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Biomedical subjects

R Pifarre

Publications and source records attributed to R Pifarre.

At least 109 records · Page 6Linked to original sources

Acute pulmonary hypertension complicating the arterial switch procedure.

Two neonates undergoing arterial switch procedure developed life-threatening pulmonary hypertension intraoperatively. In one patient, bradycardia, hypotension, and electrocardiographic (ECG) evidence of myocardial ischemia suddenly occurred 20 minutes after uneventful weaning from cardiopulmonary bypass. Lifting a palpably hypertensive main pulmonary artery (MPA) resulted in reproducible hemodynamic improvement. Because the patient was already on full ventilatory support and a nitroglycerin infusion, the MPA was suspended onto the anterior chest wall. In the other patient, after removal of intraoperative drapes, severe generalized swelling and cyanosis were noted. The central venous pressure had risen to 25 mmHg, and the PO2 had dropped to 52 mmHg on 100% FIO2. The systolic arterial pressure and ECG remained normal. Immediate reexploration revealed a palpably hypertensive MPA. The coronary arteries implanted more laterally on the neoaorta were uncompromised. Amrinone loading and infusion produced immediate improvement. We believe that surgeons should be aware that pulmonary hypertension can cause coronary artery compression and right heart failure in neonates undergoing the arterial switch procedure. Lateral placement of the coronary artery and aggressive use of pulmonary vasodilators can minimize the problem.

Acute Disease↗

Cytomegalovirus infections in heart transplant recipients: relationship to immunosuppression.

To determine the relationship of cytomegalovirus infections (CMVI) to immunosuppression in heart transplants, we retrospectively compared demographic and clinical variables in 154 consecutive heart transplant patients. Forty-one CMVI were compared; of these, 30 (73%) were identified in tissue, and nine (22%) were identified by blood or urine culture. Twenty (49%) of the CMVI were self-limited, and 21 (51%) were progressive, requiring treatment. When comparing patients with and without CMVI, demographic variables, mean preexisting heart disease, cyclosporine level, cumulative corticosteroid dose, and the use of anti-T-cell antibodies were examined. Only the use of OKT3 was significantly associated with the subsequent development of CMVI. Although CMVI subsequently developed in 30 of 79 (38%) patients who had received OKT3, CMVI developed in only 11 of 75 (15%) patients who had not received OKT3 (p = 0.01). Furthermore, the incidence of CMVI increased with increasing total OKT3 dose (none, 11 of 64 [17%]; < or = 75 mg, 23 of 66 [35%]; > 75 mg, 6 of 14 [43%]; p = 0.01). Logistic regression showed that the only two variables predictive of CMVI were the use of OKT3 (p = 0.0023) and ischemic rather than idiopathic heart disease before transplantation (p = 0.0098). Rejection rates, incidence of allograft vasculopathy, and 1-year actuarial survival were not influenced by previous CMVI. Pneumocystis carinii pneumonia occurred more frequently in patients with CMVI than in those without (13 of 41 [32%] patients versus 3/113 [3%] patients; p < 0.001). No correlation existed between CMVI and lymphoproliferative disorder (p = 0.84).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Successful use of the total artificial heart as a bridge to transplantation with no mediastinitis.

