Proceedings

Air-Eliminating Characteristics of Five Cardiotomy Reservoirs

Milwaukee Heart Surgery Associates, Milwaukee, WI

^* Direct communications to: James E. Bohby. II. C.C.P.. Milwaukee Heart Surgery Associates. S.C.. 3112 West Highland Blvd.. Milwaukee. WI 5320X

Abstract

Five unfiltered cardiotomy reservoirs were bench-tested to determine their effectiveness at producing air-free blood. The test circuit closely resembled our clinical setup.

Pump blood with a hematocrit of 22 - 25% and ACT greater than 400 seconds was pumped through the test reservoirs at flows of .3, .5, . 7, 1.0, and 1.3 liters per minute, and at reservoir levels of 0, 10, 20, 30, 40, 50, and 100 mi. Thirty-five separate runs were done on each of five reservoirs. Blood was filtered through a 20 micron filter before being recycled. The number of gaseous emboli emanating from the reservoirs was estimated using a Technique Labs bubble activity monitor. Gross air production and transmission were measured by aspiration of the accumulated air from a 20 micron cardiotomy filter.

The reservoirs were ranked at the 35 flow-level combinations as follows: lowest bubble count = 1, highest count = 5. The average ranks were: Intersept HRI8900- 10, 1.1; Harvey H500, 2.4; Shiley CARD, 2. 7; Bentley BCR 3000, 4. 1; and Dideco D 640, 4.7. Total air accumulated for all 35 runs for each reservoir was: Intersept HRI 8900- 10, 10cc.; Bentley BCR 3000, 56 cc.; Harvey H 500, 544 cc.; Shiley CARD, 918 cc.; and Dideco D 640, 2036 cc. In both tests. the Intersept was the most effective and the Dideco proved the least effective.