Device for assessing perfusion failure in a patient by measurement of blood flow

• US 20040127800A1
• Filed: 09/23/2003
• Published: 07/01/2004
• Est. Priority Date: 07/06/1995
• Status: Abandoned Application

• Current Assignee: Optical Sensors Incorporated, Weil Institute Of Critical Care Medicine
• Original Assignee: Weil Institute Of Critical Care Medicine
• Inventors: Bisera, Jose, Weil, Ma Harry, Kimball, Victor E., Tang, Wanchun
• Application Number:
  US10/668,750
• Publication Number:
  US 20040127800A1
• Time in Patent Office: Days
• US Class Current: 600/483
• CPC Class Codes: A61B 5/0261 using optical means, e.g. infrared light
• CPC Class Codes: A61B 5/027 using catheters
• CPC Class Codes: A61B 5/0295 using plethysmography, i.e. measuring the variations in the volume of a body part as modified by the circulation of blood therethrough, e.g. impedance plethysmography
• CPC Class Codes: A61B 5/14539 for measuring pH
• CPC Class Codes: A61B 5/14542 for measuring blood gases A61B5/14551 takes precedence
• CPC Class Codes: A61B 5/1459 invasive, e.g. introduced into the body by a catheter A61B5/1464 takes precedence
• CPC Class Codes: A61B 5/1473 invasive, e.g. introduced into the body by a catheter A61B5/1482 takes precedence
• CPC Class Codes: A61B 5/412 Detecting or monitoring sepsis
• CPC Class Codes: A61B 5/42 Detecting, measuring or recording for evaluating the gastrointestinal, the endocrine or the exocrine systems A61B1/00, A61B5/4857, A61B5/486, A61B5/4866, A61B5/4869 take precedence
• CPC Class Codes: A61B 5/4233 oesophagus

Abstract

A device is provided for assessing impairment of blood circulation in a patient, such as that in perfusion failure, by measurement of blood flow adjacent a mucosal surface accessible by a mouth or nose and connecting with the gastrointestinal tract or upper respiratory/digestive tract of a patient. The device includes a blood-flow sensor adapted to be positioned adjacent a mucosal surface with a patient'"'"'s body and measuring blood flow in adjacent tissue and a PCO₂ sensor adapted to be positioned adjacent the mucosal surface and measuring PCO₂. In addition a pH sensor may be used in combination with the blood flow determination. A method of detecting perfusion failure is also disclosed. The method includes utilizing blood-flow measurements in conjunction with a surface perfusion pressure index and/or an optical plethysmography index to more accurately assess perfusion failure. These measurements may also be supplement by taking measurements of pH, sublingual PCO₂, and Sa O₂. The invention affords rapid measurement and detection of perfusion failure.

Claims

1. A device for assessing the degree of systemic perfusion in a patient, the device comprising:

a blood-flow sensor, adapted to be positioned adjacent a mucosal surface within a patient'"'"'s body and measuring blood flow in adjacent tissue;

a PCO₂ sensor, adapted to be positioned adjacent the mucosal surface and measuring PCO₂ in the adjacent tissue; and

an indicating means operably connected to the sensor means, for indicating the measured blood flow and the measured PCO₂ whereby the degree of systemic perfusion of the patient may be deduced.

2. The device of claim 1, wherein the mucosal surface is in the gastrointestinal tract.

3. The device of claim 2, wherein the mucosal surface is in the esophagus.

4. The device of claim 2, wherein the mucosal surface is in the stomach.

5. The device of claim 2, wherein the mucosal surface is in the jejunum.

6. The device of claim 2, wherein the mucosal surface is in the colon.

7. The device of claim 2, wherein the mucosal surface is in the rectum.

8. The device of claim 1, wherein the mucosal surface is in the upper respiratory/digestive tract.

9. The device of claim 8, wherein the mucosal surface is in the nasal passages.

10. The device of claim 9, wherein the mucosal surface is in the vestibule of the nasal cavity.

11. The device of claim 9, wherein the mucosal surface is in the nasal cavity.

12. The device of claim 9, wherein the mucosal surface is in the middle nasal conchae.

13. The device of claim 9, wherein the mucosal surface is in the inferior nasal conchae.

14. The device of claim 9, wherein the mucosal surface is in the choana.

15. The device of claim 9, wherein mucosal surface is in the pharyngeal opening of the auditory tube.

16. The device of claim 8, wherein the mucosal surface is in the oral cavity.

17. The device of claim 8, wherein the mucosal surface is in the pharynx.

18. The device of claim 8, wherein the mucosal surface is in the oropharyngeal passage.

19. The device of claim 1, wherein the mucosal surface is accessible by a mouth and connects with the gastrointestinal tract.

20. The device of claim 1, wherein the mucosal surface is accessible by a nose and connects with the upper respiratory/digestive tract.

