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Biomedical subjects

R Haussmann

Publications and source records attributed to R Haussmann.

16 recordsLinked to original sources
PubMed2001

Crossover behavior in the isothermal susceptibility near the 3He critical point.

We present high-resolution measurements of the isothermal susceptibility of pure 3He near the liquid-gas critical point. PVT measurements were performed in the single-phase region over the reduced temperature range 3 x 10(-5)<T/Tc-1<1.5 x 10(-1). The crossover behavior of the susceptibility along the critical isochore was analyzed using a field-theoretical renormalization-group calculation based on the phi4 model. A similar crossover analysis was performed on previously obtained Xe susceptibility measurements. A comparison of the rescaled susceptibility for 3He and Xe shows theoretically predicted universal crossover behavior.

Journal Article↗
PubMed1995

Treatment of dilated cardiomyopathy with dynamic cardiomyoplasty: the Heidelberg experience.

BACKGROUND: Data concerning the efficacy of dynamic cardiomyoplasty are still inconsistent, especially in terms of improvement of left ventricular function. METHODS: Between August 1990 and February 1994, eight isolated cardiomyoplasty procedures were performed in patients with cardiomyopathy (ejection fraction, 0.14 to 0.32; New York Heart Association class III) and contraindications to heart transplantation. RESULTS: Follow-up was 41.1 +/- 14.1 months. One patient died 2 months and another 3 years after operation. Considerable symptomatic improvement was found in 6 of 7 patients, 3 of whom went back to work. One patient with severe pulmonary hypertension exhibited no improvement. Mean New York Heart Association-class decreased from 3.0 to 1.9 (p < 0.001). Echocardiography showed an increase in fractional shortening and in peak aortic flow velocity in all patients. Left ventricular ejection fraction increased from 0.21 +/- 0.05 to 0.38 +/- 0.16 (n = 7, p < 0.015) at 1 year, to 0.37 +/- 0.18 (n = 6, p < 0.05) at 2 years, and to 0.36 +/- 0.19 (n = 5, not significant) at 3 years. Pulmonary artery pressure tended to decrease over time. No significant change in exercise level or maximal oxygen consumption during treadmill testing was observed. CONCLUSIONS: Our preliminary results show that patients may exhibit an impressive clinical improvement after cardiomyoplasty, with only moderate changes in objective hemodynamic indices. We do not consider cardiomyoplasty an alternative to heart transplantation, but reserve it for patients with contraindications to heart transplantation.

Cardiomyopathy, Dilated↗
PubMed1995

[Thrombomodulin as endothelial cell marker in heart surgery patients].

OBJECTIVE: Thrombomodulin is a high-affinity receptor for thrombin on the endothelial cell surface. The aim of our study was to investigate whether plasma thrombomodulin represents a marker of endothelial injury following cardiopulmonary bypass. METHODS: Plasma levels of thrombomodulin were quantitated in 70 plasma samples obtained from 14 adult cardiac patients undergoing hypothermic pulsatile low-flow low-pressure cardiopulmonary bypass. Blood samples were taken before cardiopulmonary bypass (T1), and 15 minutes (T2), 1 hour, 6 hours, and 20 hours after termination of bypass. Plasma thrombomodulin was quantitated with a sandwich enzyme-linked immunosorbent assay (ELISA). Statistical analysis was performed by the Friedman and Wilcoxon tests. RESULTS: Plasma thrombomodulin was significantly elevated 20 hours after discontinuation of cardiopulmonary bypass, when compared with T1 and T2. CONCLUSION: We conclude from our results that a moderate elevation of plasma thrombomodulin is seen in adult patients following hypothermic, low-flow low-pressure cardiopulmonary bypass, which may reflect endothelial injury. Circulating thrombomodulin levels are thus possibly useful for assessment of endothelial damage occurring in patients undergoing cardiopulmonary bypass.

Adult↗
PubMed1995

[Anesthesiologic management in cardiomyoplasty].

