Not too long ago, an attendee at an EMS conference asked me what I thought were the most interesting scientific papers related to EMS. At that time, I was unable to answer him specifically. But now that I've had some time to think, I ve prepared a list of what I feel are some of the most interesting studies pertaining to EMS and emergency medicine.
Number 1: Hauswald M, Ong G, Tandberg D, et al: "Out-of-hospital spinal immobilization: Its effect on neurologic injury." Academic Emergency Medicine. 5(3):214 219, 1998.
The University of New Mexico (UNM) School of Medicine has an excellent Department of Emergency Medicine. In this study, one of their faculty members, Mark Hauswald, performed an interesting study. Dr. Hauswald retrospectively reviewed all cases of prehospital spinal immobilization brought to the UNM Medical Center over a five-year period. Then, these were compared with cases from a similar hospital in Malaysia for the same five-year period.
Interestingly, spinal immobilization is very rarely, if ever, used in Malaysia. In fact, most nurses and physicians in Malaysia could not recall ever seeing a patient with spinal immobilization applied. Surprisingly, the researchers found there was less neurological injury in the Malaysian patients (who were not immobilized) when compared with the patients in Albuquerque (who received state-of-the-art immobilization).
They concluded there was less than a 2% chance that prehospital spinal immobilization had any beneficial effect.
Number 2: Weisfeldt ML, Becker LB: "Resuscitation after cardiac arrest: A 3-phase time-sensitive model." JAMA. 288(23):3035 3038, 2002.
This short paper, by two prominent resuscitation researchers, clearly defines the pathophysiological processes occurring in cardiac arrest. They break down the phases of cardiac arrest into physiological stages: electrical (0 4 minutes), circulatory (4 10 minutes) and metabolic (>10 minutes). Each phase requires a totally different strategy.
This paper defines the issues in a straightforward manner and should be required reading by all paramedics.
Number 3: Lerner EB, Moscati RM: "The golden hour: Scientific fact or medical 'urban legend'?" Academic Emergency Medicine. 8(7):758 760, 2001.
Have you heard the story about how R. Adams Cowley, MD, created the concept of the "Golden Hour"? As the story goes, Cowley developed the concept on a cocktail napkin in a bar overlooking the inner harbor in Baltimore. Interestingly, this story was confirmed by a physician friend of Cowley's who was reportedly present when he came up with the idea.
The researchers of this paper decided to determine whether the Golden Hour is fact or an urban legend. They carefully reviewed all of Cowley s writings and speeches and were unable to find any scientific support or objective data for the concept of a Golden Hour.
What amazes me is this study was published more than seven years ago and most of the people in EMS still believe the Golden Hour is based on scientific fact.
Number 4: Moore C, Woollard M: "Dextrose 10% or 50% in the treatment of hypoglycaemia out of hospital? A randomised controlled trial." Emergency Medical Journal. 22(7):512 515, 2005.
I like this article on hypoglycemia for several reasons. First, it was developed and performed by two paramedics in the United Kingdom. Second, it looks at a practice that has been long-standing but evidently not based on sound scientific research.
For as long as I can remember, we have always given 50% dextrose for hypoglycemia. However, as recognized by Moore and Wollard, diabetic patients who received this concentrated dextrose solution had trouble regulating their blood glucose levels for the next 24 hours. The researchers thought that it would be prudent to give a less concentrated dose of glucose instead.
In a randomized controlled trial that compared outcomes for 10% dextrose with 50% dextrose, they found that patients receiving 10% dextrose required less dextrose overall and were able to maintain their post-treatment blood glucose levels much better. However, because this article appeared in a European journal, there has been no change in dextrose dosing in the U.S., despite the fact that this seems like a much better protocol.
Number 5: Ong ME, Tan EH, Ng FS, et al: "Survival outcomes with the introduction of intravenous epinephrine in the management of out-of-hospital cardiac arrest." Annals of Emergency Medicine. 50(6):635 642, 2007.
In parts of Australasia, epinephrine (adrenalin) has never been a part of cardiac arrest resuscitation protocols. In this before-and-after study, researchers in Singapore examined cardiac arrest resuscitation rates before and after the drug epinephrine was added to the resuscitation regimen.
They found, as many of us have come to believe, that resuscitation rates were unchanged following the introduction of IV epinephrine. Again, a long-held belief about the efficacy of epinephrine in cardiac arrest is starting to fall. In fact, epinephrine may be harmful (as noted in the 2003 Critical Care Medicine article, Myocardial ischemia in intestinal post-ischemic shock, by Douzanis EE et al).
Number 6: Shatney CH, Homan SJ, Sherck JP, et al: "The utility of helicopter transport of trauma patients from the injury scene in an urban trauma system." Journal of Trauma. 53(5):817 822, 2002.
