1、Evaluation of CPB devices relative to their capabilities of reducing the transmission of gaseous microemboli (GME) to a patient during cardiopulmonary bypass PD ISO/TR 19024:2016 BSI Standards Publication WB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06National foreword This Published Docume
2、nt is the UK implementation of ISO/TR 19024:2016. The UK participation in its preparation was entrusted by Technical Committee CH/150, Implants for surgery, to Subcommittee CH/150/2, Cardiovascular implants. A list of organizations represented on this committee can be obtained on request to its secr
3、etary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2016. Published by BSI Standards Limited 2016 ISBN 978 0 580 88268 5 ICS 11.040.40 Compliance with a British Standard c
4、annot confer immunity from legal obligations. This Published Document was published under the authority of the Standards Policy and Strategy Committee on 31 August 2016. Amendments/corrigenda issued since publication Date Text affected PUBLISHED DOCUMENT PD ISO/TR 19024:2016 ISO 2016 Evaluation of C
5、PB devices relative to their capabilities of reducing the transmission of gaseous microemboli (GME) to a patient during cardiopulmonary bypass valuation des dispositifs PCP relative leurs capacits de rduire la transmission des micro-embolies gazeuses (MEG) un patient durant un pontage cardiopulmonai
6、re TECHNICAL REPORT ISO/TR 19024 Reference number ISO/TR 19024:2016(E) First edition 2016-09-01 PD ISO/TR 19024:2016 ISO/TR 19024:2016(E)ii ISO 2016 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2016, Published in Switzerland All rights reserved. Unless otherwise specified, no part of this pu
7、blication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the co
8、untry of the requester. ISO copyright office Ch. de Blandonnet 8 CP 401 CH-1214 Vernier, Geneva, Switzerland Tel. +41 22 749 01 11 Fax +41 22 749 09 47 copyrightiso.org www.iso.org PD ISO/TR 19024:2016 ISO/TR 19024:2016(E)Foreword iv Introduction v 1 Scope . 1 2 Normative references 1 3 T erms and d
9、efinitions . 1 4 Abbreviated terms 2 5 Recommendations 2 5.1 General . 2 5.2 Materials and methods 2 5.3 Results and verification of test 3 5.4 Components . 3 Annex A (informative) Rationale for the recommendations of this document 5 Bibliography 6 ISO 2016 All rights reserved iii Contents Page PD I
10、SO/TR 19024:2016 ISO/TR 19024:2016(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body
11、 interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotec
12、hnical Commission (IEC) on all matters of electrotechnical standardization. The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO
13、 documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives). Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held res
14、ponsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents). Any trade name used in this document is information giv
15、en for the convenience of users and does not constitute an endorsement. For an explanation on the meaning of ISO specific terms and expressions related to conformit y assessment, as well as information about ISOs adherence to the World Trade Organization (WTO) principles in the Technical Barriers to
16、 Trade (TBT) see the following URL: www.iso.org/iso/foreword.html. The committee responsible for this document is ISO/TC 150, Implants for surgery, Subcommittee SC 2, Cardiovascular implants and extracorporeal systems.iv ISO 2016 All rights reserved PD ISO/TR 19024:2016 ISO/TR 19024:2016(E) Introduc
17、tion Present-generation extracorporeal circuit devices are not designed to generate gas bubbles, as was the case with bubble oxygenators, as a function of their mechanism to achieve gas transfer. Gaseous microemboli (GME), while significantly reduced in current extracorporeal circuits, are still det
18、ectable. The presence of GME in blood is not a normal condition and can trigger potentially adverse conditions as both a foreign surface and as a particle or embolus. Adverse systemic sequelae from GME may include activation of blood cells, immune responses, and blockage of blood vessels. While attr
19、ibuting a causal relationship between GME and significant adverse clinical sequelae is not clear, laboratory equipment and methodology for testing extracorporeal devices on the bench top and are clinically available for use. This document will review the current scientific literature on GME detectio
