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Biomedical subjects

J Eugene

Publications and source records attributed to J Eugene.

At least 37 records · Page 2Linked to original sources
PubMed1985

Dissociation of adrenal androgen and cortisol levels in acute stress.

Patients recovering from acute surgical stress often excrete increased 17-OH corticosteroids with no change in 17-ketosteroids. The explanation for these findings is unclear. In order to investigate possible divergence between cortisol and adrenal androgen metabolism in acute stress, repeated morning cortisol and dehydroepiandrosterone (DHA) measurements were made in patients undergoing ACTH stimulation 48 to 96 hours preoperatively, followed by determinations before and during major surgery, also performed in the morning. Cortisol and DHA are largely metabolized by the liver, so liver blood flow under a constant general anesthetic regimen known not to affect cortisol metabolism was monitored by pre- and intraoperative indocyanine green dye clearance. Results indicated no difference between the cortisol and DHA stimulation resulting from two hours of ACTH stimulation or major surgery, and a small (14.4%) decline in hepatic blood flow during general anesthesia. However, while DHA concentrations remained constant immediately preceding surgery, cortisol concentrations increased by 61% (P less than 0.05). Previous studies have also demonstrated increased concentrations of cortisol before surgical procedures, presumably due to psychological stress. However, this is the first demonstration of a dissociation between concentrations of cortisol and an adrenal androgen due to psychological stress.

Adrenal Glands↗
PubMed1985

Experimental arteriosclerosis treated by argon ion and neodymium-YAG laser endarterectomy.

The argon ion laser (488 and 514.5 nm) and the Nd-YAG laser (1.06 micron) have been used in most studies of laser radiation for treatment of arteriosclerotic cardiovascular disease because their beams can be directed through a delivery fiber. We compared the effects of argon ion and Nd-YAG lasers in vivo on arteriosclerotic rabbit aortas with open laser endarterectomy. A thoracoabdominal exploration was performed in 16 rabbits to isolate the aorta. Laser beams were directed through delivery fibers to produce a line of laser craters at the proximal and distal ends of an atheroma. The lines of laser craters were connected by continuous-wave laser radiation to loosen the plaque and the cleavage plane was developed within the media by continuous-wave laser radiation. End points were fused by continuous-wave laser radiation and the aortas were harvested for light and scanning electron microscopy. Argon ion laser endarterectomy (eight rabbits) required an energy density of 98 +/- 19 J/cm2. Nd-YAG laser endarterectomy (eight rabbits) required an energy density of 1147 +/- 129 J/cm2. Perforation did not occur with the argon ion laser but occurred in six of eight Nd-YAG experiments. Even depths of plaque removal resulted from argon ion laser endarterectomy but not from Nd-YAG laser endarterectomy. Gross and microscopic grading of the aortas showed that argon ion endarterectomy surfaces were significantly better than Nd-YAG surfaces (p less than .05). Similarly, argon ion end points were significantly better than Nd-YAG end points (p less than .01).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Cardiac assist by extracorporeal membrane oxygenation with in-line left ventricular venting.

We have used a canine heart failure model and extracorporeal circulation to study the limitations of extracorporeal membrane oxygenation (ECMO) for the treatment of cardiac failure. ECMO does not routinely achieve total biventricular bypass and does not effectively decompress the failing left ventricle. The addition of an in-line left ventricular vent (ECMO-lv) provided total biventricular bypass and complete left ventricular decompression in every experiment. ECMO-lv merits consideration as a biventricular bypass system for total mechanical support of the failing heart.

Animals↗
PubMed1983

Left atrial-to-aortic assistance with in-line left ventricular venting.

Left atrial-to-aortic assistance (LA-A) has been employed for left ventricular failure (LVF) refractory to intra-aortic balloon counterpulsation. Although clinical success has been reported, LA-A is limited by incomplete left ventricular (LV) decompression. We have developed a method to augment LA-A with an in-line LV apical vent (LA-lv-A). LVF was produced in 12 dogs by ligation of the circumflex coronary artery. Circulatory assistance was established with LA (28-32 Fr), LV apex (12-14 Fr) and femoral artery cannulation and a centrifugal pump. LA-A assistance was compared to LA-lv-A. Left atrial pressure was reduced from 10 +/- 3 torr to 5 +/- 3 torr (p less than 0.001), left ventricular systolic pressure was reduced from 48 +/- 4 torr to 9 +/- 2 torr (p less than 0.001) and left ventricular end-diastolic pressure was reduced from 10 +/- 2 torr to 1 +/- 1 torr (p less than 0.001). We conclude that LA-lv-A results in complete LV decompression. LA-lv-A should be considered as an alternative method for temporary left heart bypass.

