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Biomedical subjects

N Franke

Publications and source records attributed to N Franke.

36 records · Page 2Linked to original sources
PubMed1982

[Haemodynamic changes in infrarenal aortic aneurysm operations (author's transl)].

UNLABELLED: Haemodynamic changes after aortic cross-clamping were measured during operation of 11 patients suffering from infrarenal aortic aneurysm. Systemic vascular resistance, mean arterial pressure and pulmonary capillary wedge pressure are increased, while cardiac index is significantly decreased. Heart rate and right atrial pressure remain nearly unchanged. The elevations in systemic vascular resistance, mean arterial pressure and pulmonary capillary wedge pressure are reversed by continuous nitroglycerin infusion, cardiac index is increased. CONCLUSIONS: 1. meticulous haemodynamic monitoring is very important in operations including abdominal aortic cross-clamping in order to prevent imminent cardiac complications. 2. the haemodynamic changes induced by aortic cross-clamping can be reversed by infusion of nitroglycerin.

Aged↗
PubMed1982

[The effect of pentobarbital on the microcirculation of skeletal muscles and the subcutis. An animal-experimental study].

The effects of pentobarbitone anaesthesia on the macrohaemodynamics and the microvasculature of subcutaneous tissue and skin muscle were studied in hamsters (n = 14) utilizing intravital microscopy, quantitative video techniques and a platinum multiwire electrode for local PO2 measurements. After achieving anaesthesia with 35 mg/kg b.w. pentobarbitone, changes in macrohaemodynamic parameters, blood cell velocity and vessel diameters were not observed. However, after 30 min of pentobarbitone anaesthesia, 25% of the arteriolar blood volume coursed through arteriovenous shunts. The increase in a-v shunting was accompanied by a significant decrease of functional capillary density. As a result, local PO2 values decreased slightly after 30 min of pentobarbitone anaesthesia. These findings provide evidence that 35 mg/kg b.w. pentobarbitone cause alterations in capillary density and perfusion. It is concluded that with a dose of up to 35 mg/kg b.w. pentobarbitone, these changes have little effect on local tissue oxygenation.

Animals↗
PubMed1981

[Changes in microcirculation by the administration of sodium nitroprusside and nitroglycerin].

The effects of hypotension induced by sodium nitroprusside (SNP) or nitroglycerin (NTG) were evaluated in hamsters (n = 12). No differences in macrohemodynamic parameters were found during and after hypotension with either drug tested. SNP dilated predominantly the precapillaries and NTG dilated all microvascular segments. Blood cell velocity decreased in both groups. A significant volume of blood was diverted through av-shunts during SNP hypotension of 40 mm Hg. Capillary density decreased significantly during and after SNP-induced hypotension, whereas capillary density remained unchanged when NTG was used. The data favour the use of NTG when hypotension is deliberately induced.

Animals↗
PubMed1981

Treatment of acute left heart failure using dobutamine and intraaortic counterpulsation. Animal experiments and first clinical experiences.

Ten anesthetized mongrel dogs had a left anterolateral thoracotomy; the left anterior descending coronary artery was then ligated. After 60 min five animals each were treated either with dobutamine (4 microgram/min/kg; for 10 min), or with dobutamine and intraaortic counterpulsation. Combined treatment of cardiogenic shock proved superior. Those five dogs had significantly lower heart rates and dp/dt/p-values. Due to IABP the non-ischemic parts of the left ventricle were better perfused; there was no difference in treatment with regard to ischemic parts. The combined treatment was successfully inaugurated in two patients with cardiogenic shock.

Adult↗
PubMed1981

[Treatment of the low-output-syndrome with urapidil and dobutamine (author's transl)].

