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Biomedical subjects

A Hellinger

Publications and source records attributed to A Hellinger.

26 records · Page 2Linked to original sources

Evidence for increased nitric oxide production after liver transplantation in humans.

To evaluate the role of in vivo-produced nitric oxide (NO) after orthotopic liver transplantation, nitrate, a stable end product of spontaneous NO conversion in blood, was assayed in plasma samples of 32 patients. In 31 patients, nitrate increased from 36 +/- 2 microM to 137 +/- 8 microM within the first 6 postoperative days. In 11 out of 12 patients with an uneventful early postoperative course, nitrate increased from 33 +/- 2 microM to 70 +/- 8 microM, and returned to baseline levels within 2-3 days. In the remaining 20 patients with episodes of rejection and/or infection, the nitrate peak was augmented and prolonged. Ten patients suffering from these events in the later postoperative course showed a second nitrate elevation. In 31 patients, effective plasma levels of cyclosporine were reached 4-5 days after OLT. The patient without significant elevation in plasma nitrate had effective levels already at day 1. After liver resection or coronary bypass grafting, the median nitrate level remained at 21 microM (range 15-36 microM; healthy persons: median 24 microM, range 18-32 microM). After kidney transplantation nitrate was elevated in the early postoperative course. Thus, NO formation appears to be increased after solid organ transplantation, but not after other surgeries. After OLT, the increase appears to occur (a) in response to rejection and/or infection, and (b) 4-6 days after surgery in the absence of overt complications. In the latter case, NO might be involved in subclinical rejection and its production is possibly dependent upon the effectiveness of the immunosuppressive therapy.

Cyclosporine↗

Elimination of amrinone during continuous veno-venous haemofiltration after cardiac surgery.

We studied the elimination of amrinone during continuous veno-venous haemofiltration (CVVHF) in three anuric patients after cardiac surgery. The patients had developed low cardiac output followed by acute prerenal failure. Plasma amrinone levels measured by HPLC were fitted to a two-compartment model. We found significant amrinone clearance, with a mean sieving coefficient (S) of 0.44%, which correlates with the protein-unbound, pharmacologically effective fraction of amrinone. The AUC of the arterial plasma concentration-time curve was decreased by 49.8%. All pharmacokinetic parameters showed wide interindividual variation. To ensure the therapeutic effect of amrinone and to avoid toxic adverse effects monitoring of plasma amrinone levels is necessary.

Amrinone↗

A new technique for reconstruction of the common bile duct after severe injury by laparoscopic cholecystectomy.

Laparoscopic cholecystectomy involves a higher incidence of severe common bile duct injury than did open cholecystectomy. The severe injuries most often result from technical problems and inadequate exposure. Reconstruction of the bile duct is then possible provided that an immediate diagnosis is made and an appropriate surgical technique is applied. The report focuses on a new method of reconstruction of the common bile duct by interposition of a small jejunal conduit. The procedure was performed in five patients with severe bile duct injury (Bismuth class 3-4) that occurred during laparoscopic cholecystectomy. The outcome after follow-up periods of 9 months to more than 2 years is promising. This method of reconstruction is therefore recommended for severe forms of bile duct injury.

Adult↗

Does lung contusion affect both the traumatized and the noninjured lung parenchyma? A morphological and morphometric study in the pig.

Isolated unilateral lung contusion (LC) was induced in 12 pigs to determine the pathophysiological role of LC in the high mortality after multiple injury. The Horovitz quotient, pulmonary vascular resistance, mean pulmonary artery pressure, mixed venous oxygen consumption, inspiratory pressure and compliance were significantly decreased in the LC group as compared to controls. The number of polymorphonuclear granulocytes, the microvascular permeability of albumine and the Wilhelmy balance as determined by bronchoalveolar lavage were significantly increased after lung contusion. As indicators of a systemic reaction we found elevated plasma levels of the terminal complement complex and decreased levels of the complement factor 3a after LC. The morphological assessment revealed changes such as those encountered during the early phase of adult respiratory distress syndrome, with granulocyte sticking, endothelial cell adhesion and transendothelial diapedesis. Morphometric analysis demonstrated a significant decrease in alveolar diameter in both the injured and the contralateral lung due to impaired surfactant surface activity. A distinct increase in septal diameter, related to edema and caused by increased microvascular permeability, was found in the injured lungs. These findings emphasize that LC leads to a generalized impairment of the entire lung, which may lead to progressive lung failure.

Albumins↗

Morphometry of experimental lung contusion: an improved quantitative method.

