Method for the non-invasive detection of an intravascular injection of an anesthetic by the use of an indicator dye

• US 5,402,779 A
• Filed: 06/07/1994
• Issued: 04/04/1995
• Est. Priority Date: 04/29/1994
• Status: Expired due to Fees

• Current Assignee: Charles E. Laurito, William X. Chen
• Original Assignee: Charles E. Laurito, William X. Chen
• Inventors: Chen, William X., Laurito, Charles E.
• Primary Examiner(s): Cohen, Lee S.
• Assistant Examiner(s): NASSER, ROBERT L
• Application Number:
  US08/254,957
• Time in Patent Office: 301 Days
• Field of Search: 128/633, 128/634, 128/664-666, 128/897, 128/898, 128/653.1
• US Class Current: 600/322
• CPC Class Codes: A61B 17/3401 Puncturing needles for the peridural or subarachnoid space or the plexus, e.g. for anaesthesia local anaesthesia A61M19/00
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor

Abstract

A method and apparatus in which an anesthesia catheter is inserted into the epidural space of the patient. A blood soluble dye mixed with a local anesthetic is injected through the catheter and into the patient. A transducer clip is positioned on the finger of the patient for monitoring the light responsive characteristics of the patient'"'"'s blood. A transducer signal is fed to a microprocessor for generating a real time display for indicating to the anesthesiologist that the dye, and therefore the local anesthetic, is present in the bloodstream.

Claims

1. A method for use by an anesthesiologist for non-invasively determining whether an anesthetic has inadvertently entered a blood vessel of a patient, comprising:

inserting an anesthesia catheter into the body of a patient;

preparing a blood soluble dye having light absorption characteristics and characteristics which permit its flow within the bloodstream of the patient;

injecting the blood soluble dye through the catheter and into the patient;

non-invasively monitoring the patient'"'"'s blood at a location remote from the catheter, said monitoring detecting a change in transmitted light through the blood to sense the presence of the dye in the bloodstream; and

indicating to the anesthesiologist that the dye has been sensed in the bloodstream by said step of monitoring.

2. A method according to claim 1 wherein said step of monitoring includes transmitting light of a wavelength related to said light absorption characteristics of said dye through the patient'"'"'s blood.

3. A method according to claim 2 wherein said step of monitoring includes sensing the intensity of light transmitted through the patient'"'"'s bloodstream.

4. A method according to claim 1 wherein said step of monitoring includes securing a transducer at the fingertip of the patient'"'"'s finger.

5. A method according to claim 1 wherein said step of inserting the catheter includes positioning an end of the catheter in the epidural space of the patient.

6. A method according to claim 1 wherein said step of preparing the dye includes mixing a powdered dye with sterile water.

7. A method according to claim 1 wherein said step of preparing the dye includes adding a stabilizer.

8. A method according to claim 1 wherein said step of preparing the dye includes mixing the dye with an anesthetic;

and wherein said step of injecting the dye includes injecting the mixed dye and anesthetic.

9. A method according to claim 8 wherein said step of injecting the mixed dye and anesthetic includes continuous infusing of the mixed dye and anesthetic throughout a period of time.

10. A method according to claim 1 wherein said step of injecting the dye includes placing a dye in a syringe;

and fixing the syringe to the catheter.

11. A method according to claim 1 wherein said step of indicating includes generating an audible alarm.

12. A method according to claim 1 wherein said step of indicating includes displaying a graph of a real time monitoring of the patient'"'"'s blood.

13. A method according to claim 12 wherein said step of indicating includes visually displaying the real time light absorption characteristics of the bloodstream.

14. A method for use by a medical user for non-invasively determining whether a conduit has inadvertently entered a blood vessel of a patient, comprising:

inserting a conduit into the body of a patient;

preparing a blood soluble dye having characteristics which permit its flow within the bloodstream of the patient;

injecting the blood soluble dye through the conduit and into the patient;

non-invasively monitoring the patient'"'"'s blood at a location remote from the conduit to sense for the dye in the bloodstream; and

indicating to the medical user that the conduit has inadvertently entered a blood vessel because the dye has been sensed in the bloodstream by said step of monitoring.