20、n methodologies and their clinical relevance. GME testing is currently being performed by companies and research groups. Both users and manufacturers will benefit from the creation of standardized terminology for use in this work. Development of a consensus position on the clinical implications of G
21、ME and the capabilities and limitations of currently utilized monitoring equipment will also serve both users and manufacturers. The currently available monitoring equipment will have a cost impact on all manufacturers and may burden small enterprises more so than existing larger companies. The equi
22、pment cost, however, is less expensive than equipment currently required to evaluate many of the extracorporeal devices such as blood gas analysers, cell counters or spectrometers. Independent investigators with such equipment and expertise are also an option. ISO 2016 All rights reserved v PD ISO/T
23、R 19024:2016 Evaluation of CPB devices relative to their capabilities of reducing the transmission of gaseous microemboli (GME) to a patient during cardiopulmonary bypass 1 Scope This document recommends acceptable methodology for conducting gaseous microemboli (GME) testing and discusses limitation
24、s of current test methods. Tests described in this document are limited to those conducted using an in vitro circulatory system. This document is applicable to all devices intended for extracorporeal circulatory support during cardiopulmonary bypass (CPB). It outlines approaches currently used to as
25、sess the ability of CPB devices to handle GME. 2 Normative references There are no normative references in this document. 3 T erms a nd definiti ons For the purposes of this document, the following terms and definitions apply. ISO and IEC maintain terminological databases for use in standardization
26、at the following addresses: ISO Online browsing platform: available at http:/ /www.iso.org/obp IEC Electropedia: available at http:/ /www.electropedia.org/ 3.1 cardiopulmonary bypass extracorporeal circuit used to support a subjects circulatory and gas exchange requirements when the heart and lungs
27、are temporarily functionally excluded from normal circulation during cardiac surgery 3.2 gaseous microemboli air bubbles present in circulating blood that are in the range 10 m to 500 m diameter 3.3 ultrasonic detector device based on Doppler phenomenon (pulsed or continuous wave) that emits sound s
28、ignals from a piezoelectric crystal that are reflected from moving blood EXAMPLE 1 Transcranial Doppler, transesophageal echocardiography, or clamp-on sensors for extracorporeal tubing with the latter used for bench top in vitro testing. EXAMPLE 2 Ultrasonic detectors are able to discriminate circul
29、ating particles from background blood flow, and detected reflections (or signals) can be analysed in real time to produce a display of approximate quantities and sizes during the sampling time frame. 3.4 whole blood fluid used for bench-top studies involving gaseous microbubbles is anticoagulated wh
30、ole blood TECHNICAL REPORT ISO/TR 19024:2016(E) ISO 2016 All rights reserved 1 PD ISO/TR 19024:2016 ISO/TR 19024:2016(E) 4 Abbreviated terms CPB cardiopulmonary bypass GME gaseous microemboli 5 Recommendations 5.1 General This document addresses current state-of-the-art bench-top testing and is inte
31、nded to provide guidance to those performing such tests so that reproducible results may be obtained to compare devices. Use of anticoagulated whole blood is noted to provide more relevant results when performing bench-top GME studies. This clause provides testing recommendations. 5.2 Materials and
32、methods 5.2.1 The bench-top circuit should be described in sufficient detail so that an identical circuit can be assembled for additional testing by other parties. 5.2.2 The description of the circuit should include the following: physical components, including: tubing dimensions (material, internal
33、 diameter, wall thickness, length); types and dimensions of tubing connectors used; manufacturer and model of detector; number, specific location, and method of attachment of detector sensors in the test circuit; other circuit components such as the device being evaluated; type of pump used to circu
34、late blood; presence of a debubbling chamber (if used); conditions of the test, including temperature of test fluid, fluid flow rate, establishment of baseline conditions, site of injection of bubbles; hematocrit (should be specified); isotonic solution (shall be used for dilution); anticoagulant us
35、ed (should be specified); evidence of calibration of the bubble detector; method of introduction of bubbles into the test circuit (e.g. continuous injection vs. bolus injection), total volume over time of bubbles introduced and means of introduction (e.g. calibrated pump vs. hand injection); gas com
