ORAL END TIDAL CARBON DIOXIDE PROBE

• US 20100099999A1
• Filed: 10/14/2009
• Published: 04/22/2010
• Est. Priority Date: 10/16/2008
• Status: Abandoned Application

• Current Assignee: Vanderbilt University
• Original Assignee: Vanderbilt University
• Inventors: Newman, Alexander, Newman, John, Hemnes, Anna R.
• Application Number:
  US12/578,841
• Publication Number:
  US 20100099999A1
• Time in Patent Office: Days
• US Class Current: 600/532
• CPC Class Codes: A61B 5/0836 Measuring rate of CO2 production

Abstract

In embodiments of the present invention improved capabilities are described for evaluating pulmonary embolism. A system and method of evaluating pulmonary embolism in a subject may include measuring end tidal partial pressure of exhaled carbon dioxide in the subject, wherein the measurement is made orally, obtaining a clinical approximation of dead space ventilation based on the measurement, and excluding pulmonary embolism when the end tidal partial pressure of exhaled carbon dioxide reaches a threshold.

Claims

1. A method of evaluating pulmonary embolism in a subject comprising:

measuring a carbon dioxide content at end expiration to obtain an end tidal partial pressure of exhaled carbon dioxide in the subject to provide a measurement, wherein the measurement is made orally, wherein a clinical approximation of dead space ventilation is based on the measurement; and

excluding pulmonary embolism when the end tidal partial pressure of exhaled carbon dioxide reaches a threshold.

2. The method of claim 1 wherein the threshold is at least 36 mm Hg.

3. The method of claim 1 further comprising applying a clinical prediction rule.

4. The method of claim 3 wherein applying the clinical prediction rule includes calculating a Wells score, and wherein pulmonary embolism is excluded when the Wells score is at least four.

5. The method of claim 1, wherein the subject is at least one of sedated, intubated, and pediatric.

6. An oral capnometer comprising:

an oral gas capture member that collects expired gases from a mouth of a subject; and

a carbon dioxide measuring device attached to the oral gas capture member that determines levels of carbon dioxide at end expiration from the mouth of the subject.

7. The oral capnometer of claim 6 wherein the subject is at least one of sedated, intubated, and pediatric.

8. The oral capnometer of claim 6, wherein the levels of carbon dioxide are measured continuously.

9. The oral capnometer of claim 6 wherein the levels of carbon dioxide at end expiration include end tidal carbon dioxide.

10. A method of measuring end tidal carbon dioxide in a subject comprising:

collecting expired gas from a mouth of the subject through an oral gas capture member adapted to be disposed on a sampling input of a carbon dioxide measuring device; and

determining levels of expired carbon dioxide in the expired gas.

11. The method of claim 10 wherein the subject is at least one of sedated, intubated, and pediatric.

12. The method of claim 10 wherein the expired carbon dioxide is determined continuously.

13. The method of claim 10 wherein the expired carbon dioxide is end tidal carbon dioxide.

14. An oral capnometer comprising:

an oral gas capture member that collects expired gases from a mouth of a subject; and

a carbon dioxide measuring device integral with the oral gas capture member for determining levels of expired carbon dioxide from the mouth of the subject.

15. The oral capnometer of claim 14 wherein the subject is at least one of sedated, intubated, and pediatric.

16. The oral capnometer of claim 14 wherein the levels of expired carbon dioxide are determined continuously.

17. The oral capnometer of claim 14 wherein the expired carbon dioxide is end tidal carbon dioxide.

18. A system comprising:

an oral gas capture member that collects expired gases from a mouth of a subject;

a gas sensor that identifies and measures an exhaled gas; and

a housing that houses the gas sensor, wherein the housing is integral with the oral gas capture member.

19. The system of claim 18 wherein the exhaled gas includes one or more of carbon dioxide, carbon monoxide, nitrogen, oxygen, and ketone.

20. The system of claim 19 wherein the gas sensor measures a pH of the exhaled gas.