no surfactant therapy (untreated controls, n = 6) or 50 mg/kg body weight (prior to explantation, only graft) and 200 mg/kg body weight Alveofact (immediately after reperfusion, both lungs, n = 6). After lung transplantation, separate but synchronized ventilation of each lung was performed in a volume-controlled, pressure-limited mode for 12 hours, with the animals prone. Small catheters were inserted into the pulmonary veins of both the graft and the recipient's native lung for separate blood gas analysis. In the control group, marked protein leakage, influx of neutrophils into the alveolar space, and pulmonary edema formation (extravascular lung water; wet/dry ratio) were encountered in the transplanted lung but only to a very minor extent in the recipient's native lung.
Lung compliance values and arterial oxygenation progressively deteriorated in the transplanted but not in the native lungs. Pulmonary hemodynamics did not change significantly. Surfactant administration did not significantly influence the development of reperfusion edema, protein leakage, and neutrophil influx into the grafts. However, surfactant restored the surface activity and the gas exchange (PaO2/FIO2 of 201.2 +/- 20.2 mm Hg vs 119.8 +/- 21.7 mm Hg in controls; P <.05) in the transplanted lungs, and compliance was markedly improved in the surfactant-treated animals (18.8 +/- 1.8 mL/mbar vs 11.5 +/- 1.6 mL/mbar in the controls; P <.05).
Bronchoscopic surfactant administration does not prevent leukocyte influx or vascular leakage but does protect against respiratory failure and improves lung mechanics in single lung transplantation in dogs.
Journal of Thoracic and Cardiovascular Surgery 02/2004; 127(2):335-43. DOI:10.1016/j.jtcvs.2002.10.001 · 4.17 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Cardiopulmonary bypass is associated with the release of proinflammatory cytokines (tumor necrosis factor alpha, interleukin 1beta, interleukin 6, and interleukin 8) and anti-inflammatory cytokines (interleukin 10 and transforming growth factor beta(1)). On the one hand this cytokine release is related to the postoperative systemic inflammatory response syndrome, and on the other hand it is related to deterioration of the immune system, for example in monocyte or polymorphonuclear neutrophil function, leading to an increased susceptibility to infections. To gain further insight into the alterations of immune cell reactivity and possible regulatory mechanisms, we studied lipopolysaccharide-induced tumor necrosis factor alpha synthesis in whole blood from cardiac surgical patients.
Fifteen patients undergoing elective heart surgery with cardiopulmonary bypass were included in the study. Ex vivo lipopolysaccharide-induced tumor necrosis factor alpha synthesis was measured in a whole blood assay before, during, and after bypass. Corresponding tumor necrosis factor alpha messenger RNA levels were determined by semiquantitative reverse transcriptase-polymerase chain reaction. In addition, the influence of patient serum on whole blood responsiveness and its relationship to anti-inflammatory cytokines were evaluated in vitro.
Tumor necrosis factor alpha synthesis was significantly reduced after 30 minutes of cardiopulmonary bypass and showed the lowest values at the end of bypass (mean +/- SD 0.109 +/- 0.105 ng/10(6) white blood cells after 30 minutes of bypass and 0.050 +/- 0.065 ng/10(6) white blood cells at the end of bypass, vs 0.450 +/- 0.159 ng/10(6) white blood cells preoperatively, P <.001). As a further indication of reduced cytokine biosynthesis, diminished messenger RNA levels for tumor necrosis factor alpha were detected. Serum withdrawn from patients at the end of cardiopulmonary bypass reduced tumor necrosis factor alpha synthesis in heterologous blood from healthy volunteers highly significantly to 39.93% +/- 23.18% relative to control serum (P =.005) and preoperatively drawn serum (P =.024). This effect was dose dependent and was not specific for lipopolysaccharide-induced tumor necrosis factor alpha synthesis. Anesthesia and heparin administration did not influence tumor necrosis factor alpha production significantly. Ex vivo tumor necrosis factor alpha synthesis was negatively related to interleukin 10 serum levels, positively but weakly related to interleukin 4, and was not related to transforming growth factor beta(1) (Spearman correlation coefficients -0.565, P <.001, 0.362, P <.001, and -0.062, P =.460, respectively). However, interleukin 10 levels in patient serum after cardiopulmonary bypass were 300-fold below the quantities needed for half-maximal inhibition of tumor necrosis factor alpha synthesis in vitro. Moreover, the inhibitory activity could not be removed by immune absorption of interleukin 10.
