PubMed Health⌕ Search

Biomedical subjects

H Stopfkuchen

Publications and source records attributed to H Stopfkuchen.

At least 19 recordsLinked to original sources
PubMed1994

[Anaphylactic shock].

Anaphylactic shock is a cardiovascular collapse that occurs after the interaction of antigen and antibody. Common causes of anaphylactic shock are drugs, foods, venoms, and heterologous serum. Mechanisms of anaphylactic shock are thought to be peripheral vasodilatation, enhanced vascular permeability, leakage of plasma, and intravascular volume depletion. The recognition of an anaphylactic shock rests on the observation of cardiovascular collapse in association with temporal exposure to a foreign substance. In addition to cardiovascular collapse, cutaneous, respiratory and/or gastrointestinal events can occur, constituting other serious aspects of anaphylaxis. Anaphylactic shock is a true medical emergency. Initial therapy consists of the administration of intravenous fluids (saline, colloid), and epinephrine.

Anaphylaxis↗
PubMed1992

Evaluation of the valve area underestimation by the continuity equation.

During the last years, noninvasive determination of the aortic valve area by Doppler echocardiography using the continuity equation became popular. However, a systematic valve area underestimation of about 15% compared to invasive measurements using the Gorlin formula has been reported. The cause therefore is unknown. The purpose of this study was to evaluate whether the valve area underestimation by the Doppler method might be due to differences in the hydrodynamic background of both methods. This comparison is facilitated by the fact that the Gorlin formula is based on the continuity equation. Compared to the continuity equation, there are four changes within the Gorlin formula: (1) the additional use of a discharge coefficient, which leads to valve area overestimation by the factor 1.17; (2) neglect of the pre-stenotic velocity, causing further overestimation by the factor 1.036 (in mild stenosis this factor may be 1.18 and more); (3) the wrong calculation of the mean pressure drop, which leads to a mean change by the factor 0.95, and (4) the incorrect substitution of the height by the pressure drop in the derivation of the Gorlin formula causes underestimation by the factor 0.97. Combining these four factors results in valve area overestimation of the Gorlin formula compared to the continuity equation by the factor 1.12. This explains to a large extent the valve area underestimation by the continuity equation.

Aortic Valve↗
PubMed1992

The effect of antenatal intravenous immunoglobulin on ascending intrauterine infection after preterm premature rupture of the membranes: a pilot study.

Ascending infection is a serious threat in pregnancies complicated by preterm premature rupture of the membranes (PROM). In a controlled randomized prospective pilot study (n = 18) we have evaluated the effect of intravenous IgM enriched immunoglobulin given to the mothers 24-48 hours after preterm PROM in reducing ascending infection. Using a validated infection score from laboratory and clinical data at birth, we found a significant reduction of probable infection in the neonates of the treatment group compared to the control group (p = 0.0022). Histopathological investigation of the placentas, membranes and umbilical cords revealed significantly lower stages and grades of chorioamnionitis in the treatment group (p = 0.036). From these preliminary results we conclude, that intravenous broad spectrum immunoglobulin given antenatally to patients with preterm PROM may reduce ascending infection. However, studies with a much larger cohort of patients are necessary to confirm these preliminary results and to detect potential clinical benefits from this treatment mode.

Adult↗
PubMed1991

Effects of dopamine infusion on plasma catecholamines in preterm and term newborn infants.

Newborn infants (21 preterm and 13 term) received dopamine infusions at a low (2.5-3.4 micrograms/kg per min) and/or high (5-10 micrograms/kg per min) infusion rate and changes in plasma catecholamines were monitored. The mean baseline values for dopamine, noradrenaline and adrenaline were between 240 and 560, 125 and 144 and 62 and 82 pg/ml, respectively. During low-rate infusion of dopamine, there was a significant increase in plasma dopamine (20-100 fold), noradrenaline (three- to five-fold) and adrenaline (threefold). Administration of dopamine at the high rate resulted in an even larger increase in the plasma catecholamines (dopamine, 100-300 fold; noradrenaline, seven- to eightfold; adrenaline, four- to sixfold). In a double-log plot, there was a highly significant correlation between the plasma concentrations of dopamine and noradrenaline (r = 0.77; P less than 0.001). In conclusion, infusion of dopamine in term and preterm newborn infants is accompanied by an enhanced sympatho-adrenal tone which may contribute to the cardiovascular effects of dopamine in these patients.

