The Get With The Guidelines-Resuscitation database is an American Heart Association–sponsored, prospective, multisite, observational registry. Trained nurse abstractors input data at each site, by reviewing the medical record for in-hospital cardiac arrest (IHCA) management. The quality and completeness of site data are evaluated by a robust quality control process. Several important points have been raised by Drs. Xue et al. and Errando in response to our study.
The study has the potential for significant unmeasured confounding variables. We have acknowledged this fact in detail in our study,1 but these limitations are generic to all observational studies. Dr. Xue points out that the duration of hospital participation could be an important confounder in predicting outcome,2 but previous work within the Get With The Guidelines-Resuscitation database has not found this to be the case with IHCA.2
Telemetry was associated with better outcomes in IHCA with shockable rhythms, in comparison with general care and operating room locations. Only 20% of the operating room IHCA had shockable rhythms, with a preponderance of trauma and shock. Shockable rhythms were more frequent, whereas trauma or shock was less frequently seen in IHCA events occurring in telemetry locations. Thus, location-specific differences in outcome likely reflect primary differences in patient populations.
Monitoring was associated with improved survival in previous studies of the Get With The Guidelines-Resuscitation database.3 The presence of skilled and trained providers who recognized IHCA and instituted early defibrillation, epinephrine administration, and invasive airway placement partially explains the improved outcomes seen in monitored locations such as the operating room and postanesthesia care unit. However, as described above, it is possible that some of this improved survival relates to indication bias, in that patients at greater risk of IHCA with shockable rhythms are more likely to receive telemetry monitoring. Thus, summary conclusions to increase monitoring levels on the general care units cannot be made based on this study alone. Although expert opinion4 and emerging evidence5 continue to point toward outcome modification with increased pulse oximetry monitoring, the largest prospective study6 to date failed to show survival or outcome benefit in patients. In addition, there is some evidence of serious harm with increased monitoring, prompting the Joint Commission to issue a sentinel alert in 2013.*
I agree that improved survival in the operating room IHCA could be explained partially by reduced resuscitation errors. The quality of resuscitation as measured by time to defibrillation, epinephrine administration, or intubation was significantly superior in the operating room, suggesting better run codes.
The Get With The Guidelines-Resuscitation database does not provide information on surgical procedure or anesthetic management. Databases such as the Multicenter Perioperative Outcomes Group† could provide valuable insight, but measures of cardiac resuscitation and neurological outcome are often missing from such databases.
I would like to thank the editor and the respondents to our study for the interest and look forward to more research in this area.
Dr. Ramachandran was a paid ad-hoc consultant to Galleon Pharmaceuticals, Horsham, Pennsylvania, and Merck Sharp and Dohme, Whitehouse Station, New Jersey, in 2012–2013.
Available at: http://www.jointcommission.org/assets/1/18/sea_50_alarms_4_5_13_final1.pdf. Accessed March 7, 2014.
Available at: http://mpog.med.umich.edu/. Accessed March 7, 2014.