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Biomedical subjects

W A Baumgartner

Publications and source records attributed to W A Baumgartner.

At least 145 records · Page 8Linked to original sources
PubMed1987

The effects of age on outcome after coronary bypass surgery.

To study the effects of increasing age on outcome after coronary artery bypass grafting (CABG), 684 patients who underwent CABG from 1980 to 1985 were entered into a noncurrent prospective study. Patients were matched by date of operation and placed into three groups according to age: (1) 70 and older, (2) 55 to 69, or (3) less than 55. In addition to intraoperative and postoperative data collected on all patients, follow-up was obtained on 97% of the patients at a mean of 30 +/- 16 months. Older patients were more often female (p less than .002), and white (p less than .001) and had more preexisting cerebrovascular disease (p less than .0001), peripheral vascular disease (p less than .001), unstable angina (p less than .0001), and longer mean bypass pump times (p less than .001). Older patients had a higher hospital mortality (9.3% vs 2.2%), suffered more complications, including stroke, wound infection, reoperation for bleeding, need for intropic drug support, and prolonged ventilation, and had longer mean postoperative hospital stays (14 vs 9 days, p less than .0001). After discharge, mortality rates were similar in all groups, as was recurrence of symptoms and degree of rehabilitation. While patient age at operation significantly influenced hospital mortality and morbidity, this appeared to be a consequence of the greater frequency of risk factors in patients over 70 years of age. In addition, late follow-up failed to demonstrate any significant differences based on age alone in survival or functional status among patients undergoing CABG.

Activities of Daily Living↗
PubMed1987

Comparative analysis of mechanical and bioprosthetic valves after aortic valve replacement.

Comparative long-term performance characteristics of Björk-Shiley mechanical and bioprosthetic valves were analyzed for patients undergoing aortic valve replacement between 1976 and 1981. A total of 419 patients received either a standard Björk-Shiley (n = 266) or bioprosthetic (porcine, n = 126, or pericardial, n = 27) aortic valve. Cumulative patient follow-up was 1,705 patient-years; the average patient follow-up was 4.1 +/- 2.7 years. Survival data were obtained for all but 11 patients (97% complete follow-up) up to 9 years after operation. Survival at 5 years was 81% +/- 4% (+/- standard error) for Björk-Shiley and for bioprosthetic valve recipients. Valve failure in the Björk-Shiley group was predominantly due to valve-related mortality and did not result from structural failure. Patients with bioprosthetic valves experienced valve failure as a result of prosthetic valve endocarditis and intrinsic valve degeneration. Although patients with bioprostheses experienced a lower incidence of valve-related morbidity than Björk-Shiley valve recipients (p less than 0.03), no difference could be demonstrated in the incidence of valve-related mortality or valve failure at 5 years between bioprosthetic and Björk-Shiley valves. Mortality rate from valve failure was higher for Björk-Shiley (86%, 12/14) than bioprosthetic valves (36%, 5/14) (p less than 0.01).

Actuarial Analysis↗
PubMed1986

Hypothermic preservation of the heart and lungs with Collins solution: effect on cardiorespiratory function following heart-lung allotransplantation in dogs.

The effect of preserving the heart and lungs with hypothermia and Collins solution was studied in 13 mongrel dogs undergoing combined heart-lung transplantation. The five control animals who underwent an immediate transplant following Collins solution perfusion had small increases in extravascular lung water when measured 2.5 hours posttransplant as seen in a previous study. The eight animals who had hypothermic preservation following Collins solution perfusion had significantly higher extravascular lung water than controls (16.3 +/- 1.8 ml/kg in preserved animals; 11.2 +/- 1.7 ml/kg in controls p less than 0.05). The level of lung water reached at 2.5 hours postoperatively was similar to that reached with a previously reported, unacceptable preservation technique. Survival beyond this point was poor due to severe pulmonary edema. We conclude that the use of this solution, given under the experimental conditions which we describe, is not acceptable for hypothermic preservation of the heart and lungs for combined transplantation.

Animals↗
PubMed1986

Organization, development and early results of a heart transplant program. The Johns Hopkins Hospital experience.

Improved survival and quality of life have resulted in a resurgence in cardiac transplantation and the proliferation of centers contemplating initiation of a transplant program. Organization of such a program requires cooperation among several clinical and non-clinical departments of the hospital. Prior to implementation of such a program, a number of issues need to be addressed, including state authorization, an expeditious method for donor organ retrieval, protocols for recipient selection and evaluation, and perioperative and follow-up care of the transplant recipient. Since July of 1983, 35 patients (27 men and eight women) have undergone orthotopic cardiac transplantation. Transplantation was undertaken for cardiomyopathy (30) or end-stage ischemic heart disease (5). The mean age was 38 years (range, 16 to 57 yrs). Distant organ procurement was used for 83 percent of patients; mean ischemic time was 164 min (range, 75 to 250 min). Current immunosuppressive regimen consists of oral cyclosporine (10 mg/kg) and prednisone. Mean follow-up was 10.3 months (range, two weeks to 27 months). Transient renal dysfunction appeared early in 15 patients. Six deaths have occurred: three from rejection, one from infection, one from metastatic prostate carcinoma, and one from pulmonary hemorrhage. All but three recent patients have been rehabilitated. These initial encouraging results are a result of careful planning, institutional commitment, adequate resources and, most importantly, a dedicated transplant team.

