Biomedical subjects

J W Barr

Publications and source records attributed to J W Barr.

5 recordsLinked to original sources

PubMed1979

The bilateral isodense subdural hematoma on computerized tomographic scan.

Blood causes striking changes on computerized tomography. However, chronic subdural hematomas may become isodense with brain and therefore not visible directly. Midline and ventricular displacement, effacement of cortical sulci, narrowing of white matter on one side, and ventricular distortion should suggest a unilateral isodense process. Bilateral isodense subdural hematomas pose a major problem on computerized tomography since there are no indications of a mass lesion. A negative report could lull the clinician into a false sense of security. In these cases, general disappearance of sulci and considerable narrowing of ventricles are helpful findings. A particularly important and overlooked sign is an abnormally decreased bicaudate cerebroventricular index. Above all, a high degree of suspicion is vital.

Aged↗

PubMed1977

Therapeutic embolization for intractable chronic bleeding.

Intractable, chronic vaginal and/or vesicle bleeding complicating pelvic cancers in five women was treated by transcatheter embolization of the hypogastric artery or its branches. Bleeding was presumed to be from hypervascular granulation tissue formed in response to irradiation in two patients and from tumor tissue in three. The embolic materials were Gelfoam and Oxycel reinforced autologous clots. Bleeding was stopped or reduced in volume by at least 90% in each patient. This form of therapy was useful even though bleeding site was not demonstrated angiographically.

Chronic Disease↗

PubMed1976

Intractable bladder hemorrhage: therapeutic angiographic embolization of the hypogastric arteries.

Malignant intractable bladder hemorrhage in an elderly, high risk patient was controlled effectively with bilateral hypogastric artery occlusion by angiographic placement of oxycel autologous clot emboli. Therapeutic alternatives for intractable bladder hemorrhage are reviewed briefly with particular emphasis on angiographic arterial occlusion. Appropriate anatomic and physiologic aspects of this therapy are discussed.

Aged↗

PubMed1975

Similarity of arterial and intravenous vasopressin on portal and systemic hemodynamics.

The effects of superior mesenteric arterial and intravenous infusions of vasopressin and low and high dose intravenous infusions of vasopressin on splanchnic and systemic hemodynamics were compared in 20 anesthetized dogs. The following parameters were evaluated: flow in the superior mesenteric artery and portal vein, portal and systemic blood pressure, and cardiac output. In the comparison of selective arterial and intravenous infusions, no statistically significant difference was found between the degree of changes in portal flow, portal and systemic blood pressure, and cardiac output. Only the superior mesenteric artery flow showed a greater decrease with the selective arterial injection. In a comparison of intravenous high dose (corresponding to that used clinically) and low dose (one-fifth) infusions of vasopressin, a relatively high splanchnic and low systemic effectiveness of the low dose was found. It resulted in only a 15 to 20% smaller effect on flow in the superior mesenteric artery and portal vein and portal pressure; however, about 40% lesser systemic effect on arterial blood pressure and cardiac output than the high dose. The results of this experimental work warrant exploration in clinical practice, preferably by a controlled study. If clinical success in controlling hemorrhage confirms these hemodynamic results, an intravenous. low dose infusion of vasopressin would appear to be the method of choice in the vasoconstrictive therapy of gastrointestinal bleeding from varices.

Acute Disease↗

PubMedDate not supplied

Vasopressin and hepatic artery. Effect of selective celiac infusion of vasopressin on the hepatic artery flow.

Electromagnetic flow measurement study was performed in 20 anesthetized dogs to evaluate the effect of selective celiac infusion of vasopressin on the hepatic arterial vasculature. Teh hepatic arterial flow showed a biphasic response with an initial decrease followed by a substantial increase in spite of a continued infusion. The left gastric, splenic, and superior mesentric arteries showed a monophasic response with persistent decrease of flow during the whole infusion. The biphasic response of the hepatic arterial flow is thought to be due to autoregulatory dilative action of the liver to a decrease of the portal flow. The results and previous clinical experience suggest that the selective infusions of vasopressin into arteries supplying the liver can be used for short-term vasoconstrictive therapy of acute gastrointestinal bleeding in patients without liver damage. Further experience is necessary to evaluate the safety of prolonged hepatic infusions in patients with liver damage.

Animals↗