CO.sub.2 indicator and the use thereof to evaluate placement of tracheal tubes

• US 5,005,572 A
• Filed: 01/31/1989
• Issued: 04/09/1991
• Est. Priority Date: 02/26/1988
• Status: Expired due to Term

• Current Assignee: Bregas AB
• Original Assignee: Brigham and Women's Hospital Incorporated
• Inventors: Munkholm, Christianne, Walt, David R., Raemer, Daniel B.
• Primary Examiner(s): Burr, Edgar S.
• Assistant Examiner(s): Lewis, Aaron J.
• Application Number:
  US07/303,952
• Time in Patent Office: 798 Days
• Field of Search: 128/207.14, 128/768, 128/205.23, 422/58, 422/91, 422/55, 436/133
• US Class Current: 128/207.14
• CPC Class Codes: A61M 16/042 with separate conduits for in-and expiration gas, e.g. for limited dead volume
• CPC Class Codes: A61M 16/0488 Mouthpieces; Means for guiding, securing or introducing the tubes guiding or introducing with laryngoscopes A61B1/267; holding devices on the body A61M25/02
• CPC Class Codes: A61M 16/085 Gas sampling
• CPC Class Codes: A61M 2016/0413 with detectors of CO2 in exhaled gases
• CPC Class Codes: A61M 2230/202 partial carbon oxide pressure, e.g. partial dioxide pressure (P-CO2)
• CPC Class Codes: G01N 31/223 for investigating presence of specific gases or aerosols G01N31/221, G01N31/222 take precedence; actuation of fire alarm by presence of smoke or gases G08B17/10

Abstract

The invention relates to a CO₂ detector for the detection of CO₂ in respiratory gases. In particular, the invention relates to medical devices which contain a CO₂ detector disposed within the devices to allow detection of CO₂ within respiratory gases.

The invention also relates to a method for determining the proper placement of an intubation device comprising inserting a tracheal tube having a CO₂ detector disposed within, and observing whether the CO₂ detector changes color in response to the CO₂ which is present in respiratory gases.

The CO₂ detectors of the invention comprise a pH sensitive dye and a solid phase support. The CO₂ detectors of the invention may further comprise a phase transport enhancer which allows the CO₂ detector to respond contemporaneously with the presence or absence of CO₂ in a respiratory gas on a breath by breath basis.

Claims

1. Apparatus, comprising:

means for enabling visual observation of proper placement of an endotracheal tube in the trachea of a patient, said means comprising;

a. an endotracheal apparatus which indicates a tracheal tube defining a gas path; and

b. a CO₂ detector disposed within said endotracheal apparatus at a location which is in said gas path of said tube and is visible when said endotracheal tube is inserted, said detector comprising a backing and an indicator material, said indicator material comprising a support material, a pH-sensitive dye, and a phase transport enhancer for enhancing a reaction between H₂ CO₃ and said pH-sensitive dye, said phase transport enhancer having the formula;

##STR7## wherein X=N or P,

R₁, R₂, R₃ and R₄ are selected from the group consisting of C₁ -C₁₂ alkyl,

C₁ -C₄ substituted alkyl wherein the substituent is a C₁ -C₄ alkyl or phenyl group,

naphthyl,

benzyl, and

pyridine;

R₅ is selected from the group consisting of C₁ -C₁₂ alkyl and benzyl; and

Y^- is an anion selected from the group consisting of hydroxide, fluoride, chloride, bromide, iodide, carbonate and tetrafluoroborate.

2. Apparatus as recited in claim 1, wherein said phase transport enhancer is selected from the group consisting of tetrabutylammonium hydroxide, tetrabutylammonium chloride, tetraethylammonium bromide, tetraethylammonium ammonium, p-toluenesulphonate, phenyltrimethylammonium chloride, benzyltrimethyl-ammonium bromide, tetra-n-propyl-ammonium bromide, benzyltriethylammonium tetrafluoroborate, n-dodecyltrimethylammonium bromide, tetraphenylphosphonium chloride, n-hexadecylpyridinium bromide and triphenylmethyl-triphenylphosphonium chloride.

3. A tracheal intubation apparatus, comprising:

means for receiving gas expired from a person; and

a detector disposed within said means for visually indicating whether a substantial concentration of CO₂ is present in said gas, wherein said detector comprises indicator material which changes from one color in the presence of CO₂, and changes to another color in response to an absence of CO₂, said indicator material comprising a support material, a pH-sensitive dye, and phase transport enhancer for enhancing a reaction between H₂ CO₃ and said pH-sensitive dye, said phase transport enhancer having the formula;

##STR8## wherein X=N or P,

R₁, R₂, R₃ and R₄ are selected from the group consisting of C₁ -C₁₂ alkyl,

C₁ -C₄ substituted alkyl wherein the substituent is a C₁ -C₄ alkyl or phenyl group, naphthyl,

benzyl, and

pyridine;

R₅ is C₁ -C₁₂ alkyl or benzyl; and

Y^- is an anion selected from the group consisting of hydroxide, fluoride, chloride, bromine, iodide, carbonate and tetrafluoroborate.