Adolescent↗
PubMed1986

Anatomic and anesthetic considerations in experimental cardiopulmonary surgery in swine.

We have used immature commercial swine (13-25 kg) successfully in a variety of experimental cardiopulmonary surgical procedures in our laboratories since 1981. Multiple drug anesthetic protocols using barbiturates, narcotics, paralytic and antiarrhythmic agents have been employed in over 400 procedures per year. Complications, including fatal cardiac arrhythmias, have been greatly reduced by anesthetic protocols and surgical procedures developed through experience.

Acepromazine↗
PubMed1985

Value of intraoperative left ventricular microbubbles detected by transesophageal two-dimensional echocardiography in predicting neurologic outcome after cardiac operations.

To determine whether the presence or absence of left ventricular (LV) intracavitary microbubbles during cardiac surgery predicts neurologic sequelae, 82 patients undergoing cardiac surgery were studied using transesophageal 2-dimensional (2-D) echocardiography. Cross-sectional images were recorded just before and immediately after cardiopulmonary bypass and stop frames were reviewed for the presence of microbubbles, rated as: 0 = absent, 1 = fewer than 5/frame, 2 = 10 to 25/frame, 3 = too numerous to count. Microbubbles were detected after cardiopulmonary bypass in 34 patients (41%) and found more often in valvular or other intracardiac manipulations than in coronary revascularization, 30 of 40 vs 4 of 42, respectively (p less than 0.001). When grade 2 or 3 microbubbles were identified (22 of 34 patients), mechanical attempts to eradicate them were not successful. Postoperative follow-up in all patients revealed no new focal neurologic deficits. Prolonged encephalopathy (confusional state more than 72 hours) occurred in 4 of 48 patients with no detectable microbubbles and in 3 of 34 patients with microbubbles (difference not significant). Thus, intracavitary left ventricular microbubbles are often detected during cardiac operations, particularly during valve replacement, but are not predictive of postoperative neurologic complications. This is true even if microbubbles are densely concentrated; attempts to eradicate microbubbles are unsuccessful and may be unnecessary.

Cardiac Surgical Procedures↗
PubMed1985

Stroke following coronary artery bypass grafting: a ten-year study.

To identify possible risk factors for the occurrence of stroke during coronary artery bypass grafting (CABG), the cases of 3,279 consecutive patients having isolated CABG from 1974 to 1983 were reviewed. During this period, the risk of death fell from 3.9% to 2.6%. The stroke rate, however, fell initially but then rose from 0.57% in 1979 to 2.4% in 1983. Adjustment of these data for age clearly demonstrated that the risk of stroke has increased largely because of an increase in the mean age of patients undergoing CABG procedures. A case-control study involving all 56 stroke victims and 112 control patients was used to identify those risk factors significantly associated with the development of stroke in univariate analysis: increased age (63 versus 57 years in stroke patients and controls, respectively; p less than 0.0001); preexisting cerebrovascular disease (20% versus 8%; p less than 0.03); severe atherosclerosis of the ascending aorta (14% versus 3%; p less than 0.005); protracted cardiopulmonary bypass time (122 minutes versus 105 minutes; p less than 0.005); and severe perioperative hypotension (23% versus 4%; p less than 0.0001). Other variables not found to correlate with postoperative stroke included previous myocardial infarction, hypertension, diabetes mellitus, lower extremity vascular disease, preoperative left ventricular function, and intraoperative perfusion techniques. Elderly patients who have preexisting cerebrovascular disease or severe atherosclerosis of the ascending aorta or who require extensive revascularization procedures have a significantly increased risk of postoperative stroke.

Age Factors↗
PubMed1985

The effect of hypothermic preservation of the heart and lungs on cardiorespiratory function following canine heart-lung transplantation.

The effect of hypothermic preservation of the heart and lungs with a crystalloid solution was evaluated in 12 mongrel dogs receiving heart-lung allografts. Six animals served as controls and received an immediate heart-lung transplant. Six animals were in the experimental group and received a heart-lung transplant after 5 hours of preservation at 4 degrees C following perfusion of both organs with a crystalloid solution. Physiological function of the heart and lungs was studied for 20 hours after transplantation. While cardiac function was minimally depressed following preservation, pulmonary function testing demonstrated significantly greater increases in extravascular lung water in experimental animals, suggesting that an ischemic lung injury occurred with this preservation technique. The model allows for future evaluation of other methods of combined preservation of both the heart and lungs for transplantation.

