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Closed Circuit Cardiopulmonary Bypass with Centrifugal Pump for Open‐Heart Surgery: New Trial for Air Removal
Author(s) -
Morita Masanori,
Yozu Ryohei,
Matayoshi Toru,
Mitsumaru Atsuhiro,
Shin Hankei,
Kawada Shiaki
Publication year - 2000
Publication title -
artificial organs
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.684
H-Index - 76
eISSN - 1525-1594
pISSN - 0160-564X
DOI - 10.1046/j.1525-1594.2000.06607.x
Subject(s) - centrifugal pump , venous return curve , cardiopulmonary bypass , arterial line , medicine , anesthesia , central venous pressure , biomedical engineering , materials science , surgery , heart rate , blood pressure , mechanics , hemodynamics , physics , impeller
The purpose of this study is to examine the efficiency of venous air removal with a new cardiopulmonary bypass (CPB) circuit design for conventional open‐heart surgeries. A main concern with a closed circuit for open‐heart surgeries is air entrainment into the venous line. A venous filter was placed proximal to the centrifugal pump. The circuit proximal to the centrifugal pump was divided into two lines; one line was attached to the venous reservoir outlet. By clamping the line to the reservoir, this circuit becomes closed. Negative pressure was applied to the purge line connected to the venous reservoir for venous air removal. Micro bubbles were measured at two locations, both distal to the venous and arterial filters. When the injection rate reached 100 ml/min, with the air‐injection over 30 s, micro bubbles greater than 40 μ were observed at the outlet of venous filter. However, there was no micro bubble greater than 40 μ detected at the outlet of arterial filter. Although micro bubbles greater than 40 μ were not detected at the outlet of the arterial filter up to the injection rate of 300 ml/min, when the injection rate reached 400 ml/min, micro bubbles greater than 50 μm were detected distal to the arterial filter. From this examination, we determined that air entrained in the venous line up to approximately 300 ml/min is automatically removed by this method with the pressure‐balanced condition. This pressure balance means that resistance of venous return, gravity siphon, negative pressure by centrifugal pump, and negative pressure applied to the air‐purge line of the filter are balanced; that is, the venous return is sufficient, and the venous reservoir volume is kept stable. From this study we determined that this circuit design efficiently removes the entrained air in the venous line.