title: Luminal concentrations of L- and D-lactate in the rectum may relate to severity of disease and outcome in septic patients.
abstract: BACKGROUND
  Little is known about the condition of the large bowel in patients with sepsis. We have previously demonstrated increased concentrations of L-lactate in the rectal lumen in patients with abdominal septic shock. The present study was undertaken to assess the concentrations of L- and D-lactate in rectal lumen and plasma in septic patients including the possible relation to site of infection, severity of disease, and outcome.
  
  
  METHODS
  An intensive care unit observational study was conducted at two university hospitals, and 23 septic patients and 11 healthy subjects were enrolled. Participants were subjected to rectal equilibrium dialysis, and concentrations of L- and D-lactate in dialysates and plasma were analysed by spectrophotometry.
  
  
  RESULTS
  Luminal concentrations of L-lactate in rectum were related to the sequential organ failure assessment scores (R2 = 0.27, P = 0.01) and were higher in non-survivors compared to survivors and healthy subjects (mean [range] 5.0 [0.9 to 11.8] versus 2.2 [0.4 to 4.9] and 0.5 [0 to 1.6] mmol/l, respectively, P < 0.0001), with a positive linear trend (R2 = 0.53, P < 0.0001). Also, luminal concentrations of D-lactate were increased in non-survivors compared to survivors and healthy subjects (1.1 [0.3 to 2.5] versus 0.3 [0 to 1.2] and 0.1 [0 to 0.8] mmol/l, respectively, P = 0.01), with a positive linear trend (R2 = 0.14, P = 0.04). Luminal concentrations of L- and D-lactate were unaffected by the site of infection. Plasma concentrations of L-lactate were also increased in non-survivors compared to survivors (3.8 [1.7 to 7.0] versus 1.5 [0 to 3.6] mmol/l, P < 0.01). In contrast, plasma concentrations of D-lactate were equally raised in non-survivors (0.4 [0.1 to 0.7] mmol/l) and survivors (0.3 [0.1 to 0.6] mmol/l) compared with healthy subjects (0.03 [0 to 0.13] mmol/l).
  
  
  CONCLUSIONS
  In patients with severe sepsis and septic shock, luminal concentrations of L- and D-lactate in the rectum were related to severity of disease and outcome.
authors.affiliation: Department of Anaesthesia and Intensive Care, Herlev Hospital, Herlev Ringvej 75, DK-2730 Herlev, Denmark. v.jorgensen@dadlnet.dk
authors.forename: Vibeke L
authors.initials: VL
authors.lastname: Jørgensen
authors.forename: Nanna
authors.initials: N
authors.lastname: Reiter
authors.forename: Anders
authors.initials: A
authors.lastname: Perner
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D019344:Lactic Acid / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D012007:Rectum / Q000737:chemistry*; D018805:Sepsis / Q000145:classification / Q000378:metabolism* / Q000473:pathology; D012720:Severity of Illness Index; D012772:Shock, Septic / Q000145:classification / Q000378:metabolism* / Q000473:pathology; D013053:Spectrophotometry; D013237:Stereoisomerism
chemical_list: D019344:Lactic Acid