Airway Resistance↗
PubMed1985

Coronary artery bypass grafting in women. A ten-year perspective.

Between January 1974 and December 1983, 3279 patients have undergone isolated coronary artery bypass (CAB) grafting at the Johns Hopkins Hospital. There were 639 women in this group. Women represented 18 to 22% of the patients having isolated CAB grafting throughout the 10-year period, except in 1976 when only 13% of the CAB patients were women. Mean age-at-operation for women has increased from 53.9 to 61.1 years since 1974, and was higher than the mean operative age of men during each of the 10 years. Although the oldest woman undergoing CAB grafting in 1974 was 64 years old, the eldest in 1983 was 84 years old. Except for an older mean age-at-operation for women and a higher incidence of unstable angina prior to surgery, the only other significant difference in the clinical status of female versus male CAB patients, detected by a case control analysis, was the smaller body surface area of women compared to men. Although operative mortality was significantly greater for women during most of this review period, mortality was similar during 1983 (2.6% for men versus 2.4% for women), in spite of a significantly higher incidence of unstable angina in the female group (54% for women versus 35% for men). The improved survival noted following coronary bypass grafting in women, which occurred in spite of the advancing age of the female group, supports an aggressive approach to surgical intervention in women with severe coronary artery disease.

Age Factors↗
PubMed1985

Hair analysis for detection of phencyclidine in newly admitted psychiatric patients.

The authors implemented a new procedure for analyzing phencyclidine (PCP) content in hair. They compare the results of analyses of hair with results of analyses of blood and urine in 47 patients newly hospitalized with acute psychiatric illness. Hair analysis identified 11 patients who had used PCP, and blood and urine analyses did not identify any among the sample population. In three patients, the results of hair analysis aided in establishing a diagnosis of PCP intoxication. The authors discuss interpretations of their findings and psychiatric applications of this new technique.

Adult↗
PubMed1985

Histologic pattern of early heart allograft rejection under cyclosporine treatment.

The histologic abnormalities associated with early heart rejection in cyclosporine-treated patients are not fully characterized. To study these abnormalities, Lewis rats received ACI heart-lung allografts and two weeks of cyclosporine treatment. Then the therapy was discontinued. Controls were sacrificed at that time; other animals were sacrificed three, six, and nine days later. The rejection score was determined solely by the percentage of necrotic myocardium, while 13 other histologic parameters were semi-quantitatively graded to identify parameters of early rejection of the heart. There was no evidence of myocardial necrosis or significant inflammation three days after discontinuation of therapy. At six and nine days, despite the absence of myocyte necrosis, there were significant increases in the grades for interstitial and endocardial inflammation, venous cuffing, perivascular inflammation with intermyocyte extension and arterial vasculitis. Our quantitative and semi-quantitative histologic analysis identified abnormalities of the early stage of heart rejection that may provide clues in defining rejection prior to the development of myocyte necrosis.

Animals↗
PubMed1985

Twenty-four hour lung preservation by hypothermia and leukocyte depletion.

In lung preservation, as well as in other forms of pulmonary disease, injury is associated with sequestration of leukocytes. We hypothesized that leukocyte depletion could prevent reperfusion injury and prolong the period of safe lung preservation. The heart-lung block from 39 New Zealand white rabbits were harvested, flushed with 100 ml of a modified Collins solution, stored at 4 degrees C in a 30% inflation state, and reperfused with either whole blood or leukocyte depleted blood. Leukocyte depletion was accomplished using a blood filter and verified with selected leukocyte counts. Leukocyte readdition specimens were obtained from whole blood, the separation being done with hydroxyethyl starch and centrifugation at 4,000 rpm for five minutes. Six groups of rabbit lungs were studied. Group 1 consisted of control lungs that were not preserved and were reperfused with whole blood. Lungs in Group 2 underwent five-hour preservation and whole blood reperfusion. Lungs in Group 3 underwent five-hour preservation and leukocyte depleted blood reperfusion. Lungs in Group 4 underwent 24-hour preservation and leukocyte depleted blood reperfusion. Lungs in Group 5 also underwent 24-hour preservation, leukocyte depleted blood reperfusion, but with leukocyte readded at the onset of reperfusion. Lastly, lungs in Group 6 underwent 24-hour preservation, leukocyte depleted blood reperfusion, with leukocyte readdition after one hour of reperfusion. Group 5 showed pulmonary edema and complete reservoir emptying within the first hour of reperfusion. Group 2 had comparable poor results. Groups 3, 4, and 6 showed no significant differences from the control lungs in regard to pressure or reservoir loss.(ABSTRACT TRUNCATED AT 250 WORDS)

Airway Resistance↗