Using an investigational monitor/defibrillator that passively records CPR quality parameters, including chest compression rate and depth and ventilation rate and volume, we are prospectively recording CPR quality during sequential in-hospital cardiac arrests at the University of Chicago Hospitals. Using an audio feedback system linked to this device, we are studying whether such audio feedback improves CPR quality when provided to rescuers trained in the use of the device.

Patients who suffer cardiac arrest during their hospitalization at the University of Chicago hospitals are given CPR and other resuscitation measures by trained physician and nurse teams. This care is given with the use of defibrillators to monitor cardiac rhythm as well as provide defibrillation as needed.

We have worked closely with engineers at Laerdal Medical Corporation to develop a defibrillator that passively monitors the quality of CPR via additional external sensors (see details in the following reference: Abella BS, Alvarado JP, Myklebust H, Edelson DP, Barry A, O'Hearn N, Vanden Hoek TL, Becker LB. Quality of cardiopulmonary resuscitation during in-hospital cardiac arrest. JAMA. 2005;293:305-10).

Patients who suffer in-hospital arrest are enrolled (provided they are over 16 years of age, are not pregnant, and are not in the operating room or emergency room setting) with mechanisms to satisfy IRB waiver of consent provisions. These patients receive the same care as before the study, but CPR parameters are recorded by the device. In addition, the device provides audio/visual "coaching" in CPR, based on the actual performance of CPR as measured.

We hypothesize that this coaching will improve CPR quality and hopefully improve survival from cardiac arrest.

The first phase of investigation is now complete, where patients were enrolled and studied without feedback ("baseline" group). Now we are enrolling patients into a second group with feedback provided. Enrollment is nearly complete for this second group. We will then evaluate the baseline and feedback groups to ascertain whether CPR improved over the two cohorts.

Inclusion Criteria:

• adult patient with cardiac arrest hospitalized at University of Chicago Hospitals

Exclusion Criteria:

• pregnant
• arrest in ER or OR
• pediatric patient
• patient DNR, no CPR given
• no CPR given for other reasons (e.g. shock only)