Ten Important Papers
Medical directors, EMS operators and front-line providers gathered in Tucson, AZ, in January to share the latest and greatest in EMS practices at the National Association of EMS Physicians’ annual conference. To close the five days of innovative meetings, workshops and lectures, emergency physicians Michael Millin and Jon Rittenberger and paramedic Blair Bigham presented the top 10 EMS-related scientific articles published in 2011 in a series of pro-con debates that made the current Republican presidential primary contest look peaceful. From cardiac arrest to trauma and everything in between, the trio took a critical look at literature that promises to change the landscape of EMS care.
Teeing off the talk were two New England Journal of Medicine articles from the Resuscitation Outcomes Consortium (ROC). Long awaited, these two trials randomized out-of-hospital cardiac arrest patients without heartbeats to receive novel therapies. Patients received CPR for either a short (30-second) or long (3-minute) duration prior to first-shock analysis to study the impact of “priming the pump” with “up-front” CPR; also, the use of an impedance threshold device (ITD) was randomly assigned to investigate the hypothesis that increases in intrathoracic pressure improve survival measures. Both trials were expertly run, enrolling more than 10,000 patients and reaching field performance levels considered optimal for the prehospital setting. Ultimately, they found that survival was equal between all groups; neither novel treatment impacted it.
Also in the cardiac arrest category, Greek scientists undertook a systematic review and meta-analysis of studies comparing ALS and BLS care in cardiac arrest and trauma. By collating 18 studies together and running a new statistical analysis, they found cardiac patients treated by ALS providers survive up to twice as often as those treated by BLS providers, but trauma patients do not benefit from the presence of ALS personnel.
Two other articles explored the behavior of rescuers in cardiac arrest situations. The first, conducted at a train station in the Netherlands, asked bystanders about their ability to recognize the need for defibrillation and ability and willingness to use an automated external defibrillator. Sadly, only 9% of those surveyed were able to identify all of the required steps needed to successfully apply an AED to a patient in cardiac arrest. This exposes important gaps in public knowledge. On the responder front, a study from the ROC identified substantial variation in EMS provider practice with regards to pronouncing cardiac arrest patients on scene. In some cities and states, nearly all cardiac arrests are transported without a pulse, compared to hardly any in others. Despite clear guidelines for termination of resuscitation, it appears unnecessary transports are common in many places.
Rounding out the cardiac arrest studies was the world’s first randomized controlled trial of epinephrine vs. placebo for cardiac arrest. Its enrollment was ceased due to political intervention, but not before demonstrating that a randomized controlled trial of epinephrine was not only possible, but important; researchers found that while epinephrine may increase the odds of return of spontaneous circulation, neurologic recovery may be impaired. The guarded interpretation of this study: epinephrine is a necessary evil in resuscitation, but are we giving too much?
Changing topics, the trio reviewed a study that showed septic patients arriving to the emergency department by EMS are likely to be seen and treated quicker, regardless of their acuity. Triggering early sepsis care has a strong potential to improve patient outcomes, as numerous other studies have identified that quicker treatment means higher rates of survival.
In the world of trauma, a large review of predictors of trauma severity revealed that while some mechanisms of injury were strong predictors of the need for a trauma center, others were not. While more research is needed to better help prehospital providers determine who should be bypassed to a trauma center, the findings of this study should help improve the sensitivity and specificity of trauma-bypass clinical decision rules.
Of course, no Top 10 discussion would be complete without an airway paper. A large repository of airway calls from various U.S. states demonstrated that while intubation success rates are still below desired levels, adverse event rates are very low, suggesting that although some patients may not benefit from intubation, few are being harmed by the intervention.
The last paper reviewed was a safety “roadmap” produced at the Canadian Patient Safety in EMS Summit. An action plan to improve patient safety in the field includes such challenges as changing culture to encourage adverse event reporting, viewing errors from a system perspective, filling knowledge gaps with more comprehensive education, and collecting data in a rigorous and uniform manner.
Regardless of the topic, these research efforts enlighten the spectrum of those of us who play in EMS, from the field provider to the EMS manager to the medical director. Next year’s top 10 is sure to do the same.
Bibliography
Wang HE, Mann NC, Mears G, Jacobson K, Yealy DM. Out-of-hospital airway management in the United States. Resuscitation. 2011 Apr; 82(4):378-85.
Stiell IG, Nichol G, Leroux BG, et al. Early versus later rhythm analysis in patients with out-of-hospital cardiac arrest. N Engl J Med. 2011 Sep 1; 365(9):787-97.
Bakalos G, Mamali M, Komninos C, Koukou E, Tsantilas A, Tzima S, Rosenberg T. Advanced life support versus basic life support in the pre-hospital setting: a meta-analysis. Resuscitation. 2011 Sep; 82(9):1130-7.
Aufderheide TP, Nichol G, Rea TD, et al. A trial of an impedance threshold device in out-of-hospital cardiac arrest. N Engl J Med. 2011 Sep 1; 365(9):798-806.
Jacobs IG, Finn JC, Jelinek GA, Oxer HF, Thompson PL. Effect of adrenaline on survival in out-of-hospital cardiac arrest: A randomised double-blind placebo-controlled trial. Resuscitation. 2011 Sep; 82(9):1138-43.
Zive D, Koprowicz K, Schmidt T, et al. Variation in out-of-hospital cardiac arrest resuscitation and transport practices in the Resuscitation Outcomes Consortium: ROC Epistry-Cardiac Arrest. Resuscitation. 2011 Mar; 82(3):277-84.
Schober P, van Dehn FB, Bierens JJ, Loer SA, Schwarte LA. Public access defibrillation: time to access the public. Ann Emerg Med. 2011 Sep; 58(3):240-7.
Band RA, Gaieski DF, Hylton JH, Shofer FS, Goyal M, Meisel ZF. Arriving by emergency medical services improves time to treatment endpoints for patients with severe sepsis or septic shock. Acad Emerg Med. 2011 Sep; 18(9):934-40.
Lerner EB, Shah MN, Cushman JT, Swor RA, Guse CE, Brasel K, Blatt A, Jurkovich GJ. Does mechanism of injury predict trauma center need? Prehosp Emerg Care. 2011 Oct-Dec; 15(4):518-25.
Bigham BL, Bull E, Morrison M, Burgess R, Maher J, Brooks SC, Morrison LJ. Patient safety in emergency medical services: executive summary and recommendations from the Niagara Summit. CJEM. 2011 Jan; 13(1):13-8.
Blair Bigham, ACP, MSc, is an advanced care flight paramedic and prehospital science investigator in Toronto. Contact him at bighamb@smh.ca.