Dopamine↗
PubMed1990

Cardiovascular responses to dobutamine determined by systolic time intervals in preterm infants.

We investigated the effects of dobutamine therapy on myocardial function in premature infants. Left ventricular performance was assessed by measuring left ventricular systolic time intervals: rate-corrected pre-ejection period (PEPI), rate-corrected left ventricular ejection time (LVETI), and pre-ejection period to left ventricular ejection time ratio (PEP/LVET) which was obtained by echocardiography. Measurements were performed in 17 hemodynamically unstable premature infants who had an elevated PEP/LVET ratio before and 30 min after starting dobutamine infusion (10 micrograms/kg.min). Dobutamine infusion resulted in a significant decrease in PEPI (from 108 +/- 16 [SEM] to 95 +/- 17 msec; p less than .01) and in PEP/LVET ratio (from 0.55 +/- 0.16 [SEM] to 0.45 +/- 0.17; p less than .01), and in a significant increase in LVETI (from 255 +/- 15.7 [SEM] to 264 +/- 16.2 msec; p less than .01). Heart rate increased significantly from 146 +/- 17 (SEM) to 163 +/- 16 beat/min; p less than .01. Mean arterial pressure increased in 12 of 14 infants. These results show that dobutamine enhances left ventricular performance in premature infants who have depressed left ventricular function.

Birth Weight↗
PubMed1989

Hemodynamic monitoring in childhood.

Hemodynamic monitoring is indicated in children with impending or manifest cardiocirculatory failure. Since cardiocirculatory failure is characterized by an imbalance between oxygen delivery and oxygen demand due to perfusion failure, the parameters monitored should aid in the assessment of these oxygen variables. Oxygen delivery depends on oxygen content and cardiac output. Cardiac output is determined by heart rate and stroke volume; stroke volume by preload, afterload and contractility. Since the direct measurement of oxygen consumption routinely is almost impossible, global oxygen utilization represented by mixed venous oxygen saturation may be used to quantify the relationship between oxygen delivery and oxygen consumption. Justification of invasive hemodynamic monitoring depends among other things on an optimal balance between usefulness of information and complications associated with the techniques used. In future, the development of further noninvasive techniques and the scientific evaluation of recommended monitoring techniques are prospects in cardiovascular monitoring in childhood.

Cardiac Output↗
PubMed1989

Continuous monitoring of mixed venous oxygen saturation in infants after cardiac surgery.

Continuous mixed venous oxygen saturation (SvO2c) was measured in 16 infants immediately after cardiac surgery. A polyurethane 4F, dual channel catheter (Opticath, Modell U440, Oximetrix) with fiberoptic filaments was introduced into the pulmonary artery during cardiothoracic surgery. The catheters were left in place for an average of 67.5 h (range 27 h -125 h) and there were no catheter-related complications. Correlation between continuous in vivo SvO2 values and in vitro values was satisfactory (r = 0.85), whereas a correlation between SvO2c and arterial oxygen saturation (SaO2) was not found (r = 0.07). The sampled arterial lactate values were inversely correlated to the simultaneously measured SvO2c, but the correlation coefficient was only r = -0.4. There was an inverse correlation between SvO2c and arteriovenous oxygen content difference (Ca-vDO2) (r = -0.82), and a marked inverse correlation to the calculated oxygen utilization ratio (r = -0.97). Therefore SvO2c continuously reflects the overall balance between oxygen consumption and delivery, but the use of SvO2 as a predictor of blood lactate levels is unreliable. A further purpose of the present study was to demonstrate the clinical applications and to show the usefulness of SvO2c-monitoring; particularly as a surveillance and early warning system, as a guide for assessing therapy and its relevance in interpreting other monitored parameters. In our opinion continuous SvO2 measurement is a reliable and valuable indicator of cardiopulmonary function in the immediate post-operative period, even in infants with complicated repair of cardiac malformations.

