title: Cardiopulmonary bypass: Evidence or experience based?
abstract: OBJECTIVE
  Evidence-based medicine is emerging as a new paradigm for medical practice. The purpose of this study was to evaluate the amount and quality of scientific evidence supporting principles that are currently applied for cardiopulmonary bypass performance.
  
  
  METHODS
  A survey of all German departments of cardiac surgery regarding cardiopulmonary bypass performance disclosed major differences. Consequently, for 48 major principles of cardiopulmonary bypass performance, relevant Medical Subject Headings were identified, and a literature search of the Medline database was performed. Two sequentially applied sets of inclusion-exclusion criteria were selected to assess the best available evidence.
  
  
  RESULTS
  Thirty-three thousand articles relating to the subject were identified. Among these, 1500 fulfilled the first set of inclusion criteria: meta-analysis of (randomized) controlled clinical trials and in vitro and animal studies. Rigorous methodological criteria were then applied to further select remaining publications. Ultimately, 225 articles referring to major cardiopulmonary bypass principles were identified as providing the best available evidence. These were graded according to their methodological rigor (susceptibility to bias). The scientific evidence on the investigated cardiopulmonary bypass principles did not prove to be of a high enough level to allow general recommendations to be made.
  
  
  CONCLUSIONS
  The scientific data concerning the effectiveness and safety of key principles of cardiopulmonary bypass are insufficient in both amount and quality of scientific evidence to serve as a basis for practical, evidence-based guidelines.
authors.affiliation: Clinic for Cardiac Surgery, Medical University of Luebeck, Germany.
authors.forename: Claus
authors.initials: C
authors.lastname: Bartels
authors.forename: Anja
authors.initials: A
authors.lastname: Gerdes
authors.forename: Jörg
authors.initials: J
authors.lastname: Babin-Ebell
authors.forename: Friedhelm
authors.initials: F
authors.lastname: Beyersdorf
authors.forename: Udo
authors.initials: U
authors.lastname: Boeken
authors.forename: Torsten
authors.initials: T
authors.lastname: Doenst
authors.forename: Peter
authors.initials: P
authors.lastname: Feindt
authors.forename: Michael
authors.initials: M
authors.lastname: Heiermann
authors.forename: Christian
authors.initials: C
authors.lastname: Schlensak
authors.forename: Hans-Hinrich
authors.initials: HH
authors.lastname: Sievers
mesh_terms: D000136:Acid-Base Equilibrium; D000818:Animals; D002315:Cardiopulmonary Bypass; D002560:Cerebrovascular Circulation; D019317:Evidence-Based Medicine; D006801:Humans; D007036:Hypothermia, Induced; D016032:Randomized Controlled Trials as Topic