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Biomedical subjects

A Barankay

Publications and source records attributed to A Barankay.

At least 37 records · Page 2Linked to original sources
PubMed1991

The influence of preoperative anticoagulation on heparin response during cardiopulmonary bypass.

The effect of preoperative anticoagulant therapy on intraoperative heparin response in patients undergoing cardiac operations was examined in a prospective study. The study included 45 patients with different preoperative anticoagulant treatments: 10 patients received treatment with phenprocoumon (a warfarin analogue) (group M), 12 patients received treatment with intravenous heparin (group Hiv), and 13 patients received treatment with subcutaneous heparin (group Hsc). The control group consisted of 10 patients who did not receive anticoagulant therapy before operation (group C). Preoperative antithrombin III activity was highest in group M (85% +/- 6%) and lowest in group Hiv (70% +/- 15%, p less than 0.05). The activated clotting time, determined 10 minutes after bolus injection of 250 IU (group M) or 375 IU heparin (all other groups), was 529 +/- 109 seconds in group C, greater than 1000 seconds in group M, 483 +/- 99 seconds in group Hsc, and 406 +/- 63 seconds in group Hiv (p less than 0.05). Heparin consumption during cardiopulmonary bypass varied between 4.6 +/- 1.4 IU/kg.min (group Hiv) and 2.6 +/- 0.9 IU/kg.min (group M) (p less than 0.05). Despite this increased heparin consumption, the patients who had received heparin before operation demonstrated increased activation of coagulation at the end of cardiopulmonary bypass (thrombin-antithrombin III complex, 19 +/- 4.1 ng/ml in group M and 61 +/- 7 ng/ml in group Hsc, p less than 0.05; cross-linked fibrin fragments, 257 +/- 92 ng/ml in group M and 875 +/- 152 ng/ml in group Hiv, p less than 0.05). Increased platelet activation was also found in patients with preoperative heparin therapy (beta-thromboglobulin at the end of cardiopulmonary bypass was 585 +/- 88 ng/ml in group M versus 1341 +/- 190 ng/ml in group Hsc, p less than 0.05). Drainage from the chest tube 24 hours after operation was 815 +/- 305 ml in group C, 644 +/- 238 ml in group M, 1133 +/- 503 ml in group Hsc, and 950 +/- 505 ml in group Hiv (p less than 0.05 for group M versus group Hsc). This study suggests that patients who receive heparin therapy before operation face a high risk of insufficient anticoagulation during cardiopulmonary bypass if standard heparin doses are used. Therefore, for patients who receive preoperative heparin therapy, a larger (500 IU/kg) initial bolus of heparin is recommended before cardiopulmonary bypass. On the other hand, patients who undergo preoperative treatment with phenprocoumon receive sufficient anticoagulative effect with a heparin bolus of 250 IU/kg.(ABSTRACT TRUNCATED AT 400 WORDS)

Antithrombin III↗
PubMed1990

Influence of high-dose aprotinin treatment on blood loss and coagulation patterns in patients undergoing myocardial revascularization.

Intraoperative administration of the proteinase inhibitor aprotinin causes reduction in blood loss and homologous blood requirement in patients undergoing cardiac surgery. To ascertain the blood-saving effect of aprotinin and to obtain further information about the mode of action, 40 patients undergoing primary myocardial revascularization were randomly assigned to receive either aprotinin or placebo treatment. Aprotinin was given as a bolus of 2 x 10(6) kallikrein inactivator units (KIU) before surgery followed by a continuous infusion of 5 x 10(5) KIU/h during surgery. Additionally, 2 x 10(6) KIU were added to the pump prime. Strict criteria were used to obtain a homogeneous patient selection. Total blood loss was reduced from 1,431 +/- 760 ml in the control group to 738 +/- 411 ml in the aprotinin group (P less than 0.05) and the homologous blood requirement from 838 +/- 963 ml to 163 +/- 308 ml (P less than 0.05). In the control group, 2.3 +/- 2.2 U of homologous blood or blood products were given, and in the aprotinin group, 0.63 +/- 0.96 U were given (P less than 0.05). Twenty-five percent of patients in the control group and 63% in the aprotinin group did not receive banked blood or homologous blood products. The activated clotting time as an indicator of inhibition of the contact phase of coagulation was significantly increased before heparinization in the aprotinin group (141 +/- 13 s vs. 122 +/- 25 s) and remained significantly increased until heparin was neutralized after cardiopulmonary bypass (CPB).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[Efficacy of prophylactic nifedipine therapy during aortocoronary vein bypass interventions. Drug concentration with oral or intravenous nifedipine administration; hemodynamics and plasma catecholamines].

