title: Sublingual capnometry and indexes of tissue perfusion in patients with circulatory failure.
abstract: OBJECTIVE
  To examine the relationship between sublingual PCO(2) (PslCO(2)) and other indexes of tissue perfusion.
  
  
  METHODS
  Prospective observational study.
  
  
  METHODS
  Medical and coronary ICUs in a tertiary-care teaching hospital.
  
  
  METHODS
  Twenty-five patients with circulatory failure, 19 patients with sepsis, and 6 patients with cardiac failure.
  
  
  RESULTS
  PslCO(2), gastric intramucosal PCO(2) (PiCO(2)), arterial lactate concentration, systemic oxygen delivery, and systemic oxygen consumption were measured at baseline and at 1, 3, 6, 12, and 24 h after the beginning of the study. PslCO(2) and the PslCO(2)-PaCO(2) gradient were increased but not significantly different in nonsurvivors compared to survivors at baseline. At 24 h, the mean (+/- SE) PslCO(2) was 45 +/- 4 mm Hg in survivors and 61 +/- 4 mm Hg in nonsurvivors (p = 0.06), while the PslCO(2)-PaCO(2) gradient was 14 +/- 3 mm Hg in survivors and 29 +/- 4 mm Hg in nonsurvivors (p < 0.05). No other significant differences in survivors and nonsurvivors were observed in any other index of perfusion. For all patients, the correlations between PslCO(2) and PiCO(2) (r = 0.459; p < 0.05) and cardiac index (r = 0.285; p < 0.05) were observed. The PslCO(2)-PaCO(2) gradient also was correlated with the PiCO(2)-PaCO(2) gradient (r = 0.323; p < 0.05). When patients were placed into subsets of sepsis and cardiac failure, the strength of the correlations increased in the patients with cardiac failure (PslCO(2) vs lactate, r = 0.611 and p < 0.05; PslCO(2) vs PiCO(2), r = 0.613 and p < 0.05; PslCO(2) vs PiCO(2)-PaCO(2) gradient, r = 0.648 and p < 0.05).
  
  
  CONCLUSIONS
  PslCO(2) correlated best with PiCO(2) and arterial lactate concentration in patients with cardiac failure. PslCO(2) and the PslCO(2)-PaCO(2) gradient may be useful as indexes of the severity of perfusion failure.
authors.affiliation: Saint Vincents Hospital and Medical Center, New York, NY 10011, USA.
authors.forename: E C
authors.initials: EC
authors.lastname: Rackow
authors.forename: P
authors.initials: P
authors.lastname: O'Neil
authors.forename: M E
authors.initials: ME
authors.lastname: Astiz
authors.forename: C M
authors.initials: CM
authors.lastname: Carpati
mesh_terms: D018806:APACHE; D001775:Blood Circulation; D019296:Capnography / Q000379:methods; D002245:Carbon Dioxide / Q000097:blood; D002303:Cardiac Output, Low / Q000503:physiopathology; D005753:Gastric Mucosa / Q000737:chemistry; D006439:Hemodynamics; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008875:Middle Aged; D010100:Oxygen / Q000032:analysis; D010101:Oxygen Consumption; D011446:Prospective Studies; D018805:Sepsis / Q000503:physiopathology; D012769:Shock / Q000378:metabolism / Q000503:physiopathology*
chemical_list: D002245:Carbon Dioxide; D019344:Lactic Acid; D010100:Oxygen