4. A tracheal intubation apparatus, comprising:

means for receiving gas expired from a person; and

a detector dispersing within said means for visually indicating whether a substantial concentration of CO₂ is present in said gas;

wherein said detector comprises a phase transport enhancer and a dye solution applied to a support material, said phase transport enhancer enhancing a reaction between H₂ CO₃ and said dye solution, said phase transport enhancer having the formula;

##STR9## wherein X=N or P,

R₁, R₂, R₃ and R₄ are selected from the group consisting of C₁ -C₁₂ alkyl,

C₁ -C₄ substituted alkyl wherein the substituent is a C₁ -C₄ alkyl or phenyl group,

naphthyl,

benzyl, and

pyridine;

R₅ is C₁ -C₁₂ alkyl or benzyl; and

Y^- is an anion selected from the group consisting of hydroxide, fluoride, chloride bromide, iodide, carbonate and tetrafluoroborate.

5. A breath indicator comprising:

a. means for receiving CO₂ ;

b. a detector disposed within said means for receiving CO₂, said detector comprising means for changing between a first color and a second color, said first color indicating an absence of CO₂ and said second color indicating a presence of CO₂, said means for changing between a first color and a second color comprising indicator material, said indicator material further comprising a dye and a phase transport enhancer for enhancing a reaction between HC₂ 0₃ and said dye, said phase transport enhancer having the formula;

##STR10## wherein X=N or P,

R₁, R₂, R₃ and R₄ are selected from the group consisting of C₁ -C₁₂ alkyl,

C₁ -C₄ substituted alkyl wherein the substituent is a C₁ -C₄ alkyl or phenyl group,

naphthyl,

benzyl, and

pyridine;

R₅ is C₁ -C₁₂ alkyl or benzyl; and

Y^- is an anion selected from the group consisting of hydroxide, fluoride, chloride, bromide, iodide, carbonate and tetrafluoroborate.

6. A breath indicator comprising:

a. means for receiving CO₂ ;

b. a detector disposed within said means for receiving CO₂, said detector comprising means for changing between a first color and a second color, said first color indicating an absence of CO₂ of said second color indicating a presence of CO₂, said means for changing between a first color and a second color comprising indicator material, said indicator material comprising a support material, a pH-sensitive dye applied to said support material, and a phase transport enhancer for enhancing a reaction between H₂ CO₃ and said pH-sensitive dye, said phase transport enhancer having the formula;

##STR11## wherein X=N or P,

R_l, R₂, R₃ and R₄ are selected from the group consisting of C₁ -C₁₂ alkyl,

C₁ -C₄ substituted alkyl wherein the substituent is a C₁ -C₄ alkyl or phenyl group,

naphthyl,

benzyl, and

pyridine;

R₅ is C₁ -C₁₂ alkyl or benzyl; and

Y^- is an anion selected from the group consisting of hydroxide, fluoride, chloride, bromide, iodide, carbonate and tetrafluoroborate.

7. A method for determining the proper placement of an endotracheal intubation device comprising the steps of

(1) inserting a device into the trachea of a patient, said method comprising to steps of providing:

(a) an endotracheal apparatus which includes a tracheal tube defining a gas path; and

(b) a CO₂ detector disposed within said endotracheal apparatus at a location which is in the gas path of said tube and is visible when said endotracheal tube is inserted, said detector being capable of indicating whether a substantial concentration of CO₂ is present n said gas, said CO₂ detector comprising a backing, and an indicator material, said indicator material comprising a solid phase support, a pH-sensitive dye, and a phase transport enhancer for enhancing a reaction between H₂ CO₃ and said pH-sensitive dye, said phase transport enhancer having the formula;

##STR12## wherein X=N or P,

R₁, R₂, R₃ and R₄ are selected from the group consisting of C₁ -C₁₂ alkyl,

C₁ -C₄ substituted alkyl wherein the substituent is a C₁ -C₄ alkyl or phenyl group,

naphthyl,

benzyl, and

pyridine;

R₅ is selected from the group consisting of C₁ -C₁₂ alkyl or benzyl; and

Y^- is an anion selected from the group consisting of hydroxide, fluoride, chloride, bromide, iodide, carbonate and tetrafluoroborate; and

(2) observing a color change of the indicator which indicates the presence of CO₂ in the respiratory gas and thereby the proper placement of the endotracheal tube.

8. The method of claim 7, wherein said phase transport enhancer is selected from the group consisting of tetrabutylammonium hydroxide, tetrabutylammonium chloride, tetraethylammonium bromide, tetraethylammonium p-toluenesulphonate, phenyltrimethylammonium chloride, benzyltrimethylammonium bromide, tetra-n-propylammonium bromide, benzyltriethylammonium tetrafluoroborate, n-dodecyltrimethylammonium bromide, tetraphenylphosphonium chloride, n-hexadecylpyridinium bromide, and triphenylmethyltriphenylphosphonium chloride.