DENVER – Results of the first-ever head-to-head comparison of MRI vs. CT for diagnosis of occult hip fractures in the elderly show MRI to be the unequivocal winner.

"The take-home message is clear: MRI is the study of choice in this setting. If you suspect hip fracture in a patient whose plain films are difficult to interpret, get advanced imaging. Push for MRI," Dr. William K. Mallon said in his annual standing-room-only talk on recent highlights in the literature at the annual meeting of the American College of Emergency Physicians.

This study by investigators at the University of California, San Francisco’s Fresno campus earned a spot on Dr. Mallon’s short list of papers published in the last year with which he believes every emergency physician should be familiar. That’s because hip fracture in the elderly is such a common problem in community hospital EDs as well as trauma centers. It’s estimated that 4% of all hip fractures in the elderly are occult, meaning not diagnosable by plain x-ray.

"If you think you’re going to encounter 25 broken hips in your career, you’re going to encounter an occult fracture, so this is an important issue," observed Dr. Mallon of the University of Southern California, Los Angeles.

The study involved 235 patients aged 60 years and over with hip fracture, 211 of which were apparent on plain films. Of the 24 occult fractures, MRI detected 4 that 64-slice CT missed (J. Emerg. Med. 2012;43:303-7).

In his animated and entertaining talk before a capacity audience in the largest hall in the convention center, Dr. Mallon steered clear of articles published in the Annals of Emergency Medicine, reasoning that board-certified emergency physicians have already seen them. Here are some of his top picks from other journals on key topics:

• ALARA: This is an acronym for ‘As Low as Reasonably Achievable’ radiation exposure.

"I believe that in the year 2050, they’ll look back at us as the barbarians of our day, shamelessly and heedlessly irradiating an entire generation and causing cancer," Dr. Mallon declared. "They’re going to say, ‘Did they not think about what happened in Hiroshima? You can’t get away with this radiation crap.’ "

ALARA is not about finding workable alternatives to CT, such as ultrasound, whenever possible. That’s a given. It’s about developing lower-radiation methods of CT when nothing but CT will do. One commercially available low-radiation-exposure device, known as the Lodox Statscan, is on line at L.A. CountyUSC Medical Center, where Dr. Mallon practices.

"It’ll do a whole body AP and lateral in a multisystem trauma patient for less radiation than a chest x-ray," he noted.

Dr. Mallon singled out as one of the past year’s most provocative studies a South Korean trial in which 891 patients with suspected acute appendicitis were randomized single-blind to diagnostic evaluation using either low-dose or standard-dose CT. The low-dose group received 116 mGy/cm, a radiation exposure 80% less than in the standard-dose arm.

"This paper asks, with 80% less zap, can you still make the diagnosis? And the answer is yes," he said.

The negative appendectomy rate was 3.5% in the low-dose group and not statistically different at 3.2% in the standard-dose group. The perforation rate was 26.5% in the low-dose group and 23.3% with regular CT imaging.

Low-dose abdominal CT yields grainier images than physicians are accustomed to. Yet the 3.2% secondary imaging rate in the low-dose group wasn’t statistically different from that in the standard-dose arm (N. Engl. J. Med. 2012;366:1596-605).

This study will have to be replicated in the United States before American radiologists and surgeons will accept low-radiation CT to rule out appendicitis. The academic community must lead the way here, in Dr. Mallon’s view.

"As an emergency physician, I think I can easily live with those numbers, if they are the real numbers. We could start now with lower-radiation protocols. I think this is an important thing, and if we as a specialty aren’t going to advocate and push for it, I just think it’ll stay status quo forever," he added.

• Pulmonary embolism overdiagnosis: Pulmonary embolism, in Dr. Mallon’s view, is the bane of the emergency department, a double-edged sword.

"If you miss the diagnosis, they could die of the next one. And if you diagnose it and treat it, they risk serious anticoagulation-related complications. The fact is, the most dangerous inpatient drug in terms of serious, life-threatening complications is heparin. And the most dangerous outpatient drug in all of medicine in terms of serious, life-threatening complications is Coumadin," he asserted.

An analysis of time trends in pulmonary embolism (PE) in the United States nicely captured his frustration on this score, thereby making his ‘best-of’ list. The investigators compared national rates of PE and treatment outcomes before and after 1988, the year that CT pulmonary angiography became widely available. After 1988, the incidence of PE climbed by 81% through 2006, and the rate of in-hospital anticoagulation-related complications rose by 71%, from 3.1 to 5.3 cases per 100,000. Yet there was no significant reduction in the death rate due to PE (Arch. Intern. Med. 2011;171:831-7).