These results suggest that during cardiac operations cytokine-inhibitory serum activities are released or newly formed. These activities could not be explained by the actions of interleukins 4 and 10 or transforming growth factor beta(1). Although their exact nature remains undetermined, these substances may contribute to the diminished immune cell functions after cardiopulmonary bypass and thus need further characterization.
Journal of Thoracic and Cardiovascular Surgery 09/2002; 124(3):608-17. DOI:10.1067/mtc.2002.122300 · 4.17 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Vasoconstriction after lung transplantation is a well-known phenomenon, but only limited information is available on blood flow distribution after ischemia and reperfusion. The aim of our study was to determine the regional flow characteristics in transplanted and native dog lungs after 24 hours of cold storage and preservation with Euro Collins-solution.
Six pairs of weight-matched Foxhounds (25 to 30 kg) were used. In donors and recipients, aortic and pulmonary artery catheters were inserted percutaneously and a reference withdrawal catheter was placed into the main pulmonary artery. For preservation, the lungs were perfused with modified Euro Collins-solution and stored at 4 degrees C. After 24 hours, the left lung was transplanted. Regional pulmonary blood flow was assessed by injection of colored microspheres into the right atrium using the reference withdrawal technique. Measurements of regional pulmonary blood flow were conducted twice in donors and recipients (baseline and 3 hours after reperfusion). Tissue samples from five distinct regions (apical, medial, dorsal, ventral, and lateral) were taken to assess regional pulmonary blood flow and wet-dry ratios.
The relative (per thousand Confidence Intervals/100 mg dry weight) regional pulmonary blood flow was significantly reduced in the transplanted lung but not in the native organ. This reduction was most pronounced in apical regions and smallest in regions close to the hilum. Edema formation occurred in both lungs, as judged from wet-to-dry ratios of lung tissue specimen.
Two separate processes can be observed after single lung transplantation: (1) reduced regional pulmonary blood flow, which is a regional phenomenon restricted to the transplanted organ, and (2) extensive edema affecting both the transplanted and the native lung.
The Annals of Thoracic Surgery 02/2002; 73(1):226-32. DOI:10.1016/S0003-4975(01)03357-4 · 3.85 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Protection from reperfusion injury by ischemic pre-conditioning (IPC) before prolonged ischemia has been proven for the heart and the liver. We now assess the efficacy of IPC to protect lungs from reperfusion injury.
Eighteen foxhounds (25 to 30 kg) were anesthetized, intubated, and ventilated with a fraction of inspired oxygen of 0.3 at a volume-controlled mode to maintain arterial pCO2 of 30 to 40 mm Hg. After left thoracotomy, we performed warm ischemia for 3 hours by clamping the left hilus, and followed with 8 hours of reperfusion (control, n = 6). In the treated groups, IPC was performed either for 5 minutes followed by 15-minute reperfusion (n = 6, IPC-5), or by 2 successive cycles of 10-minute ischemia, followed by 10-minute reperfusion (n = 6, IPC-10) before prior to the 3-hours warm-ischemia period. Pulmonary compliance and gas exchange were determined separately for each lung, and we recorded pulmonary and systemic hemodynamics. We performed bronchoalveolar lavage (BAL) at the end of the experiment and determined total protein concentration as well as tumor necrosis factor alpha (TNF-alpha) mRNA expression in cell-free supernatant and in BAL cells, respectively. We also assessed the wet/dry ratio of the lung.
In the controls, on reperfusion, we encountered a progressive deterioration of gas exchange, especially of the reperfused left lung, which we could largely avoid using the IPC-5 protocol. Similarly, pulmonary compliance steadily declined but was much better in the ICP-5 group. Parallel to the improvement of gas exchange and lung mechanics, we found less total alveolar protein content and TNF-alpha mRNA expression in BAL cells in the IPC-5 than in the controls. However, we did not find IPC-10 to be paralleled by a significant improvement of lung function. Neither IPC-5 nor IPC-10 influenced the pulmonary vascular resistance index or the fluid accumulation in the lung.
