Biomedical subjects

N Friedel

Publications and source records attributed to N Friedel.

26 records · Page 2Linked to original sources

PubMed1991

Patient selection for mechanical circulatory support as a bridge to cardiac transplantation.

Between 7/87 and 9/90 thirty-four patients underwent total artificial heart (Berlin Heart) (n = 2) or biventricular assist device (Berlin Heart) (n = 32) implantation as a bridge to cardiac transplantation. The time of mechanical support ranged from 2 to 60 days, for a mean of 19.2 days. Twenty-three patients received heart transplants, with 74% 30-day survival and 52% long-term survival. Implantation of a mechanical support system became indicated in those patients whose hemodynamic and clinical condition deteriorated despite treatment with enoximone in addition to maximal sympathomimetic medication. The strategy to administer enoximone routinely was the result of a prospective study on 24 pretransplant patients in whom enoximone therapy reduced the need for mechanical assistance by 62%. At the time of device implantation shock-related organ impairment such as cerebral, renal, hepatic, and respiratory dysfunction was present in 62% of patients. In addition, 7 patients had pneumonia. During mechanical support complete recovery of end-organ failure and resolution of pneumonia was observed in the majority of patients. The results indicate that end-organ dysfunction per se should not be considered a contraindication to mechanical circulatory support as a bridge to cardiac transplantation. However, further clinical investigations are needed to identify predictive indicators of irreversible organ damage.

Adult↗

PubMed1991

[Enoximone as pharmacologic "bridging" to heart transplantation].

The efficacy of enoximone (EN), a new phosphodiesterase inhibitor, was studied in 24 patients (pts.) with end-stage cardiac disease due to dilative cardiomyopathy (21 pts.) or coronary heart disease (3 pts.). All pts. admitted for urgent transplantation or mechanical circulatory support demonstrated advanced cardiac failure unresponsive to conventional pharmacotherapy. Despite maximal catecholamine and vasodilator therapy the cardiac index averaged 2.08 l/min per m2, the pulmonary capillary wedge pressure (PCWP) 24 mmHg, and the systemic vascular resistance (SVR) 1450 dyn* s* cm-5. In addition to the previous sympathomimetic medication EN was administered as a bolus injection of 1 mg/kg followed by a continuous infusion of 4 to 10 micrograms/kg/min. In all but 4 non-responding pts., who eventually died, clinical and hemodynamic conditions improved significantly within 4 h: CI increased from 2.08 to 3.1 l/min/m2, PCWP dropped from 24 to 17 mmHg, and SVR decreased from 1450 to 950 dyn* s* cm-5 (all p less than 0.05). After initial improvement, 9 pts. experienced acute hemodynamic and clinical deterioration leading to implantation of a biventricular-assist device (Berlin Heart) in 6 pts., while 3 pts. died of irreversible cardiogenic shock. However, of the remaining 15 pts., who demonstrated sustained hemodynamic improvement, 11 could be weaned off their adrenergic medication and remained on oral EN (1.0 to 1.5 mg/kg TID). Three pts. received heart transplants within 8 to 12 weeks; 7 pts. were still on the waiting list at the end of the study, and 1 pt. died after withdrawal of oral EN.2

Adolescent↗

PubMed1986

[Attempt at classification in patients with peritonitis--evaluation of 53 patients].

Classification is necessary when comparing and judging the results of the treatment of patients with peritonitis. Staging of peritonitis was developed according to interoperative findings. The spreading and age of peritonitis has been considered when contemplating further operative management. In order to judge the general clinical picture, a grading of severity into three groups, using a point scheme, was developed. 22 patients with localised peritonitis in an advanced stage received a closed peritoneal lavage. 31 patients with generalised peritonitis received continual open dorsoventral peritoneal lavage.

Drainage↗

PubMed1983

Effect of antrectomy on small intestinal structure and function in the rat.

Antrectomy reduced the levels of circulating gastrin but did not change jejunal morphology. In vitro and in vivo absorption as well as the activity of some brush border enzymes were increased. The observed alterations are discussed on the basis of antrectomy-induced alterations in the release of gastrointestinal hormones, gastric and pancreatic secretion and gastric emptying.

Animals↗

PubMedDate not supplied

Mechanical circulatory support and heart transplantation. Pre-operative status and outcome.

