Overview of Science and Mission
Clinical Science
Introduction
An estimated 370,000-750,000 patients in the United States suffer an in-hospital cardiac arrest each year, with survival rates of less than 20%. CPR is one of only few interventions known to improve outcomes from this critical condition. International guidelines set forth recommendations for the proper administration of CPR but until recently there was no way to objectively measure compliance with those guidelines.
Measuring CPR Quality
New defibrillators have recently been introduced into the marketplace that allow objective measurement of CPR performance. Equipped with CPR-sensing technology, these devices can now measure chest compression rate and depth, ventilation rate and pauses in chest compression during actual cardiac arrests.
We began using a CPR-sensing monitor/defibrillator during resuscitations in 2002 and published our results in landmark article showing that compression and ventilation rates were out of recommended range more than 50% of the time. Additionally, we found that compression depth was frequently low and that there were long pauses in chest compressions, comprising, on average, one quarter of each resuscitation event.
In another study, we measured pauses in chest compression prior to defibrillation and showed that defibrillation success decreased in a dose response fashion with pre-shock pauses longer than 10 seconds in duration. We noted a similar decrease in shock success with decreasing compression depth immediately preceding the pauses.
Improving CPR
Having shown that CPR quality in actual practice is less than optimal, we have set about trying to improve resuscitation practices using several modalities, including feedback, debriefing, and simulation.
We conducted a study of real-time audio-visual feedback which showed a modest improvement in compression rate and depth, ventilation rate, and time without compression, when compared to our baseline resuscitations.
In addition to real-time audio-visual feedback, we added weekly debriefing sessions for our providers which integrated actual performance transcripts from the previous week’s resuscitations and showed a marked improvement in CPR quality and, more importantly, an improvement in the rate of return of spontaneous circulation.
Our current work seeks to study the added benefits of high-fidelity simulation training.
Preventing In-hospital cardiac arrest
Studies have shown that more than half of cardiac arrest patients show some sign of clinical deterioration in the 6 to 8 hours leading up to a cardiac arrest, suggesting the possibility of early intervention to avert the cardiac arrest.
- Rapid Response Systems have been proposed as means to identify and rapidly treat patients in the early stages of clinical deterioration to reduce the risk of cardiac arrest and improve morality.
- We are currently rolling out the University of Chicago Adult Rapid Response Team and studying the impact of this and other preventive measures on in-hospital cardiac arrest rates and overall mortality.