ASTM_F_1841_-_97_2013.pdf

Designation:F184197(Reapproved 2013)Standard Practice forAssessment of Hemolysis in Continuous Flow BloodPumps1This standard is issued under the fixed designation F1841;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.INTRODUCTIONThe goal of blood pump development is to replace or supplement the function of the human heart.As a result,continuous flow blood pumps,including roller pumps and centrifugal pumps,arecommonly used in clinical extracorporeal circulation.They are used not only for cardiopulmonarybypass in routine cardiac surgery but also for ventricular assist,percutaneous cardiopulmonarysupport,and extracorporeal membrane oxygenation.Many investigators have attempted to develop an atraumatic blood pump.Hemolysis is one of themost important parameters of blood trauma induced by blood pumps.However,comparative in vitroevaluation of the reported results of hemolysis are difficult due to the lack of uniformity of the testmethods employed.Thus,it is necessary to standardize the method of performing in vitro hemolysistests for the evaluation of continuous flow blood pumps.1.Scope1.1 This practice covers a protocol for the assessment of thehemolytic properties of continuous flow blood pumps used inextracorporeal or implantable circulatory assist.An assessmentis made based on the pumps effects on the erythrocytes overa certain period of time.For this assessment,a recirculation testis performed with a pump for 6 h.1.2 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system may not be exact equivalents;therefore,eachsystem shall be used independently of the other.Combiningvalues from the two systems may result in non-conformancewith the standard.1.3 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2F1830 Practice for Selection of Blood for in vitro Evaluationof Blood Pumps3.Terminology3.1 Definitions:3.1.1 continuous flow blood pumpa blood pump thatproduces continuous blood flow due to its rotary motion.3.1.2 free plasma hemoglobinthe amount of hemoglobin(iron or heme-containing protein)in plasma.3.1.3 hemolysisdamage to erythrocytes resulting in theliberation of hemoglobin into the plasma.3.1.4 Index of Hemolysis3.1.4.1 normalized index of hemolysisadded grams ofplasma free hemoglobin per 100 L of blood pumped,correctedfor plasma volume using hematocrit and normalized by flowrate and circulation time.3.1.4.2 normalizedmilligramindexofhemolysisnormalized index of hemolysis expressed by milligram valueof free plasma hemoglobin.1This practice is under the jurisdiction ofASTM Committee F04 on Medical andSurgical Materials and Devices and is the direct responsibility of SubcommitteeF04.30 onCardiovascular Standards.Current edition approved March 1,2013.Published March 2013.Originallyapproved in 1997.Last previous edition approved in 2005 as F1841 97(2005).DOI:10.1520/F1841-97R13.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.1.4.3 modified index of hemolysismass of hemoglobinreleased into plasma normalized by the total amount ofhemoglobin pumped through the loop.4.Formulas4.1 Normalized Index of Hemolysis(N.I.H.)(1,2,3,4)3:N.I.H.g/100l 5 freeHb3V 31002 Ht1003100Q 3T(1)free Hb=increase of plasma free hemoglobin concentra-tion(g/L)over the sampling time interval,where:V=circuit volume(L),Q=flow rate(L/min),Ht=hematocrit(%),andT=sampling time interval(min).4.2 Normalized Milligram Index of Hemolysis.(mg.N.I.H.)(2,3,4):2mg.N.I.H.mg/100l 5 freeHb3V 31002 Ht1003100Q 3T(2)4.3 Modified Index of Hemolysis(M.I.H.):4.3.1 Modified index of hemolysis(M.I.H.)(5,6)that canbe written with no units or as(milligram of hemoglobinreleased into plasma/mg of total hemoglobin pumped throughthe loop):M.I.H.5 freeHb3V 31002 Ht1003106Q 3T 3Hb(3)where:Hb=total blood hemoglobin concentration at timezero(mg/L),andfree Hb=increase of plasma free hemoglobin concentra-tion(mg/L)over the sampling time interval.4.3.2 Among these indices,M.I.H.is recommended as anindex to express the degree of hemolysis caused by a bloodpump in a recirculating system.N.I.H.was proposed to accountfor the plasma volume based on the hemotocrit.Recentdevelopment of less hemolytic blood pumps has si