36、position (should be room atmosphere only); reservoir level when using a hard shell (should be specified); volume of blood and the presence (when a soft bag venous reservoir is being tested) and the position of volume regulation mechanism (should be described).2 ISO 2016 All rights reserved PD ISO/TR
37、 19024:2016 ISO/TR 19024:2016(E) 5.2.3 The duration of the test, sampling schedule, and number of tests should be described. 5.3 R esults and v erific ation of t est 5.3.1 Bubble counts according to the location of the detector sensors should be quantified in terms of sizes and numbers. 5.3.2 The to
38、tal volume of gas may be reported based on calculations of sizes and numbers. 5.3.3 Results may be reported in numerical or graphical form. 5.3.4 As noted in 5.2.3 above, the number of tests performed under a given set of conditions must be reported with the results, and if the results represent mea
39、n values of several tests, this should be noted. 5.4 Components Components that may be tested include, but are not limited to, one or a combination of the following: 5.4.1 Combination cardiotomy/venous reservoir This component consists of a hard shell reservoir with multiple inlet connectors and int
40、ernal chambers used to process either cardiotomy-suctioned blood or venous blood. These components may contain gross filters and defoamers for removal of large bubbles and blood debris such as large clots or fat particles. After processing both types of blood, a settling chamber collects the blood f
41、or removal by a pump and transmission through the gas exchange section of the oxygenator. 5.4.2 Standalone cardiotomy reservoir This component is used for processing either cardiotomy-suctioned blood or vent blood. After processing, blood typically drains by gravity into a larger reservoir and becom
42、es part of the circulating blood. Processed blood may be sequestered in the reservoir for additional processing by a cell salvage/wash unit. 5.4.3 Standalone v enous r eserv oir , either har d shell or fle xible bag type These components only collect blood from the CPB venous drainage tubing. 5.4.4
43、Oxy genat or with o r without int egr al art erial filt er This component consists of multiple fine strands of hollow fibres containing flowing gas arranged in a configuration to promote mixing of venous blood near the fibre surfaces for gas exchange to take place. A heat exchanger for circulation o
44、f temperature-controlled water most often is integral to the oxygenator. An integral arterial filter may or may not be part of the oxygenator. 5.4.5 Standalone art eria l filt er This component consists of a fine screen mesh fan-folded to provide sufficient surface area for flows used during CPB wit
45、h an acceptable pressure drop. ISO 2016 All rights reserved 3 PD ISO/TR 19024:2016 ISO/TR 19024:2016(E) 5.4.6 Venous bubble trap This component consists of a chamber intended to trap and remove air bubbles that may be present in the CPB venous tubing. 5.4.7 Blood pump Either a roller pump or a centr
46、ifugal pump may be used in the test circuit. When using a roller pump, the specifications (e.g. dimensions of pump, tubing inner diameter and type, and method of setting the occlusion) must be described. When using a centrifugal pump, the model number must be described.4 ISO 2016 All rights reserved
47、 PD ISO/TR 19024:2016 ISO/TR 19024:2016(E) Annex A (informative) Rationale for the recommendations of this document Ultrasonic bubble detectors are commonly used today, both during clinical perfusion (in vivo) and in the laboratory (in vitro), for measuring bubble activity. Some current-generation C
48、PB circuits have bubble detectors that can be adjusted to distinguish gross bubbles from GME. Ultrasonic detectors have also been used on the CPB circuit at various locations to assess GME removal or production by specific CPB components (e.g. open vs. closed cardiotomy/venous reservoir, roller vs.
49、centrifugal pump or arterial line filter). Echo imaging systems have also been used in recent years (e.g. transesophageal, transthoracic or transcranial) but they are more commonly used to assess effectiveness of cardiac de- airing manoeuvres when cardiac chambers have been opened during valve surgery and are not the subject of this document. The quantification of GME in some studies has been difficult to verify and reproduce due to lack of standardized calibration techniques. It has been suggested tha
