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Biomedical subjects

A H Tahir

Publications and source records attributed to A H Tahir.

At least 19 recordsLinked to original sources

Recurrent Cushing's disease after transsphenoidal surgery.

Thirty-four patients with proven Cushing's disease underwent transsphenoidal surgery between January 1976 and August 1988. Postoperatively, all the patients had biochemically proven remission. Seven patients who had recurrence of their disease (incidence, 20.6%) were evaluated clinically and biochemically and the results are presented. All of seven patients had surgically and pathologically proven pituitary adenomas. All of seven patients had postoperative adrenal insufficiency necessitating steroid replacement for a mean of 8 months. The time of recurrence varied widely and ranged from 29 to 62 months, with a mean of 40 months. We conclude that (1) the longer the period of follow-up, the higher the incidence of recurrence; (2) although the recurrence rate is low (20.6%), it is certainly appreciable; and (3) the time of recurrence can be delayed (62 months) and thus we recommend yearly follow-up with urinary free cortisol determinations.

Adenoma

Increased pulmonary arteriovenous shunting in humans following blood transfusion. Relation to screen filtration pressure of transfused blood and prevention by Dacron wool (Swank) filtration.

Transfusion through standard filters to dogs of stored blood containing microaggregates results in an increase in pulmonary arteriovenous shunting (Qs/Qt) and a decreased diffusion capacity of the lung for O2. These effects are due to microemboli that pass the filters and are prevented by use of Dacron wool (Swank) micropore transfusion filters. It was the purpose of this study to determine whether alterations in pulmonary shunting occur in humans following transfusions of stored blood through standard transfusion filters. In eight patients transfused over 20% of blood volumes through standard filters, Qs/Qt and alveolar-arterial O2 tension differences increased significantly. These changes did not occur in patients transfused comparable amounts of blood through Dacron wool (Swank) filters or in patients transfused less than 20% of blood volumes. A direct correlation was found between the absolute percent change in Qs/Qt and the quantity of microaggregates passing the filter and present in the transfused blood. It is concluded that removal from stored blood of microaggregates by administration of the blood through effective micropore transfusion filters prevents an increase in Qs/Qt caused by administration of such material.

Adult

Acute systemic toxicity from bupivacaine during epidural anesthesia in obstetric patients.

Convulsions occurred within 30 seconds after the injection of bupivacaine through the epidural catheter in four obstetric patients in labor, and mild excitation without convulsions occurred in three others. Since the time between injection and the reaction was so short and since the dose was so small, the response probably was due to intravenous injection resulting from lodgement of the catheter in a vein, rather than to absorption from the epidural space itself. It is not generally known that the epidural veins become thin-walled and engorged during labor; thus, inadvertent placement of a cathether in a vein can occur readily. Convulsions, therefore, may follow even injection of a test dose of a drug. Other colleagues have had similar though unreported experiences. Physicians performing epidural blocks should be aware that such an occurrence is possible and that the catheter may be within a vein without blood returning on aspiration.

Adult