Biomedical subjects

L Fagan

Publications and source records attributed to L Fagan.

8 recordsLinked to original sources

PubMed1992

A history-taking system that uses continuous speech recognition.

Q-MED is an automated history-taking system that uses speaker-independent continuous speech as its main interface modality. Q-MED is designed to allow a patient to enter her basic symptoms by engaging in a dialog with the program. Error-recovery mechanisms help to eliminate findings resulting from misrecognitions or incorrect parses. An evaluation of the natural language parser that Q-MED uses to map user utterances to findings showed an overall semantic accuracy of 87 percent; Q-MED asks more specific questions to capture findings that were not volunteered, or that were unable to be parsed in their initial, open-ended form.

Back Pain↗

PubMed1991

Comparison of transthoracic and transesophageal echocardiography for assessment of left-sided valvular regurgitation.

To compare transthoracic and transesophageal echocardiography in the clinical assessment of left-sided valvular regurgitation, 118 patients who underwent both transesophageal and transthoracic echocardiographic studies within a 24-hour period were included in this study. Presence or absence of aortic regurgitation was identified concordantly by both techniques in 93 patients (79%). Complete agreement between both techniques was found in 88 patients (75%). Presence or absence of mitral regurgitation was identified concordantly by both techniques in 89 patients (75%). Complete agreement in grade was found in only 74 patients (63%). Twenty-nine patients (25%) had mitral regurgitation detected by transesophageal echocardiography, but not by transthoracic echocardiography. Four of these patients (14%) had significant (2 to 3+) mitral regurgitation. Differences between transesophageal and transthoracic echocardiography do not appear to be clinically important in patients with aortic regurgitation. In mitral regurgitation, significant differences exist between these 2 techniques, with transesophageal echocardiography being much more sensitive.

Aortic Valve↗

PubMed1991

VentPlan: a ventilator-management advisor.

VentPlan assists physicians, nurses, and respiratory therapists in the management of artificial respiration for critically ill patients in the intensive-care unit (ICU). VentPlan interprets clinical observations, monitored data, and arterial-blood-gas analyses to make recommendations for setting the ventilator. The VentPlan interface allows users to examine the physiologic model, to inspect details of the data on which the model is based, and to exercise the model to try out different ventilator settings before they implement a new setting. We also report here a preliminary evaluation of VentPlan's ability to predict the arterial oxygen and carbon-dioxide tensions following adjustments to the ventilator. We conclude that VentPlan's physiologic models are acceptably accurate for predicting the effects of small adjustments of the ventilator.

Critical Care↗

PubMed1990

Spontaneous echocardiographic contrast in the descending aorta.

The visualization of echocardiographic spontaneous contrast is a common phenomenon in patients undergoing transesophageal echocardiographic studies. Its pathophysiology is not well understood, but it has been related to the presence of a low flow state in the cardiac chambers. We report the presence of spontaneous contrast in the descending aorta of four patients, a location not previously described in the absence of aortic dissection. In two patients, spontaneous contrast was noted in both the left atrium and the descending aorta. In one patient with moderate left ventricular dysfunction, spontaneous contrast was noted in the descending aorta and in the left ventricle. In the remaining case, no cardiac or aortic abnormalities were observed and this represents the first time that spontaneous contrast has been identified in a patient with an echocardiographically normal heart. The occurrence of spontaneous contrast has been considered an abnormal echocardiographic finding, since it has always been described in patients with clinical symptoms and cardiac abnormalities. The fact that spontaneous contrast can be visualized in patients with very mild structural cardiac abnormalities or none at all, warrants further investigation, especially when therapeutic or prognostic implications are considered.

Aged↗

PubMed1978

Repair of aortic coarctation in the first year of life.

