Biomedical subjects

W Buzello

Publications and source records attributed to W Buzello.

At least 73 records · Page 4Linked to original sources

PubMed1979

[The place of autotransfusion with normovolaemic haemodilution in vascular surgery (author's transl)].

The ever-increasing demand for donor blood, the risks of donor-blood transfusions and economic considerations have made the use of autotransfusion desirable. Among methods for producing autologous blood stores that of obtaining autologous blood with simultaneous normovolaemic haemodilution (using dextran 60; Macrodex 6%) 2--4 days before operation is especially practicable for elective reconstructive vascular surgery. But the same method can also be used in general surgery. Personal experience in operations on 120 patients has shown that the need for donor blood was reduced to 20% of all transfused blood. Improved flow properties of the blood by decreasing viscocity after normovolaemic haemodilution is of particular value in stages III and IV of chronic arterial occlusive disease.

Arterial Occlusive Diseases↗

PubMed1978

Comparative clinical pharmacokinetics of tubocurarine, gallamine, alcuronium and pancuronium.

Data about plasma concentration, renal and biliary elimination of tubocurarine, gallamine, alcuronium and pancuronium are taken from the literature for synoptical pharmacokinetic analysis. All plasma concentration curves can be described by triexponential functions according to an open three-compartment pharmacokinetic model in line, the elements of which are an application and measuring compartment, a pharmacologically specific compartment and a non-specific one. The corresponding results for all drugs represent the same range and there is no substantial basis for a further differentiation of clinically significant drug specific characteristics, neither regarding the time course of neuromuscular blockade nor the excretory or metabolic disposition. Thus no particular advantage or disadvantage of any drug can be stated from the kinetic or metabolic point of view and especially none seems to have a striking advantage in patients with impaired renal function. Drug specific peculiarities are more likely to be found in the field of side effects.

Alcuronium↗

PubMed1978

Kinetics of intercompartmental disposition and excretion of tubocurarine, gallamine, alcuronium and pancuronium in patients with normal and impaired renal function.

Pharmacokinetic data of tubocurarine, gallamine, alcuronium and pancuronium in patients with normal and without renal function are taken from the literature. They are adapted to an open three compartment pharmacokinetic model, and the proportional intercompartmental distribution is calculated as a function of time from 1 min to 8 h. All drugs show similar kinetic properties: During the first 10 min rapid disappearance from compartment 1 results in saturation of compartment 2. Maximum saturation of compartment 3 is achieved after 1 to 2 h followed by a gradual disappearance of the relaxants from the whole system. 20-25% of the dose undergo sequestration apart from intercompartment equilibrium. In normal individuals sequestration is observed after 2 to 3 h whereas in anuric patients it is already demonstrated during the first hour. Intercompartmental redistribution is the basic principle governing the pharmacodynamic profile of all of the four drugs if given in clinical dosage.

Alcuronium↗

PubMed1978

Pharmacokinetics of pancuronium in patients with normal and impaired renal function.

Plasma concentration curves of patients with normal and impaired renal function are fitted to a tri-exponential function according to an open three compartment pharmacokinetic model. A detailed discussion of the relationship between theoretical distribution volumes, clinical pharmacodynamics and morphological or biochemical structures provides the basis for the concept of a central application and measuring compartment, a pharmacologically specific compartment and a non specific one. The distirbution of pancuronium from the application compartment to the specific compartment results in the onset of muscular paralysis. The recovery is governed by renal elimination of the unchanged drug as well as by its redistribution into the non specific compartment. In anuric patients the spontaneous recovery after 3--4 h is the effect of redistribution only. Neither metabolic degradation nor increased biliary elimination can sufficiently compensate for the lack of the renal pathway. The clinician should always keep in mind that after the recovery from pancuronium-induced muscular paralysis, both in patients with or without renal pathology, considerable residues of the active drug are stored at nonspecific and even specific receptor sites for many hours.

Anuria↗

PubMed1976

[Serum concentrations of pancuronium in anuric patients (author's transl)].

After a single intravenous dose of 6 mg serum concentrations of pancuronium were measured in 6 anuric patients by means of the bromophenol blue colorimetric method at 1, 5, 45 min and 3 h. After 45 min and 3 h there was a retention of 1.7 and 4 times the control values respectively. The prolongation of pancuronium induced muscular paralysis which has been demonstrated by other authors now can definitely be related to elevated serum concentrations of the active drug. The termination of muscle relaxation in anuric patients is considered merely to be due to redistribution of the drug from the motor end plates to non specific structures. Prolonged neuromuscular blockade may occur in as much as the redistribution mechanism is overloaded by inadequate doses.

Adult↗

PubMed1975

[The metabolism of pancuronium in man].

The metabolic disposition of pancuronium was investigated in man under clinical condition. Pancuronium and its desacetylated derivatives were determined in body fluids using the previously described bromophenol blue method (3). The metabolites were isolated by thin layer chromatography. One minute after the intravenous injection of a mg of pancuronium the drug reaches a serum concentration of 2,2 plus or minus 0,2mug/ml. As an exponential function the concentration curve then falls to half of the initial value during the first 30 to 60 min. The end of the neuromuscular block conincides with a concentration of 0,1 to 0,3 mug/ml serum which is reached about 2 hours after the injection. After 3 to 4 hours no more pancuronium can be detected in the serum. The renal elimination of pancuronium can be folowed up for 12 hours. On average half of the injected dose is recovered in the urine. 80% of this proportion is unchanged pancuronium and 20% desacetylated metabolites. The monodesacetylated derivatives of pancuronium are still pharmacologically active. The biliary excretion 24 hours after the administration of pancuronium accounts for 5 to 10% of the injected dose...

Bile↗

PubMed1975

[The influence of ethrane on the electro- and pentylenetetrazol-convulsions in mice (author's transl)].

The influence of Ethrane upon electro shock and pentylenetetrazol-induced convulsions was studied in mice. Similar to other inhalation anaesthetics and to barbiturates Ethrane exerts a powerful anticonvulsive activity. There is a dose response relationship between the rate of electro shock (20 mA/0.2 sec) induced convulsions and inspiratory Ethrane concentration, convulsions being completely prevented by 1.5 vol.-percent of Ethrane. The LD(50) of pentylentetrazol increases five fold under a 2 vol.-percent Ethrane anaesthesia.

Anesthesia, Inhalation↗

PubMed1974