Like Us and Follow Us on

November 11, 2011

ARDMS Updates and Headlines in the News:

ARDMS: Important Testing Center Update

Relaxed Muscles Go Shorter Than Short

Choosing Ultrasound Over CT for Pediatric Pneumonia Improved Outcomes

Ultrasound-Guided Nerve Blocks Blunt Leg Fracture Pain

ARDMS: Important Testing Center Update

• At the test center, you must present two current, valid signature IDs, one of which must be a non-expired government-issued photo ID with your signature; see the accepted list of IDs here.
• The name on your application must EXACTLY MATCH the name on both current, valid signature IDs.
• Jane R. Doe and Jane Rachel Doe DO NOT EXACTLY MATCH.
• Failure to present two acceptable IDs will prevent your admission to the test center. If this happens, you will be marked absent and you will forfeit the entire examination fee and seat.
• If the names do not EXACTLY MATCH, update your ARDMS name of record. 

Back To Top

Relaxed Muscles Go Shorter Than Short

Australian researchers have discovered an entirely new aspect of human muscle behavior which has implications for treating stroke and multiple sclerosis.

Professor Simon Gandevia, of Neuroscience Research Australia and the University of New South Wales, and colleagues, report their findings in the Journal of Physiology.

Gandevia and team have discovered that when human muscles are completely relaxed, the muscle fibers don't just shorten, but actually become wavy and buckle.

Although this sounds paradoxical, it means that at rest, muscles are under no tension whatsoever." Just imagine a coil of rope or wire that had become so low in tension [or slack] that it buckled," said Gandevia.

Gandevia and colleagues recruited 25 adults aged 21 to 86 with no history of musculoskeletal injury for their study.

While the participants lay on a table with their left knee bent, their left ankle was strapped into a footplate.

The footplate moved up and down so it alternately bent and straightened the ankle, forcing the fibers within the muscles to alternately lengthen and shorten.

'Shorter than short'

Ultrasound images were taken to see what was going on in the muscle fibers themselves.

"We were completely surprised at what we saw. We had previously put together some evidence that when muscle fibers are short, they really weren't producing any effective tension - but we never knew they got 'shorter than short' - that they actually buckled," says Gandevia.

"It's dramatic in physiology when you can visualize something on a screen that nobody has ever seen before in human muscle."

Gandevia said his team had been interested in what happens in the passive property of muscles, when there is no contraction.

"These properties are important, because they determine at what angle your joints might sit when you are relaxed," he said.

Implications

The discovery will allow researchers to build more accurate models of muscle function and improve understanding of disorders where the muscles become really short, says Gandevia, including after a stroke, or in multiple sclerosis, where you can't, for example, straighten out your elbow all the way.

Gandevia said the next stage in the research would be to pick some patients who have an abnormal muscle state to see whether the tendency to form this buckling is altered or not.

"It would give us insight into the changes that have taken place in the pathologically affected muscle. It would probably give us some clues as to which part of the muscle have had those changes," he said.

"Now we know about the buckling, it could give you a measurement point because you can take the muscle to a particular length and know it begins to buckle at that length. Then you could follow patients up later, and see whether or not that particular angle [of the limb] at which buckling began had altered."

View the article online.

Article written by staff at abc.net.au and adapted for the purposes of this newsletter.

Back To Top

Choosing Ultrasound Over CT for Pediatric Pneumonia Improved Outcomes

A hospital-wide algorithm for diagnosing and managing complicated bacterial pneumonia in children led to a marked cut in unnecessary chest CT examinations and a reduced number of surgical interventions. It also produced better outcomes, with fewer readmissions and no change in average length of stay or vancomycin use.

A key element of the management algorithm, implemented 3 years ago for children with a pleural effusion, empyema, or both complicating community-acquired bacterial pneumonia, was the emphasis on assessing children with ultrasound rather than with CT. This change produced a drop in chest CT examinations in these patients from 60% before the algorithm became hospital policy to 17% after.

The algorithm called for preferentially using ultrasound to assess these cases. During the first 15 months of its use, chest ultrasounds in these patients was performed in 71% of cases, compared with 27% of cases before the algorithm, Dr. Roberta L. DeBiasi said.

The preferential use of more ultrasound examinations in children with a pleural-space infection meant that fewer children received the large radiation dose delivered by a CT exam, and the sedation required for CT. While safer, ultrasound also produces better imaging than CT in these patients "to sort out who has a loculated empyema that needs VATS [video-assisted lung surgery] and who has a nonloculated effusion that generally doesn’t need VATS," said Dr. DeBiasi, a pediatric infectious diseases specialist on the staff of Children’s National Medical Center in Washington, D.C.

