PubMed Health⌕ Search

Biomedical subjects

L W Miller

Publications and source records attributed to L W Miller.

At least 91 records · Page 5Linked to original sources
PubMedDate not supplied

Experience with an emergency resuscitation system.

The need for a portable extracorporeal support system that can be rapidly initiated for various types of cardiopulmonary failure is well known. The authors report on a system consisting of 3/8 inch tubing, a Sci-Med membrane oxygenator, Omnitherm heat exchanger, Biomedicus or Sarns centrifugal pump, portable battery, and oxygen tanks. The system is mounted on a cart for easy mobility and can be primed in 5-10 min. USCI, DLP, or Axiom cannulas can be inserted femorally. Over 30 months, 29 patients, aged 19-78 years, underwent extracorporeal membrane oxygenation (ECMO) support for cardiac arrest during catheterization (10 patients), shock secondary to acute myocardial infarction (MI) (10 patients), elective percutaneous transluminal coronary angioplasty (PTCA) support (four patients), postcardiotomy failure (four patients), and exposure hypothermia (one patient). Adequate support was achieved in all but one patient. Device flows ranged from 0.2 to 6.0 l/min. There were six survivors (elective PTCA support, three patients; cardiac arrest during catheterization, three patients). Complications included bleeding (15 patients), deep venous thrombosis (three patients), and pump failure (one patient). A portable ECMO system has been developed that allows rapid institution of circulatory support.

Angioplasty, Balloon, Coronary↗
PubMedDate not supplied

The incidence of isolated left ventricular failure in bridge-to-transplant candidates.

Twenty-one patients (pts) were supported with mechanical devices as a bridge to cardiac transplantation (Tx). Ventricular function was assessed by a combination of angiography, echocardiography, nuclear scans, hemodynamics, and visual inspection at the time of device insertion. Twelve pts had biventricular failure (BVF) and 11 received biventricular support with extracorporeal membrane oxygenation (two pts), biventricular assist devices (VAD) (eight pts), or an artificial heart (one pt). One BVF pt received a left VAD (LVAD) and drug support for severe right ventricular failure (RVF), which resolved after 48 hr. The remaining nine pts had left ventricular failure (LVF), with only mild to moderate RVF, and received LVADs with minimal drugs. Eleven pts were tx, with nine survivors. A comparison of pts with LVF vs BVF revealed no differences in age, gender, device flows, duration of support, diagnosis, number tx, or number survived. The incidence of LVF was 43% vs 57% BVF in bridge-to-transplant pts. LVAD support alone is often successful in pts with mild or moderate BVF, but is rarely successful in pts with severe BVF.

Adult↗
PubMedDate not supplied

Cytomegalovirus and other herpesviruses: do they have a role in the development of accelerated coronary arterial disease in human heart allografts?

In conclusion, a great deal of indirect and inferential data point to herpesviruses as having a role in atherogenesis. It has been shown that the herpesviruses are able to remain within vascular tissue in a latent state, allowing for reactivation to occur with subsequent sequelae of an active infection. Herpesviruses affect the cellular metabolic activity of cells, induce the accumulation of lipids, and inhibit the production of matrix proteins. They have the ability to inhibit endothelial cell binding to the basement membrane. It is also known that the herpesviruses, particularly CMV, can initiate a variety of immunologic responses that may contribute to endothelial damage, precipitating atherogenesis. We are only beginning to understand how CMV may participate in ACAD. Greater attention must be focused on the exact cause-and-effect relationship between CMV infection and ACAD. Even the presence of CMV genomes in arterial walls of allografts must be viewed conservatively in the knowledge of CMV ubiquity and other probable contributions to ACAD. If CMV is involved in the development of ACAD, as an active or latent infection, directly or indirectly, it probably involves numerous coexistent mechanisms (Figure 5).

Coronary Artery Disease↗
PubMedDate not supplied

Successful withdrawal of corticosteroids in heart transplantation.

The ability to withdrawal corticosteroids from the maintenance immunosuppression regimen has been reported in heart transplant recipients. Most patients tested have had corticosteroids discontinued by 3 to 4 weeks after transplantation and have received perioperative administration of lymphocyte antibody therapy. To assess the importance of the additional "induction" therapy and the comparative results of delaying steroid withdrawal until after most rejections had occurred in our program, we withdrew maintenance steroids from 48 patients who were an average of 11 months (median, 8.6 months, range, 5 to 59 months) after transplantation. Mean patient age was 48 years, 95% were men, and 60% of the patients had never been treated for rejection before steroid withdrawal. Forty of the 48 patients (82%) were successfully withdrawn and remain free of steroids with an average of 25 months (range, 5 to 39 months) of follow-up off steroids. Ten episodes of rejection occurred in eight patients (82% rejection free). Six patients had a single rejection and two had more than one rejection. The average time to rejection after steroid withdrawal was 4 1/2 months, but two patients developed their first-ever rejection at 11 1/2 and 12 1/2 months after steroid withdrawal. Three of the rejections after steroid withdrawal were treated with intravenous steroids (10 mg/kg/day for 3 days) without a return to maintenance steroids. These three patients have not had a subsequent episode of rejection in 15 months of follow-up. The other three patients with rejection were returned to steroid therapy because of an inability to tolerate azathioprine, as were three patients without rejection for unrelated reasons.(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗
PubMedDate not supplied

Status I heart transplant patients: conventional versus ventricular assist device support.

