Biomedical subjects

N S Talner

Publications and source records attributed to N S Talner.

At least 55 records · Page 3Linked to original sources

PubMed1976

Markedly improved pulmonary function after open heart surgery in infancy utilizing surface cooling, profound hypothermia, and circulatory arrest.

The use of surface-induced profound hypothermia with limited cardiopulmonary bypass and circulatory arrest markedly diminished the need for mechanical ventilation for patients undergoing cardiac surgery. Eleven of twenty-two patients were extubated in the operating room and five more patients within 70 minutes postoperatively. Five patients required mechanical ventilation. Four of the five were extubated within 24 hours (mean, 19.05 hours); only one patient required mechanical ventilation greater than 24 hours. This experience would indicate that as the age of surgery is decreased, in conjunction with improved technics of cardiac surgery and anesthesia, the need for mechanical ventilation should be diminished.

Anesthesia, Inhalation↗

PubMed1976

Myocardial LDH isozyme distribution in the ischemic and hypoxic heart.

Small myocardial specimens were obtained from 12 patients undergoing coronary reconstructive surgery and from 12 patients undergoing surgical correction for cyanotic congenital heart defects. The specimens were analyzed for LDH isozyme distribution. A control analysis was performed on myocardial specimens obtained at the time of surgical correction for acyanotic congenital heart defects in seven patients with normal coronary arteries. There was a 42% increase in the proportion of A subunits in the hearts of coronary patients as compared to controls. This represented a shift toward an anaerobic isozyme distribution. There was no change in the percentage of A units from the hearts of cyanotic patients as compared to acyanotic hearts of the same age. Cardiac muscle from patients with coronary vascular disease had an altered LDH subunit composition. Such an alteration was not present with chronic systemic hypoxia. These deficiencies may or may not be related to differing local metabolic responses to the two conditions. However, in the clinical situations, ischemic heart muscle may be oxygen deprived to the point of lactic acid production while hypoxic heart muscle usually is not. Consequently, these findings may represent a compensatory cellular mechanism which provides for continued energy production during chronic ischemia by enhancing glycolysis.

Adolescent↗

PubMed1976

Effects of acutely increasing systemic vascular resistance on oxygen tension in tetralogy of Fallot.

Effects of phenylephrine hydrochloride on the degree of hypoxia were studied in six cyanotic patients with tetralogy of Fallot. Baseline aortic and right atrial oxygen saturations, blood gas tensions, pH, and indicator-dilution curves were obtained under stable conditions. Phenylephrine was infused while systemic arterial pressure was monitored continuously. Aortic and right atrial blood samples were measured at each 10 mm Hg systolic pressure increment and decrement and analyzed for pH, PO2, PCO2, and oxygen saturation. A 40 mm Hg peak systolic aortic pressure rise was the arbitrary end point for phenylephrine infusion and the indicator-dilution curve repeated. Aortic oxygen tensions rose in all from 4 to 28 mm Hg (mean, 14 mm Hg). The net right-to-left shunt decreased from 10% to 40% (mean, 25%) with phenylephrine infusion as compared to the shunt under basal conditions. The presumed mechanism related to the increase in systemic vascular resistance relative to right ventricular outflow obstruction with resultant augmentation of pulmonary blood flow. It is concluded that acutely raising systemic vascular resistance in patients with tetralogy of Fallot using phenylephrine infusion has a beneficial effect on systemic arterial oxygen level and might be the medical treatment of choice for protracted hypoxic spells.

Child↗

PubMed1975

Prosthetic valve replacement in children.

Reported clinical experience with prosthetic valve replacement in children have suggested a high operative mortality. We placed 25 valves in 24 children with one operative death. There has been one late death related to pacemaker malfunction, but the remainder of the patients have generally done extremely well. The children have not undergone elective anticoagulation, and the long-term embolism rate has not exceeded the incidence of systemic embolization in adults who have been controlled on warfarin sodium (Coumadin) therapy. The objective of prosthetic valve replacement is myocardial preservation. We believe that valve replacement with currently available prostheses should be undertaken in any child with valvular malfunction who is not well controlled with good medical management.

Adolescent↗

PubMed1975

Postnatal development of obstruction in coarctation of the aorta: role of the ductus arteriosus.

The sequence of events leading to the development of acute obstruction in two infants with coarctation has been defined by clinical, hemodynamic, and angiographic studies. One infant had normally related great arteries and an isolated coarctation, while the other infant had transposition with a hypoplastic right ventricle, a ventricular septal deffect, narrowing of the aortic isthmus, and a localized site of coarctation. In each instance, a posterior aortic shelf--the basic pathologic lesion in coarctation--could be observed angiographically. Signs of aortic obstruction were absent, however, as long as the ductus arteriosus was widely patent. Following ductal obliteration, femoral pulsations diminished, a peak systolic pressure difference was recorded between the ascending and descending aorta, and a discrete area of juxtaductal coarctation was seen. The basic malformation (posterior aortic curtain) would appear to exist in utero, possibly as an aortic branch point. This lesion is nonobstructive as long as blood can traverse the aortic isthmus through the aortic end of the ductus into the descending aorta. Postnatally, as the ductus arteriosus undergoes constriction at its aortic insertion, signs of acute aortic obstruction may b =ecome apparent. Normal femoral arterial pulsations during the newborn examination do not definitively exclude coarctation. Pediatricians should recheck at 2 weeks of age if the infant is asymptomatic or sooner if there are signs of cardiac failure to establish the presence or absence of this defect.

Angiography↗

PubMed1974