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Biomedical subjects

L S Fox

Publications and source records attributed to L S Fox.

26 records · Page 2Linked to original sources
PubMed1982

Relationship of whole body oxygen consumption to perfusion flow rate during hypothermic cardiopulmonary bypass.

Whole body oxygen consumption (Vo2) and its relationship to randomly selected arterial perfusion flow rates (Q) during profoundly hypothermic (20 degrees C) cardiopulmonary bypass were determined in 17 adult patients undergoing routine coronary artery bypass operations. Vo2 falls progressively as Q decreases, from 33 +/- 8.2 ml . min(-1) . m(-2) at Q of 2.0 L . min(-1) . m(-2) to 28 +/- 5.8 at Q of 1.5, 25 +/- 5.7 at Q of 1.0, 20 +/- 4.1 at Q of 0.5, and 14 +/- 5.4 at Q of 0.25. This progressive decrease suggests shutdown of areas of the microcirculation. The upper 70% confidence limit overlaps the asymptote at Qs above 1.2. Percent oxygen extraction increases progressively as Q decreases, from 11 +/- 3.3% at Q of 2.0 to 45 +/- 9.6% at Q of 0.25, suggesting reduced reserves. Mixed venous Po2 and oxygen saturation fall linearly with decreasing Q below 1.2 (r = 0.78 and r = 0.89, p less than 0.0001, respectively), suggesting decreasing flow to perfused areas. Internal jugular venous Po2 and oxygen saturation (measured in 10 patients) fall linearly with decreasing Q below 1.8 (r = 0.72 and r = 0.88, p less than 0.0001, respectively), suggesting decreasing flow to perfused areas of the brain and a difference from the rest of the body in its behavior with decreasing Q. Thus, during cardiopulmonary bypass cerebral blood flow, autoregulation seems present at 20 degrees C. The data set indicates that flows of about 1.2 may be adequate despite limited reserves.

Aged↗
PubMed1979

Pulmonary arteriovenous malformations in children.

Pulmonary arteriovenous malformations are a life-threatening, but curable, cause of persistent cyanosis in children. Abnormal communications may be single or multiple and are usually in the lower lobes. Three patients with pulmonary arteriovenous malformations have recently been managed at this hospital. Ranging in age from 2 to 4 yr, all were female, all were from families with Rendu-Osler-Weber syndrome, and all underwent pulmonary angiography with confirmation of diagnosis. All have had uneventful resection, one of the left lower lobe, one the right upper lobe, and the other the right middle and lower lobes.

Arteriovenous Malformations↗
PubMed1977

Bilateral catamenial pneumothorax.

Bilateral catamenial pneumothorax occurred in a 32-year-old parous woman. The 41 previously reported cases of catamenial pneumothorax occurred on the right side. This patient was treated with left-sided pleurodesis and, subsequently, with hysterectomy and bilateral salpingo-oophorectomy. The pathologic mechanism of this peculiar syndrome has been attributed to reflux of air via the genitalia and fenestrations in the diaphragm, menstrual shedding of endometrial cells growing in the visceral pleura, or, possibly, aveolar tissue damage secondary to vascular and bronchiolar spasm resulting from dinoprost tromethamine released from menstrual debris. Treatment needs to be tailored to fit the individual patient's specific pelvic and intrathoracic pathology and procreative desires.

Adult↗
PubMed1976

Intracardiac repair of cardiac malformations with atrioventricular discordance.

Twenty-six patients with atrioventricular discordance and a variety of ventriculo-arterial connections have had appropriate intracardiac repairs. Seven of 26 patients (26.9%) died early postoperatively, but only two (11.1%) of 18 patients operated upon since May 1972 have died. Ten patients (40%) developed permanent complete heart block. Two patients died late postoperatively; 16 (84.1% of those surviving the early postoperative period) were in NYHA Class I or II at late follow-up. Seventeen of the patients had "corrected transposition." Six developed tricuspid incompetence with regurgitation into the left atrium after repair. Two patients with atrioventricular discordance and double outlet right ventricle survived operation and are asymptomatic but have permanent pacemakers. One patient died after repair of double outlet left ventricle with atrioventricular discordance. Three of four patients with atrioventricular discordance and "pseudotruncus arteriosus" survived repair with valved external conduits and are well. One of two patients is well after repair of "isolated ventricular inversion" and ventricular septal defect.

Adolescent↗