New method for describing the performance of cardiac surgery cannulas.
Cardiac surgery cannulas are characterized by external diameter only, which provides little information about the pressure-flow characteristics of a cannula. A system has been developed to describe pressure-flow characteristics with a single, unitless number, M, which is patterned after a Reynolds friction factor correlation. A cannula with a lower M number has a more favorable pressure-flow relationship. The M number was determined for 16 arterials cannulas ranging in size from 10F to 26F and 27 venous cannulas sized 12F to 36F. Pressure-flow characteristics vary considerably among cannulas from different manufacturers despite having similar French sizes. Clinical decisions regarding choice of cannula can be simplified by using the M number, which gives a more accurate description of the performance characteristics of a cannula than the French size designation.
Delius
R E
RE
Department of Surgery, University of Michigan Medical Center, Ann Arbor 49109-0331.
Montoya
J P
JP
Merz
S I
SI
McKenzie
J
J
Snedecor
S
S
Bove
E L
EL
Bartlett
R H
RH
D006328:Cardiac Catheterization / Q000295:instrumentation*; D002408:Catheters, Indwelling / Q000592:standards*; D002648:Child; D004867:Equipment Design; D006801:Humans; D011312:Pressure; D012212:Rheology