title: Noninvasive measurement of carbon monoxide levels in ED patients with headache.
abstract: OBJECTIVE
  Carbon Monoxide (CO), the third most common cause of acute poisoning death, is easily overlooked in the emergency department (ED). Nonspecific complaints such as headache, weakness, or malaise may easily result in misdiagnosis. The objectives of this study are to determine the frequency of CO poisoning in patients presenting to the ED complaining of headaches and to determine the feasibility of using noninvasive CO analyzers as a screening tool.
  
  
  METHODS
  This prospective controlled study examined, during the winter months, adult patients presenting with a complaint of atraumatic, afebrile headaches. All subjects submitted a sample for a CO breath analyzer. Participants with elevated carboxyhemoglobin (COHb) levels (nonsmokers >2%, smokers >5%) underwent venous COHb testing. Control patients, without headaches, presenting to the ED were similarly studied.
  
  
  RESULTS
  We enrolled 170 subjects and 98 controls. Of the 170 subjects, 12 (7.1%) had elevated COHb levels confirmed by venous COHb levels. Of the 98 controls, 1 (1.0%) had an elevated COHb level (p < 0.05). There were no differences in demographic factors between the two groups (p > 0.16).
  
  
  CONCLUSIONS
  Noninvasive measurement of CO levels in ED patients with headaches is rapid and specific. During winter months, elevated CO levels are present in over 7% of ED patients with headaches.
authors: Emergency Medicine Residency, St. Luke's Hospital, 801 Ostrum Street, Bethlehem, PA 18015, USA. eberham@slhn.org
authors: Mary
authors: M
authors: Eberhardt
authors: Andrew
authors: A
authors: Powell
authors: Gary
authors: G
authors: Bonfante
authors: Valerie
authors: V
authors: Rupp
authors: Joseph R
authors: JR
authors: Guarnaccia
authors: Michael
authors: M
authors: Heller
authors: James
authors: J
authors: Reed
mesh_terms: D000328:Adult; D002248:Carbon Monoxide / Q000097:blood*; D002249:Carbon Monoxide Poisoning / Q000150:complications; D004636:Emergency Service, Hospital; D005260:Female; D006261:Headache / Q000097:blood / Q000209:etiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies
chemical_list: D002248:Carbon Monoxide