Assessment of the breath alcohol concentration in emergency care patients with different level of consciousness

Annika Kaisdotter Andersson, Josefine Kron, Maaret Castren, Asa Muntlin Athlin, Bertil Hok, Lars Wiklund

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)


Background: Many patients seeking emergency care are under the influence of alcohol, which in many cases implies a differential diagnostic problem. For this reason early objective alcohol screening is of importance not to falsely assign the medical condition to intake of alcohol and thus secure a correct medical assessment. Objective: At two emergency departments, demonstrate the feasibility of accurate breath alcohol testing in emergency patients with different levels of cooperation. Method: Assessment of the correlation and ratio between the venous blood alcohol concentration (BAC) and the breath alcohol concentration (BrAC) measured in adult emergency care patients. The BrAC was measured with a breathalyzer prototype based on infrared spectroscopy, which uses the partial pressure of carbon dioxide (pCO2) in the exhaled air as a quality indicator. Result: Eighty-eight patients enrolled (mean 45 years, 53 men, 35 women) performed 201 breath tests in total. For 51% of the patients intoxication from alcohol or tablets was considered to be the main reason for seeking medical care. Twenty-seven percent of the patients were found to have a BAC of <0.04 mg/g. With use of a common conversion factor of 2100:1 between BAC and BrAC an increased agreement with BAC was found when the level of pCO2 was used to estimate the end-expiratory BrAC (underestimation of 6%, r = 0.94), as compared to the BrAC measured in the expired breath (underestimation of 26%, r = 0.94). Performance of a forced or a non-forced expiration was not found to have a significant effect (p = 0.09) on the bias between the BAC and the BrAC estimated with use of the level of CO2. A variation corresponding to a BAC of 0.3 mg/g was found between two sequential breath tests, which is not considered to be of clinical significance. Conclusion: With use of the expired pCO2 as a quality marker the BrAC can be reliably assessed in emergency care patients regardless of their cooperation, and type and length of the expiration.

Original languageEnglish
Article number11
Number of pages9
JournalScandinavian Journal of Trauma, Resuscitation and Emergency Medicine
Publication statusPublished - 6 Feb 2015
Externally publishedYes

Bibliographical note

© 2015 Kaisdotter Andersson et al.; licensee BioMed Central. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated.


  • Blood alcohol concentration
  • Breath alcohol concentration
  • Emergency care patients
  • Patient cooperation


Dive into the research topics of 'Assessment of the breath alcohol concentration in emergency care patients with different level of consciousness'. Together they form a unique fingerprint.

Cite this