UNLABELLED: High rates of infection, especially mediastinitis, have been reported with the use of the total artificial heart (TAH), thereby limiting its usefulness. We have used the TAH as a bridge to transplantation with only minor infectious complications and a zero incidence of mediastinitis. Between February 1988 and August 1990, the TAH was inserted at Loyola University Medical Center in 19 patients, ages 16 to 64 years (mean, 44 years). Seventeen patients (89%) underwent transplantation within 1 to 34 days (mean, 9.8 days). Of the patients who did not undergo transplantation, one was brain dead and the other died of bleeding diathesis. Early (30-day) deaths occurred in two patients (11.7%): acute rejection at 18 days and multiple cerebral infarcts at 14 days. Three late deaths (17.6%) occurred: one patient, cytomegalovirus and pneumocystis pneumonia at 4 months; one patient, bronchopneumonia and multisystem failure at 9 months; and one patient, chronic rejection at 14 months. Minor infectious complications during the TAH implantation included Enterobacter pneumonia treated with antibiotics and positive sputum cultures (Escherichia coli; Candida), with no clinical evidence of infection in two patients. No cases of mediastinitis occurred either while the TAH was implanted or after transplantation. All patients were on antibiotics while the device was in place. CONCLUSION: Our experience with the TAH shows this to be an excellent device for successful bridging of patients for heart transplantation. We have had minimal infectious complications and none directly attributed to the use of this device. This device should continue to be used safely as a bridge to transplantation.

Adult↗

Comparison of results after heart transplantation: mechanically supported versus nonsupported patients.

Between March 1984 and July 1990 our team transplanted 168 hearts. One hundred twelve patients did not require mechanical support (group I). Fifty-six patients required mechanical support (group II). Intraaortic balloon counterpulsation was used in 37 patients (66%). The total artificial heart (TAH) was used in 16 patients (29%), and the ventricular assist device (VAD) was used in three patients (5%). The time spent on the device ranged from 1 to 35 days. No statistical difference was noted on the survival between the two groups. The 30-day and 1-year survival rate was 95% (106 patients) and 71% (79 patients) in group I and 91% (51 patients) and 68% (38 patients) in group II. As of July 31, 1990, 70% in group I and 68% in group II are alive. No significant differences were found between the two groups for the following variables (after heart transplantation): length of stay, 30-day survival, 1-year survival, and complications. The only significant difference found between the two groups was the incidence of infections: group I, 23%; group II, 51.7% (p = 0.001). Mechanical support as a bridge to transplantation provides excellent support until a donor becomes available. No difference was found in the 30-day and 1-year survival between the two groups.

Cause of Death↗

Obesity and hyperlipidemia after heart transplantation.

Body weight and serum lipids were retrospectively analyzed in 54 heart transplant recipients (mean age, 43 years; 80% male) who survived at least 1 year. Data were collected preoperatively and at 1, 2, and 3 years after heart transplantation. Analysis was performed using item frequencies, analysis of variance, and Pearson product moment correlations. From preoperatively to 1 year after heart transplantation, the weight of patients increased significantly from 100% to 117% of ideal body weight and did not decrease significantly over the first 3 postoperative years. Serum cholesterol and triglyceride values increased significantly from preoperative values of 175 mg/dl and 139 mg/dl, respectively, to 1-year postoperative values of more than 200 mg/dl (p = 0.01). Serum cholesterol, but not triglyceride levels, decreased significantly 3 years after surgery as compared with 1 year after surgery. In addition, overall serum cholesterol and triglyceride levels were higher in patients with coronary artery disease (248 mg/dl) than with dilated cardiomyopathy (207 mg/dl). Serum high-density lipoproteins remained within acceptable clinical levels (greater than 35 mg/dl) during all 3 postoperative years. Serum low-density lipoproteins, elevated (139 mg/dl) for the first 2 postoperative years, fell to within the desirable range (less than 130 mg/dl) by the third posttransplant year. Heart function was normal throughout all 3 years. Six patients (11%) were given lipid-lowering medications after heart transplantation (mean, 25 postoperative months).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Prospective randomized trial of OKT3- versus horse antithymocyte globulin-based immunosuppressive prophylaxis in heart transplantation.