To assess the usefulness of prophylactic nifedipine in coronary artery surgery, in this study nifedipine plasma concentrations were determined in patients, who had been given 10 mg nifedipine orally before operation. Furthermore, plasma and tissue concentrations of nifedipine were measured in patients receiving a nifedipine infusion. In this group of patients the efficacy of nifedipine, based on changes in hemodynamics and plasma catecholamines was also investigated. Patients with normal global left ventricular function (LVEDP less than 15 mm Hg, EF greater than 0.5) undergoing coronary artery bypass grafting (CABG) operations were included in this study. The preoperative antianginal therapy was continued until the time of surgery, the last beta-adrenoceptor blocker was given on the day of surgery. A standardized premedication and anesthesia (fentanyl-flunitrazepan infusion) was given to all patients. Hemodynamic parameters were obtained using indwelling arterial, venous and pulmonary artery thermodilution catheters. The high-pressure-liquid-chromatography (HPLC) method was used to measure plasma catecholamines as well as plasma and tissue nifedipine concentrations. Eight patients received 10 mg nifedipine orally one hour prior to anesthetic induction. Plasma nifedipine concentration (Figure 1) showed a wide interindividual scattering at anesthetic induction (25 +/- 38 ng/ml) in this group and they decreased to low, noneffective levels during surgical stimulation (12 +/- 12 ng/ml) and aortic cannulation (8 +/- 8 ng/ml). 24 patients with a nifedipine infusion of 0.30 micron/kg/min prior to extracorporeal circulation (start: following intubation, termination: at aortic cannulation) were compared to a control group of 24 patients with respect to hemodynamics, plasma catecholamines, anesthetic requirements and need for additional vasodilator and vasopressor therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1989

The influence of rapid potassium administration on hemodynamics and endogenous catecholamine production during extracorporeal circulation.

In a prospective randomized double-blind study, the peripheral vascular effects of potassium chloride (KCl) and potassium-magnesium-aspartate (KMA) were compared. Twenty patients undergoing coronary artery bypass graft surgery received either 12 mmol of KCl (n = 10) or 12 mmol of KMA (n = 10) into the oxygenator of the heart-lung machine during extracorporeal circulation (ECC). The most striking difference between these two solutions was vasoconstriction following KCl administration and vasodilation after KMA injection. In the KMA group, decreases of perfusion pressure (MAP) and systemic vascular resistance (SVR), as well as changes in the oxygenator volume (dV), were significant (P less than 0.01) between the first and the fifth minutes. Maximal changes of MAP, from 72 +/- 13 to 59 +/- 12 mmHg (mean +/- SD), and SVR were recorded in the first and second minutes. Oxygenator volume changes reached their maximum (285 +/- 163 mL) in the tenth minute. In the KCl group, maximal increases in MAP, from 70 +/- 16 to 81 +/- 20 mmHg (mean +/- SD), and SVR were found in the fourth minute. Maximal changes in dV (300 +/- 315 mL) were measured in the tenth minute. Plasma epinephrine levels, which were already elevated during ECC, showed further increases in all cases in the KCl group and in most of the cases in the KMA group. The change in plasma epinephrine concentration following KCl injection was significant (P less than 0.01). No characteristic change in plasma norepinephrine was found in either of the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1989

Autotransfusion and hemoseparation in cardiac surgery. What can be saved in cardiac reoperations and operations of thoracic aortic aneurysms?

In 149 patients, scheduled for cardiac reoperations, repair of cyanotic heart disease or resection of aneurysms of the ascending or descending aorta, the effect of intraoperative hemoseparation was studied. The amount of autologous blood which was collected before, during, and after systemic heparinisation and processed to washed packed red cells was registered. Mean packed cell quantities gained intraoperatively were: 1275 (1006-2067) ml (descending aortic aneurysm), 1800 (1186-2500) ml (ascending aortic aneurysm), 1524 (1030-1801) ml (single valve rereplacement), 1896 (1398-2368) ml (double valve rereplacement), 946 (800-1050) ml (coronary artery reoperation), 1362 (922-1455) ml (cyanotic heart disease) and 1519 (1194-2066) ml (miscellaneous cardiac operations). In 35 patients more than 2000 ml and in 14 patients more than 3000 ml packed cells were harvested. Based on body weight, relatively more packed cells could be gained in patients with cyanotic heart disease (41 ml/kg) than in the other groups (21 ml/kg). In these young patients the application of a smaller centrifuge bowl (125 ml) can be helpful. These results demonstrate that cell saving by means of a cell separator with a special suction line and collecting system can help to reduce the donor blood requirement in cardiac operations, in which large intraoperative blood loss is anticipated.

