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Biomedical subjects

J F Cockburn

Publications and source records attributed to J F Cockburn.

6 recordsLinked to original sources
PubMed1995

Device to enhance visibility of needle or catheter tip at color Doppler US.

The authors tested a device that allows the tip of a needle to be visualized at color Doppler ultrasonography. The device directs an oscillating air column through a 0.016-inch inner-diameter hollow stylet, creating movement at only the needle tip. The movement is reliably and accurately displayed as a beacon of color at depths of 15 cm in vitro.

Catheterization↗
PubMed1992

Thrombin-soaked embolization coils: the effect on whole blood clotting time.

Embolization coils are well established as embolic agents for the treatment of various conditions. Several authors have commented on the increased 'thrombogenicity' of coils following soaking in thrombin solutions. We have carried out an in vitro study, carefully measuring the effect on whole blood clotting time (WBCT), of soaking coils in thrombin solutions of different concentrations (100, 200, 400, 1000 U/ml). Untreated steel coils are shown to have clot promoting activity (CPA) in vitro, reducing WBCT from 14.85 min to 5.53 min. Passing the coils down a saline-filled catheter slightly reduces their CPA, but not significantly (p = 0.21). With thrombin concentrations above 100 U/ml, a significant reduction in WBCT is recorded, but although there is a trend of increasing CPA with increasing thrombin concentration from 200-1000 U/ml, a plateau in WBCT is seen, and the difference is not significant. It therefore appears that the clot promoting activity of embolic coils is significantly increased by soaking them in a relatively weak thrombin solution. The use of such a solution (e.g. 200 U/ml) in vivo would have obvious value in limiting the potential systemic effects of thrombin.

Blood Coagulation↗
PubMed1992

Insertion of Hickman central venous catheters by using angiographic techniques in patients with hematologic disorders.

During a 9-month period, 69 Hickman catheters were successfully inserted by using angiographic techniques in 59 patients with hematologic disorders. A pneumothorax, which did not require drainage, developed in one patient. No other significant complications occurred at the time of insertion. Eighteen catheters were removed electively, 15 are still in situ, six were removed for thrombosis, and five were accidentally removed. Infection precipitated removal in six subjects. Ten patients died with the catheter in place. Five catheters were removed in patients with refractory septicemia of unknown origin. One catheter burst during an injection and had to be removed. Three patients were lost to follow-up. There were 3.24 infectious episodes per 1000 days of catheterization, more than twice the rate found in some other series. The results of this study are compatible with the growing body of evidence in favor of the angiographic insertion of Hickman catheters. The apparently high rate of infection is ascribed to factors other than insertion in the angiography suite, including the high proportion of bone marrow transplantation patients.

Adolescent↗