I've always liked Dr. Shatney's paper for several reasons. First is because of the author. Dr. Shatney was a contemporary of R. Adams Cowley, MD, founder of the University of Maryland Shock Trauma Center. Shatney was present in Baltimore when Cowley developed the Shock Trauma unit, and he went on to develop trauma systems in Jacksonville, Fla., and Santa Clara, Calif.
Like most trauma surgeons, he witnessed an increasing overuse of medical helicopters. So, he studied all medical helicopter transports for trauma to the Santa Clara Valley Hospital during a 10-year period. He found 947 consecutive trauma patients transported. Of these, most had minor injuries, and only 1.8% of all patients in the 10-year period required truly emergency surgery.
Overall, he found that only 22% of patients transported possibly benefited from helicopter transport and recommended that helicopter usage be curtailed.
Number 7:Maguire BJ, Hunting KL, Smith GS, et al: "Occupational fatalities in emergency medical services: A hidden crisis." Annals of Emergency Medicine. 40(6):625 632, 2002.
This paper, by Brian Maguire from the University of Baltimore-Baltimore County, was the first look at the growing issue of EMS provider safety. It was the first study that provided specific numbers on the dangers of EMS work.
He found that the occupational fatality rate for EMS workers was 12.7 fatalities per 100,000 workers annually. This is slightly fewer than police officers and firefighters, but it was more than many people suspected.
This paper has been the impetus for increased EMS provider safety, especially as it relates to ground ambulance accidents.
Number 8: Green RJ, Pierce JM: "The ideal tool for decorators: A novel use for disposable laryngoscope blades." British Medical Journal. 333(7582):1297 1298, 2006.
You have to love the British sense of humor. Typically, at the end of the year, the British Medical Journal will run in an irreverent "scientific" article in their journal.
In 2006, they looked at the effectiveness of using disposable laryngoscope blades for opening cans of paint. In an article full of charts and photographs, they measured the force necessary to open a can of paint using disposable laryngoscope blades of various sizes. They found that the #3 Macintosh blade was the best for opening cans of paint. However, they found that a screwdriver was still preferred for stirring paint. They also concluded that disposable laryngoscope blades made excellent stocking stuffers.
Number 9: Smith GC, Pell JP: "Parachute use to prevent death and major trauma related to gravitational challenge: Systematic review of randomised controlled trials." British Medical Journal. 327(7429):1459 1461, 2003.
In this interesting article, the researchers sought to call attention to the fact that some physicians are overly reliant on the need for randomized controlled trials to guide clinical practice. So, they performed a literature search to determine how much evidence exists, in the form of randomized controlled trials, to support the use of parachutes.
They concluded that there's a lack of empiric evidence to support the use of parachutes for people experiencing gravitational challenge. Again, this article was written with that dry British sense of humor that makes it hilarious. But it goes to show that there are some things in medicine that are intuitive.
There's an old saying in the hospital where I completed my residency: "You don't have to run a Chi Square test of common sense."
Number 10: Benson H, Dusek JA, Sherwood JB, et al: "Study of the Therapeutic Effects of Intercessory Prayer (STEP) in cardiac bypass patients: A multicenter randomized trial of uncertainty and certainty of receiving intercessory prayer." American Heart Journal. 151(4):934 942, 2006.
This is a fascinating paper on a very emotional topic. I'm in awe of the researchers for taking on such a controversial issue. In addition, the researchers went on to publish the article despite the fact that the findings were probably different than what they expected.
This was a multicenter study of conducted in Integris Baptist Medical Center, Oklahoma City, Okla.; Beth Israel Deaconess Medical Center, Boston; Washington Hospital Center, Washington, D.C.; Baptist Medical Center, Memphis, Tenn.; Mayo Clinic, Rochester, Minn.; and St Joseph s Hospital, Tampa, Fla. These facilities represent several different religious belief systems.
The researchers, both physicians and theologians, equally contributed to the project. The patients in the study were scheduled to undergo coronary artery bypass grafting (CABG) and were randomly assigned to one of three groups.
The first group (604) received intercessory prayer after being informed that they may or may not receive prayer. The second group (597) did not receive intercessory prayer also after being informed that they may or may not receive prayer. The last group (601) received intercessory prayer after being informed they would receive prayer.
Intercessory prayer was provided for 14 days, starting the night before CABG. The primary outcome was presence of any complication within 30 days of CABG.
In the first two groups -- those uncertain about receiving intercessory prayer -- complications occurred in 52% of patients who received intercessory prayer versus 51% of those who did not. In the third group (those certain of receiving intercessory prayer), complications occurred in 59% of patients, compared with the 52% of those uncertain of receiving intercessory prayers.
They concluded that intercessory prayer itself had no effect on complication-free recovery from CABG, but that certainty of receiving intercessory prayer was associated with a higher incidence of complications.
I'm not saying that I agree or disagree with the study. I just think these researchers were extremely bold and extremely honest in conducting this research. It just goes to show that anything in medicine should be subject to scrutiny.