12 patients suffering from a low cardiac output syndrome following aorto-coronary bypass-graft surgery were treated with a combined therapy. The left ventricular afterload was decreased by Urapidil, and a low dose positive inotropic agent, dobutamine, was added. The right and left ventricular filling pressures were kept constant by simultaneous volume replacement. Decreasing the mean arterial pressure by Urapidil alone from 122 +/-5 mm Hg to 90 +/-3mm Hg raised the cardiac index from 1.8 1/m2 x min to 2.71 1/m2 x min. By addition od dobutamine 5 mu/kg BW x min the cardiac index was further increased to 3.4 1/m2 x min. The heart-rate was unchanged. The pressure-rate-product was decreased by 25% with Urapidil alone (p 7E 0.01) and was only slightly increased after addition of dobutamine. It is concluded that in the patients studied, reduction of the mechanical load on the heart by Urapidil in combination with positive inotropic stimulation of the myocardium by dobutamine improved cardiac haemodynamics without a significant detrimental effect on the myocardial oxygen balance.

Adult↗
PubMed1980

[Hemodynamics and myocardial O2 consumption at induction of anesthesia (author's transl)].

The hemodynamics and the myocardial oxygen consumption during sleep and induction of anesthesia was studied in 10 patients with good left heart function (group I) and in 8 patients with bad left function (group II). Anesthesia was induced with diazepam (0.1 mg/kg BW), fentanyl (0.01 mg/kg BW), etomidate (0.2 mg/kg BW), and pancuronium (0.1 mg/kg BW). Four min after induction under ventilation with mask the cardiac index (CI) in both groups and the whole body oxygen consumption (VO2) diminished in exact the same degree. After intubation in patients of group I the CI and the VO2 decreased further, the arterio-venous oxygen content difference (avDO2) remained constant. In patients of group II the CI decreased to 0.9 1/min x m2, the avDO2 increased to 9.9 Vol%.

Anesthesia, General↗
PubMed1980

[Hemodynamic response to surgery of infrarenal aortic aneurysm (author's transl)].

Hemodynamic changes after aortic cross-clamping were measured during operation of 11 patients suffering from infrarenal aortic aneurysm. Systemic vascular resistance, mean arterial pressure and pulmonary capillary wedge pressure are increased, while cardiac index is significantly decreased. Heart rate and right atrial pressure remain nearly unchanged. The elevations in systemic vascular resistance, mean arterial pressure and pulmonary capillary wedge pressure are reversed by continuous nitroglycerin infusion, cardiac index is increased. It is concluded that a meticulous hemodynamic monitoring is very important in operations including abdominal aortic cross-clamping in order to prevent imminent cardiac complications.

Aged↗
PubMed1980

[Antihypertensive therapy with diazoxide during anaesthesia (author's transl)].

The haemodynamic effects of antihypertensive therapy with diazoxide were studied during anaesthesia in 14 patients. Mean arterial pressure decreased after diazoxide from 135 -/+ 14 mm Hg to 98 -/+ 9 mm Hg (p < 0.01) and did not increase within 30 minutes of observation. Cardiac-index increased 23% (p < 0.01) and the heart rate 14%. These parameters reached control values after 30 min of observation. Pulmonary capillary wedge pressure showed no significant variations. The results confirm that diazoxide is an effective antihypertensive drug. the authors conclude that the use of diazoxide is indicated in the perioperative period, when the patient is not under close and invasive observation.

Anesthesia, General↗
PubMed1980

[Haemodynamic and respiratory effects of pentazocine. Studies on cardio-surgical patients (author's transl)].

The effects of different doses of pentazocine on circulation and respiration were investigated in 28 patients divided into three groups. The circulatory reactions occurred in two phases. In the first, immediately after the injection, ventilated patients showed vasodilation and therefore a decrease in the peripheral and pulmonary blood pressure due to the reduction in peripheral and pulmonary vascular resistance. In contrast, the second phase is characterized by a vasoconstriction with maximal alterations ten minutes after injection. As a consequence, the peripheral and pulmonary arterial pressure is increased by a raise in peripheral and pulmonary vascular resistance. These circulatory effects were more pronounced in the group receiving the higher dose of pentazocine. In spontaneously breathing patients pentazocine causes ventilatory depression indicated by a decrease in PaO2 and an increase in PaCO2. In these patients pulmonary vascular resistance and pulmonary arterial pressure are increased within the first minute after injection in contrast to the ventilated patients receiving the same dose. These increases are accompanied by the maximum of ventilatory depression. This change can be explained by the pulmonary hypoxic vasoconstriction.

