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Biomedical subjects

W Kramer

Publications and source records attributed to W Kramer.

At least 145 records · Page 8Linked to original sources
PubMed1987

[Determination of active components of amrinone by analysis of pressure-volume results; use of the conductance (volume) catheter technic and rapid load change by balloon occlusion of the inferior vena cava].

Endsystolic pressure-volume relationships (ESPVR) were determined using the conductance (volume) catheter-technique and the required rapid load changes by applying vasoactive drugs (nitroprusside = NP; phenylephrine = PE) or brief preload reduction by balloon occlusion of the vena cava inferior (BOVCI). With this load-independent index of contractility, we analyzed the hemodynamically active components of amrinone (AM) over a range of different LV-loading conditions. In 19 patients (study I) with still normal LV-function (LVF) in group A (dP/dtmax 1585 +/- 386 mmHg/s; n = 10) and impaired LVF in group B (dP/dtmax 1044 +/- 164 mmHg/s; n = 9) an infusion of AM, 1.5 mg/kg over 2 min, failed to induce changes in ESPVR (p greater than 0.05), but rather caused load changes, resembling like those seen with NP. During continuously paced heart rates (90/min) brief infusion phases with NP and PE provided the necessary load changes. In 11 patients (study II) with impaired LVF (dP/dtmax = 1177 +/- 163 mmHg/s) 2.5 mg/kg AM i.v. induced an increase in contractility, which was more pronounced after the additional application of dobutamine (DOB) at 10 micrograms/kg/min.; (1) Slope k rose from 0.52 to 0.80 mmHg/ml; (2) dP/dtmax increased by an average of 39% and 57% (p less than 0.01), respectively. The BOVCI provided the necessary load changes. Thus AM demonstrates its contractility-increasing effects in a dose-related fashion, probably (at least in part) via an increase in heart rate; inotropic effects further increased with the combination of AM and DOB. The use of the conductance technique for the assessment of ESPVR during acute decrease of preload by temporary BOVCI is innocuous to the patient, reproducible and can be carried out under the conditions of a routine cardiac catheter procedure. This technique seems to be useful in the assessment of relative inotropic effects of the newer cardiotonic drugs.

Amrinone↗
PubMed1987

Effects of forskolin on left ventricular function in dilated cardiomyopathy.

The adenylate cyclase activator 17 beta-acetoxy-8, 13-epoxy-1 alpha,6 beta,9 alpha-trihydroxylabd-14-en-11-one (forskolin) was studied for its beneficial effect as therapeutic agent for the treatment of dilated cardiomyopathy (DCM). In 7 DCM-patients with normal (group A) and 8 DCM-patients with pathological dP/dtmax-values (group B), we analyzed serially (computer-assisted) the pressure/volume (P/V) effects as P/V-loops (microtip catheter/Tc-99m scintigraphy) and on-line MV02 (indirectly: Bretschneider equation) under dobutamine, 10 micrograms/kg/min i.v., and forskolin, 3 micrograms/kg/min i.v. For the total group (A + B) there was no change of contractility during forskolin (p greater than 0.05); with dobutamine, however, it rose by an average of +25%. The preload decline was more pronounced with forskolin (LVEDP by -27%) as compared to dobutamine (by-19%); while left ventricular (LV-)function improved moderately only with forskolin (by +9%) and significantly (by +34%) with dobutamine. Thus, forskolin improved LV-function primarily via reduction of preload in DCM-hearts and without rising metabolic costs. Beneficial hemodynamic effects with forskolin are quantitatively less as compared to those with dobutamine (accompanied by higher MVO2-costs). It is concluded that residual myocardial reserves in DCM are mobilized by dobutamine rather than forskolin. Serial P/V-loop and on-line MVO2 registration aided in the demonstration of forskolin efficacy as compared to dobutamine.

Angiography↗
PubMed1986

[Results of conservative treatment of distal radius fractures].

The results of conservative treatment of fractures of the distal radius in 303 patients over a period of two years are demonstrated. 226 patients could be followed-up. The healing of the fracture was satisfactory in 78%, while the results regarding the various age groups showed considerable differences. Along with the demonstration of the functional and anatomical results in relation to age, sex, and localization the technique of fracture treatment as well as follow-up treatment are discussed.

Adolescent↗
PubMed1986

[First aid and transport in injuries of the spine].

Prognosis of lesions of the spine and spinal cord has greatly improved in recent years. It depends significantly and decisively on early recognition of such lesions and can be improved further by on-target immediate or early measures. Especially after traffic accidents, every unconscious person must be assumed to have suffered an injury of the spine until definite proof to the contrary. Appropriate measures must therefore be taken during rescue and transportation.

Accidents, Traffic↗
PubMed1986

[Long-term intubation following tracheotomy].

Between 1981 and 1983 tracheotomy was performed on 61 patients in the Surgical University Clinic of Tübingen. The dominant factors in indication of tracheotomy was for 49% of patients the persistingly necessary artificial respiration, for 26% a better bronchial toilet and other reasons for 25%. With 40.5% of all cases pneumonia was the most frequent complication encountered with our patients. The most frequent bacteria was Pseudomonas aeruginosa. Because of the decisive advantage constituted by the possibility of unproved bronchial toilet an earlier realisation of tracheotomy is to be recommended.

Bronchitis↗
PubMed1985

Mechanisms of altered myocardial contractility during hemodialysis: importance of changes in the ionized calcium to plasma potassium ratio.