To compare monoclonal anti-T3-receptor antibody (OKT3) and horse antithymocyte globulin (HATG) immunoprophylaxis, 23 heart transplant recipients were randomized to OKT3 (N = 12) 5 mg IV x 14 days of HATG (N = 11) 5 mg/kg IV x 10 days and followed up for 216 +/- 137 days receiving triple immunosuppression. Recipient groups were demographically and clinically similar. First rejection occurred later in OKT3 recipients vs HATG recipients (31.7 +/- 18.3 vs 15.1 +/- 2.3 days; p less than 0.01), but the first rejection necessitating intensified immunosuppression occurred at similar times (30.9 +/- 14.6 vs 21.9 +/- 10.2 days; NS). Phenotypic characterization of peripheral blood lymphocytes by flow cytometry revealed that OKT3 and HATG recipients had similar decreases in total T lymphocytes and lymphocyte subpopulations. During the follow-up period rejection rates in the OKT3- and in the HATG-treated patients were 3.4 +/- 2.7 and 5.9 +/- 4.7, respectively (NS). The number of rejection episodes per recipient treated with intensified immunosuppression was 1.4 +/- 1.2 in the OKT3- and 2.0 +/- 3.1 in the HATG-treated patients (NS). Infection rates were 4.9 +/- 5.2 in the OKT3- and 2.7 +/- 1.7 in the HATG-treated patients (NS). The number of infection episodes that necessitated intravenous antimicrobial therapy was 2.7 +/- 2.3 in the OKT3- and 1.6 +/- 1.3 in the HATG-treated recipients (NS). The number and length of hospitalizations were similar in patients given OKT3-based or HATG-based immunoprophylaxis. We conclude that immunosuppressive prophylaxis with OKT3 vs HATG in heart transplant recipients is associated with a slightly lower incidence and severity of rejection and slightly higher infection rates.

Animals↗

Use of the total artificial heart and ventricular assist device as a bridge to transplantation.

The proliferation of transplant programs has not been paralleled by a similar increase in the availability of organ donors. This has significantly prolonged the waiting period and consequently has resulted in increased mortality of the patients with end-stage heart disease who are awaiting transplantation. Between 1984 and 1987, 104 orthotopic heart transplants were performed at Loyola University Medical Center. During the same period, 25 patients died while waiting for a suitable donor. To reduce the mortality of our patients waiting for transplantation, we began using the total artificial heart and a ventricular assist device as a bridge to transplantation in 1988. Of 29 patients who underwent transplant procedures in 1988, 18 required either a total artificial heart (15) or a ventricular assist device (3) as a bridge to transplantation. The underlying heart conditions were ischemic cardiomyopathy (11), dilated cardiomyopathy (5), giant cell myocarditis (1), and allograft failure (1). The average duration of mechanical support was 10 days (range, 1 to 35 days). Seventeen of the supported patients had successful transplants. One patient had brain death and did not receive a heart transplant. Of the 17 patients who survived surgery, two died within 30 days: one at 17 days because of acute rejection, the other at 14 days because of a cerebral vascular event. Fifteen patients (83%) were long-term survivors. Nine of the supported patients required reoperation because of bleeding after device implantation. There was no mediastinal or incisional infection. While the mechanical device was in place, the activated clotting time was maintained between 170 and 200 seconds with the administration of heparin (400 to 1000 units per hour).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Patients receiving quinolones and cyclosporine after heart transplantation.

Six patients required fluorinated quinolone therapy for a variety of infections after heart transplantation. In contrast to findings in a previous report, none of the patients showed any evidence of nephrotoxicity or required a significant change in cyclosporine dose during the treatment period.

Bacterial Infections↗

Use of cyclosporine in the mouse heterotopic heart transplant model.

