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Biomedical subjects

R H Zeff

Publications and source records attributed to R H Zeff.

49 records · Page 3Linked to original sources
PubMed1977

A newly designed arterial monitoring/perfusion cannula for cardiac operations.

A newly designed arterial monitoring and perfusion cannula for cardiopulmonary bypass eliminates the need for cannulation of a peripheral artery for pressure monitoring. The double-lumen cannula is designed as follows: the large central lumen (12 to 26f) acts as the arterial inflow conduit from the pump oxygenator, while a second, smaller lumen (18 gauge)constructed in the wall of the first cannula acts as the pressure-monitoring port and the source for blood sampling and drug infusion. This monitoring/perfusion cannula has been used succesfully in more than 250 clinical patients in a variety of settings--total cardiopulmonary bypass, left heart bypass, and when multiple arterial inflow lines were necessary (as in aortic arch replacement). Use of this cannula is advantageous in the infant and pediatric patient or in the emergency setting, when insertion of a peripheral arterial line can be difficult. Used in conjunction with a Doppler system, the cannula provides accurate, dependable blood pressure monitoring.

Blood Pressure↗
PubMed1977

Cardiac hypothermia.

Explore the source record for details and available documents.

Cardiac Surgical Procedures↗
PubMed1976

Reoperation for amputation neuroma of the cystic duct.

Two cases of amputation neuroma of the cystic duct are reported. In both instances, significant symptoms were totally relieved by excision of the neuroma. Review of the literature reveals at least twenty similar cases with the same results. Emphasis is placed on the importance of considering this diagnosis in postcholecystectomy patients after all the usual causes of right upper quadrant symptoms have been ruled out.

Adult↗
PubMed1976

Sternal and costochondral infections following open-heart surgery. A review of 2,594 cases.

From a series of 2,594 patients undergoing open-heart surgery, 39 had sternal or costochondral infections. Most of these infections were associated with a number of predisposing factors: prolonged perfusion time, excessive postoperative bleeding, depressed cardiac output in the postoperative period, and a history of re-exploration for the control of hemorrhage. One important factor was the use of bilateral internal mammary artery implants. The prognosis for patients with sternal wound infections appears related to the length of time required for institution of treatment and the adequacy of initial therapy. Most of these infections are caused by staphylococcus, although the more complicated infections often are caused by fungus. The prevention of serious sternal infections depends on a combination of proper preoperative preparation, attention to minute details at the time of operation, and recognition of variables predisposing to wound complications.

Anti-Bacterial Agents↗
PubMedDate not supplied

A disposable heart-lung machine. Results of animal testing.

A small wave propagation pump (WPP) was incorporated into oxygenators to create a disposable heart-lung machine. The WPP provides undirectional micropulsatile laminar flow of 8 L/min against 800 mmHg. The smaller WPP can generate 4 L/min against 400 mmHg (cardioplegia), or reversed, and can create up to 150 mmHg negative pressure for suction. Power needs were 110 volts and 0.5 amps or 24 volts DC and 1.5 amps. The WPP is self priming (20 cc) and de-aired in less than 3 min. Seven dogs (average weight, 36 kg) were supported for 3 hrs. Flows could accurately be adjusted from 0.005 to 8 L/min. Flow through the oxygenator and perfusion circuit averaged 3.1 L/min (2.0 to 4 L/min). Serial analysis of blood samples showed minimal hemolysis and no significant change in hematocrit, hemoglobin, white blood count, red blood count, or platelet count (p > 0.01). The inexpensive WPP oxygenator combination function as a disposable heart-lung machine.

Animals↗
PubMedDate not supplied

Using magnostrictive metal as a pump for biomedical application.

A new theory of pumping fluids, including blood, has been developed using magnetostrictive technology. This new pump uses the magnetostrictive material known as Terfenol-DTM. A magnetic field is imposed on the Terfenol in periodic pulses causing it to expand and then relax to its original state. The expansion and relaxation of the terfenol cause a smooth, continuous flow of fluid. This pump is currently being built and will be tested as a left ventricular assist device, totally implantable artificial heart, or both.

Electric Power Supplies↗
PubMedDate not supplied

Hemopump support for the failing heart.

Under fluoroscopy, the hemopump is passed through the aortic valve into the left ventricle through a Gortex (WF Gore, Denver, CO) chimney sewn to a surgically exposed femoral artery. The system aspirates the left ventricular blood and actively pumps it into the aorta. Five patients (four men, one woman), aged 47-71 years (mean, 62 years), were candidates for hemopump support because of refractory cardiogenic shock. Three were recovering from repeated coronary artery bypass graft (CABG) surgery, and two required postoperative emergency CABG for failed percutaneous transluminal coronary angioplasty (PTCA). One patient died during insertion, and four had the hemo-pump successfully placed. All patients had low cardiac out-put and had intraaortic balloons in place. Average insertion time took 20 min, with maintenance on the hemopump for an average of 13 hr. One patient was maintained on the hemopump for 12 hr, but because of continued deterioration, was placed on a total artificial heart (Harvik 7-70). Patients 3 (hemopump inserted transthoracically) and 4 had the hemopump discontinued because of brain death, and the fifth survived. This patient is alive and working 1 yr later. The hemopump is an effective left ventricular support system that is less invasive than conventional transthoracic systems.

Aged↗
PubMedDate not supplied

Bridging circulatory support before heart transplant without invasion of the mediastinum.

Heart transplantation is becoming a useful tool in the clinical treatment of patients with end-stage cardiac decompensation. Donor organs are not always available at a critical time for a patient waiting for a transplant. Bridging techniques have been described that use mechanical support systems. This article describes the use of femoral-venous to femoral-arterial bypass over a period of 50 hours in a 38-year-old woman waiting for a donor heart. Because the patient sustained cardiopulmonary arrest before organ availability, mechanical circulatory support that used femoral-venous to femoral-arterial bypass was instituted. The patient's own lungs were used as an oxygenator. Pump flow levels were determined by the level of central aortic oxygen saturation. Successful transplant was performed, and bridging, therefore, was done without invasion of the mediastinum.

Adult↗
PubMedDate not supplied

A new left ventricular assist device: clinical experience in two patients.

A permanent parallel aortic pump (PAP), essentially a permanent intra-aortic balloon pump or modified dynamic aortic patch, has been designed to support failing left ventricles The PAP is a counterpulsation system in which an external energy source delivers a pulsatile wave into the central circulation during cardiac diastole and relaxes during cardiac systole. Clinical improvement occurred in two patients after PAP implantation. The initial regimen of continuous pumping evolved to intermittent left ventricular assistance, and the patients were able to be periodically disconnected from the pump and ambulated. The patients expired 39 and 34 days after implantation due to gastrointestinal bleeding and complications of chronic emphysema and tracheostomy. Autopsy revealed that surgery for both devices had entirely healed.

Aged↗