Adult↗
PubMed1979

Enflurane in patients with coronary artery disease.

In 12 patients with coronary artery disease, hypertensive periods during aortocoronary bypass surgery were treated with 1 MAC enflurane. The effect of enflurane on the major determinants of myocardial oxygen consumption was studied. Systolic arterial pressure was reduced to a level of about 120 mmHg (16 kPa). The heart rate diminished by 16.5%. The cardiac index during enflurane application was unchanged. Pulmonary artery wedge pressure was measured at short intervals and remained unchanged. The fall in arterial pressure and heart rate under unchanged preload produced a significant reduction in myocardial oxygen consumption as determined by calculation of the systolic wall tension and the tension time index. In five patients, the O2 content in coronary sinus blood was measured and the arterial-coronary sinus O2 difference was found to be diminished. In the concentration used, enflurane reduced the myocardial oxygen consumption of patients with coronary artery disease.

Aged↗
PubMed1979

[Control of afterload by intravenous nitroglycerin in patients undergoing myocardial revascularisation (author's transl)].

In 18 patients undergoing aortocoronary bypass grafting haemodynamic measurements were made before and after hypertensive episodes and intravenous administration of nitroglycerin (NTG). Patients of group I (n = 10) had good left heart function before operation. The mean arterial pressure (MAP) rose during the hypertensive episode from 82 +/- 12 mm Hg to 119 +/- 8 mm Hg (p less than 0.001), the pulmonary capillary wedge pressure (PCWP) increased from 11 +/- 3 mm Hg to 15 +/- 2 mm Hg (p less than 0.05). The cardiac index (CI) was not significantly altered. Infusion of NTG decreased the MAP to 84 +/- 3 mm Hg (p less than 0.001), the PCWP to 9 +/- 3 mm Hg (p less than 0.01). The CI remained unchanged. Patients of group II (n = 8) had poor left heart function before operation. During the hypertensive episode the MAP increased from 77 +/- 15 mm Hg to 115 +/- 6 mm Hg (p less than 0.001), the PCWP from 13 +/- 4 mm Hg to 25 +/- 5 mm Hg (p less than 0.001). The CI decreased from 2.2 +/- 0.3 1/min x m2 to 1.5 +/- 3.41/min x m2. Infusion of NTG decreased the MAP to 83 +/- 4 mm Hg (p less than 0.001), the PCWP to 11 +/- 3 mm Hg (p less than 0.001). The CI rose to 2.3 +/- 0.3 1/min x m2 (p less than 0.01). The authors conclude that NTG is an effective antihypertensive agent. No untoward side effects were noted.

Adult↗
PubMed1979

[Haemodynamic effects of combined dopamine and nitroprusside therapy early after open heart operations (author's transl)].

In 12 patients with moderate low-output-syndrome following aortocoronary bypass grafting, the pump function of the left ventricle was improved by sodium nitroprusside (SNP) and dopamine. The cardiac index (CI) on termination of cardio-pulmonary bypass was 2.2 +/- 0.2 1/min.m2 and the pulmonary capillary wedge pressure (PCWP) 20 +/- 3 mm Hg. Folowing infusion of SNP the Cl reached 2.4 +/- 0.2 l/min.m2 (p less than 0.05) and the PCWP was reduced to 13 +/- 3 mm Hg (p less than 0.01). After transfusion of blood the PCWP increased to 18 +/- 2 mm Hg (p less than 0.01), and the CI increased to 2.8 +/- 0.2 l/min.m2 (p less than 0.05). After administration of dopamine the CI was further improved to 3.3 l/min.m2, the PCWP remained constant. The combined therapy with dopamine and SNP is a rational concept to improve the function of the heart in failure following open heart surgery.

Blood Pressure↗
PubMed1979

Afterload reduction by enflurane.