Adolescent↗
PubMed1989

Reduction of homologous blood requirement in cardiac surgery by intraoperative aprotinin application--clinical experience in 152 cardiac surgical patients.

The protease inhibitor aprotinin interacts with plasmin and kallikrein, which are generated in cardiac surgery during cardiopulmonary bypass (CPB). The influence of high-dose aprotinin application (2 million kallikrein inactivator units given i.v. at the beginning of anaesthesia followed by a 500,000 KIU/h infusion throughout the operation and additional 2 millions KIU added to the priming of the oxygenator) on perioperative blood loss and donor blood requirement was studied in 152 adult cardiac surgical patients. This group was compared to 317 patients having cardiac surgery without the application of aprotinin. Aprotinin reduced the homologous blood requirement by 43% (1783 +/- 100 vs 1015 +/- 131 ml, p less than 0.05), while the reduction of postoperative blood loss was 29% (1070 +/- 43 vs 761 +/- 51 ml, p less than 0.05). Fortytwo percent of the aprotinin treated patients completed their hospital stay without having any donor blood transfusion compared to 18% in the group without aprotinin. The blood saving effect was even more pronounced in operations with prolonged perfusion times. Intra- and postoperative complications were equally distributed in both groups. The blood-saving effect of aprotinin may be due to a platelet-preserving effect and/or kallikrein inhibition during CPB. There were no clinically relevant side effects related to aprotinin observed. It is concluded that high dose aprotinin therapy reduces both postoperative blood loss and homologous blood requirement, and therefore the routine application of aprotinin during cardiac surgical procedures is to be recommended.

Aprotinin↗
PubMed1989

Effect of urapidil on the performance of ischaemic myocardium in anaesthetized dogs.

The effect of urapidil on the ischaemic myocardium was studied in eight anaesthetized dogs. Stenosis of the left descending coronary artery reduced blood flow and systolic contraction of the post-stenotic myocardium by about 50%; the end-diastolic length of the post-stenotic myocardium and the end-diastolic pressure increased, while aortic pressure slightly decreased. Subsequent administration of urapidil (0.25 + 0.25 + 0.5 + 1.0 mg/kg intravenously) did not affect the systolic shortening and end-diastolic length of the myocardium supplied by the left circumflux coronary artery, while the stroke volume and the systolic shortening of the ischaemic myocardium increased. The latter was correlated with a decrease in the heart rate (r = -0.92), but not with the reduction in aortic pressure. Urapidil by itself does not impair the performance of the ischaemic myocardium, but might be beneficial in decreasing the heart rate or suppressing reflex tachycardia during reduction of the afterload.

Adrenergic alpha-Antagonists↗
PubMed1989

[Sufentanil-N2O2/O2 or halothane-N2O/O2 anesthesia in surgery of infants and children with congenital heart defects. Hemodynamics and plasma catecholamines].

Sufentanil-nitrous oxide/oxygen anesthesia was compared to halothane-nitrous oxide/oxygen anesthesia in 44 infants and children undergoing cardiac surgery. Patients were randomly assigned to one of the two techniques studied, with 22 patients in each group. The mean weight was 8.3 (4.4-15.8) kg in the sufentanil (S) group and 11.7 (5.2-18) kg in the halothane (H) group. All patients were premedicated with IM atropine 0.01 mg/kg, morphine 0.2 mg/kg, and flunitrazepam 0.04 mg/kg. In the S group 1 micrograms/kg S was given intravenously for induction, followed by a cumulative dose of 4 micrograms/kg S until the beginning of surgery. In the H group anesthesia was induced with H 0.5-1.0 vol.% and for deepening of anesthesia increasing H concentrations of 0.5-1.0-1.5 vol.% were applied. Following intubation all patients were ventilated with nitrous oxide/oxygen (1:1). There were no significant differences between the two groups in systolic, diastolic and mean arterial blood pressures or in heart-rate response to induction and intubation. Peripheral arterial oxygen saturation increased significantly in cyanotic patients in both groups following induction. There were dose-dependent decreases in heart rate and small but significant decreases in mean and diastolic arterial pressure in the S group during deepening of anesthesia. There was a significantly greater decrease in systolic, diastolic and mean blood pressures during the same period in the H group whereas the reduction in heart rate was minimal. In addition, in 5 of 22 patients receiving H there were episodes of nodal rhythms with dramatic decreases in systemic arterial pressure and peripheral arterial oxygen saturation in cyanotic patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, General↗
PubMed1989

