Biomedical subjects

D T Popescu

Publications and source records attributed to D T Popescu.

8 recordsLinked to original sources

PubMed1981

Pharmacokinetics of etomidate in surgical patients.

Eight adult surgical patients received a single i.v. injection of etomidate-base (mean 0.22 mg.kg(-1)). Venous blood samples were drawn at frequent intervals for up to 10 hr following drug administration. Plasma concentrations of etomidate were measured with a newly developed capillary gas chromatographic method. Plasma concentrations fitted best to an open three compartment pharmacokinetic model by a non-linear regression computer programme. The following mean parameters were computed: distribution half-life 2.8 + or - 2.3 min, half-life of the alpha-phase: 22.3 +or - 10.4 min and half-life of the beta-phase 208.8 + or - 64.9 min, distribution volume 3.68 + or - 0.66 l.kg(-1) (Vd area) and 2.16 l.kg(-1) (Vdss) and plasma clearance 879 + or - 135 ml.min(-1). High tissue uptake is indicated by the rapidity and the large volume of distribution. Etomidate is rapidly redistributed from the central to peripheral compartments and rapidly eliminated by metabolism.

Adult↗

PubMed1977

Althesin (alphadione, CT 1341) a 'new' induction agent for anesthesia.

Althesin (alphadione) is a hypnotic agent introduced in the U.K. a few years ago by the firm of Glaxo. It is mixture of two steroids: alphaxalone 9 mg per ml and alphadolone 3 mg per ml, in solution in cremophore EL. After a concise review of the history of steroid anesthetics, the pharmacology of the new product is described. In a personal investigation, Althesin was used to induce anesthesia in 100 patients. The dose equivalent with thiopentone was determined first. It was found to amount to 52 microliter per kg corresponding to 3 mg per kg of thiopentone. A separate form was completed for each individual patient, to record the side effects, if any. The pulse and blood pressure were checked once a minute after the induction (for 5 minutes). In 8 patients the following parameters were recorded: plethysmogram, ECG, central venous pressure, pulse rhythm arterial pressure, stroke volume and cardiac output. Compared with thiopentone, Althesin is not significantly worse, but neither does it present any advantages where the circulatory parameters determined are concerned. In view of this and the recent publication concerning hypersensitivity reactions, we have ceased to use this hypnotic agent in our department.

Aged↗

PubMed1976

Clinical study of althesin and hypnomidate.

A simple clinical and a more elaborate instrumental study are presented on the cardio-circulatory action of Althesine and Etomidate (Hypnomidate) compared to thiopental (Pentothal). Statistically is Althesin not significantly worse than thiopental but significantly worse than Hypnomidate. Hypnomidate is less aggressive than thiopental although non significantly. Succinylcholine (1 mg/kg) aggravates the heart depressant actions of the tested drugs, while the intubation of the trachea produces sometimes a serious pressor response which can not be always blocked by prior administration of a low dose (0.1 mg i.v.) Fentanyl.

Alfaxalone Alfadolone Mixture↗

PubMed1975

Orthotopic liver transplantation: an experimental study on the prevention of infections with Gram-negative organisms.

Infection with Gram-negative bacteria is frequently the cause of death in human liver transplantation. In experimental liver transplantation in mongrel dogs we detected Gram-negative septicaemia in 73% of our first 15 cases; maximal survival was 26 days. In a second series of 27 orthotopic liver transplantations in tissue-typed littermate dogs and littermate pigs the standard surgical technique and aftercare were changed with regard to four factors: an end-to-end common bile duct anastomosis was made instead of a gallbladder to duodenum anastomosis; the continuous postoperative bacteriostatic antibiotic therapy was changed to a single 2-day course of bactericidal antibiotics; preoperative selective bowel decontamination combined with postoperative protective isolation was introduced; the dosage of azathioprine used for immunosuppression was reduced..

Ampicillin↗

PubMed1975

Orthotopic liver transplantation: an experimental study on mechanisms of hemorrhagic diathesis and thrombosis.