Hemodialysis is associated with alterations in myocardial contractility, but duration and precise determinants responsible for these changes are unknown. We investigated the effect of several variables, established to influence left ventricular (LV) contractility, which normally changed during dialysis: the plasma concentrations of ionized calcium, potassium, bicarbonate, and magnesium and the removal of uremic toxins. The influence of three different isovolemic bicarbonate-dialysis procedures in 16 patients with normal (group 1) and hypertrophied myocardium (group 2) was assessed by echocardiography prior to and up to 44 h following each dialysis. During the first procedure, ionized calcium and potassium concentration decreased, but LV performance remained unchanged in both groups. The second procedure with increased ionized calcium and decreased potassium concentration resulted in an improvement of mean circumferential fiber shortening (VCF from 1.15 to 1.56 circ/s (P less than 0.001) in group 1 and from 1.05 to 1.16 circ/s (P less than 0.05) in group 2. The positive inotropic effect declined gradually up to 12 h (group 1) and 2.5 h (group 2) respectively. In the third procedure when ionized calcium was increased and potassium concentration remained unchanged contractility did not improve. Removal of uremic toxins, decrease in magnesium, and increase in bicarbonate concentrations were comparable during each procedure. These results suggest that the ionized calcium to potassium ratio is the important determinant of dialysis-related augmentation in LV contractility. In LV hypertrophy the expected contractile response is diminished indicating a depressed inotropic state.

Adult↗
PubMed1985

Analysis of the efficacy of the new cardiotonic agent TA-064.

TA-064 is a new cardiotonic agent which is also effective orally, according to investigations conducted in Japan. We analyzed computer-assisted alterations of pressure-volume relationships serially and of indirect myocardial oxygen consumption (MVO2) estimations on line during TA-064 influence in 16 patients with congestive cardiomyopathy: left ventricular function was moderately decreased in seven patients (group A) and drastically decreased in nine (group B). Results showed that TA-064, 8 micrograms/kg/min intravenously, exerted positive inotropic effects in both groups and induced mean maximal delta percentage changes at about 5 minutes of infusion as follows: left ventricular stroke work index +65% and +47%; dP/dtmax +61% and 59%; left ventricular efficiency +62% and 53%; MVO2 +31% and +11% (p less than 0.05). TA-064, 20 mg by mouth induced serum levels (group A = 23.8 +/- 12ng/ml and group B = 26.4 +/- 20 ng/ml) corresponding to the effects with dosages of 1 to 2 ng/kg/min intravenously (p greater than 0.05), thus implying that significant changes in left ventricular function require higher oral dosages. We conclude that TA-064 improves left ventricular function, primarily via a contractility increase, also in group B patients without toxic side effects. On-line indirect MVO2 assessment and analysis of serial pressure-volume relationships helped to provide a more complex definition of the mechanism and efficiency of the cardiotonic agent under study.

Administration, Oral↗
PubMed1985

Progressive cardiac involvement by Fabry's disease despite successful renal allotransplantation.

Enzyme replacement by renal allotransplantation has been suggested as a specific mode of therapy for Fabry's disease. We report a case of Fabry's disease who developed symptoms and signs of heart failure despite successful renal transplantation 14 years ago. Echo- and angiocardiographic features resembled findings in patients with hypertrophic non-obstructive cardiomyopathy. Endomyocardial biopsy specimens demonstrated cardiac manifestation of Fabry's disease.

Biopsy↗
PubMed1985

Dialysis-induced cardiac arrhythmias: fact or fiction? Importance of preexisting cardiac disease in the induction of arrhythmias during renal replacement therapy.

Frequency and grade of premature ventricular depolarizations were assessed in 10 patients on maintenance renal replacement therapy. All medication was withdrawn prior to the study. Each patient was treated sequentially by 8 different methods [acetate and bicarbonate hemodialysis (HD), hemofiltration, hemodiafiltration, ultrafiltration, use of 5 different membranes]. Despite marked changes in serum electrolyte concentrations there was no difference in frequency or grade of premature ventricular beats between the periods before, during, and after renal replacement therapy. Comparison of the 8 methods tested revealed no superiority of 1 method during the observation period of 192 h for each patient. In a second group of 8 patients with confirmed coronary artery disease, acetate HD had no effect on grade and frequency of ventricular arrhythmias, although arrhythmias occurred more often (p less than 0.05) and were more dangerous. We therefore conclude that the incidence of ventricular arrhythmias is primarily dependant on the presence of preexisting coronary artery disease and that HD or related methods do not increase the risk of ventricular ectopies in patients without digitalis medication.

Adult↗
PubMed1985

[Acute post-traumatic cholecystitis. Caused by or following polytrauma?].

Traumatic acute cholecystitis is of secondary importance beside many other complications in the polytraumatised patient, since it is rarely diagnosed--possibly too rarely. Difficulties often arise because of a multitude of injuries, which are often life-threatening and which must be given top priority (3). Men are chiefly involved (4). In most cases, the condition is preceded by shock, but not necessarily by gallstones (10, 11). First pointers in literature were given by Mennenga (8). As early as 1939 he pointed out that blunt abdominal trauma may produce tears in the gallbladder and bile duct regions. Marre (7) described acute signs in the upper abdomen due to rupture of the bile duct. Genesis of post-traumatic acute cholecystitis is still unclarified. Apart from rupture or perforation of the gallbladder or bile ducts, it is mainly shock (4, 9, 12) which is considered to be an important causative factor.

Abdominal Injuries↗