Systems and procedures for treating cardiac arrest

• US 20040230140A1
• Filed: 06/06/2003
• Published: 11/18/2004
• Est. Priority Date: 05/12/2003
• Status: Active Grant

• Current Assignee: Physio-Control Incorporated (Stryker Corporation)
• Original Assignee: Jolife AB (Stryker Corporation)
• Inventors: Steen, Stig
• Granted Patent: US 7,226,427 B2
• Time in Patent Office: Days
• US Class Current: 601/41
• CPC Class Codes: A61H 2201/0157 portable
• CPC Class Codes: A61H 2201/107 Respiratory gas
• CPC Class Codes: A61H 2201/1246 by piston-cylinder systems
• CPC Class Codes: A61H 2201/5007 computer controlled
• CPC Class Codes: A61H 2230/105 used as a control parameter for the apparatus
• CPC Class Codes: A61H 31/006 Power driven
• CPC Class Codes: A61H 31/008 Supine patient supports or bases, e.g. improving air-way access to the lungs
• CPC Class Codes: A61M 16/0048 Mouth-to-mouth respiration teaching or training models G09B23/288
• CPC Class Codes: A61M 16/024 including calculation means, e.g. using a processor
• CPC Class Codes: A61M 16/04 Tracheal tubes catheters in general A61M25/00
• CPC Class Codes: A61M 16/06 Respiratory or anaesthetic masks
• CPC Class Codes: A61M 16/202 electrically actuated
• CPC Class Codes: A61M 16/204 used for inhalation control
• CPC Class Codes: A61M 16/205 used for exhalation control
• CPC Class Codes: A61M 2016/0027 pressure meter
• CPC Class Codes: A61M 2205/3331 Pressure; Flow
• CPC Class Codes: A61N 1/39044 in combination with cardiopulmonary resuscitation [CPR] therapy
• CPC Class Codes: Y10S 601/10 Artificial respiration combined with non-artificial respiration therapy

Abstract

Improved procedures for cardiopulmonary resuscitation of a victim of cardiac arrest are provided. In the resuscitation the victim chest is mechanical compressed and decompressed to stimulate the heart. The victim is induced to inspire and expire against insufflating breathing gas during the chest compression/decompressions. The breathing gases are adduced under pressure to promote the development of a positive coronary perfusion pressure.

Electro-stimulation of the heart can be carried after positive coronary perfusion pressures have been achieved. The electro-stimulation can be defibrillation or heart pacing or both. The chest compression/decompression cycles and the electro-stimulation measures are synchronized to promote sufficiently body circulation of oxygenated blood in a subject suffering from cardiac arrest. Medical equipment systems are provided for implementing the CPR procedures.

Claims

1. A method for cardiopulmonary resuscitation of a person, comprising:

providing a breathing gas under positive pressure to the airways of the person;

mechanically stimulating the person'"'"'s heart while inducing the person to inspire and expire against the positive pressure of the breathing gas for at least a period of time until a positive coronary perfusion pressure develops; and

electrically stimulating the heart once the positive coronary perfusion pressure exceeds a threshold pressure.

2. The method of claim 1 wherein the threshold value of the coronary perfusion pressure is selected in the range of about 10 mm Hg to about 25 mm Hg.

3. The method of claim 1, wherein the breathing gas is cooled to a temperature of about at least 5°

C. below the ambient temperature.

4. The method of claim 1, wherein the positive pressure of breathing gas maintained in the person'"'"'s lungs is in the range from about from 1 mm Hg to 30 mm Hg.

5. The method of claim 1 further comprising administering medications using the breathing gas as a carrier.

6. The method of claim 1 further comprising using a pneumatic drive means to mechanically stimulate the person'"'"'s heart, and wherein the pneumatic drive means is driven by a gas that is recycled for use as a breathing gas.

7. The method of claim 1 wherein mechanically stimulating the person'"'"'s heart comprises using a driver means to compress the person'"'"'s chest to a compression depth, further comprising adjusting the drive means to control the compression depth in response to changes in the chest resistance during the course of cardiopulmonary resuscitation of the person.

8. The method of claim 1 wherein mechanically stimulating the person'"'"'s heart comprises externally compressing and decompressing the person'"'"'s chest.

9. The method of claim 8, wherein externally compressing and decompressing the person'"'"'s chest comprises compressing the person'"'"'s chest at a rate between about 60 cycles/min to about 200 cycles/min.

10. The method of claim 8, wherein externally compressing and decompressing the person'"'"'s chest further comprises:

in cycles, compressing the chest to a fully compressed state in a compression phase of a cycle; and

decompressing the person'"'"'s chest to a fully decompressed state in a decompression phase of the cycle, and

wherein the transition times in cycling between the two states are no more than a fraction of a cycle period.