Twenty-five infants under 1 year of age (mean, 10.3 weeks and 4.0 kg) underwent coarctation repair. Eight had ventricular septal defect (VSD), 3 had transposition of the great arteries with VSD, and 5 had severe tubular hypoplasia. One infant required mitral valve replacement, and 1 required repair of total anomalous pulmonary venous return. Fifteen had repair by primary anastomosis. Seven underwent Dacron or subclavian aortoplasty; the advantages and technique of angioplasty are reviewed. Three patients required bypass grafts. Seventeen patients survived operation. All 5 patients who had severe tubular hypoplasia died postoperatively. The mortality for repair of coarctation with VSD by simultaneous pulmonary artery banding was high; for coarctation with VSD we currently recommend repair without banding, followed by VSD closure if indicated. Three infants have been treated successfully in this manner, with early VSD closure in 1 and regression of the VSD during follow-up in 2. The 17 survivors have been followed for a mean of 41 months with 3 late deaths. Of the 17 survivors, all of whom had a primary anastomosis, 3 have residual gradients. Of the 11 survivors who had preoperative hypertension, 6 are still hypertensive; 3 of these have a gradient between the upper and lower extremities. It is striking that 3 have persistent hypertension despite repair under the age of 1 year.

Aortic Coarctation↗

PubMed1978

The Blalock-Taussig shunt in the neonate.

With improvements in the techniques of microvascular surgery, the Blalock-Taussig shunt has been applied to smaller infants. We report our experience in 17 neonates (mean age 9 days, mean weight 3.2 kg) who underwent emergency shung operations. The early mortality was 17.6% (3 of 17), with only 1 death (7%) from renal failure and sepsis, in the last 14 patients. Three shunts were patent but inadequate and required a secondary procedure, which was successful in all 3. There were 3 patients with late shunt failures at a mean of 15 months postoperatively, while 2 are still doing well at 15 and 18 months. No patients developed congestive cardiac failure. The late mortality was high (5 of 14), but was due to late shunt failure and was preventable in only 1 patient. These results are encouraging, and we continue to perform the Blalock-Taussig shung in neonates. It is hoped that improvements in technique will reduce the incidence of inadequate shunts.

Adolescent↗

PubMed1977

Long-term effect of the superior vena cava-pulmonary artery anastomosis on pulmonary blood flow.

The long-term effects of the superior vena cava-pulmonary artery anastomosis were evaluated in 15 patients a mean of 8.5 years postoperatively. There were eight patients with tricuspid atresia and seven with other complex anomalies. Ten patients underwent 133xenon ventilation scans and 99mtechnetium perfusion scans in the upright and suprine positions. Perfusion scans showed decreased perfusion of the right upper lobe which improved in the supine position. Shunt flow, measured by thermodilution in nine patients, was a mean of 1.7 L. per minute per square meter, with a mean superior vena caval pressure of 8 mm. Hg and a resistance of 3.0 units. Right and left pulmonary venous saturations were 94 and 96 percent, respectively, showing little intrapulmonary shunting. Venous collaterals were the major cause for shunt failure. Six patients underwent a left Blalock-Taussig shunt and division of venous collaterals a mean of 6 years after the Glenn shunt and are all doing well. The superior vena cava-pulmonary artery anastomosis did not result in progressive pulmonary deterioration in the patients studied. The staged treatment of tricuspid atresia by the Glenn shunt followed by a systemic-pulmonary artery shunt and ligation of venous collaterals gives prolonged effective palliation.

Adolescent↗

PubMed1977

Valve replacement in children.

Since 1964, 27 valve replacements have been performed in patients who ranged from 5 months to 20 years of age. Fourteen underwent aortic valve replacement, 10 underwent mitral valve replacement, two had systemic atrio-ventricular valve replacement, and one had tricuspid valve replacement. Nineteen patients had congenital heart disease, five had rheumatic disease, and three had Marfan's syndrome. Starr-Edwards prostheses were used in 17 patients, Björk-Shiley prostheses in six, and procine xenografts in for. There were five early deaths and five late deaths. Patients were followed for 2 months to 6 years postoperatively (mean 2.1 years). All survivors showed clinical improvement. There were no episodes of thromboembolism. Minor bleeding, arrhythmias, and bacterial endocarditis occurred infrequently.

Adolescent↗