Between July 1988 and December 1993, 118 patients waiting for heart transplantation underwent mechanical circulatory support by an extracorporeal, pneumatically driven assist device (the Berlin Heart System) to maintain a sufficient circulation and to restore impaired organ function (109 patients requiring a biventricular assist device [BVAD], 9 patients requiring a left ventricular assist device [LVAD]). Before implantation, all patients were in severe cardiogenic shock, despite maximum inotropic support; all had end organ failure. The aim of a retrospective study in 70 patients (for whom pre-operative parameters were available) was to identify patients who would permit from this procedure and could undergo successful transplantation. After a mean bridging time of 34.8 days, 75 (63.5%) patients underwent transplant, and 52 (44.1%) were discharged. Pre-operative coagulation parameters (fibrinogen, antithrombin III, platelet count, and kinetics) were correlated to post-operative blood loss and outcome. Patients who had no or mild coagulation disorders because of a shorter phase of low cardiac output before implantation of the assist device proved to gain faster restitution of organ function and most underwent transplantation. As a result of these observations, implantation of an assist device before shock-induced coagulopathy could occur allowed a greater number of patients to undergo successful bridging and be discharged after heart transplantation.

Adolescent↗

PubMedDate not supplied

Effects of the Berlin Heart biventricular assist device on microvascular responses in pre-transplant patients.

Microcirculatory forearm cutaneous blood flow was monitored continuously and noninvasively by laser doppler flow-metry (LDF) in 15 patients treated with the Berlin Heart biventricular assist device system (BVAD) for end-stage heart failure under stable hemodynamic states (BVAD pts, n = 10) and norepinephrine therapy (BVAD nor pts, n = 5). Ten healthy human subjects served as controls (C). Cutaneous blood flow was measured before, during, and after external brachial artery occlusion to evaluate the post-occlusive reactive hyperemia (PORH) as a standardized response. To examine microvascular responses to macrohemodynamic changes, the cardiac output (CO) was decreased by a 20% reduction in BVAD pump rate. No significant differences in baseline LDF measurements (in millivolts) were observed among the three groups (C, 470.7 mV +/- 177.3; BVAD pts, 328.0 mV +/- 122.7; BVAD nor pts, 360.0 mV +/- 160.0). After cuff pressure release (1 min later), a significant (p < 0.004) three-fold to four-fold blood flow increase (PORH) occurred in each group (C, 1113.6 mV +/- 469.2; BVAD pts, 813.0 mV +/- 190.1; BVAD nor pts, 498.0 mV +/- 191.8). The difference in PORH between the BVAD pts and BVAD nor pts was significant (p < 0.01), and the time to peak PORH values was different (p < 0.05) among the three groups (C, 22.2 s +/- 10.7; BVAD pts, 11.3 s +/- 12.5; BVAD nor pts, 7.0 s +/- 5.8). A markedly delayed return to baseline occurred in the BVAD pts. The 20% reduction in BVAD pump rate decreased CO significantly (p < 0.05) and increased (p < 0.01) systemic vascular resistance (SVR).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMedDate not supplied

Mechanical circulatory support and heart transplantation.

Mechanical circulatory support systems are currently in clinical use to keep patients alive with the aim of either cardiac recovery after open heart surgery, myocardial infarction and after heart transplantation with acute graft failure, or as a bridge to transplantation in heart transplant candidates. At the German Heart Institute the "Berlin Heart" mechanical circulatory support system has been used invariably since 1987. Up to 1991 there were 22 patients in the "recovery" group. Four patients could be weaned from the system, but only one patient was discharged from the hospital. In 65 patients mechanical circulatory support systems were implanted as a bridge to transplantation, 39 patients had transplants, and 22 patients left the hospital. Risk factor analysis in the bridging group revealed that previous heart surgery, infective pneumonia, shock-related coagulation disorders, and an age greater than 50 years had an unfavorable influence on patient survival. It is concluded that patients may be kept alive for weeks and months after any kind of cardiogenic shock. Complete cardiac recovery may be achieved in the case of early posttransplant graft failure. Reliable prediction of outcome in the bridge to transplantation group requires further experience.

Female↗

PubMedDate not supplied

Clinical use of the Berlin Biventricular Assist Device as a bridge to transplantation.

The Berlin Artificial Heart System/Biventricular Assist Device (BVAD) was used in 38 patients. 1) Twenty-eight patients were awaiting cardiac transplantation (Tx) (age 23-56 yrs). All patients had contraindications not allowing immediate Tx. 2) Five patients were emergency cases not on our Tx list (postcardiotomy cardiac failure, acute myocarditis) (age 28-59). 3) Five patients were post Tx patients with graft failure (age 22-52). Extracorporal circulation was used for implantation of the BVAD. In group 1, 21 of 28 patients (pts) recovered, and all were subsequently transplanted after 6 hours to 39 days, when all organ function was restored. In 7 pts, mechanical circulation was terminated after 1-40 days because of further deterioration. Five of the transplanted pts died, 14 pts survived (greater than 30 days), and 2 pts were just transplanted with satisfactory postoperative courses. Of group 2 and 3 pts, two were successfully weaned. In one patient the allograft recovered after 11 days of support.

Cardiac Output↗