Abstract 223: End Tidal Carbon Dioxide Levels Predict Cardiac Arrest
Introduction: End tidal carbon dioxide (CO2) correlates with cardiac output during cardiopulmonary resuscitation in cardiac arrest patients. Increasing CO2 during CPR can also indicate the return of spontaneous circulation.
Hypothesis: CO2 will decrease prior to a cardiac arrest in patients that are intubated in an intensive care setting.
Methods: CO2 was continuously monitored and recorded every hour in forty-three patients who were intubated and on vasopressor medication.
Results: There were four cardiac arrest events, six patients who were acutely withdrawn from care, and six patients who had hypotensive events (systolic blood pressure<90) while on vasopressors. CO2 measurements were evaluated in patients with an adverse event (acute withdrawal of care, cardiac arrest, and hypotension) at time periods of 1, 2, 3, 4, and 5 hours prior to the adverse event. Normal patients were categorized as those patients enrolled who did not have an adverse event. Mean CO2 values were significantly higher in normal patients when compared to those in patients who had a cardiac arrest (30.18 + 4.93 vs. 17.45 + 4.76; p<0.001). CO2 levels were significantly lower in cardiac arrest patients when compared to hypotensive patients 1, 2, 3, and 4 hours prior to a cardiac arrest (see Table). CO2 levels were significantly lower in cardiac arrest patients when compared to patients who were acutely withdrawn from care 1,2,3, and 4 hours prior to event (see Table). CO2 levels 5 hours prior to hypotension or acute withdrawal of care were not significantly different than cardiac arrest (see Table).
Conclusions: CO2 levels are lower overall in cardiac arrest patients in comparison to normal patients. CO2 values are lower in the four hours prior to cardiac arrest patients in comparison to the four hours prior to a hypotensive event. A patient who is withdrawn from care does not have a decrease in CO2. Increased numbers are needed to see if this relationship holds true on a large scale.
- © 2010 by American Heart Association, Inc.