Cardiac & Resuscitation, Patient Care, Trauma

Studies Measure Latest Cardiac Arrest Data

Issue 11 and Volume 37.

Prolonged Resuscitation
Goldberger Z, Chan P, Berg A, et al. Duration of resuscitation efforts and survival after in-hospital cardiac arrest: An observational study. Lancet. Epub ahead of print. Sept. 5, 2012.

How long is long enough? The question of how long to attempt resuscitation during cardiac arrest has long plagued our industry. Recent advances with therapeutic hypothermia and improved CPR with mechanical devices have demonstrated neurological survival to discharge is feasible even in prolonged resuscitation attempts. But how long should we try before the attempt is considered futile?

In this retrospective observational review of a hospital database, Goldberger and co-authors tried to identify the average length of resuscitation attempts in U.S. hospitals and correlated them to outcomes.

A total of 64,339 cardiac arrest charts from 2000 to 2008 from 435 U.S. hospitals were reviewed. Of these, 31,198 (48.5%) achieved a return of pulse and 9,912 (15.2%) survived to discharge.

This isn’t a great survival rate, but it’s very consistent with other studies. The median time of resuscitation was 12 minutes for survivors and 20 minutes for non-survivors. Interestingly, when the authors analyzed data comparing hospitals with shorter vs. longer resuscitations, they reported a higher likelihood of survival in longer resuscitation attempts (25 minutes).

What does this mean? Although it’s an interesting study and was published in a prestigious medical journal, the association between survival and longer resuscitation in this case can’t be considered a “causal” relationship. This is a retrospective analysis with many uncontrolled variables.

The golden rule still applies here: EMS providers should give every patient the benefit of the doubt and provide the best care possible for as long as necessary to achieve a positive outcome. Seek guidance from your medical directors. In my area, many services now require a minimum attempt of 30 minutes before cessation of efforts. This is due to repeated anecdotal cases of prolonged cases with neurologically intact survival.

Bottom Line
What we know: A wide variation in the duration of time spent on resuscitation attempts exists. Small studies have shown decreased survival after 20 minutes, but recent improvements in CPR and hypothermia care have shown good results with prolonged attempts. No definitive evidence suggests an ideal duration of resuscitation.

What this study adds: A very weak association between longer resuscitation times (> 25 minute) and survival exists in certain hospitals. Providers should consult their local medical direction guidelines and continue to provide the best care possible for as long as necessary to ensure positive outcomes.

STEMI Success?
Cantor W, Hoogeveen P, Robert A, et al. Prehospital diagnosis and triage of ST-elevation myocardial infarction by paramedics without advanced care training. Am Heart J. 2012;164(2):201–­206.

By now, one would hope that most EMS systems have read the research and embraced 12-lead acquisition for the rapid identification and transport of ST elevation myocardial infarction (STEMI) patients. The crucial role EMS can play in the appropriate field triage of these patients to cardiac catheterization centers has been clearly demonstrated in repeated studies. But is it necessary for a paramedic or advanced-level provider to perform the ECG? This Canadian study explores the idea of having basic-level EMS providers perform and interpret 12-lead ECGs after a four-hour class. This includes activation of and transport directly to the catheterization lab.

These non-advanced EMS providers triaged 134 patients as potential STEMIs. Only one of these required an advanced intervention because of an ECG dysrhythmia. Base station physician interpretation was in agreement with the EMS interpretation for 121 (90%) of the cases. The 105 STEMI patients who received percutaneous coronary intervention (PCI) were correctly identified, and median door-to-balloon time was 91 minutes. A false positive rate of 28 patients (20.9%) was recorded.

Although individual systems will need to evaluate the cost, and risk-benefit for activating a catheterization lab with 90% accuracy and a false positive rate of 21%, it seems clear that 12-lead ECGs in the hands of basic level providers with minimal training is feasible and can significantly decrease door-to-needle times. This is especially good news for patients served by EMT-level services with prolonged transport times.

Watch Box
Cornwall A, Zaller N, Warren O, et al. A pilot study of emergency medical technicians’ field assessment of intoxicated patients’ need for ED care. Am J Emerg Med. 2012;30(7)1,224–1,228.

Can EMT-intermediates accurately triage an intoxicated patients’ need for emergency department (ED) care? This Rhode-Island based group says, “yes.” Well, actually the conclusion is a weak “maybe” after reading the full paper.

EMTs in this Providence (Rhode Island) fire-based system used a 14-point checklist to determine who should/shouldn’t have been transported. They reviewed 197 prehospital and in-hospital patient records over a four-month period. While 93% sensitive (great at including all possible people who might need in-hospital care), the checklist was only 40% specific (more often than not, the checklist did not correctly identify the primarily intoxicated individual).

Readers may recall a San Francisco study on the same subject reviewed in this column in December 2011. It’s great to see research attempting to improve field triage and decreasing in-hospital costs by improving EMS decision making. Unfortunately, the checklists proposed so far don’t appear to give us a “best case” workable solution. Hopefully, an EMS researcher will read this and undertake a more robust and definitive study.