Reduction of blood utilization during myocardial revascularization.

The efficacy of four different blood conservation techniques in decreasing the homologous blood requirement in cardiac operations was studied prospectively in 100 patients undergoing myocardial revascularization. The patients were randomly assigned to four groups of 25 each as follows: group I, retransfusion of oxygenator blood after termination of extracorporeal circulation; group II, processing of oxygenator content by means of a cell separator; group III, predonation of autologous blood and isovolumetric substitution of hydroxyethyl starch (10 ml/kg bodyweight) after the induction of anesthesia in addition to the use of a cell separator; and group IV, predonation and the use of a cell separator plus postoperative retransfusion of shed mediastinal blood. To form homologous groups, we accepted only male patients without impairment of left ventricular function for the study. In addition, patients with internal mammary artery grafts and a duration of extracorporeal circulation less than 45 minutes or more than 90 minutes were excluded. The bank blood requirement during hospitalization was 2132 +/- 824 ml in group I, 1371 +/- 928 ml in group II, 833 +/- 599 ml in group III, and 408 +/- 559 ml in group IV. The use of blood conservation techniques resulted in reductions of homologous blood requirements of 34%, 60%, and 80%, respectively, in groups II to IV as compared with the requirement in group I. There were no complications related to autologous blood transfusion. We conclude that the use of blood conservation techniques can considerably reduce the homologous blood requirement in cardiac operations and therefore decrease transfusion-related risks.

Blood Transfusion↗
PubMed1985

[Experiences with Swan-Ganz-catheter placement in the external jugular vein].

Clinical experience concerning the placement of Swan-Ganz catheters (SGC) via the external jugular vein is presented. After puncture of either the right or left external jugular vein, placement of SGC was possible in 90 per cent of patients. Compared to techniques involving puncture of the internal jugular vein this method has less complications. The placement of 167 SGC could be done without any problems, thus proving that the external jugular vein is a safe way of insertion. The external jugular vein as a primary route can be recommended if the vein is visible, especially in cases where puncture of the internal jugular vein may be difficult and could only be performed with an increased risk of complications.

Anesthesia, Intravenous↗
PubMed1984

[Antithrombin III substitution for optimization of the heparin effect during extracorporeal circulation in heart surgery].

In a prospective randomised study 20 patients undergoing coronary bypass surgery were assigned to two groups. Patients in group I (n = 10) received initially 250 IU heparin X kg-1 before the start of extracorporeal circulation. Patients in group II (n = 10) were given the same amount of heparin and in addition 1 000 units of purified human antithrombin III (AT III) concentrate. A highly significant lower heparin coefficient [2.69 +/- 0.57 IU X kg-1 X min-1, which is a parameter of heparin consumption (units of heparin X kg-1 given per minute during the time of heparinisation)], was found in group II compared to group I (3.73 +/- 0.56 IU X kg-1 min-1). Heparin sensitivity, measured as an increase in the ratio of activated coagulation time (ACT) X IU heparin-1 X kg-1 as a response to initial heparin dose, was found to be significantly higher (1.22 +/- 0.30 sec X IU heparin-1 X kg-1) in patients receiving AT III as measured in the control group (0.95 +/- 0.23 s X IU heparin-1 X kg-1). Mean values of ACT during the period of heparinisation were comparable (group I: 533 +/- 81 s, group II: 512 +/- 62 s) in the two groups. The substitution of AT III led to an increase of plasma AT III activity of 1.4% per substituted unit AT III X kg-1. AT III plasma activity, corrected to initial haematocrit levels to avoid dilution dependency, decreased as a consequence of extracorporeal circulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Antithrombin III↗