21. The device of claim 15, wherein the mucosal surface is a sublingual surface.

22. The device of claim 1, wherein the device further comprises a positioning means for locating or maintaining the blood flow sensor at a position in the upper respiratory/digestive tract.

23. The device of claim 22, wherein the positioning means is a holder adapted to fit within the oral-nasal cavity of the patient and maintain the blood flow sensor in place adjacent the mucosal surface.

24. The device of claim 23, wherein the positioning means is a holder adapted to fit within the mouth of the patient and hold the blood flow sensor in place adjacent the mucosal surface.

25. The device of claim 23, wherein the holder is adapted to position the blood flow sensor adjacent a sublingual mucosal surface.

26. The device of claim 23, wherein the holder is constructed to fit between the inside of a lip and gum of the patient.

27. The device of claim 23, wherein the positioning means is a holder adapted to fit within the vestibule of the nasal cavity of the patient and hold the sensor in place adjacent the mucosal surface.

28. The device of claim 1, wherein the blood-flow sensor is a laser-Doppler blood-flow sensor.

29. The device of claim 1, wherein the blood-flow sensor is an ultrasound-Doppler blood-flow sensor.

30. The device of claim 1, further comprising a pH sensor.

31. The device of claim 1, further including a means for determining the rate of change of blood flow.

32. The device of claim 31 wherein the determining means comprises a circuit for generating a signal representing rate-of-change of blood flow.

33. A device for assessing the degree of systemic perfusion in a patient, the device comprising:

a blood-flow sensor, adapted to be positioned adjacent a mucosal surface within a patient'"'"'s body and measuring blood flow in adjacent tissue;

an indicating means operably connected to the sensor means, for indicating the measured blood flow whereby the degree of systemic perfusion of the patient may be deduced; and

a sensor holder with an inner portion and an outer portion, said inner portion shaped to fit in the mouth of a patient under the patient'"'"'s tongue, said holder forming at least one holder passage extending from said outer portion to said inner portion, wherein the sensor is located within the holder passage.

34. The device of claim 33, wherein the sensor holder has an upper surface that supports the tongue of the patient.

35. The device of claim 33, wherein the outer portion has a slot for receiving the patient'"'"'s frenulum, and the holder passage has an inner end lying on one side of said slot.

36. The device of claim 33, wherein at least a portion of the holder is comprised of an elastomeric material.

37. A device for assessing the degree of systemic perfusion in a patient, the device comprising:

a blood-flow sensor, adapted to be positioned adjacent a mucosal surface within a patient'"'"'s body and measuring blood flow in adjacent tissue;

a pH sensor, adapted to be positioned adjacent the mucosal surface and measuring pH in the adjacent tissue; and

an indicating means operably connected to the sensor means, for indicating the measured blood flow and the measured pH whereby the degree of systemic perfusion of the patient may be deduced.

38. A device for assessing the degree of systemic perfusion in a patient, the device comprising:

a blood-flow sensor, adapted to be positioned adjacent a mucosal surface accessible by a mouth and connecting with an upper respiratory/digestive tract in a patient'"'"'s body and measuring blood flow in adjacent tissue;

an indicating means operably connected to the sensor means, for indicating the measured blood flow whereby the degree of systemic perfusion of the patient may be deduced; and

a sensor holder adapted to hold the blood-flow sensor adjacent the upper respiratory/digestive tract mucosal surface.

39. A method for assessing the degree of systemic perfusion in a patient comprising:

measuring the surface perfusion pressure in the patient by utilizing a surface perfusion pressure monitor;

measuring blood pressure in the patient;

calculating the SPP index;

deducing the degree of systemic perfusion of the patient.

40. The method of claim 39 including taking an optical plethysmography measurement in a patient by utilizing a photoplethysmograph;

measuring blood pressure in the patient; and

calculating an optical plethysmography index.

41. The method of claim 40 including taking measurements selected from the group consisting of pH, sublingual PCO₂, and Sa O₂.

42. The method of claim 39 including measuring the blood-flow of a patient by utilizing a blood-flow sensor, adapted to be positioned adjacent a mucosal surface accessible by a mouth and connecting with an upper respirator/digestive tract in a patient.

43. A method for assessing the degree of systemic perfusion in a patient comprising:

taking an optical plethysmography measurement in a patient by utilizing a photoplethysmograph;

measuring blood pressure in a patient;

calculating the optical plethysmography index;

deducing the degree of systemic perfusion of the patient.

44. The method of claim 43 including measuring the surface perfusion pressure in a patient by utilizing a surface perfusion pressure monitor;

measuring blood pressure in the patient; and

calculating a SPP index.

45. The method of claim 44 including taking measurements selected from the group consisting of pH, sublingual PCO₂, and Sa O₂.

46. The method of claim 44 including measuring the blood-flow of a patient by utilizing a blood-flow sensor, adapted to be positioned adjacent a mucosal surface accessible by a mouth and connecting with an upper respirator/digestive tract in a patient.