Blood Gas Analysis↗
PubMed1989

Acute hemodynamic response to intravenous enoximone: an animal study and preliminary report in infants after cardiac surgery.

In light of previous studies in adults, we considered that enoximone could be useful in treating children with therapy-resistant cardiovascular insufficiency. Prior to clinical administration, we investigated the cardiovascular properties of enoximone in anesthetized and ventilated piglets characterized by small stroke volume and high heart rate. Enoximone was administered intravenously in increasing doses (0.25, 0.5, and 1 mg/kg). The animals were monitored with heart rate, systemic and pulmonary arterial pressures, and continuous electromagnetic flow. Enoximone induced a dose-dependent flow increase, whereby heart rate and systemic arterial pressure changed only slightly. With regard to persistent pulmonary hypertension in newborns, enoximone was also used in piglets to investigate the effects on endotoxin-induced, dopamine-resistant pulmonary hypertension. Enoximone (1 mg/kg i.v.) was given immediately after E. coli endotoxin (1.5 micrograms/kg i.v.) and inhibited the endotoxin-induced, eicosanoid-mediated pulmonary hypertension, whereas during infusion of dopamine (2 mg/kg/h), no drop in systemic blood pressure could be observed. In the clinical study, six infants with post-cardiac surgery low output syndrome despite maximal catecholamine inotropic support were given enoximone (i.v. bolus of 0.2, 0.5, or 1 mg/kg followed by continuous infusion of 7.5-10 micrograms/kg/min). Continuously measured mixed-venous oxygen saturation increased in a dose-related manner. Cardiac output increased significantly by 28%, accompanied by a decrease of arteriovenous oxygen content difference and O2 utilization ratio. The preliminary results show that intravenous enoximone produces acute useful hemodynamic effects in infants, in particular allowing a weaning of vasoactive amines.

Animals↗
PubMed1988

The effect of nifedipine alone or combined with low dose acetylsalicyclic acid on endotoxin-induced pulmonary hypertension in the piglet.

Cardiovascular responses to the calcium antagonist nifedipine, alone and combined with low dose acetylsalicyclic acid (ASA), were evaluated in a piglet model of endotoxin-induced pulmonary hypertension. All animals were anesthetized, paralyzed and mechanically ventilated. Cardiac output (CO), pulmonary artery pressure (PAP), aortic blood pressure (SAP), pulmonary capillary wedge pressure (PCWP), right atrial pressure (RAPM) and arterial blood gases were measured before and after induction of pulmonary hypertension by E. coli endotoxin and after treatment. Results of treated groups were compared to a control group of piglets subjected to the same dose (0.15 micrograms/kg i.v.) of endotoxin. Control animals responded to a bolus injection of endotoxin within 15 min with an increase in mean PAP by 110%. Pulmonary vascular resistance (PVR) increased by 144%. Mean arterial pressure did not change significantly from baseline values. In animals treated with a single dose of 1 mg/kg ASA prior to endotoxin, the initial pulmonary response was not quantitatively different from control values, whereas ASA 20 mg/kg abolished the pulmonary vascular reaction. The increase of systemic vascular resistance (SVR) produced by endotoxin was aggravated by high dose ASA. In piglets treated with nifedipine (4 micrograms/kg/min) over 30 min after the application of endotoxin with and without additional infusion of nifedipine 60 min prior to endotoxin the PVR could be attenuated. The combination of nifedipine and low dose ASA showed synergistic effects compared to control. The increase of mean PAP was significantly reduced, the PVR remained in baseline range due to a marked elevation of cardiac output.

Animals↗