We refined the mouse ear-heart transplant model developed by Fulmer and coworkers and tested cyclosporine as a sole immunosuppressive agent in this model. Three-week-old CBA mice were used as heart recipients, and unsexed newborn BALB/c mice were used as heart donors. The heart grafts were examined for visible pulsations at 10-fold to 20-fold magnification daily for the first 10 days and every other day thereafter. Graft electrocardiograms were also obtained on the same schedule. Preliminary studies had established that a dose of 15 mg/kg/day was the optimal cyclosporine dose in our model. This dose was administered subcutaneously to each of two treatment groups. Group 2 received this dose for the entire 30-day experimental period. Group 3 received this dose for the first 16 days of the experimental period. Group 1 consisted of allografts receiving no immunosuppression. Group 1 grafts showed evidence of initial successful engraftment by day 7; however, by day 13 none of the grafts remained viable. In group 2, 19 of 23 grafts remained viable for the entire experimental period. In group 3, all of the grafts remained viable until day 17 (after day 16 cyclosporine was discontinued) and rapidly lost evidence of viability thereafter. By day 21, none of the grafts in group 3 remained viable. Survival curves for the three groups as determined by electrocardiogram and visible pulsations were constructed, and the differences between the curves were significant (p = 0.001). The results of this study demonstrate the potential usefulness of the ear-heart transplantation model in screening immunosuppressive agents.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Traumatic descending thoracic aneurysms: discussion and nursing care.

Traumatic aneurysms of the descending thoracic aorta are a rare but lethal event, having a mortality of 85-90%. Mortality of this population remains high due to the occurrence of aortic rupture. The isthmus of the aorta, just distal to the left subclavian artery is the most frequent site of injury. Acute traumatic injury to the aorta is characterized by hemorrhagic shock symptoms due to the tear in the layers of the aortic wall. Chronic traumatic injury with aneurysmal formation may not surface with symptoms for months or years after initial trauma. Patients who have formed a chronic aneurysm after a trauma incident can experience dysphagia, chest pain, dyspnea, or cough. Surgical repair involves placing a dacron graft in the area of aneurysmal formation. Protection of the lower extremities during the surgical procedure may prevent paraplegia. In a review of ten cases of chronic traumatic aneurysms at Loyola University Medical Center during the past twenty (20) years, all patients underwent surgical repair. There was no incidence of paraplegia. Post-operative nursing care focuses on monitoring hemodynamic stability, preventing respiratory complications and controlling pain.

Aorta, Thoracic↗

Long-term follow-up of heart transplant recipients treated with murine antihuman mature T cell monoclonal antibody (OKT3): the Loyola experience.

We describe the long-term follow-up of 25 patients treated with murine antihuman mature T cell (OKT3) monoclonal antibody at Loyola University Medical Center. After OKT3 rescue therapy, 12 patients were monitored for 16.5 +/- 6.5 months. Twenty-two moderate and three severe rejection episodes occurred 11 to 469 days (166.8 +/- 126.0) after OKT3 therapy in nine of 12 patients. During the follow-up period three patients died, and one required retransplantation because of recurrent rejection. The coronary arteries of three failed allografts had severe intimal thickening and infiltration with lymphocytes. Thirteen patients received OKT3 for prophylactic immunosuppression, and their course was compared to that of 13 patients who underwent transplantation during the same period but were given prophylactic horse antihuman thymocyte globulins (HATG). There were no differences between the two drugs with respect to long-term incidence and severity of rejection and infection, cardiac allograft function, and survival. Our results indicate that, despite successful reversal with OKT3, heart transplant recipients with refractory rejection remain plagued by recurrent rejection. Cardiac allografts in recipients who die as a result of recurrent rejection show evidence of immune-mediated vasculitis, which results in severe and diffuse coronary luminal narrowing. OKT3 and HATG appear to be equally effective for rejection prophylaxis.

Adult↗

Technique for insertion of the intra-aortic balloon through the aortic arch.

A technique for rapid insertion of the intra-aortic balloon (IABP) through the proximal portion of the aortic arch is described. This method is beneficial in patients who require balloon support but in whom extensive aorto-femoral disease prevents the usual retrograde insertion. In these circumstances the balloon is inserted in the proximal aortic arch because multiple proximal vein grafts, ascending aorta replacement, and aortic valve surgery may make the ascending aorta an unsuitable site. The technique has been used in four patients with benefit sufficient to permit coronary artery bypass grafting with survival.

Aorta, Thoracic↗