Neil Canavan

April 12, 2013

NEW YORK, New York — Point-of-care ultrasound in the emergency department might detect fractures in injured children as effectively as computed tomography (CT), without the radiation exposure.

These are the findings of a small pilot study and they suggest that portable ultrasound is faster and safer than CT, the current standard of care.

Joni Rabiner, MD, from the Children's Hospital at Montefiore in the Bronx, New York, presented the results here at the American Institute of Ultrasound in Medicine 2013 Annual Convention.

Her team examined the effectiveness of the 2 approaches and looked at the learning curve for point-of-care ultrasound.

They conducted a 1-hour hands-on session to train a group of novice sonographers in the technique. The clinicians then used the approach to evaluate pediatric patients for skull fracture, defined as a cortical disruption or irregularity of the skull.

The 72 study patients, with a median age of 6.5 years, underwent an initial ultrasound evaluation in the emergency department. After that, a standard-of-care head CT or skull x-ray was performed.

An experienced sonographer evaluated the ultrasound results to establish interobserver agreement; attending radiologists — blinded to the sonographers' findings — interpreted the CT scans and x-rays.

Table. Performance of Point-of-Care Ultrasound for Skull Fracture

Characteristic Performance 95% Confidence Interval
Sensitivity 88% 53–98
Specificity 97% 89–99
Positive predictive value 0.78 0.45–0.94
Negative predictive value 0.98 0.92–1.00
Likelihood ratio of positive test 28 7–112
Likelihood ratio of a negative test 0.13 0.02–0.81

 

Dr. Rabiner reported there was "almost perfect" agreement between the novice and expert sonographers. The scans, which involved only the immediate area of hematoma or suspected trauma, took a mere median of 67 seconds to perform.

There was 1 missed call with ultrasound — a parietal nondepressed skull fracture was identified with CT in a 7-month-old with temporal scalp hematoma. The child was admitted for observation, but no further intervention was required, said Dr. Rabiner.

There are several advantages of point-of-care ultrasound: the high negative predictive values, the lack of need for sedation, the lack of radiation, and the timing. "In a serious situation, we can get the neurologist involved much more quickly," Dr. Rabiner said.

High Hopes

After her presentation, Dr. Rabiner, responding to audience questions, explained that the novice sonographers were able to distinguish between a fracture and a skull suture; this had been covered in the training session.

Overall, the data were enthusiastically received. "The high, albeit imperfect, sensitivity in this study speaks well of skull ultrasound, and adds to an overall screening panel that the clinician can use," David McLario, DO, a pediatric emergency specialist from the University of Louisville, in Kentucky, told Medscape Medical News.

"The ideal is to come up with a battery of tests that make up a screening instrument that would decrease skull cranial radiation in young children, who are the most prone to its deleterious effects," he said.

Dr. McLario added that there is a potential for cost savings with point-of-care ultrasound. "Given the enormous number of head CTs we do, even a modest reduction would reduce costs dramatically. And then of course there is the 10- to 20-year window of malignant transformation that will certainly come back to increase costs further."

Will point-of-care ultrasound be a game changer in this setting? "It's going to come down to how sensitive we can be overall and how well a normal skull ultrasound screens for injury," said Dr. McLario. "It's encouraging, but not proven at this point."

Dr. Rabiner and Dr. McLario have disclosed no relevant financial relationships.

American Institute of Ultrasound in Medicine (AIUM) 2013 Annual Convention: Abstract 1540708. Presented April 10, 2013.

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