Top Recent Articles: One ED Professor's View

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.