The hemorrhagic diathesis after transplantation of preserved livers generally is attributed to intravascular coagulation, whereas postoperative "hypercoagulability" of the blood is considered the main cause of thrombosis of the hepatic artery anastomosis. Since our preliminary studies, however, suggested other mechanisms, parameters of coagulation, fibrinolysis, and platelet function were prospectively studied before and after 28 orthotopic liver transplantations, with and without preservation, in dogs and pigs. In addition, the arterial anastomoses were evaluated routinely by angiography and, after removal at reintervention or autopsy, inspected for thrombosis and tested for fibrinolytic activity and fibrin deposition. Concerning the hemorrhagic diathesis, prolongation of bleeding time without concomitant thrombocytopenia was the main abnormality found and occurred only in the nine dogs with liver transplants previously preserved for 3 to 6 hours. As only two of the nine dogs had postoperative hemorrhage of clinical significance, we consider surgically imperfect hemostasis facilitated by an acquired platelet dysfunction the principal cause of hemorrhage. Thrombosis of the arterial anastomosis was found in 38 percent of animals in which an end-to-end anastomosis was made but was not encountered with celiac artery-aorta anastomoses. Local factors due to surgical technique therefore appear most important in the pathogenesis of thrombosis of the hepatic artery anastomosis, although the postoperative hyperfibrinogenemia and diminished local and systemic fibrinolytic activity may contribute as well.

Animals↗

PubMed1975

Orthotopic liver transplantation after preservation without perfusion for up to six hours: A controlled trial evaluating different preservation fluids in dogs and pigs.

The important extension of the ischemic period recently described with a simple hypothermic liver preservation method is attributed to the use of specific preservation fluids. However, there is no consensus about the optimal preservation fluid. In order to investigate the effect of the composition of the preservation fluid on the immediately postoperative transplant function and on subsequent long-term survival, orthotopic liver transplantations were performed in 13 dogs and 12 pigs. To reduce immunologic interference in postoperative transplant evaluation, donor and recipient pairs always were litter mates, the dogs being identical according to lymphocyte typing. The ischemic periods were 1, 3, and 6 hours. Four different preservation fluids were used with marked differences in ionic composition (extracellular vs. intracellular), pH, and osmolarity. Within each ischemic period group the sequence of experiments was randomized with respect to the different preservation fluids. Twenty-four animals survived the transplantation procedure. No differences were found between the preservation fluid groups. Postoperative function of all livers preserved for 6 hours was comparable to those with 1 hour ischemia. Three dogs and four pigs (six of seven with livers preserved for 3 to 6 hours) are still alive more than 1 year after transplantation. So consistently excellent liver function leading to long-term survival in 36 percent of cases can be obtained after liver transplantation with preservation up to 6 hours; for this result the composition of the preservation fluid is of minor importance.

Animals↗

PubMed1974

[Local anesthesia].

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Anesthesia, Conduction↗

PubMedDate not supplied

Creatinine excretion in urine of man under hypokinesia and physical exercise.

It was assumed that creatinine loss in urine of man may increase or decrease under hypokinesia (diminished muscular activity) and physical exercise. Thus the aim of this study was to calculate creatinine excretion in urine of 12 healthy men, aged 19-23, under 100-days' exposure to hypokinesia (HK) and PE. They were divided into two groups, with 6 men in each. The 1st group of men was subjected to pure HK and the 2nd group was submitted to combined HK and PE. For the simulation of the hypokinetic effect both groups of men were kept under 100 days of ad-libitum bedrest protocol. A full nutritions diet was given to both groups of men. The creatinine excretion in urine was measured by conventional methods. By the 18th day of hypokinesia an increase in the rate of excretion of creatinine in urine was demonstrated, and by the 55th day there was a more pronounced increase in creatinine excretion. Physical exercise failed to diminish creatinine excretion. It was concluded that hypokinesia and physical exercise increased creatinine excretion in urine of man.

Adult↗