End-tidal carbon dioxide and amplitude spectral area as non-invasive markers of coronary perfusion pressure and arterial pressure

Abstract

End-tidal carbon dioxide (ETCO 2 ) measurements may be used alone as a guide to determine when to defibrillate an individual. Alternatively, ETCO 2 measurements may be used in combination with amplitude spectral area measurements as a guide to determine when to defibrillate an individual.

What is claimed is: 
     
         1 . A computer-implemented method, comprising:
 obtaining, by a computing system, an end-tidal carbon dioxide (ETCO 2 ) measurement of an individual during a cardiopulmonary resuscitation (CPR) procedure performed on the individual;   comparing, by the computing system, a particular ETCO 2  value derived from the ETCO 2  measurement to a predetermined threshold value; and   providing, by the computing system based on the comparing, a perceivable indication that designates a time to deliver a defibrillation shock to the individual.   
     
     
         2 . The method of  claim 1 , further comprising:
 providing the indication when the particular ETCO 2  value is less than or equal to the predetermined threshold value.   
     
     
         3 . The method of  claim 1 , further comprising
 providing the indication when the particular ETCO 2  value is greater than or equal to the predetermined threshold value.   
     
     
         4 . The method of  claim 1 , further comprising:
 providing, by the computing system based on the comparison, at least one of an audio indication and a visual indication that designates the time to deliver the defibrillation shock to the individual.   
     
     
         5 . The method of  claim 1 , further comprising:
 obtaining an electrocardiogram (ECG) measurement of the individual during the CPR procedure;   deriving from the ECG measurement an amplitude spectral area value; and   providing the indication that designates the time to deliver the defibrillation shock to the individual based upon the amplitude spectrum area value and the comparison of the ETCO 2  value to the predetermined threshold value.   
     
     
         6 . A method, comprising:
 performing a cardiopulmonary resuscitation (CPR) procedure on an individual; and   delivering a defibrillation shock to the individual at a particular time based upon an indication provided by a computing system when a particular end-tidal carbon dioxide (ETCO 2 ) value derived from an ETCO 2  measurement of the individual during the CPR procedure is determined by the computing system as less than or greater than a predetermined threshold value.   
     
     
         7 . The method of  claim 6 , further comprising:
 performing an intrathoracic pressure regulation procedure or a reperfusion injury protection procedure at or during the CPR procedure.   
     
     
         8 . The method of  claim 6 , further comprising:
 periodically extracting respiratory gases from the airway of the individual to create an intrathoracic vacuum that lowers pressure in the thorax to at least one of: enhance the flow of blood to the heart of the individual; lower intracranial pressures of the individual; and enhance cerebral profusion pressures of the individual.   
     
     
         9 . The method of  claim 6 , further comprising:
 preventing air from at least temporarily entering the lungs of the individual during at least a portion of a relaxation or decompression phase of the CPR procedure to create an intrathoracic vacuum that lowers pressure in the thorax to at least one of: enhance flow of blood to the heart of the particular individual; lower intracranial pressures of the particular individual; and enhance cerebral profusion pressures of the individual.   
     
     
         10 . The method of  claim 6 , further comprising performing a standard CPR procedure on the individual. 
     
     
         11 . The method of  claim 6 , further comprising performing a stutter CPR procedure on the individual. 
     
     
         12 . The method of  claim 6 , further comprising performing an active compression-decompression CPR procedure on the individual. 
     
     
         13 . The method of  claim 6 , further comprising:
 positioning a mechanical CPR device relative to the chest of the individual; and   activating the mechanical CPR device to perform a mechanized CPR procedure on the individual.   
     
     
         14 . The method of  claim 6 , further comprising:
 delivering the defibrillation shock to the individual upon perception of the indication provided by the computing system at the particular time based upon an amplitude spectrum area value of the individual as derived from a measurement during the CPR procedure and when the particular ETCO 2  value is determined as less than or equal to the predetermined threshold value.   
     
     
         15 . The method of  claim 6 , further comprising:
 delivering the defibrillation shock to the individual upon perception of the indication provided by the computing system at the particular time based upon an amplitude spectrum area value of the individual as derived from a measurement during the CPR procedure and when the particular ETCO 2  value is determined as greater than or equal to the predetermined threshold value.   
     
     
         16 . The method of  claim 6 , further comprising:
 delivering the defibrillation shock to the individual upon perception of at least one of an audio indication and a visual indication provided by the computing system.   
     
     
         17 . An apparatus, comprising:
 a first device that monitors concentration of carbon dioxide in respiratory gases of an individual at least during a cardiopulmonary resuscitation (CPR) procedure performed on the individual;   a second device that compares a particular end-tidal carbon dioxide value derived from the concentration of carbon dioxide in respiratory gases of the individual to a predetermined threshold value; and   a third device that provides based on the comparison a perceivable indication that designates a time to deliver a defibrillation shock to the individual.   
     
     
         18 . The apparatus of  claim 17 , further comprising:
 an electroencephalogram (EEG) sensor that measures an EEG signal of the individual at least during the CPR procedure performed on the individual, wherein the second device derives an amplitude spectrum area value from the EEG signal, and the third device provides the perceivable indication based upon the amplitude spectrum area value and the comparison of the particular end-tidal carbon dioxide value to the predetermined threshold value.   
     
     
         19 . The apparatus of  claim 17 , further comprising:
 a circulation enhancement device that enhances circulation of the individual at least during the CPR procedure performed on the individual   
     
     
         20 . The apparatus of  claim 17 , wherein the third device is selected from one of a visual output device and an audio output device.