title: Introducing intravascular microdialysis for continuous lactate monitoring in patients undergoing cardiac surgery: a prospective observational study.
abstract: BACKGROUND
  Lactate is a marker of hypoperfusion and may be used for risk assessment in critically ill patients. Although evidence suggests that repeated lactate measurements are of clinical interest, how and when lactate should be analyzed is controversial. Intravascular microdialysis provides a novel method for the continuous monitoring of lactate, which may be clinically beneficial in critically ill patients.
  
  
  METHODS
  Circulating lactate levels were continuously monitored in 80 patients undergoing cardiac surgery using either a separate single-lumen microdialysis catheter or a triple-lumen central venous catheter with an integrated microdialysis function. The catheter was placed with the tip positioned in the superior vena cava. Arterial blood gas samples were taken every hour to obtain reference values, and the lactate levels were analyzed in a blood gas analyzer.
  
  
  RESULTS
  A total of 1,601 paired microdialysis-arterial blood gas lactate samples were obtained. Bland-Altman analysis showed a bias (mean difference) ± limits of agreement (±1.96 SD) of 0.02 ± 0.42 mmol/L. The regression coefficient was 0.98 (P = 0.0001).
  
  
  CONCLUSIONS
  Central venous microdialysis is an accurate and reliable method for continuous blood lactate monitoring in patients undergoing cardiac surgery. The system may be useful for early lactate-guided therapy in critically ill patients.
authors.forename: Fanny
authors.initials: F
authors.lastname: Schierenbeck
authors.forename: Maarten W N
authors.initials: MW
authors.lastname: Nijsten
authors.forename: Anders
authors.initials: A
authors.lastname: Franco-Cereceda
authors.forename: Jan
authors.initials: J
authors.lastname: Liska
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D001784:Blood Gas Analysis / Q000379:methods; D006348:Cardiac Surgical Procedures / Q000379:methods; D019344:Lactic Acid / Q000097:blood; D017551:Microdialysis / Q000379:methods; D016343:Monitoring, Intraoperative / Q000379:methods; D010865:Pilot Projects; D011446:Prospective Studies
chemical_list: D019344:Lactic Acid