title: Tissue ischemia microdialysis assessments following severe traumatic haemorrhagic shock: lactate/pyruvate ratio as a new resuscitation end point?
abstract: BACKGROUND
  Intensive care of severe trauma patients focuses on the treatment of haemorrhagic shock. Tissues should be perfused sufficiently with blood and with sufficient oxygen content to ensure adequate tissue oxygen delivery. Tissue metabolism can be monitored by microdialysis, and the lactate/pyruvate ratio (LPR) may be used as a tissue ischemia marker. The aim of this study was to determine the adequate cardiac output and haemoglobin levels that avoid tissue ischemia.
  
  
  METHODS
  Adult patients with serious traumatic haemorrhagic shock were enrolled in this prospective observational study. The primary observed parameters included haemoglobin, cardiac output, central venous saturation, arterial lactate and the tissue lactate/pyruvate ratio.
  
  
  RESULTS
  Forty-eight patients were analysed. The average age of the patients was 39.8 ± 16.7, and the average ISS was 43.4 ± 12.2. Hb < 70 g/l was associated with pathologic arterial lactate, ScvO2 and LPR. Tissue ischemia (i.e., LPR over 25) developed when CI ≤ 3.2 l/min/m(2) and Hb between 70 and 90 g/l were observed. Severe tissue ischemia events were recorded when the Hb dropped below 70 g/l and CI was 3.2-4.8 l/min/m(2). CI ≥ 4.8 l/min/m(2) was not found to be connected with tissue ischemia, even when Hb ≤ 70 g/l.
  
  
  CONCLUSIONS
  LPR could be a useful marker to manage traumatic haemorrhagic shock therapies. In initial traumatic haemorrhagic shock treatments, it may be better to maintain CI ≥ 3.2 l/min/m(2) and Hb ≥ 70 g/l to avoid tissue ischemia. LPR could also be a useful transfusion trigger when it may demonstrate ischemia onset due to low local DO2 and early reveal low/no tissue perfusion.
authors.affiliation: Department of anesthesiology and intensive care medicine, University Hospital Ostrava, Faculty of Medicine Universitas Ostrava, 17. listopadu, 1790 Ostrava-Poruba, Czech Republic.
authors.forename: Filip
authors.initials: F
authors.lastname: Burša
authors.affiliation: Traumatology Centre, University Hospital Ostrava, Faculty of Medicine Universitas Ostrava, 17. listopadu, 1790 Ostrava-Poruba, Czech Republic.
authors.forename: Leopold
authors.initials: L
authors.lastname: Pleva
authors.affiliation: Department of anesthesiology and intensive care medicine, University Hospital Ostrava, Faculty of Medicine Universitas Ostrava, 17. listopadu, 1790 Ostrava-Poruba, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Máca
authors.affiliation: Department of anesthesiology and intensive care medicine, University Hospital Ostrava, Faculty of Medicine Universitas Ostrava, 17. listopadu, 1790 Ostrava-Poruba, Czech Republic.
authors.forename: Peter
authors.initials: P
authors.lastname: Sklienka
authors.affiliation: Department of anesthesiology and intensive care medicine, University Hospital Ostrava, Faculty of Medicine Universitas Ostrava, 17. listopadu, 1790 Ostrava-Poruba, Czech Republic.
authors.forename: Pavel
authors.initials: P
authors.lastname: Ševčík
mesh_terms: D000328:Adult; D002302:Cardiac Output / Q000502:physiology; D005260:Female; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D019344:Lactic Acid / Q000378:metabolism*; D008297:Male; D017551:Microdialysis / Q000379:methods; D008875:Middle Aged; D010100:Oxygen / Q000378:metabolism; D011446:Prospective Studies; D019289:Pyruvic Acid / Q000378:metabolism*; D012151:Resuscitation / Q000379:methods; D012720:Severity of Illness Index; D012771:Shock, Hemorrhagic / Q000503:physiopathology / Q000628:therapy*; D012774:Shock, Traumatic / Q000503:physiopathology / Q000628:therapy*; D055815:Young Adult
chemical_list: D006454:Hemoglobins; D019344:Lactic Acid; D019289:Pyruvic Acid; D010100:Oxygen
keywords: Cardiac output; Haemoglobin; Lactate; Microdialysis; Pyruvate; Shock; Transfusion; Trauma