Since 1985, 59 United Network for Organ Sharing status I patients have been considered for heart transplantation. Thirty-four patients were supported with drugs and/or intraaortic balloon pump (IABP) (group I). Twenty-five patients were supported with ventricular assist devices (VADs, group II). Forty percent of the patients in each group died before transplantation. Of the 20 group I patients who underwent transplantation, all received inotropic drugs, and five also required IABPs. All 14 group II patients who underwent transplantation were bridged with VADs. No difference was found in age, sex, or cause of disease between the groups. Complications after transplantation were more common in group I. Fourteen group I patients (70%) and 14 group II patients (100%) were discharged from the hospital (p = 0.03). One year after transplantation, mean left ventricular ejection fraction by cardiac catheterization was 53% in group I (12 patients) and 72% in group II (11 patients; p = 0.0008). Although VAD support does not insure transplantation, it strongly favors transplantation survival in status I patients. These data further suggest an advantage of VAD support for long-term survival.

Actuarial Analysis↗
PubMedDate not supplied

Device related infections in patients supported with mechanical circulatory support devices for greater than 30 days.

Mechanical circulatory support with systems that require transcutaneous cannulas or drive lines are associated with a high incidence of device related infections. The development of infection often is related to the duration of support. Data were reviewed on 10 patients (nine men and one woman) supported with assist devices (Thoratec-five, Nova-cor-three, Sarns-one, Jarvik-one) for longer than 30 days (range, 31-440; mean, 137 days). Seven patients had device related infections. Five also had positive blood cultures with the same organisms responsible for the device related infection. Two had mediastinitis from an ascending infection (one cannula and one drive line). Eight patients were transplanted, with seven survivors. One patient was weaned and survived, and one died during support. These data show that device related infections are common and severe, but they do not preclude successful transplantation, weaning, or survival.

Anti-Bacterial Agents↗
PubMedDate not supplied

Outpatient dobutamine for refractory congestive heart failure: advantages, techniques, and results.

Patients with refractory, end-stage congestive heart failure awaiting heart transplantation may be treated efficaciously with intermittent infusions of dobutamine given on an outpatient basis. The treatment appears to be well tolerated. Nevertheless, careful attention to electrolyte balance and arrhythmia control is essential to minimize the risk of sudden death. Use of a tunneled subcutaneous catheter essentially eliminates the risk of infection associated with this type of delivery system. Patients who have worsening heart failure while receiving dobutamine as outpatients should be fitted for a mechanical assist device before complications develop that may contraindicate transplantation.

Ambulatory Care↗
PubMedDate not supplied

Univentricular versus biventricular assist device support.

Controversy continues over whether patients should receive selective univentricular assist devices (UVADs) or biventricular assist devices (BVADs). Data from 39 patients supported for more than 2 days with Thoratec VADs were analyzed to compare mortality and morbidity between those receiving UVAD versus BVAD. Twenty-three patients received UVADs and 16 BVADs. Age, gender, and duration of support did not differ significantly between the two groups. Morbidity in VAD patients does not differ between UVAD and BVAD support. Survival is determined by the reversibility of pre-VAD myocardial damage or the eligibility for transplantation, rather than by the number of devices used. These data do not support the use of BVAD in all patients; they support a selective approach based on hemodynamic requirements.

Cardiac Surgical Procedures↗
PubMedDate not supplied

Bridge to heart transplantation: importance of patient selection.

Since 1986, 26 candidates were evaluated for mechanical support as a bridge to heart transplantation. Group 1 consisted of 15 patients who were accepted and who received support with a ventricular assist device (14 patients) or a total artificial heart (1 patient). Seven of the 15 patients received transplants and survived, whereas contraindications to transplant developed in seven patients while they were receiving support, and these seven died. One patient remains hospitalized after transplantation. Group 2 consisted of 11 patients rejected for circulatory support because of renal insufficiency or infection (9), pulmonary embolus (1), and cerebrovascular accident (1). Two group 2 patients underwent transplant procedures after their complications resolved, and one survived. One other group 2 patient who recovered without transplantation or mechanical support was discharged. There was no significant difference in age, gender, or cause of cardiogenic shock between the two groups. Four of five patients accepted for mechanical support on the first evaluation survived, and three of 10 accepted after the initial evaluation survived, indicating that delayed selection often results in complications that preclude transplantation and survival. Only one of the 26 patients survived without transplantation or support. These data emphasize the importance of patient selection on the outcome of bridging to transplantation.

Adult↗