Dynamic cardiomyoplasty is a therapeutic possibility in irreversible cardiac insufficiency. With this operation, the latissimus dorsi muscle is mobilised and drawn into the thorax where it is placed around the heart. Lateral and supine positioning as well as thoracotomy and direct manipulation of the heart are associated with particular risks during surgery. Eight patients with the diagnosis of cardiomyopathy underwent cardiomyoplasty. The patients were classified as NYHA III-IV. Continuous dobutamine infusions were routinely started after induction of anaesthesia. All patients were intubated with single-lumen tubes. After sternotomy, lidocaine was administered. Monitoring included Swan-Ganz catheterisation and invasive blood pressure measurement. With early use of inotropic and vasodilatator agents the cardiac index and peripheral vascular resistance were adequately maintained. Double-lumen intubation seems to be unnecessary during cardiomyoplasty and only increases patient risk. Prophylactic lidocaine infusions are effective in preventing ventricular tachycardia and fibrillation. We conclude that adequate intraoperative management can improve the haemodynamic status of these patients so that cardiomyoplasty may be performed without significant morbidity.

Adult↗
PubMed1995

Safety and effectiveness of an oral premedication regimen before cardiac surgery.

Thirty-five adult cardiac surgical patients received 20 mg dipotassium clorazepate orally the evening before surgery and 2 mg flunitrazepam 60 min before induction of anaesthesia. If anaesthesia was to be induced after 08.30 hours patients received an additional 20 mg dipotassium clorazepate at 06.15 hours. The following measurements were made: peripheral arterial oxygen saturation (Spo2) breathing room air; anxiety by visual analogue scale; degree of sedation; and haemodynamic variables. Mean (Spo2) was 95.9% (SD 1.8%) on the day before surgery and 95.4% (SD 1.5%) on arrival at the operating room. When the operation started after 08.30 hours, mean (Spo2) at 09.00 hours was 96.0% (SD 1.4%). There were no detected episodes of hypoxaemia after premedication. Mean anxiety score decreased significantly from 3.9 (SD 2.6) on the day before surgery to 3.3 (SD 2.1) on arrival at the operating room (patients' score; P < 0.002) and from 4.6 (SD 2.4) to 3.3 (SD 2.0) (anaesthesiologists' score; P < 0.001). Nearly all patients were considered well sedated, which was reflected by normal haemodynamic variables on arrival at the operating room. The combination of clorazepate and flunitrazepam is effective oral premedication for adult cardiac surgery, causing no obvious desaturation even when supplemental oxygen is not given.

Administration, Oral↗
PubMed1994

Evoked potential monitoring during repeatedly induced ventricular fibrillation for internal defibrillator implantation.

Repeated induction of ventricular fibrillation (VF) with circulatory compromise during implantable cardioverter defibrillator (ICD) testing may cause cerebral injury. To test this hypothesis, somatosensory evoked potentials (SEP), a more sensitive marker of injury, were recorded in patients (N = 10) undergoing ICD implantation. SEP were recorded before induction of anesthesia, after induction of anesthesia, before and at several times following induction of VF. Possible modifying factors of the SEP measurements such as anesthetic application, blood pressure, body temperature, and hematocrit remained constant throughout the operations. Central conduction time was unaffected by ICD defibrillation testing. Amplitude of SEP primary complexes was transiently reduced at 34.9% (P < 0.01) by defibrillation testing, but returned to control within 10 minutes after testing. It is concluded that while ICD defibrillation testing may produce transient changes in SEP, there is no evidence of residual cerebral injury.

Adult↗
PubMed1992

[Acute jugular engorgement in liver transplantation].

A 56-year-old patient with chronic liver failure underwent liver transplantation; a Denver shunt had been placed 6 months previously. Following an initially uneventful operative course, during fashioning of the proximal caval anastomosis in the anhepatic phase, the patient developed very marked jugular engorgement. The central venous pressure rose to 45 mmHg and this lasted some 15 min. With the opening of the venous anastomosis and placement of the liver in its anatomical site, the central venous pressure returned to normal values once again. It can be concluded that during fashioning of the anastomosis, both the right atrium and distal superior vena cava were obstructed. While normally not haemodynamically significant, in this case, however, the superior vena cava became more narrow by the routinely placed venous lines and the Denver shunt. This in turn, gave rise to this particular clinical manifestation.

Acute Disease↗