11. The method of claim 8, wherein the positive pressure of breathing gas is maintained in the person'"'"'s lungs while the person'"'"'s chest is decompressed.

12. The method of claim 8 wherein the fully compressed state corresponds to a static portion of the compression phase, and wherein electrically stimulating the heart according to claim 1 further comprises initiating defibrillation within the last third of the static portion of the compression phase.

13. The method of claim 8 wherein electrically stimulating the heart according to claim 1 comprises initiating pacing the heart in a time interval in between the start of the compression phase and the start of the decompression phase.

14. The method of claim 13, wherein a transition from a decompressed state to the fully compressed state corresponds to a dynamic portion of the compression phase, and wherein the time interval is within 0.10 to 0.15 seconds before the end of the dynamic compression phase

15. The method of claim 1 wherein the period of time for which the person'"'"'s heart is mechanically stimulated is adjusted in proportion to the duration of asystolia undergone by the person'"'"'s heart.

16. The method of claim 1 further comprising:

assessing the state of the person'"'"'s heart; and

accordingly selecting a method for electrically stimulating the heart.

17. The method of claim 1 wherein the person'"'"'s heart is concurrently both mechanically stimulated and electrically stimulated.

18. The method of claim 1 wherein the person'"'"'s heart is alternately mechanically stimulated and electrically stimulated.

19. The method of claim 1 wherein electrically stimulating the person'"'"'s heart comprises defibrillation.

20. The method of claim 1 wherein electrically stimulating the person'"'"'s heart comprises applying heart pacing pulses.

21. The method of claim 20 wherein a pacing pulse rate is proportional to a cycle rate of concurrently administered chest compression/decompression cycles.

22. The method of claim 21, wherein the pacing pulse rate is substantially flat when the cycle rate is below about 80 cycles/min and then increases substantially linearly with the cycle rate when the cycle rate exceeds about 80 cycles/min.

23. The method of claim 1, wherein electrically stimulating the heart further comprises initiating electric stimulation after a quantity of blood is accumulated in the left ventricle of the person.

24. The method of claim 1, wherein electrically stimulating the heart further comprises initiating electric stimulation after a time average-mean volume of blood pooled in the right atrium has been substantially reduced by mechanical stimulation of the heart.

25. The method of claim 1 wherein electrically stimulating the person'"'"'s heart comprises using a stimulation method selected on an evaluation of the person'"'"'s heart condition during the course of the cardiopulmonary resuscitation.

26. The method of claim 25 wherein the evaluation comprises ECG analysis.

27. A system for administering steps in a course of cardiopulmonary resuscitation to a person, comprising:

a chest compression device for administering mechanical stimulation to the person'"'"'s heart;

a module for administering electric stimulation to the heart; and

a control unit for co-coordinating the administration of mechanical and electric stimulation to the heart over the course of the cardiopulmonary resuscitation.

28. The system of claim 27 wherein the control unit further comprises an analysis unit for assessing the state of the person'"'"'s heart during the course of the cardiopulmonary resuscitation.

29. The system of claim 28 wherein the analysis unit is an electrocardiogram recorder/analyzer.

30. The system of claim 28 wherein the control unit comprises a program for automatically modifying steps in the course of the cardiopulmonary resuscitation in response to assessments made by the analysis unit.

31. The system of claim 27 further comprising means for supplying pressurized breathing gas to the person'"'"'s lungs during the course of the cardiopulmonary resuscitation.

32. The system of claim 29 wherein the means for supplying pressurized breathing gas to the person'"'"'s lungs comprises means for disposing medication in the breathing gas for administration to the person.

33. The system of claim 27 wherein the chest compression device is pneumatic device operating on a gas and wherein the means for supplying pressurized breathing gas recycles gas that used to operate the pneumatic device.

34. A method for administering a course of cardiopulmonary resuscitation to a person using the system of claim 27, comprising;

assessing an improvement in heart function by administration of mechanical stimulation to the heart; and

administering electric stimulation to the person'"'"'s heart after the improvement in heart function crosses a threshold.

35. The method of claim 34 wherein assessing the improvement in heart function comprises evaluating at least one parameter from the group of parameters that includes:

a percent reduction in the volume of blood pooled in the right atrium;

a quantity of blood accumulated in the left ventricle; and

a coronary perfusion pressure.

36. The method of claim 30 further comprising applying breathing gas under pressure to the airways of the person during mechanical stimulation of the heart for raising the coronary perfusion pressure.