title: Sublingual capnometry: a new noninvasive measurement for diagnosis and quantitation of severity of circulatory shock.
abstract: OBJECTIVE
  To investigate the feasibility and predictive value of sublingual Pco2 (P(SL)CO2) measurements as a noninvasive and early indicator of systemic perfusion failure.
  
  
  METHODS
  A prospective, criterion study.
  
  
  METHODS
  Emergency department and medical and surgical intensive care units of an urban community medical center.
  
  
  METHODS
  Five normal human volunteers and 46 patients with acutely life-threatening illness or injuries.
  
  
  METHODS
  Intra-arterial or automated cuff blood pressure and arterial blood lactate (LAC) were measured concurrently with P(SL)CO2.
  
  
  RESULTS
  P(SL)CO2 in five healthy volunteers was 45.2 +/- 0.7 mm Hg (mean +/- sD). Twenty-six patients with physical signs of circulatory shock and LAC >2.5 mmol/L had a P(SL)CO2 of 81 +/- 24 mm Hg. This contrasted with patients admitted without clinical signs of shock and LAC of <2.5 mmol/L who had a P(SL)CO2 of 53 +/- 8 mm Hg (p < .001). The initial P(SL)CO2 of 12 patients who died before recovery from shock was 93 +/- 27 mm Hg, and this contrasted with 58 +/- 11 mm Hg (p < .001) in hospital survivors. Increases in P(SL)CO2 were correlated with increases in LAC (r2 = .84; p < .001). When P(SL)CO2 exceeded a threshold of 70 mm Hg, its positive predictive value for the presence of physical signs of circulatory shock was 1.00. When it was <70 mm Hg, it predicted survival with a predictive value of 0.93.
  
  
  CONCLUSIONS
  P(SL)CO2 may serve as a technically simple and noninvasive clinical measurement for the diagnosis and estimation of the severity of circulatory shock states.
authors.affiliation: Institute of Critical Care Medicine, Palm Springs, CA 92262-5309, USA. Weilm@aol.com
authors.forename: M H
authors.initials: MH
authors.lastname: Weil
authors.forename: Y
authors.initials: Y
authors.lastname: Nakagawa
authors.forename: W
authors.initials: W
authors.lastname: Tang
authors.forename: Y
authors.initials: Y
authors.lastname: Sato
authors.forename: F
authors.initials: F
authors.lastname: Ercoli
authors.forename: R
authors.initials: R
authors.lastname: Finegan
authors.forename: G
authors.initials: G
authors.lastname: Grayman
authors.forename: J
authors.initials: J
authors.lastname: Bisera
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001785:Blood Gas Monitoring, Transcutaneous / Q000379:methods; D002140:California / Q000453:epidemiology; D019296:Capnography / Q000379:methods*; D005260:Female; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D012720:Severity of Illness Index; D012769:Shock / Q000097:blood* / Q000175:diagnosis* / Q000401:mortality; D014059:Tongue / Q000378:metabolism*
chemical_list: D019344:Lactic Acid