Authors: Mark Winstanley, Diana Holbert, Andy Neill, Calvin Lightbody, Dave McCreary, Jon Carter, Tessa Davies, Becky Maxwell, Chris Connolly / Codes: EnC2, NeuC12, PalC1, PalC2, PalC4, PalC6, PalC7, RC2, RP6, SLO1, SLO10, SLO3, SLO5, SLO9, TP1 / Published: 01/08/2019


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Diana Holbert – EM Consultant in Southampton
Mark Winstanley


Andy Neill
Calvin Lightbody

Calvin is an EM Consultant, University Hospital Hairmyres, NHS Lanarkshire. He has an interest in end of life care and we chatted about how best to engage with patients, families and other staff in patients who are on a dying trajectory.

Calvin has also started his own podcast to explore this further.

You can also hear him over on our friend’s site at St Mungos.

Calvin on Twitter


Dave McCreary
Andy Neill

Clinical Question:

IV access for CTPA – does size / location matter?

Title of Paper:

Rethinking Intravenous Catheter Size and Location for Computer Tomography Pulmonary Angiography

Journal and Year:

Western Journal of Emergency Medicine. March 2019.

Lead Author:

Travis Marshall


* How many times have you been called to CT to site a larger, more proximal cannula for a CTPA?

* CTPA is the gold standard for diagnosing PE – but even then its sensitivity and specificity is reported as 89 and 95% assuming proper technique, which is why radiology get so precious about decent IV access for their contrast

* The American College of Radiology recommend at least a 20-gauge (the pink one) in the ACF/forearm

* In many patients this may be easier said than done

* This a recommendation _may_ have been plucked from the air

Study Design:

* Retrospective chart review

* Single centre

Patients Studied:

* Adult patients having a CTPA for investigation of PE

* Excluded patients not being investigated for PE

What they did:

* Trained medical students to perform chart review

* Assessed the final radiology report and defined a ’suboptimal’ study as any comment of:

* Inadequate filling / suboptimal timing of a contrast bolus

* Motion artefact

* Any radiology impression of ’technically limited’ or ‘inadequate to exclude PE’

* They allowed inability to exclude sub-segmental

* They did the quality measures you want for a chart review:

* Physician investigator audited 50 charts from each abstractor

* Both abstractors reviewed a sample of 50 of the other’s to assess inter-rater reliability


* Primary: difference in rate of inadequate filling for 20-gauge + in ACF_forearm versus all other catheter sizes_locations


* Percentage of inadequate studies stratified by catheter size and location

* Compared % inadequate studies of 20G+ vs smaller catheters

* Compared % inadequate studies of ACF/Forearm (all sizes) vs other location (all sizes)

Summary of Results:

* 1500 consecutive CTPAs looking for PE included

* 289 (19.3%) = suboptimal

* 54% motion artefact

* 52% inadequate filling

* 2% other

* 11% multifactorial


* 20G+ in ACF/Forearm: 9.2% inadequate

* Smaller than 20G or other location: 13.2% inadequate

* 4.0% difference [-1.7% – 9.7%] – not statistically significant


* ACF/Forearm vs other locations: 9.3% vs 12.2% inadequate

* Difference 2.9% [-2.7% – 8.5%]

* 20G+ vs smaller (22G): 9.7% vs 23.1% inadequate

* Difference 13.4% [-9.6% – 36.4%]

* Note: Only 13 patients had a 22G

* 10/13 had completely adequate filling

* In their breakdown in Tables 2 & 3:

* Access in the hand (unfortunately my favourite go-to spot for access) looks to have the highest rate of inadequacy at 18.4% – makes sense anatomically

* Central lines are close behind at 16.7%

Authors Conclusion:

We did not detect any statistically significant differences in the rate of inadequate contrast filling based on IV catheter locations or sizes.  While small differences not detected in this study may exist, it seems prudent to proceed with CTPA in patients with difficult IV access who need emergent imaging even if they have a small or distally located IV.

Clinical Bottom Line:

I reckon with larger sample size those differences would have become significant.  And as the authors point out this is only a single site study so external validity is the question.  That being said this at least gives some evidence to support just getting the scan done in emergency situations.
I think this data is pointing in the direction of location matters more than cannula size (so long as you confirm your cannula brand can take the pressure as the investigators did here).
Obviously if time and access allows then yes, give the radiographers the best chance to get the best images, but if I have no other option I’d be pushing for the scan to just get done.

Other #FOAMed Resources / References:

* [Journal Feed’s]( spoon feeding review of this paper


Jon Carter
Nikki Abela


This guideline covers interventions in the acute stage of a stroke or transient ischaemic attack (TIA). It offers the best clinical advice on the diagnosis and acute management of stroke and TIA in the 48 hours after onset of symptoms.

Thinking about diagnosis

1: Recommended to use ‘FAST’ I prehospital. A significant push exists to rapidly diagnose stroke and obtain a CT in patients with concern for stroke ASAP, as provision of thrombolytics requires specific time criteria and contraindication considerations. However, the diagnosis of stroke is not always straightforward. Classically, strokes present as the sudden onset of a focal neurologic deficit in a vascular distribution. There are multiple diagnoses that may mimic this presentation.

2: Check a sugar for anyone with neurological symptoms – watch out for all stroke mimics and chameleons

• MIMIC – Stroke mimic is the term employed for manifestations of nonvascular disease processes when a stroke- like clinical picture is produced. The presentation resembles or may even be indistinguishable from an ischemic stoke syndrome. The mimics include both processes occurring within the CNS and systemic events.

• CHAMELEONS – some strokes can present in ODD ways – with confusion, delirium. Lacunar strokes are caused by occlusion of a small branch of a larger blood vessel. These smaller vessels are deeper within the central nervous system. There are five categories of lacunar stroke: pure motor, pure sensory, sensorimotor lacunar, ataxic hemiparesis, and dysarthria clumsy-hand syndrome

3: Use a score such as ROSIER to make the diagnosis in ED.

ROSIER score:

Negative points
• Presence of syncope or seizure
• New onset
• Asymmetrical face, arm or leg weakness, (one each)
• Speech disturbance
• Visual defect.
Anything more than 0 makes stroke likely.


Remember this is a transient event so symptoms should have resolved to make this diagnosis.
1) Don’t do a CT unless there’s suspicion of a diagnosis that CT will reveal.
2) AFTER specialist assessment consider an MRI to look for ischaemia or bleeding.
3) Refer immediately to a TIA service for the patient to be seen within 24 hours.
4) Start 300mg aspirin a day unless contraindicated. What do you do if it is? We use clopidogrel at our place. What if they are already on aspirin?
5) Don’t use ABCD2
6) Offer secondary prevention in those who diagnosis is confirmed

Link to guidelines:


Andy Neill
Tessa Davis

Tessa Davis is a PEM Consultant at The Royal London Hospital and is one of the co-founders of Don’t Forget the Bubbles website and conference.

This interview was recorded at the 2019 CPD conference in Belfast and there is a great blog of it with all the links to the papers

You can follow Tessa on Twitter