31P NMR measurement of ATP synthesis rate in perfused intact rat hearts.

Using 31P NMR and the saturation-transfer method, the unidirectional rate of ATP synthesis was measured in isolated, Langendorff-perfused, isovolumic rat hearts operating at a rate pressure product of 25.6 +/- 2.5 (SE) X 10(3) mmHg X min-1 and consuming O2 at a rate of 35 +/- 2 mumol O2 X min-1 X (g dry wt)-1, at 37 degrees C. This rate was 7.2 +/- 0.9 mumol X s-1 X (g dry wt)-1 and was related to the rate of oxygen atom consumption by a ratio of 6.3 +/- 0.9. These data show that in the intact heart the unidirectional rate of ATP synthesis exceeds the net rate of ATP synthesis and consumption by approximately a factor of 2.

Scheduled reoperations (etappenlavage) for diffuse peritonitis.

Etappenlavage, a new concept of scheduled multiple laparotomies with abdominal lavage for diffuse peritonitis, has been in use since 1979. The purpose of etappenlavage is to ensure exclusion of the infected source, promote maximal elimination of toxic necrotic material, and allow prompt recognition of complications to effect immediate repair. Patients with diffuse peritonitis at high risk of developing multiple system organ failure (as assessed by high scores in the Peritonitis Index Altona and Acute Physiology and Chronic Health Evaluation classifications) were routinely reexplored on a daily basis until evidence of improvement or healing was noted. From 1980 to 1984, 61 patients with intra-abdominal sepsis were treated. Thirty-four cases were due to spontaneous perforation of an intestinal viscus, and 27 cases were secondary to postoperative infections. In 51 cases the primary process was present for more than 48 hours. A total of 235 etappenlavages were performed (mean, 3.9 per patient). In ten cases, additional bowel lacerations were noted and repaired at the second laparotomy. In the last 31 patients, closure with a zipper has facilitated reoperation. No drains were used. After definitive closure, primary wound healing was seen in 79% of cases. The overall mortality in this high-risk group was 22.9%.

Clinical considerations of cardiac transplantation in organ transplantation: preoperative and postoperative evaluation.

Cardiac transplantation is being performed with increasing frequency worldwide; over 840 transplants were performed in 1985. All facets of cardiac transplantation are reviewed, including preoperative evaluation of both recipients and donors, technical aspects of the surgical procedure, and postoperative care of the recipient. Immunosuppression, complications, and long-term statistics are also reviewed. Particular care is taken to discuss pertinent radiographic studies as they apply to cardiac transplantation.

Multiple ex vivo organ preservation with warm whole blood.

To determine the feasibility of en bloc removal of the heart, lungs, liver, kidneys, and pancreas for preservation with warm blood autoperfusion, organs from 34 dogs were preserved ex vivo for periods of between 3 and 22 hours. The lungs were ventilated with a Bird Mark 7 respirator, and the heart served as the pump to perfuse all organs of the multiple organ block. In the first group of 28 animals, surgical and pharmacologic techniques were developed to permit management of the ex vivo model. The last six experiments were conducted in a standardized fashion for a period of 6 hours and evaluated on the basis of hemodynamic, biochemical, and pathologic measurements. In this group the pH level remained stable and blood gas levels remained within normal limits for inspired oxygen of 0.2. Serum and urine electrolyte levels were easily maintained within normal limits. Serum enzyme values were elevated initially after operation, and this increase persisted throughout the preservation period in most animals. Continuing refinements in surgical technique, pharmacologic management, and chamber development resulted in a dramatic reduction of the edema and organ damage seen on pathologic studies of the initial experiments. The presence of focal lymphatic congestion, however, was noted even in the animals in group II and may have been related to ligation of major lymphatic channels or to endothelial loss. These changes could contribute to the development of the pathologic changes seen in irreversible shock. Preservation of the multiple organ block by warm autoperfusion is an important step in understanding the physiology of organ preservation and has potential for permitting prolonged organ preservation. Studies are continuing to further analyze this model and prolong the time of preservation. Final assessment of the model will be transplantation of the preserved organs and evaluation of function after implantation.

Reduction of infectious complications following heart transplantation with triple-drug immunotherapy.

Infection remains the major cause of mortality and is a significant source of morbidity following heart transplantation. Between March 1978 and March 1986, 62 orthotopic heart transplants were performed at the University of Minnesota. There were 56 clinically significant infectious episodes in 31 of the 58 patients surviving the perioperative period. The era I (1978-1982) experience with antilymphocyte globulin, prednisone, and azathioprine and the era II (1982-1983) experience with high-dose cyclosporine and prednisone were associated with a high incidence of cytomegalovirus and fungal infections. The conversion to low-dose triple-drug immunosuppression with cyclosporine, prednisone, and azathioprine in 1983 (era III) has markedly reduced infectious deaths and altered the spectrum of clinical infection by decreasing serious fungal and cytomegalovirus infections. This protocol has also significantly reduced the incidence of rejection. The reduction of infection and rejection complications with triple-drug immunosuppression has led to improved patient survival of 94% at 1 year and 87% at 2 years.