title: In emergently ventilated trauma patients, low end-tidal CO2 and low cardiac output are associated and correlate with hemodynamic instability, hemorrhage, abnormal pupils, and death.
abstract: BACKGROUND
  In a smaller experience, the authors previously demonstrated that end-tidal carbon dioxide (PetCO2) and cardiac output (CO) had a positive association in emergently intubated trauma patients during Emergency Department resuscitation. The aim of this larger study was to reassess the relationship of PetCO2 with CO and identify patient risk-conditions influencing PetCO2 and CO values.
  
  
  METHODS
  The investigation consists of acutely injured trauma patients requiring emergency tracheal intubation. The study focuses on the prospective collection of PetCO2 and noninvasive CO monitor (NICOM®) values in the Emergency Department.
  
  
  RESULTS
  From the end of March through August 2011, 73 patients had 318 pairs of PetCO2 (mm Hg) and CO (L/min.) values. Mean data included Injury Severity Score (ISS) ≥15 in 65.2%, Glasgow Coma Score of 6.4 ± 4.6, hypotension in 19.0%, and death in 34.3%. With PetCO2 ≤ 25 (15.9 ± 8.0), systolic blood pressure was 77.0 ± 69, CO was 3.2 ± 3.0, cardiac arrest was 60.4%, and mortality was 84.9%. During hypotension, CO was lower with major blood loss (1.9), than without major loss (5.0; P = 0.0008). Low PetCO2 was associated with low CO (P < 0.0001). Low PetCO2 was associated (P ≤ 0.0012) with ISS > 20, hypotension, bradycardia, major blood loss, abnormal pupils, cardiac arrest, and death. Low CO was associated (P ≤ 0.0059) with ISS > 20, hypotension, bradycardia, major blood loss, abnormal pupils, cardiac arrest, and death.
  
  
  CONCLUSIONS
  During emergency department resuscitation, a decline in PetCO2 correlates with decreases in noninvasive CO in emergently intubated trauma patients. Decreasing PetCO2 and declining NICOM CO are associated with hemodynamic instability, hemorrhage, abnormal pupils, and death. The study indicates that NICOM CO values are clinically discriminate and have physiologic validity.
authors.affiliation: Trauma/Critical Services, Level I Trauma Center, St, Elizabeth Health Center, 1044 Belmont Avenue, Youngstown, OH 44501, USA. dunham.michael@sbcglobal.net.
authors.forename: C Michael
authors.initials: CM
authors.lastname: Dunham
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Chirichella
authors.forename: Brian S
authors.initials: BS
authors.lastname: Gruber
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Ferrari
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Martin
authors.forename: Brenda A
authors.initials: BA
authors.lastname: Luchs
authors.forename: Barbara M
authors.initials: BM
authors.lastname: Hileman
authors.forename: Renee
authors.initials: R
authors.lastname: Merrell
references.citation: J Trauma Acute Care Surg. 2012 Aug;73(2):479-85
references.pmid: 23019674
references.citation: J Trauma. 2007 Nov;63(5):1032-42
references.pmid: 17993948
references.citation: Crit Care Med. 2009 Sep;37(9):2642-7
references.pmid: 19602972
references.citation: J Trauma. 2006 Aug;61(2):429-33; discussion 433-5
references.pmid: 16917461
references.citation: Crit Care Med. 2000 Jul;28(7):2415-9
references.pmid: 10921572
references.citation: Crit Care Med. 1994 Nov;22(11):1827-34
references.pmid: 7956288
references.citation: J Trauma. 2002 Oct;53(4):738-43
references.pmid: 12394876
references.citation: Anesth Analg. 1994 Nov;79(5):829-33
references.pmid: 7978395
references.citation: Ann Emerg Med. 1990 Oct;19(10):1104-6
references.pmid: 2121075
references.citation: J Cardiothorac Vasc Anesth. 2013 Feb;27(1):121-34
references.pmid: 22609340
references.citation: Crit Care. 2008;12(5):R115
references.pmid: 18786260
references.citation: J Emerg Med. 2012 Nov;43(5):e277-82
references.pmid: 22560133
references.citation: Anesth Analg. 2001 Feb;92(2):306-13
references.pmid: 11159221
references.citation: Crit Care. 2010;14(3):R118
references.pmid: 20553586
references.citation: Semin Cardiothorac Vasc Anesth. 2010 Dec;14(4):274-82
references.pmid: 21059611
references.citation: Crit Care Med. 1991 Feb;19(2):231-43
references.pmid: 1989759
references.citation: J Trauma. 2009 Jan;66(1):32-9; discussion 39-40
references.pmid: 19131803
references.citation: Crit Care Med. 1987 Oct;15(10):958-9
references.pmid: 3115681
references.citation: J Extra Corpor Technol. 2004 Sep;36(3):255-7
references.pmid: 15559744