Alterations of lung tissue following pulmonary contusion are mainly assessed qualitatively. Quantitative examinations were limited up to now, to investigations in X-ray and computer tomography images, since morphometry of contused and normal biotic lung tissues seemed to be methodologically unfeasible. In order to overcome this shortcoming, the lungs of pigs were examined after unilateral lung contusion. In semithin sections, the thickness distribution of the interstitium and the volume distribution of the alveolar cavities were studied. Using an image analysis system a sequence of detection, erosion and skeletonisation steps were used to recognize the septal tissue correctly. The percent distributions were calculated from chord measurements after a sequence of erosion steps. It turned out that this technically simple procedure enabled highly reliable and valid results to be obtained, concerning the morphometric analysis of the alterations in the contused, as well as in the non-injured lungs.

Animals↗

[The concept of lung and heart-lung preservation within the scope of multiple organ procurement].

Preservation of the lung is still one of the most challenging problems, because due to limited procurement time not all organs available can be used. The most common procurement technique is flush perfusion of the pulmonary artery system. Alternative methods in clinical use are either the autologous working heart-lung preparation or donor core-cooling (DCC). The own concept presented here, modified to the special demands of multi-organ-procurement, combines DCC and interstitial equilibration adapted to intracellular ion concentration. DCC is induced by extracorporeal circulation (ECC) using a transportable heart lung machine including a highly effective cooling system: cooling circuit based on two parallel heat exchangers with ice-water cooling produced by a high-pressure overflow of a low-temperature ice block (-40 degrees C). While cooling by ECC stepwise hemodilution is achieved by priming volume and incorporation of the cardioplegic solution (Bretschneider-HTK). The aim of equilibration is to lower the extracellular levels of sodium and calcium, and to increase the level of potassium. Additionally, the buffer capacity of donor blood is increased by the incorporated histidine-buffer system (alpha-stat). To avoid donor organ edema the time of ECC should be as short as possible. Using our system donor organ temperatures below 10 degrees C are reached within less than 30 min. In addition to ECC, lung surface cooling is achieved by external overflow with cold arterial blood (internal mammary artery). Besides lung preservation the main advantage of this concept is the profound precooling of all visceral organs before their individual flush perfusion.

Animals↗

[Therapeutic concepts in treatment of circulatory and heart failure in surgery].

Perioperative circulatory disorders in patients may take the form of a transitory reduction in oxygen transport to the peripheral tissues (pre-shock), manifest circulatory insufficiency in the presence or absence of concomitant heart insufficiency or general congestive heart failure due to the destabilization of an preexisting heart disease. The least problematical stage in this programme of therapy is the treatment of transitory perioperative circulatory insufficiency by manipulation of the oxygen transport system using the following means: comparative volume optimization [according to the central venous pressure (CVP)], positive inotropic support with dobutamine (5-10 micrograms.kg-1.min-1), monitoring of the blood pressure, heart rate and oxygen consumption and, in severe cases, insertion of a Swan-Ganz catheter. In manifest circulatory insufficiency, sepsis or acute congestive heart failure, the Swan-Ganz catheter seems to be obligatory. In such cases, the positive inotropic therapy is based on catecholamines of medium (dobutamine) or high (epinephrine) positive inotropic efficacy, as a normal pattern and functioning of beta-adrenoceptors can be assumed in such cases if there is no history of cardiac insufficiency. The systemic vascular resistance (SVR) is adjusted to 800-1200 n.s.cm-5 to relieve the working capacity of the heart and to maintain sufficient perfusion pressure by means of constrictors (phenylephrine, norepinephrine) or dilators [nifedipine, nitroglycerin or, if necessary, angiotensin-converting-enzyme (ACE) inhibitors].(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Output, Low↗

Management of nephroblastoma with intracardiac extension: three case reports and review of the literature.

A single institution's experience of three patients with nephroblastoma extending via the inferior vena cava to the right heart is described. The case reports and the pertinent literature illustrate that preoperative failure to detect the intracardial extension increases the risk of right outflow obstruction and pulmonary embolism during or after surgery. Simultaneous thoraco-abdominal surgery with total circulatory arrest is advocated to remove the cardiac and caval tumor together with the primary tumor in order to prevent sudden hemodynamic and embolic complications. Noninvasive diagnostic methods usually suffice to detect this rare complication of nephroblastoma and to plan an interdisciplinary surgical procedure. The presence of this complication should not worsen the stage- and histology-related prognosis of the patient.

Child, Preschool↗