title: Retrograde autologous priming: is it useful in elective on-pump coronary artery bypass surgery?
abstract: BACKGROUND
  The effect of reduced cardiopulmonary bypass (CPB) prime volume by retrograde autologous priming (RAP) was studied.
  
  
  METHODS
  Twenty patients undergoing elective coronary artery bypass grafting were randomized to either standard prime (SP) volume (1,602 +/- 202 mL crystalloid prime, n = 10) or RAP (395 +/- 150 mL). RAP was performed by draining crystalloid prime from the arterial and venous lines into a recirculation bag before CPB. Cardiac index, pulmonary vascular resistance index, systemic vascular resistance index, alveolar-arterial oxygen tension difference, pulmonary shunt fraction, extravascular lung water (EVLW), plasma colloid osmotic pressure (COP), crystalloid fluid balance, body weight, and clinical parameters were evaluated perioperatively.
  
  
  RESULTS
  Demographic data and operative parameters were equal for patients in both groups. During CPB, COP was reduced by 55% in the SP group (9.8 +/- 2.0 vs 21.4 +/- 2.1 mm Hg) and by 41% in the RAP group (12.4 +/- 1.1 vs 20.9 +/- 1.8 mm Hg) (p = 0.008, SP vs RAP group). Compared with preoperatively, EVLW was unchanged in the RAP group 2 hours post-CPB, but it was elevated by 21% in the SP group (p = 0.002, SP vs RAP group). End-CPB crystalloid fluid balance was significantly reduced in the RAP group (1,857 +/- 521 vs 2,831 +/- 637 mL). Postoperative (day 2) weight gain in the SP group (1.5 +/- 1.2 kg, p = 0.021) was absent in the RAP group (0.1 +/- 0.9, NS). Postoperative time to full mobilization was shorter in the RAP group. Postpump cardio-respiratory function did not differ among groups.
  
  
  CONCLUSIONS
  This small-scale pilot study indicates that by reducing crystalloid fluid administration and fall of COP during CPB, RAP reduces postpump EVLW accumulation and weight gain in uncomplicated coronary artery bypass graft patients with no associated effects on cardio-respiratory function.
authors.affiliation: Department of Cardiovascular Surgery, Institute of Anesthesiology, German Heart Center Munich, Technical University, Munich, Germany. eising@dhm.mhn.de
authors.forename: Gregory P
authors.initials: GP
authors.lastname: Eising
authors.forename: Martin
authors.initials: M
authors.lastname: Pfauder
authors.forename: Markus
authors.initials: M
authors.lastname: Niemeyer
authors.forename: Peter
authors.initials: P
authors.lastname: Tassani
authors.forename: Hubert
authors.initials: H
authors.lastname: Schad
authors.forename: Robert
authors.initials: R
authors.lastname: Bauernschmitt
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Lange
mesh_terms: D001804:Blood Transfusion, Autologous; D001835:Body Weight; D002315:Cardiopulmonary Bypass / Q000379:methods*; D001026:Coronary Artery Bypass / Q000379:methods*; D017558:Elective Surgical Procedures; D015633:Extravascular Lung Water / Q000502:physiology; D006801:Humans; D008875:Middle Aged; D010100:Oxygen / Q000032:analysis; D011652:Pulmonary Circulation / Q000502:physiology; D014655:Vascular Resistance; D014882:Water-Electrolyte Balance
chemical_list: D010100:Oxygen