title: Patterns of lactate values after congenital heart surgery and timing of cardiopulmonary support.
abstract: BACKGROUND
  We sought to determine if postoperative serial lactate determinations follow predictable patterns that could be useful in directing management, especially the initiation of postoperative mechanical cardiopulmonary support (CPS).
  
  
  METHODS
  Eight patients undergoing CPS in a 2-year period and 147 patients not requiring postoperative CPS in 6 months of that period were stratified into 6 categories based on short-term risk for mortality (1 being the lowest risk). Lactate values for the first 48 hours postoperatively were retrospectively analyzed.
  
  
  RESULTS
  Survivors not requiring CPS in category 6 (n = 16) followed a distinct pattern different from those of categories 1 through 4 (n = 128). Review of postoperative CPS survivors (n = 4) indicated that CPS was initiated electively without cardiac arrest in all 4, and lactate values showed a downward trend within 12 hours of initiation in all cases (mean lactate, 10.12 +/- 1.88 mmol/L; range, 1.4 to 16 mmol/L; mean initiation time, 16.5 hours postoperatively). Three fourths of the CPS nonsurvivors suffered cardiac arrest before CPS and showed rising lactate values despite support (mean lactate, 11.95 +/- 1.37 mmol/L; range, 1.6 to 18.6 mmol/L; mean initiation time, 21.25 hours postoperatively). Indications for initiation of CPS in patients with elevated lactate values were reviewed. Two thirds of patients who died without CPS had preterminal cardiac arrest.
  
  
  CONCLUSIONS
  We have defined the normal pattern of postoperative lactate values in our institution. These data suggest that an abnormal lactate pattern may be useful in determining the timing of CPS initiation in hemodynamically stable patients with high or rising lactate values, before cardiac arrest or end organ damage.
authors.affiliation: Congenital Heart Institute, Miami Children's Hospital, Miami, Florida 33155, USA. rhannan001@aol.com
authors.forename: Robert L
authors.initials: RL
authors.lastname: Hannan
authors.forename: Marion A
authors.initials: MA
authors.lastname: Ybarra
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: White
authors.forename: Jorge W
authors.initials: JW
authors.lastname: Ojito
authors.forename: Anthony F
authors.initials: AF
authors.lastname: Rossi
authors.forename: Redmond P
authors.initials: RP
authors.lastname: Burke
mesh_terms: D016887:Cardiopulmonary Resuscitation; D006323:Heart Arrest / Q000209:etiology / Q000517:prevention & control; D006330:Heart Defects, Congenital / Q000097:blood* / Q000150:complications / Q000601:surgery*; D006801:Humans; D019344:Lactic Acid / Q000097:blood*; D011182:Postoperative Care / Q000379:methods; D011184:Postoperative Period; D012189:Retrospective Studies; D016019:Survival Analysis; D013997:Time Factors
chemical_list: D019344:Lactic Acid