The major finding of the present study was that 5 minutes of IPC improved lung function after 3 hours of warm ischemia of the lung.
The Journal of Heart and Lung Transplantation 10/2001; 20(9):985-95. DOI:10.1016/S1053-2498(01)00290-X · 6.65 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The introduction of minimally invasive coronary artery bypass surgery has expanded the technical armementarium for operative treatment of coronary artery disease. Minimal access surgery using partial sternotomy or anterior intercostal minimal thoracotomy can be combined with videoscopic techniques or port-access-methods. Either atrio-aortal cannulation, femoro-femoral or jugular-femoral connections to the pump are possible for extracorporal circulation (ECC). Even endoluminar occlusion of the aorta and application of cardioplegia into the aortic root can be considered and applied. Extracorporal circulation has developed into a safe standardized method. As far as pathophysiology is concerned, the decision to use ECC or not is of much more importance than the grade of invasiveness. Fundamentally we therefore need to distinguish between minimally invasive methods with and without ECC. Video-assisted coronary surgery in hearts under hypothermia and fibrillation with ECC is also recommended occasionally. Minimally invasive coronary artery procedures on beating hearts without ECC have to be done in a stabilized and bloodless operative field to allow the construction of high standard anastomoses between bypass grafts and coronary arteries. In practice, silicon occluders, epicardial and myocardial suture occlusion and fixation, mechanical stabilization devices, and pharmacologic induction of bradycardia are used. In principle a skilled surgeon should be familiar with all these methods to select the most suitable solution for the special clinical problem. A final judgement about each method is not possible up to now. High patients numbers have to be recruited in the groups and subgroups due to low mortality (1%) and morbidity (5%), otherwise statistical significance of the results cannot be gained.
Zeitschrift für Kardiologie 04/1999; 88(3):179-84. · 0.97 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Zusammenfassung Durch die Einfhrung der minimalinvasiven Koronarchirurgie ist das methodische Spektrum zur Behandlung der koronaren Herzerkrankung erneut differenzierter geworden. Die Mglichkeiten des minimalen Zugangs durch Teilsternotomie oder durch interkostale anteriore Minithorakotomie knnen mit videoskopischen Methoden und mit sog. Port-access-Verfahren kombiniert werden. Neben der normalen atrio-aortalen Kanlierung fr den Anschlu der Herz-Lungen-Maschine sind jugular- und femoro-femorale Anschlsse an die Herz-Lungen-Maschine mglich. Sogar die intravasale endoluminale Ballonokklusion der Aorta ascendens und die Applikation von kardioplegischer Lsung ber den Okklusionskatheter in den Aortenbulbus knnen in die berlegung einbezogen werden. Die Anwendung der Herz-Lungen-Maschine ist heute eine Standardmethode geworden, wenn auch pathophysiologisch die Entscheidung zur Operation mit oder ohne Herz-Lungen-Maschine das wesentlichere Unterscheidungskriterium als die Gre des operativen Zugangs ist. Es mu also zwischen minimalinvasiven Methoden mit oder ohne Herz-Lungen-Maschine streng unterschieden werden. Videoassistierte koronare Bypass-Chirurgie am hypotherm fibrillierenden oder stillgestellten Herzen unter Anwendung der Herz-Lungen-Maschine ist ebenfalls als sichere Methode empfohlen worden. Minimalinvasive Koronaroperationen am schlagenden Herzen ohne Herz-Lungen-Maschine setzen ein stabilisiertes und blutfreies "Kleinstoperationsgebiet" zur Anastomosierung von Bypass-Gef und Koronararterie voraus. Technisch werden intraluminale Silikon-Okkluder, epikardiale und tiefe myokardiale Nahtfixierung, Fingerstabilisierung, pharmakologische Induktion einer Bradykardie, myokardiale Stabilisierungsklemmen sowie am OP-Sperrer fixierte Hufeisenstabilisatoren genutzt. Dem Grunde nach sollte der erfahrene Operateur alle diese Methoden beherrschen, um ein methodisches Konkurrenzdenken zu vermeiden und um die beste Mglichkeit zur Lsung des klinischen Problems auswhlen zu knnen. Eine sichere Beurteilung der Vor- und Nachteile der einzelnen Methoden und ihrer Kombinationen ist zur Zeit nicht mglich, da bei den geringen Letalitten (ca. 1%) und Morbiditten (ca. 5%) sehr groe Patientenzahlen bentigt werden, um die einzelnen Gruppen und Untergruppen statistisch in ihren Ergebnissen vergleichen zu knnen. Summary The introduction of minimally invasive coronary artery bypass