In 12 patients with coronary artery disease, hypertensive period during aortocoronary bypass grafting were treated with enflurane. The effects of enflurane on the general hemodynamic and the major determinants of myocardial oxygen consumption were studied. Heart rate and systolic arterial pressure were significant reduced, cardiac index and pulmonary capillary wedge pressure remained unchanged. The calculated determinants of myocardial oxygen consumption decreased, as well as the measured arterial-coronary venous oxygen content difference. The authors conclude, that enflurane can reduce the afterload in patients with coronary heart disease.

Coronary Artery Bypass↗
PubMed1979

[Haemodynamics of the systemic and pulmonary circulation during surgery of hip fractures in spinal anaesthesia in elderly persons (author's transl)].

The haemodynamics of the pulmonary and systemic circulation during anaesthesia and surgical treatment of a hip fracture were investigated in 26 patients (mean age 73 +/- 4.5 years). After induction of spinal anaesthesia the mean arterial pressure, right atrial pressure, pulmonary capillary wedge pressure and systemic vascular resistance were significantly reduced. The cardiac index remained constant due to mild tachycardia. During the operation no significant variations of the haemodynamic parameters were observed. Implantation of methylmethacrylate in 10 patients was followed by a significant increase of the mean pulmonary pressure and pulmonary vascular resistance. The PaO2 DECREASED. 15 minutes after implantation the original values were again reached.

Aged↗
PubMed1978

[Therapy of low-output syndrome in patients following cardiopulmonary bypass with sodium nitroprusside and dopamine].

In 12 patients with low output after open-heart surgery the therapeutic effect of vasodilatation with sodium nitroprusside (SNP) and dopamine was studied. All patients underwent aortocoronary bypass operations. After cardiopulmonary bypass, the cardiac index (CI) was 2.2 liters/min.m2. The pulmonary wedge pressure (PCWP) was about 20 mm Hg. Application of SNP lowered mean arterial pressure to 82 and PCWP to 13 mm Hg. Then PCWP was elevated to the control level by tranfusion of blood. This therapy increased CI by about 30% without positive inotropic intervention. Additional application of 5 micrograms dopamine/kg.min improved the CI to 3.8 liters/min.m2.

Blood Pressure↗
PubMed1978

[Haemodynamic response to sodium nitroprusside in healthy people and in patients with left heart failure (author's transl)].

In 10 healthy persons (group I) and in 10 patients with left heart failure the haemodynamic response to reduction of the arterial blood pressure with sodium nitroprusside (SNP) is studied. The systolic arterial pressure (SAP) is reduced in two stages first to 100 mm Hg and than to 90 mm Hg. The SAP was then allowed to reach 100 mm Hg by reduction of the SNP dose. At this SAP a constant amount of SNP and 500 ml Dextran 60 were infused. In group I the cardiac index (CI) decreases from 3,6 +/- 0,4 1/minXm2 at a SAP of 136 +/- 11 mm Hg to 3,2 +/- 0,2 1/minXm2 (p less than 0,05) at a SAP of 101 +/- 2 mm Hg. At a SAP of 89 +/- 3 mm Hg the CI is 3,0 +/- 0,3 1/minXm2 (p less than 0,05). The right atrial pressure (RAP) and the pulmonary capillary wedge pressure (PCWP) are significantly reduced (p less than 0,01). After infusion of 500 ml Dextran 60 the CI increases to 3,9 +/- 0,3 1/minXm2 (p less than 0,05). In group II at a SAP of 132 +/- 8 mm Hg the CI is 2,7 +/- 0,2 1/minXm2, at a SAP of 99 +/- 3 mm Hg the CI is 3,0 +/- 0,3 1/minxm2 (p less than 0,05) and at a SAP of 91 +/- 2 mm Hg decreases to 2,7 +/- 0,2 1/minXm2. RAP and PCWP are significantly reduced (p less than 0,01). After infusion of 500 ml Dextran 60 the CI increases to 3.3 +/- 0,2 1/minxm2 (p less than 0,05). These results show, that SNP-Infusion in patients with left heart failure can improve cardiac performance. In patients without cardiac disease the CI decreases after SNP-Infusion due to the low preload of the heart. In both groups preload restoration with Dextran 60 can increase the cardiac index.

Adult↗