Animals↗
PubMed1982

Upper gastrointestinal hemorrhage in cirrhosis: timing and indications for active intervention.

The medical treatment of upper gastrointestinal hemorrhage was assessed in 101 patients with alcoholic liver disease. Mortality was proportional to the number of blood transfusions required, regardless of the severity of liver disease. Overall mortality was 73% when transfusion requirements exceeded four units, compared with 19% when less than this amount was required (p less than 0.05). A more direct approach to the control of variceal hemorrhage is indicated when blood loss reaches 21.

Adult↗
PubMed1981

Clinical significance of erosive gastritis in patients with alcoholic liver disease and upper gastrointestinal hemorrhage.

Since, in many patients with alcoholic liver disease and upper gastrointestinal hemorrhage, varices and erosive gastritis frequently coexist, the purpose of this study was to assess the severity of hemorrhage, rebleeding and mortality rates when these lesions are present singly or concomitantly. In 104 patients not operated upon, 31 had both lesions present on endoscopic examination, and their clinical courses paralleled the severity of 29 patients who had bleeding varices as the sole finding. In 13 patients with alcoholic liver disease and upper gastrointestinal hemorrhage who were found to have erosive gastritis as the sole lesion, the clinical course was as benign as in 31 patients with ethanol-induced gastritis without liver disease, and their blood loss, rebleeding and mortality rates were significantly less than in patients with both varices and gastritis. It is concluded that the course and prognosis of upper gastrointestinal hemorrhage in patients with alcoholic liver disease and erosive gastritis is dependent upon the presence or absence of gastroesophageal varices.

Esophageal and Gastric Varices↗
PubMed1981

Complete neurological recovery after 13 minutes of hypovolemic hypotension.

It has been shown experimentally that irreversible brain injury and death may follow after 5-7 min of cerebral ischemia and that even brief periods, 2 min or less, can produce focal damage to the nervous system. All published studies demonstrating a protective effect of barbiturates have been performed in animals. A patient is presented who recovered full neurological function after 13 min of hypovolemic hypotension. This remarkable outcome may have been due to the rapid institution of high-dose barbiturate therapy. The extent to which such therapy affected his outcome is unclear, but does add to the growing body of evidence suggesting a favorable effect from this type of barbiturate therapy.

Brain Damage, Chronic↗
PubMed1981

Hemoptysis and pneumothorax after removal of a persistently wedged pulmonary artery catheter.

Significant resistance was encountered when an attempt was made to withdraw a persistently wedged pulmonary artery catheter. A small amount of air was injected into the balloon lumen with great difficulty. This injection freed the catheter which was removed, but produced significant sudden hemoptysis and a pneumothorax. The etiology of this complication and guidelines to avoid it are presented.

Catheterization↗
PubMed1981

Erythrocyte survival following extracorporeal circulation. A question of membrane versus bubble oxygenator.

Five groups of seven dogs were studied. Each animal had 250 ml of blood withdrawn and tagged with Cr51. Group I (control) samples were combined with 500 ml of lactated Ringer's solution and reinfused into the respective animals after 3 hours of incubation at 37 degrees C. Group II samples were pumped in a closed-circuit bubble oxygenator with 500 ml of lactated Ringer's prime for 2 hours before reinfusion into the animals. Group III samples were pumped in a bubble oxygenator for 3 hours before reinfusion. Group IV samples were pumped in a closed-circuit membrane oxygenator for 2 hours, and Group V samples were pumped in a membrane circuit for 3 hours. All extracorporeal pump runs were performed at 37 degrees C. Blood samples were drawn from the dogs at regular intervals after bypass for 30 days. Erythrocyte survival was determined by Cr51 activity recorded by a gamma counter. The red cell half-life was determined for each dog. The control half-life was 24.1 +/- 2.03 days; Group II, 19.88 +/- 1.69 (p < 0.05); Group III, 9.63 +/- 1.4 (p < 0.001); Group IV, 19.4 +/- 1.65 (p < 0.05); and Group V, 9.13 +/- 1.45 (p < 0.001). These data indicate that serious red cell injury does occur with extracorporeal circulation but that the injury is a function of pump time, rather than of the type of oxygenator.

Animals↗
PubMed1978

Colonic varices. A complication of pancreatitis with splenic vein thrombosis.