surgery has expanded the technical armementarium for operative treatment of coronary artery disease. Minimal access surgery using partial sternotomy or anterior intercostal minimal thoracotomy can be combined with videoscopic techniques or port-access-methods. Either atrio-aortal cannulation, femoro-femoral or jugular-femoral connections to the pump are possible for extracorporal circulation (ECC). Even endoluminar occlusion of the aorta and application of cardioplegia into the aortic root can be considered and applied. Extracorporal circulation has developed into a safe standardized method. As far as pathophysiology is concerned, the decision to use ECC or not is of much more importance than the grade of invasiveness. Fundamentally we therefore need to distinguish between minimally invasive methods with and without ECC. Video-assisted coronary surgery in hearts under hypothermia and fibrillation with ECC is also recommended occasionally. Minimally invasive coronary artery procedures on beating hearts without ECC have to be done in a stabilized and bloodless operative field to allow the construction of high standard anastomoses between bypass grafts and coronary arteries. In practice, silicon occluders, epicardial and myocardial suture occlusion and fixation, mechanical stabilization devices, and pharmacologic induction of bradycardia are used. In principle a skilled surgeon should be familiar with all these methods to select the most suitable solution for the special clinical problem. A final judgement about each method is not possible up to now. High patient numbers have to be recruited in the groups and subgroups due to low mortality (1%) and morbidity (5%), otherwise statistical significance of the results cannot be gained.
Zeitschrift für Kardiologie 02/1999; 88(3):179-184. DOI:10.1007/PL00007360 · 0.97 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Mediastinal infection is a feared complication observed after 0.4%-5% of cardiac operations. Even today the mortality remains as high as 20%-40%. We discuss the aetiology, mechanisms, prevention, diagnosis, and medical management. The staging system for mediastinal wound infections developed at a joint conference of German cardiac surgical centres is presented. The use of parenteral polyvalent immunoglobulins is also discussed.
The European journal of surgery. Supplement.: = Acta chirurgica. Supplement 02/1999; 164(584):12-6.
[Show abstract][Hide abstract] ABSTRACT: End-stage renal failure requiring dialysis is considered a significant risk factor in cardiac surgery. To assess the risk we performed a retrospective analysis of 17 patients with end-stage renal failure who underwent open heart surgery during 1994 and 1995. Pre-, peri-, and postoperatively we evaluated the following factors: renal failure etiology, risk factors, concurrent diseases, previous heart diseases, complications, mortality, and long-term outcome. All patients were dialyzed on the day before surgery. Intraoperative hemofiltration was performed in each patient. The first postoperative hemodialysis was performed on the second postoperative day or earlier for hyperkalemia or pulmonary edema. Postoperative complications occurred in seven patients: three patients expired postoperatively of noncardiac and nonrenal causes and four died during follow-up. With an average follow-up of 16.5 months (range 7-30 months) NYHA class had improved by an average of 1.7 in the 10 patients who were alive and their quality of life was acceptable. Because of these acceptable short- and long-term results and relatively low operative risk, we support an approach of prompt diagnostic work-up and surgical intervention when necessary.
International Journal of Angiology 09/1998; 7(4):335-8.
[Show abstract][Hide abstract] ABSTRACT: Two types of heparin-associated thrombopenia (HAT) can be distinguished. Patients with type II HAT (HAT II) present a particularly difficult management problem when they require full anticoagulation. There is no consensus about the proper anticoagulation management for patients with HAT II who have to undergo cardiopulmonary bypass (CPB). We present a HAT II patient who underwent successful aortocoronary saphenous vein grafting. Sodium-danaparoid (SD) was used for anticoagulation. The anti-factor Xa level was kept below the values reported in the literature for patients undergoing CPB. We did not observe any fibrin formation during the time of CPB or any severe postoperative hemorrhage, which is frequently described in the literature. We discuss the management of our patient with SD intra- and postoperatively.
