Perfusion Techniques that may Decrease Brain Injury During Cardiopulmonary Bypass

Membrane oxygenators do not create bubbles but most will transmit the bubbles which are common in venous reservoir bags. We previously reported the elimination of arterial micro-air in the 0.8m2 Capiox when operated in the inverted position with an open purge line. This same lung failed to eliminate micro-air when operated in the conventional orientation. The purpose of this study was to test the effectiveness of the Capiox as a bubble trap in lungs with a larger surface area (subgroup a-1.6m2) (subgroup b-5.4m2) and at higher flows. Two test circuits were constructed for each size lung (Group 1—conventional orientation) (Group 11—inverted). The circuits were primed with dilute, outdated human blood (Hct. 20 ± 2%). Ten injections of air (5ml) were done for each lung in both test positions. A bubble counter on the outlet side of the lung was used to count bubbles passed through the membrane oxygenator following the air challenge. Thirty second counts were significantly higher (p<.001) in Group I than in Group II for both size lungs. The counts for both groups were: Group I(alb) Group II-inverted (alb) Size 39.4 ± 20.2/30.7 ± 7.8 0.6 ± 0.96/2.0 ± 1.3 (21-30μ), 23.6 ± 11.6/19.6 ± 7.93 0.22 ± 0.6/0.2 ± 0.6 (31-40μ), 18.8 ± 9.13/13.4 ± 4.03 0/0.1 ± 0.3 (41-50μ), 14.5 ± 7.53/21.1 ± 2.99 0/0 (51-60μ), 10.7 ± 6.38/10.1 ± 3.18 0/0 (61-70μ), 8.6 ± 3.47/7.5 ± 3.5 0/0 (71-80μ), 7.9 ± 3.51/5.7 ± 2.91 0/0 (81-90μ) 17.7± 14.67/50.0 ± 4.52 0/0 (>90μ). The inverted orientation of both the Capiox 1.6 and 5.4 m2 lungs with an open purge line was superior to the conventional orientation for micro-air removal. As a bubble trap, both lungs compare favorably to an arterial filter in air handling characteristics. (All data reported as mean ± S.D.).

Section: Materials and Methods _ _ _ _ _ _ _ _ _mentioning

confidence: 99%

An Experimental Evaluation of the Capiox 1.6 and 5.4M² Membrane Oxygenators for Air Removal Efficiency in the Conventional and Inverted Positions

Berryessa,

Tyndal,

Osbourn

1988

“…This lack of human interaction makes it difficult to develop a sense of compassion for the patient, and makes the job mechanical. 5 Statistically, the larger your experience, the greater the chance that you will be forced to recognize the magnitude of the perfusion accident problem. We have seen the need in our practice to relentlessly improve the level of safety we provide our patients.…”

Section: Introduction _____________ _mentioning

confidence: 99%

Perfusion Error Cause Removal: The Perfusion Case Conference

Tyndal,

Berryessa

1988

Prevention of accidents is one of the fundamental elements of perfusion quality. Unfortunately, errors and accidents frequently occur during cardiopulmonary bypass. A recent retrospective survey of perfusionists identified some common accidents. We have previously reported a method of developing protocols to prevent and treat the ten most common perfusion related problems. Until we reach the day when perfusion accidents no longer occur, we need to be able to systematically evaluate failures and prevent their recurrence. We have developed a non-judgmental forum to discuss, analyze, and prevent variances or unusual circumstances that occur during cardiopulmonary bypass. We hold a monthly case conference where we discuss all cases from which we can learn something–interesting cases and cases during which there was a departure from protocol. The purpose of this paper is to discuss the development of a case conference and to outline the format and benefits of such an Error Cause Removal program.

“…3 In a recent review of the literature, sixty to seventy percent of patients who undergo CPB will have at least transient neurological dysfunction postbypass. 30 This is only one of a number of pathophysiologic changes that occur with bypass procedures. It cannot be overstated that these statistics are tragic and unacceptable.…”

Section: Introduction ______________ _mentioning

confidence: 99%

Ten Common Perfusion Problems: Prevention and Treatment Protocols

Schabel,

Berryessa,

Justison

et al. 1987

(J. Extra-Corpor. Technol. 19[3] p. 392-398 Fall 1987, 30 ref.) Research has been done regarding the unfortunate consequences of cardiopulmonary bypass (CPB) problems, but written recommendations for preventing these problems have not been addressed. There are few, if any, commonly accepted protocols (which may decrease morbidity and/or mortality) to deal with specific perfusion accidents. We studied reports dealing with the incidence and nature of perfusion complications and found the most common perfusion problems included: protamine reaction, hypoperfusion, oxygenator failure, blood clotting within the extracorporeal circuit, line separation, gross contamination, transfusion errors, drug errors, gas embolism, and electrical failure. The purpose of this paper is to identify the perfusion problems that are “most likely” to occur, to recommend preventive measures, and to give examples of emergency protocols for treatment of these events. It is felt that the risk of perfusion accidents can be decreased through the use and practice of written prevention and treatment protocols and we recommend that perfusionists, surgeons, and anesthesiologists together do a failure analysis of their own systems and develop prevention and treatment protocols designed for their own needs.