A patient with recurrent gastrointestinal bleeding was found to have varices at the splenic flexure at colonoscopy. Angiography revealed complete occlusion of the splenic vein. Although the patient did not have cirrhosis, he did have a history of pancreatitis which presumably was responsible for the splenic vein thrombosis. This case represents a compartmentalized form of portal hypertension which requires careful endoscopic and radiographic studies for proper evaluation. Successful treatment was accomplished by splenectomy.

Colon↗
PubMed1977

Fifteen year experience with subcutaneous bypass grafts for lower extremity ischemia.

A 15-year experience with 92 subcutaneous arterial bypass grafts for lower extremity revascularization has been reviewed. Fifty-nine AF and 33 FF bypass operations were performed on 89 patients whose average age was 66 years. The overall five-year survival was 33% compared to an expected survival of 80%. 88% of the AF, and 76% of the FF operations were performed for limb salvage, bypass of an aortic aneurysm, or replacement of an infected aortic graft. The remainder were performed for intermittent claudication on patients who were too ill to withstand an intra-abdominal operation. 75% of the patients with AF grafts and 64% of those with FF grafts experienced complete relief of lower extremity ischemia, including all of the patients with claudication. Graft patency was analyzed by the life table method. In the FF series, 74% of the grafts remained patent for one year; 73% for two years; 66% for three years; and 53% for four years. A 50% incidence of thrombosis occurred at the end of two years in the AF group. The patency rate of the AF grafts was also studied with regard to the type of graft material employed: a 50% incidence of thrombosis was reached at 36 months with knitted Dacron; at 18 months with weave-knit Dacron; and at 9 months with woven Dacron. THESE DATA INDICATE THAT: (1) contrary to our previous report, weave-grafts provide adequate blood flow to the lower extremities but do not remain patent as long as more conventional types of reconstruction; (2) subcutaneous grafts should be performed only when an intra-abdominal procedure is contraindicated or life expectancy is limited.

Aged↗
PubMedDate not supplied

Retrograde aortic dissection during cardiopulmonary bypass.

Femoral artery perfusion for cardiopulmonary bypass is still employed for reoperation, procedures involving the thoracic aorta, and partial bypass in critical patients. Retrograde aortic dissection is the most significant complication of femoral perfusion. The reported incidence is from 0.6% to 14% with a mortality of 66%. Most of the deaths occurred in patients in whom the dissection was not recognized , or in whom the dissection was recognized but not treated appropriately. Our experience with retrograde dissection totals six patients of 640 (0.9%) in whom femoral inflow was used. Four of the six patients survived the dissection. Sudden increase in extracorporeal line pressure shortly after beginning cardiopulmonary bypass associated with decreased venous return, dampened radial arterial pressure, and the abrupt appearance of a bluish, bulging ascending aorta establishes the diagnosis. Survival is enhanced if cardiopulmonary bypass is promptly discontinued, aortic cannulation established, and bypass reinstituted with the induction of profound hypothermia. Circulatory arrest may then be employed to repair the false passage. In this series the proposed operation was completed in all six patients.

Adult↗
PubMedDate not supplied

Clinical choices for circulatory assist devices.

Approximately 1.0% of open heart surgery patients become unweanable from cardiac bypass during the surgical procedure. In addition, nearly 20% of patients accepted for cardiac transplantation die while waiting for a donor heart. Pulsatile pneumatic ventricular assist devices (VADs) provide a realistic solution to these dilemmas. Currently, there are five manufacturers who are competing for the major market share in the clinical use of these devices. Novacor, Thermetics, Thoratec, Symbion, and Abiomed all have competitive VAD systems. Because no one system is optimal for all patients, the limitations, similarities, and strengths of each system should be known to enhance the patient's outcome when using these devices. Successful use of VAD systems, either as a bridge to transplantation or to ventricular recovery, is best approached by adherence to strict patient selection. Once instituted, VAD management centers on detailed attention to anticoagulation and prompt diagnosis and treatment of various complications.

Blood Loss, Surgical↗
PubMedDate not supplied

Successful treatment of acute allograft failure using pneumatic biventricular assistance.

A 61-year-old man underwent orthotopic heart transplantation complicated by acute allograft failure. Management entailed placement of two ventricular assist devices, and there was subsequent hemodynamic stabilization. Ventricular assistance continued for 8 days, at which time graft recovery resulted in successful explanation of the devices. Subsequent recovery was uneventful, and the patient was discharged on the 28th postoperative day. Methods of optimizing interoperative device cardiac output and synchronous-mode weaning are discussed.

Cardiomyopathy, Dilated↗