THE USE of cardiopulmonary bypass has enabled the delivery of complex cardiovascular surgical procedures. Cardiopulmonary bypass (CPB), at its best, involves a highly technical process that is executed carefully through a complex interaction among a surgeon, an anesthesiologist, and a cardiovascular perfusionist. More than a decade ago, early practice was to review the literature and summarize best practices based on the published evidence that began to appear in the literature.
We were coauthors of one such review that has been highly cited in the literature.2 More recently, professional societies have convened expert panels to write clinical practice guidelines based on evidence using a more rigorous and structured methodology. The Institute of Medicine defines clinical practice guidelines as “statements that include recommendations, intended to optimize patient care, that are informed by a systematic review of evidence and an assessment of the benefits and harms of alternative care options.”4 Some of the first  guidelines in anesthesiology were undertaken by the Society of Thoracic Surgeons (STS) and were related to technical surgical procedures
and device implants such as valve replacements and repairs or pacemaker implants. Some of the early guidelines were related to
surgical care and CPB. In 2007, guidelines related to blood management and transfusion for cardiac surgery were written with
collaboration from the Society of Cardiovascular Anesthesiologists (SCA), and an update to these guidelines was written in
2011, which included collaboration with the American Society of Extracorporeal Technology’s (AmSECT’s) International Consortium for Evidence Based Perfusion Committee. The STS, SCA, and AmSECT also have collaborated on guidelines for anticoagulation and temperature management during CPB. Guidelines provide clinicians with actionable evidence informed by expert opinion.
The recently published 2019 European Association for Cardio-Thoracic Surgery (ECTS)/European Association for Cardiothoracic Anaesthesiology (EACTA)/European Board for Cardiovascular Perfusion guideline on CPB in adult cardiac surgery, is a timely, well-informed collaborative document that includes an exhaustive structured review of the related literature, and where evidence is lacking, expert consensus from all 3 disciplines is provided.5 To promote wide dissemination, the guideline was copublished with permission in the British Journal of Anaesthesia, the European Journal of Cardio-Thoracic Surgery, and the Interactive CardioVascular and Thoracic Surgery journal. Many of our colleagues in North America took notice of this work and are reading it with great interest. The authors of the guidelines are a multidisciplinary, world class group comprising European surgeons, anesthesiologists, perfusionists, and an epidemiologist.

The guideline was written following the EACTS practice guideline writing instructions. This methodology was modeled after the handbook for guideline writing by the American College of Cardiology (ACC) and American Heart Association (AHA). It is important to note that the EACTS framework uses slightly different definitions for the levels of evidence and classification.
Some of the more important differences between the ACC/AHA and EACTS classifications were pointed out by Baker et al. in their recent editorial.6 However in both cases, the stated aim is to provide well-balanced, objective, and unbiased multidisciplinary recommendations that will be embraced by clinicians and encourage decision- making that endorses patient care on the basis of the best available science and expert opinion. Another benefit of this work is that it identifies areas for which currently there is low evidence and that may perhaps
attract future investigation.