Creation of a new algorithm for the hospital depended on getting physicians and surgeons from all the divisions and departments involved in managing these children – infectious diseases, surgery, radiology, hospitalists, pulmonology, and emergency department – together to decide on the best management approach and make it hospital policy.

"We asked, don’t you realize there are data that ultrasound is preferable, so why use CT so often? The answer was that an ultrasound technician wasn’t available at night in the emergency room." After seeing the data, the radiologists agreed that having ultrasound available 24/7 was important and so arranged it, she said in an interview. The hospital gets on average one or two patients a week with community-acquired bacterial pneumonia complicated by a pleural space infection.

Although no society guidelines existed in November 2008 when the revised algorithm went into effect, last August the Pediatric Infectious Diseases Society and the Infectious Diseases Society of American issued joint recommendations on the management of community-acquired pneumonia in children and included a recommended approach similar to the Children’s National algorithm, Dr. DeBiasi said.

The only difference was that her hospital’s guidelines are more specific, and guide the staff through the local protocol step by step. For example, the new society recommendations say that either video-assisted lung surgery or fibrinolytic therapy are appropriate options for managing loculated empyema. Because surgeons at Children’s National Medical Center do not use fibrinolytic therapy on these cases, the algorithm specifies VATS only, she said.

To examine the impact of the algorithm, Dr. DeBiasi and her associates analyzed patient management and outcomes during the 15 months before the revised algorithm went into effect and then during the first 15 months after. The review showed that the 83 patients managed before November 2008 were an average of 6 years old, similar to the 87 patients treated during the first 15 months using the algorithm, who were an average of 5 years old.

The reduced number of CT exams and increased ultrasound use led to a reduction of VATS from 45% of cases before the algorithm to 29% after. Patient outcomes were better – with a "nice," statistically significant drop in readmission rates from 8% before the algorithm to none during the period after – but during both periods, vancomycin use and average length of stay remained constant (35% and 8 days, respectively), Dr. DeBiasi noted.

"Our [inference] is that some patients didn’t need VATS, and so the algorithm reduced unnecessary interventions. These patients were just managed medically," Dr. DeBiasi said. "I think it was the ultrasound that led to less VATS, because ultrasound is better than CT to see who needs VATS and who doesn’t."

View the article online.

Article written by staff at familypracticenews.com. and adapted for the purposes of this newsletter.

Back To Top

Ultrasound-Guided Nerve Blocks Blunt Leg Fracture Pain

For children with painful femur fractures, nerve blocks performed with ultrasound guidance can significantly improve pain control while reducing adverse effects and nurses' workloads, researchers reported at the American Academy of Pediatrics 2011 National Conference and Exhibition.

In children who received femoral nerve blocks that were guided by ultrasound, the interval between initial pain treatment and a subsequent dose of pain medication was 2 to 3 times longer than in children who did not receive a nerve block, Alyssa L. Turner, MD, from the University of Louisville, Kentucky, said.

This suggests a longer duration of analgesia than systemic analgesic medication, she said.

Coauthor Keith P. Cross, MD, also from the University of Louisville, said that he and his colleagues were inspired to do this study after researchers at the Denver Children's Hospital in Colorado had some success with femoral nerve blocks for controlling the pain of femoral fractures.

"Joe Wathen and his group reported better pain control than with narcotics," Dr. Cross said. "We decided to start using femoral nerve blocks, but to improve on the safety and efficacy by adding ultrasound guidance where we actually watch the needle deliver the anesthetic right next to the nerve."

After doing these blocks with good results for a period of time, the group conducted a study to compare pain outcomes in patients the year before (n = 50) and the year after (n = 49) the implementation of ultrasound-guided femoral nerve blocks.

All patients were 1 to 17 years of age (average age, 6.5 years in the before group and 7.2 years in the after group) and presented within 24 hours of sustaining a femur fracture.

Patients in the before group received routine pain control, usually with intravenous morphine. The fracture types were similar in both groups, Dr. Cross said.

The team found that the mean time until the next dose of pain medication was 176 minutes (95% confidence interval [CI], 116 to 236) in the before group and 435 minutes (95% CI, 327 to 544) in the after group.

"We are continuing to analyze medication-related adverse events, pain scores, and resource utilization. For now, we are hopeful that this technique will improve pain control, particularly for children with these painful injuries," Dr. Cross said.

View the article online.

Article written by staff at medscape.com and adapted for the purposes of this newsletter.

Back To Top