Nurse practitioner administered point-of-care ultrasound compared with X-ray for children with clinically non-angulated distal forearm fractures in the ED: a diagnostic study

Abstract

BackgroundPaediatric distal forearm fractures are a common ED presentation. They can be diagnosed with point-of-care ultrasound (POCUS) as an alternative to X-rays. Given that ED nurse practitioners (NPs) are relied on for the diagnosis of paediatric fractures, it is important to describe the diagnostic accuracy of NP-conducted POCUS versus X-ray.MethodsThis prospective diagnostic study was conducted in a tertiary paediatric hospital in Queensland, Australia, between February 2018 and April 2019. Participants were children aged 4–16 years with a clinically non-angulated, suspected distal forearm fracture. Diagnosis from 6-view NP-administered POCUS of the distal radius and ulna was compared against the reference standard of 2-view X-ray. Each patient received both imaging modalities. Overall forearm diagnosis was classified as ‘no’, ‘buckle’ or ‘other’ fracture for both modalities. The primary outcome was diagnostic accuracy for ‘any’ fracture (‘buckle’ and ‘other’ fractures combined). Secondary outcomes included diagnostic accuracy for ‘other’ fractures versus ‘buckle’ and ‘no’ fractures combined, and pain, imaging duration and preference for modality.ResultsOf 204 recruited patients, 129 had X-ray-diagnosed forearm fractures. The sensitivity and specificity for NP-administered POCUS were 94.6% (95% CI 89.2% to 97.3%) and 85.3% (95% CI 75.6% to 91.6%), respectively. ‘Other’ fractures (mostly cortical breach fractures), when compared with ‘buckle’/ ‘no’ fractures, had sensitivity 81.0% (95% CI 69.1% to 89.1%) and specificity 95.9% (95% CI 91.3% to 98.1%). Pain and imaging duration were clinically similar between modalities. There was a preference for POCUS by patients, parents and NPs.ConclusionsNP-administered POCUS had clinically acceptable diagnostic accuracy for paediatric patients presenting with non-angulated distal forearm injuries. This included good sensitivity for diagnosis of ‘any’ fracture and good specificity for diagnosis of cortical breach fractures alone. Given the preference for POCUS, and the lack of difference in pain and duration between modalities, future research should consider functional outcomes comparing POCUS with X-ray in this population in a randomised controlled trial.

Bedside Ultrasound Conducted in Kids with distal upper Limb fractures in the Emergency Department (BUCKLED): a protocol for an open-label non-inferiority diagnostic randomised controlled trial

“…The current pragmatic reference standard for diagnosis is 2-view forearm x-rays, reported by a radiologist, which is also utilised in routine follow-up outpatient appointments to monitor progress. In most urban district centres, radiology services are readily available, including after-hours access, and are generally a quick process but can be delayed by more urgent cases [ 10 ]. However, in regional or austere settings, radiographic services can be less available, leading to potential delay in management or unnecessary transfers to larger centres [ 32 ].…”

“…Participants will be allocated to an initial diagnostic imaging modality of POCUS or x-ray. POCUS was chosen as the intervention for this trial as, for paediatric distal forearm fractures, it is non-invasive, accurate and well-tolerated; does not emit ionising radiation; and is preferred by patients [ 10 ]. X-ray was chosen as the control comparator as not only is it a pragmatic reference standard, but also it currently guides routine practice in the ED and subsequent standard outpatient follow-up.…”

“…Credentialing consists of a 2-h simulated training package with a phantom arm model [ 16 ], followed by proctored scanning, the collection of a logbook of scans demonstrating a total of 20 patients with a mixture of at least 10 buckle or cortical breach fractures, image interpretation from a bank of case examples and a final observed assessment. A modified 6-view forearm POCUS protocol will be conducted, whereby the distal radius and ulna are interrogated on their dorsal, lateral and volar aspects with a high frequency linear probe in a longitudinal axis with the probe marker orientated distally [ 10 ]. Secondary signs will also be assessed (Table 2 ), which includes the pronator quadratus haematoma sign [ 19 ].…”

“…These x-rays convey a small dose of ionising radiation, which should be minimised where possible in the paediatric population [ 8 ]. Bedside ultrasound, otherwise known as point-of-care ultrasound (POCUS), a portable form of non-ionising imaging conducted at the patient bedside [ 9 ], has the potential to avoid unnecessary x-ray imaging in children with clinically non-angulated distal forearm fractures [ 10 ], thereby supporting the ‘as low as reasonably achievable’ (ALARA) principle [ 11 ]. POCUS has been proposed as a potential alternative to x-rays to diagnose non-angulated paediatric distal forearm fractures.…”

“…POCUS could potentially be used as a screening tool to determine the presence and type of fracture [ 10 , 15 ]. Patients without any fracture or with only a buckle fracture can be conservatively managed akin to soft tissue injuries [ 6 ].…”