Can you see what I see?

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When it comes to imaging children we are all about the ALARA (as low as reasonably achievable) approach. One of the best ways to do this is not to use radiation at all. Unfortunately not all of us can be Casey Parker, and so we might need some help with our ultrasound skills.

An enterprising study group in Italy have looked at whether remote guidance of paediatricians by trained radiologists might help. Here is the paper…

Zennaro F, Neri E, Nappi F, Grosso D, Triunfo R, Cabras F, et al. (2016) Real-Time Tele-Mentored Low Cost “Point-of-Care US” in the Hands of Paediatricians in the Emergency Department: Diagnostic Accuracy Compared to Expert Radiologists. PLoS ONE 11(10): e0164539. doi:10.1371/journal.pone.0164539

 

What did they set out to do?

They wanted to find out if a paediatrician, guided remotely by a radiologist, was as accurate as a radiologist at the bedside. Each child that was entered into the study had three scans within the hour.

  • First by remote control (TELE-POC)
  • Secondly by the same radiologist but at the bedside (UNBLIND RAD)
  • Finally by an independent radiologist (BLIND RAD)

They used low cost, off the shelf equipment, and open source software to transmit the images from the ultrasound machine to a radiographer in another room that was looking at the scan in realtime and telling them where to move the probe. The paediatricians were not total novices, however, as they had undertaken a rigorous two hour course on how to switch on the machine (and look for pertinent findings).

What sort of conditions did they look at?

Their convenience sample looked at children between the ages of 0 and 18 (!) years of age that presented to their Paeds ED, during working hours. They didn’t want to study children that were acutely unwell as it would not have been ethical to subject them to three scans. Instead they chose children in which they felt an ultrasound might help them turn an equivocal diagnosis into a firm one. They chose eight conditions to look at – and this is where it gets interesting…

  • Traumatic abdomen (i.e. a FAST scan)
  • Suspected appendicitis
  • Suspected intussusception
  • Suspected hypertrophic pyloric stenosis
  • Suspected pulmonary infection
  • Hip pain
  • Soft tissues swelling
  • Non-specific abdominal pain

What they don’t tell you is the sensitivity or specificity of ultrasound in making the diagnoses.

FAST in kids is as good as flipping a coin with only 50% sensitivity. At least ultrasound has a sensitivity of around 88% and a sensitivity of 94% for detecting acute appendicitis in children when performed by radiologists.

What outcomes were they looking at?

They were looking at three main outcomes.

  • Did the radiologist reach the same diagnosis if he performed the scan him/herself or via telemedicine?
  • Did the blinded radiologist come to the same conclusion as the tele-mentored paediatrician?
  • Did the scans performed by the blinded and unblinded radiologist tally up?

What sort of numbers did they get?

During the six month study period 59 children were possible candidates for inclusion and 52 were included (some refused consent). 8 of these kids were examined for two or three of potential conditions. This meant that there were a potential 62 clinical conditions for scanning. Somehow this works out as 170 ultrasound scans. Here is the distribution of scans, taken directly from the paper.

journal-pone-0164539-t002

By far, the majority of scans were performed for traumatic injury to the abdomen. If you want to hear Ross Fisher rant on about this then listen to this St Emlyns’s podcast.

What were their results?

Take a look at Table 3 from the paper.

journal-pone-0164539-t003

Of the 170 scans performed, 155 were negative. Every positive finding in the tele-mentored group was, understandably, found by the experts so there were no false positives. There were 3 false negatives – a minimal peri-hepatic effusion missed by the mentored paediatrician and a case of intermittent intussusception only spotted by the blinded radiologist.  They go on to derive a Kappa of 0.93 for inter-rater reliability but with such small numbers of positive findings this is not generalisable to the real world.

It is also interesting to note what included in the positive findings – an effusion in the Pouch of Douglas and a distended bladder.

If the detection of free fluid is only 50% sensitive at best then its inclusion as a positive diagnosis makes little sense.

What were their conclusions?

They concluded that POCUS performed by ED physicians with real-time tele-mentoring produced reliable and timely diagnosis. They acknowledged that some of the rarer conditions were not as amenable to study.

What does this mean for me, in the real world?

I really like the premise, that an expert, sitting in a room across the campus, state, country or even in another continent could help guide my hand and help me make ultrasound based diagnoses. Haney Mallemat spoke of the same at SMACCDub. Intuitively it makes sense, but this study does not provide much evidence for its benefit. No mention is made of the potential improvement in clinical outcomes for the children studied. I am also concerned that over half of the patients had a type of FAST scan for traumatic abdominal injury. We know that FAST in kids is as useful as tossing a coin and in adults it has very little place in the haemodynamically stable patient that will end up going to CT anyway.

Will this study change my practice? It is unlikely to. I have utilized a similar approach in my adult retrieval work, using telehealth to look at bedside images and perhaps in the age of smartphones this will become more ubiquitous. If the clinician at the bedside can obtain good images then a short video clip can make selling the patient to a receiving unit so much easier.

For the future

I’d like to see the study done on  different patient group. How about a study comparing tele-mentored emergency physicians looking for fractures, comparing them with radiologists and against the gold standard radiograph (that would have been performed anyway)?

References

Zennaro F, Neri E, Nappi F, Grosso D, Triunfo R, Cabras F, et al. (2016) Real-Time Tele-Mentored Low Cost “Point-of-Care US” in the Hands of Paediatricians in the Emergency Department: Diagnostic Accuracy Compared to Expert Radiologists. PLoS ONE 11(10):  e0164539. doi:10.1371/journal.pone.0164539

Fox, J.C., Boysen, M., Gharahbaghian, L., Cusick, S., Ahmed, S.S., Anderson, C.L., Lekawa, M. and Langdorf, M.I., 2011. Test characteristics of focused assessment of sonography for trauma for clinically significant abdominal free fluid in pediatric blunt abdominal trauma. Academic emergency medicine, 18(5), pp.477-482.

Scaife ER, Rollins MD, Barnhart DC, Downey EC, Black RE, Meyers RL, Stevens MH, Gordon S, Prince JS, Battaglia D, Fenton SJ. The role of focused abdominal sonography for trauma (FAST) in pediatric trauma evaluation. Journal of pediatric surgery. 2013 Jun 30;48(6):1377-83.

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An Emergency Physician with a special interest in education and lifelong learning. When not drinking coffee and reading Batman comics he is playing with his children.

@andrewjtagg | + Andrew Tagg | Andrew’s DFTB posts

Author: Andrew Tagg

An Emergency Physician with a special interest in education and lifelong learning. When not drinking coffee and reading Batman comics he is playing with his children.

@andrewjtagg | + Andrew Tagg | Andrew’s DFTB posts

3 Responses to "Can you see what I see?"

  1. Rachel Rowlands
    Rachel Rowlands 1 year ago .Reply

    oh oh oh! I think that study you are wanting may just be about to be published on line…
    I may have helped write it 🙂

  2. Andrew Tagg
    Andrew Tagg 1 year ago .Reply

    I shall look forward to having a read. I think the principle is a sound one it is just I was not happy with what they were looking at in this paper.

  3. Andrew Tagg
    Andrew Tagg 1 year ago .Reply

    And here is the link to Rachels paper that is now in press

    http://www.jem-journal.com/article/S0736-4679(16)30888-5/fulltext?rss=yes

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