"Ouch! All we’ve done is harm a lot more people without a lot of evidence that we’ve saved more people," Dr. Mallon commented.

"I remember when I was in medical school I was told this: If a person has a PE of significance, they will have the diagnostic duet of tachypnea and tachycardia. They’ll be sick from their PE. And PE morphed from that life-threatening thing to us finding these small, subsegmental little things we don’t even really know the meaning of in a person with a totally normal ECG who maybe had a twinge of chest pain and couldn’t catch their breath for 5 minutes," he said. "I think there’s compelling evidence that what we used to think a PE was is not what PE is today, and that the need for treatment of these newer PEs isn’t being talked about in a sensible way. There’s room for that discussion."

• Hyperbaric oxygen therapy for carbon monoxide poisoning: The hyperbaric oxygen chamber is well accepted as standard therapy for divers with the bends, but its utility in cases of domestic acute carbon monoxide toxicity has been highly controversial. A pair of recent French prospective randomized trials concluded it is ineffective and possibly harmful.

One study randomized 179 noncomatose patients with transient loss of consciousness to a real or sham hyperbaric oxygen therapy session. There was no difference in outcomes.

The other trial involved 206 comatose carbon monoxide overdose patients randomized to one or two sessions of hyperbaric oxygen therapy. It was halted early because the group that received more hyperbaric oxygen had less complete recovery, worse delayed neurologic symptoms, and more persistent sequelae (Intensive Care Med. 2011;37:486-92).

• Nonsurgical hemorrhage control: Hyperfibrinolysis is present in 10%-15% of trauma patients and is associated with sharply higher 6- and 24-hour mortality. It can now be detected in 15 minutes at the bedside using thromboelastogram measurement. And, in several recent studies, early administration of tranexamic acid to trauma patients in order to block hyperfibrinolysis has demonstrated improved survival.

The most recent of these studies, MATTERS, (Military Application of Tranexamic Acid in Trauma Emergency Resuscitation), was a retrospective observational study that included 896 trauma patients who received packed red blood cells, 293 of whom also received tranexamic acid.

Unadjusted mortality was significantly lower in tranexamic acid recipients by a margin of 17.4%, compared with 23.9%, even though they had higher mean Injury Severity Scores and thus should have done worse.

The survival benefit associated with tranexamic acid was greatest in the subgroup who received massive transfusions. Their mortality rate was 14.4% compared to 28.1% in controls. In a multivariate analysis, administration of tranexamic acid in this subgroup was associated with a 7.2-fold increased likelihood of survival (Arch. Surg. 2012;147:113-9).

Tranexamic acid is a relatively inexpensive, Food and Drug Administration–approved synthetic blocker of the conversion of plasminogen to plasmin. It has a reasonable safety profile. Remaining questions regarding its incorporation into trauma management protocols include optimal dosing and whether thromboelastogram measurement should be used to guide therapy such that only those patients with hyperfibrinolysis would get tranexamic acid.

Look for answers to come from two ongoing major randomized trials: CRASH-3 (Clinical Randomisation of an Antifibrinolytic in Significant Head Injury) and PROPPR (Pragmatic, Randomized Optimal Platelets and Plasma Ratios), Dr. Mallon said.

• ‘ARDS, acronyms, and the Pinocchio effect’: This was the title of an essay by British physicians (Anaesthesia 2010; 65: 976-9) who argued that the medical world has gone acronym-crazy, with vast research money being spent trying to find cures for ARDS (acute respiratory distress syndrome), SIRS (systemic inflammatory response syndrome), ARF (acute respiratory failure), and the like.

"This is the oldest paper in the series, but I thought it was important enough to bring up," Dr. Mallon explained. "The Pinocchio effect is an important new concept in medicine. The authors point out that these aren’t diseases, they’re just acronyms. When you look at ARDS or SIRS, there are dozens of causes of each of them. Why on earth would we think there’s going to be a magic bullet therapy when there’s such tremendous underlying heterogeneity in the cause? Yet, we keep doing research trials trying to find a treatment for SIRS or ARDS."

"These authors point out, ‘Pinocchio, you’re lying. Organ failure is not a specific diagnosis but a constellation of signs and symptoms.’ We’ve got to stop lying to ourselves that there’s going to be a unifying therapy," Dr. Mallon said.

He reported having no financial conflicts.

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