International Journal of Angiology 06/1998; 7(3):268-70.
[Show abstract][Hide abstract] ABSTRACT: Humidification of inspired gas in artificially ventilated patients positively influences mucociliary function and secretolysis. We performed this study to examine the properties of heat and moisture exchangers in comparison with hot water humidifiers and dry artificial ventilation.
We measured inspired humidity with a special sensor in 41 patients after coronary artery bypass grafting with cardiopulmonary bypass. Three Heat and Moisture Exchangers (HME) and a hot water humidifier were used to humidity the inspired gas of artificially ventilated patients. Humidity measurements were compared.
Hot water humidifiers produced the highest humidification (average of 38.4 mg/l, 37-43 mg/l); lowest humidification was produced by dry artificial ventilation (average of 8.7 mg/l, 6-11 mg/l). Heat and moisture exchangers (HME) produced humidity between 24 and 36 mg/l. Highest humidification was produced by HME hygrobac s (average of 32.2 mg/l, 31-36 mg/l) and hygrovent s (average of 31.4 mg/l, 29-35 mg/l); lowest humidification was produced by HME hygroster (average of 28.6 mg/l, 24-31 mg/l). Multifactorial analysis shows a significant impact of the humidification method on the humidity of inspired gas. The multiple comparison procedure (Tukey) shows significant differences (alpha = 0.05) between all humidification techniques on inspired gas except the heat and moisture exchangers hygrobac s and hygrovent s.
Hygrobac s and hygrovent s may be an alternative to hot water humidifiers. Further clinical studies of HMEs and hot water humidifiers will be necessary to evaluate the influence of inspired gas humidity on the outcome of artificially ventilated patients.
[Show abstract][Hide abstract] ABSTRACT: Two types of heparin-associated thrombopenia can be distinguished. Patients with the type II condition present a particularly difficult management problem when they require full anticoagulation. There is no consensus about the proper anticoagulation management for type II patients who have to undergo cardiopulmonary bypass. The case is reported of a type II heparin-associated thrombopenia patient who underwent successful aortocoronary saphenous vein grafting. Sodium-danaparoid was used for anticoagulation. The anti-factor Xa level was kept below the value reported in the literature for patients undergoing cardiopulmonary bypass. No fibrin formation was observed during the time of cardiopulmonary bypass, nor was any severe postoperative haemorrhage seen, as is frequently described in the literature.
Cardiovascular Surgery 02/1998; 6(1):90-3. DOI:10.1016/S0967-2109(97)00114-2
[Show abstract][Hide abstract] ABSTRACT: End-stage renal failure is commonly considered a significant factor for an increased risk after coronary artery bypass grafting. This holds true for patients who have received a kidney transplant (NTX group) as well as for patients who require chronic hemodialysis (HD group). To assess the risk in our population we performed a retrospective analysis of 22 patients with end-stage renal failure (HD group: 17, NTX group: 5) who underwent cardiac surgery. The perioperative course was compared to a normal population. In addition to standard data we assessed the following factors: renal failure etiology, risk factors, concurrent diseases, duration of renal failure, function of renal graft, ECG (paying special attention to signs of previous myocardial infarctions and rhythm disorders), results of cardiac catheterization and coronary angiography, NYHA class and urgency of operative intervention. Complications and mortality were the main measures of the perioperative course. We analyzed the hospital charts retrospectively and requested the patients' physicians to complete a questionnaire about the patient's present condition. All HD group patients were dialyzed on the day before surgery. The first postoperative HD was performed for hyperkalemia or signs of volume overload (pulmonary capillary wedge pressure > 20 mmHg) when signs of pulmonary function deterioration were seen. HD was successful in treating these conditions. 3 of the 17 patients on HD expired postoperatively, 4 died within 3 years, all of unrelated diseases. Mortality and morbidity was 0% in the NTX group. In one NTX patient who required intermittent HD preoperatively because of poor renal graft function, renal function improved postoperatively, presumably secondary to better renal perfusion, and he did not require HD after his cardiac surgery. By surgical intervention the NYHA class of all patients improved (by 1.6 on the average) as well as their quality of life. Because of these good short- and long-term results and relatively low operative risk we support an approach of prompt work-up and surgical intervention when necessary in HD and NTX patients.
