Biomedical subjects

P Urbanek

Publications and source records attributed to P Urbanek.

6 recordsLinked to original sources

PubMed2001

Significant reduction of air microbubbles with the dynamic bubble trap during cardiopulmonary bypass.

Air microbubbles mostly occur unnoticed during cardiopulmonary bypass and are predominantly responsible for serious postoperative psychoneurological dysfunction. A dynamic bubble trap (DBT), which removes air microbubbles from the arterial blood, was tested in a clinical study. The aim was to evaluate the efficiency of microbubble removal under clinical conditions. As blood passes through the DBT, which is placed in the arterial line between the arterial filter and arterial cannula, it is converted into a rotating stream. The bubbles are directed to the centre of the blood flow and are collected in the distal end of the DBT, from where they are returned to the cardiotomy reservoir. Doppler ultrasonography was used to detect the microbubbles before and after the DBT, and also the number of high-intensity transient signals (HITS) in the right and left middle cerebral artery during extracorporeal circulation. A significant reduction of microbubbles in the arterial line (3,990 before DBT, 537 after, p < 0.001) and HITS in the brain (51 in the DBT group, 77 in the placebo group, p = 0.04) was measured.

Adult↗

PubMed2000

A dynamic bubble trap reduces microbubbles during cardiopulmonary bypass: a case study.

Microemboli passing to the cerebral circulation during cardiopulmonary bypass can contribute to postoperative neurologic dysfunction. Many studies conclude that air microbubbles predominantly are responsible for this problem. A dynamic bubble trap (DBT) was developed to diminish the number of microbubbles in the arterial line of extracorporeal circulation. The DBT is able to substantially reduce the number of air microbubbles, as shown in two patients undergoing coronary artery bypass grafting, where a high number of microbubbles was assessed. Although a 40-micron arterial filter was used, many bubbles larger than 40 microns occurred in the arterial line. The DBT reduced the number of large microbubbles from 2,267 to 67 in patient 1 and from 897 to 61 in patient 2.

Aged↗

PubMed1994

Percutaneous cardiopulmonary support (PCPS).

The cardiopulmonary support system allows to maintain the patient's cardiac and pulmonary functions when the patient's cardiac or pulmonary status is failing. This system consists of a centrifugal pump with its control system, membrane oxygenator, measure devices for blood flow and pressure and a heating system for temperature conditioning of blood. The percutaneous application is easy and fast. Rapid priming, rapid insertion and high flow rates are characteristic for this method. The material costs for cardiac support of one patient are high, the price for one patient amounts to approximately DM 3,500. For the application the presence of an operating cardiologist, an anesthetist and a perfusionist is necessary.

Blood Flow Velocity↗

PubMed1992

Diminished release of atrial natriuretic factor in calves with a total artificial heart.

Venous hypertension after total artificial heart (TAH) replacement, a common problem in humans as well as experimental animals, is thought to be related to reduced release of atrial natriuretic factor (ANF) due to atrial damage. To verify this hypothesis, we stimulated the release of ANF in 6 calves before (-7 days) and after TAH replacement (+25, +50, +80, and +100 days) by the rapid (+ = 10 min) infusion of 2 L of Ringer's solution. In normal calves (-7 days) this procedure induced a rise in plasma concentration of ANF from 18.5 +/- 12 to 31.6 +/- 12 pmol/L (p < 0.05). After TAH the ANF release continuously decreased (analysis of variance, p < 0.02). Thus, ANF increased by 9.8 +/- 9.3, 6.8 +/- 17.5, 0.4 +/- 5.2, and 0.5 +/- 3.2 pmol/L at days 25, 50, 80, and 100, respectively. The central venous pressure increased by 3.4 +/- 1.5 mm Hg (before TAH) and by 6 +/- 2.9 mm Hg (after TAH) during this procedure. A decrease in plasma concentrations of aldosterone, most likely due to extracellular volume expansion and a decrease in total protein plasma concentrations and in hematocrit due to the dilution of blood, was seen in each experiment. Necropsy demonstrated massive atrial dilatation and myocardial dystrophy with atrial fibrosis. ANF granules were present to a small extent in every calf. We conclude that rapid intravenous infusion is an adequate stimulus to release ANF in normal calves. After TAH implantation the release of ANF by high venous pressure declines although ANF granules are still present in the damaged atrial stumps. Therefore, the loss of stimulated ANF could contribute to the observed increase in venous pressure in TAH calves although other pathophysiologic mechanisms cannot be excluded.

Aldosterone↗

PubMedDate not supplied

Intraluminal brachytherapy and selfexpandable stents in nonresectable biliary malignancies--the question of long-term palliation.

BACKGROUND/AIMS: To evaluate the effect of a combination of intraluminal brachytherapy and metallic stent implantation in the treatment of patients with nonresectable biliary tumors. METHODOLOGY: Thirty-two patients aged 41-80 years with nonresectable biliary malignancies--Klatskin's tumor (n = 17), gallbladder carcinoma (n = 11) and carcinoma of papilla Vateri (n = 4)--were treated with a combination of intraluminal brachytherapy (source Ir192, high-dose radiation regimen, total dose 30 Gy) and metallic stent implantation. Intraluminal brachytherapy and stent insertion (metallic, spiral-Z stent) were performed percutaneously in all patients. RESULTS: The mean survival in patients with Klatskin's tumor was 457 days (range: 64-1186; median: 358 days), in patients with gallbladder carcinoma 237 days (range: 92-609; median: 210 days) and in patients with carcinoma of papilla Vateri 850 days (range: 48-1518; median: 1277 days). The rate of 2-year survival in these groups as 27, 0 and 50%, respectively. The survival time differed significantly at the 5% level. The mean time of stent patency was 418, 220 and 850 days, respectively. No complications related directly to intraluminal brachytherapy were observed. CONCLUSIONS: Intraluminal brachytherapy combined with stent implantation is a safe method and appears to prolong survival in inoperable patients with Klatskin's tumor and carcinoma of papilla Vateri compared with nontreated patients in previous studies. In contrast no similar effect should be expected in patients with gallbladder carcinoma.

Adult↗

PubMedDate not supplied

Double-blind randomized, comparative multicenter study of the effect of terlipressin in the treatment of acute esophageal variceal and/or hypertensive gastropathy bleeding.

BACKGROUND/AIMS: 1) To compare the effect of 2-day application of 0.2 mg terlipressin i.v. every 4 hours (group I) with that of 5-day application of 1 mg i.v. every 4 hours (group II) in the treatment of bleeding esophageal varices and portal gastropathy. 2) To assess the incidence of adverse events. METHODOLOGY: Eighty-six patients with liver cirrhosis (54 men and 32 women, average age 51 years) were randomized over a period of 2 years into 2 groups. Acute bleeding was diagnosed endoscopically within 24 hours of its onset. The two groups fully comparable; treatment failure rated according to "Baveno II". RESULTS: Success rate in group I was 78% at day 2 and 75% at day 5; in group II 89% and 79%, respectively (no statistical significance). Rebleeding had occurred by day 5 in 15% in group I, and in 16.3% in group II. Transfusion needs by day 2 were significantly lower in group II (2.4 units compare to 3.4 units in I). The 30-day mortality was 17.1% in group I and 20% in group II. No statistical difference between I and II in the occurrence of adverse events. CONCLUSIONS: At a dosage of 1 mg i.v. every 4 hours, the success rate at day 2 was as much as 90% while blood consumption was significantly lower compared with the lower dosage. Rebleeding during first 48 hours occurred almost exclusively at lower dosage. There was no increase in the rate of adverse events relative to the higher dosage.

Acute Disease↗