[Show abstract][Hide abstract] ABSTRACT: Improvement of interventional techniques, sophisticated patient selection, and individual experience has decreased the probability of emergency operative revascularization of increasing numbers of PTCA cases in recent years. This rate is now between 0.5 to 3%, including highrisk dilatations. Dissection is the most common complication of PTCA, while perforation is rare. Patients with high risk for PTCA-procedures (age, concomittant diseases, female gender) are, in general, risk patients for operative revascularization. The postoperative course of emergency bypass surgery after PTCA-complication (infarction rate, mortality) is dependent on duration and severity of the myocardial ischemia and preoperative circulatory function. Complete revascularization in cases of multi-vessel disease and the use of the internal mammary artery as a graft vessel is being achieved in increasing numbers.
[Show abstract][Hide abstract] ABSTRACT: We examined 20 patients undergoing coronary bypass grafting for coronary artery disease with NYHA classifications of II and III who had been treated with beta-blocking agents. Patients were randomised for administration of either adrenaline (0.1 microgram/kg/min) or amrinone (bolus 1 mg/kg, continuous infusion of 5-10 micrograms/kg/min), if following cardiopulmonary bypass their cardiac index was < 2.4 L/min/m2 with normal peripheral resistance and normal or increased right- or left-ventricular filling pressures. Over a period of 1 hour, the hemodynamic parameters mean arterial pressure (MAP), cardiac index (CI), heart rate (HR), coronary perfusion pressure (CPP), total peripheral resistance (TPR), as well as the pressure-work index (PWI) were registered or calculated. By means of a coronary sinus catheter myocardial arterio-venous oxygen content difference (AVDO2cor), myocardial blood flow (MBF), using the thermodilution method, and myocardial oxygen consumption (MVO2) could be measured or calculated. Simultaneously, arterial and myocardial lactate concentrations and, using the arterio-venous lactate ratio, myocardial lactate extraction or production were quantified. Using a transseptal approach, the left-ventricular pressure curve was measured and used to differentiate for myocardial contractility (dp/dtmax). Following induction of anesthesia and after cardiopulmonary bypass, plasma levels of the used beta-blocking agent were determined. Both substances caused a significant increase in myocardial contractility, with adrenaline showing a more potent effect than amrinone. Both substances caused a significant increase in CI with a mild increase in HR. Amrinone caused a significant drop in TPR, while MAP remained practically constant.(ABSTRACT TRUNCATED AT 250 WORDS)
The Thoracic and Cardiovascular Surgeon 06/1995; 43(3):153-60. DOI:10.1055/s-2007-1013790 · 0.98 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Perioperative deterioration of the circulatory performance of patients undergoing heart surgery ranges from transitory impairment in cardiac output by deterioration of the compensation range of the oxygen transport system to manifest circulatory failure without previous myocardial damage and the acute decompensation of pre-existing chronic heart failure. On the basis of the current state of knowledge in this field, a concept for rational staged treatment should be based on the different myocardial beta-adrenoceptor conditions related to the type and stage of the individual underlying heart disease and on adrenoceptor subtype specific properties of positive inotropic drugs. 1. The therapy of perioperative "circulatory" insufficiency after extra-corporal circulation consists of the use of drugs to adapt the performance of the oxygen transport system to increased overall oxygen demand. Simultaneous volume loading (by CVP) and positive inotropic support with dobutamine are the best means of treating this (normally transitory) dysregulation. 2. In the case of manifest severe circulatory insufficiency (low cardiac output syndrome), sepsis or acute heart failure (e.g., following acute myocardial infarction), the use of a pulmonary artery catheter for determining perioperative cardiac output and resistance is essential. In such cases, positive inotropic therapy is based on catecholamines of medium (dobutamine) to high (adrenaline) efficacy, because it can be assumed that the beta-adrenoceptor pattern will remain normal with regular functioning and regulation of the (remaining) myocardium up to the onset of acute heart failure.(ABSTRACT TRUNCATED AT 250 WORDS)