Diagnostic or therapeutic?

This is a new patient, 58 female who presents with acute on chronic left hip pain. She is slow to rise from the waiting room chair and limps to approach my room.  She describes two months of increasing left hip pain.

There are two components – a deep pain with a pointing sign to the groin crease and a pain that tracks down the lateral thigh. There was no recalled trauma or prior history.

On examination there was both tenderness over the greater trochanter, a positive Trendelenburg sign and positive impingement tests (FABER and flexed int/ext rotation).  Interestingly this patient had previous had a plain radiograph and CT at St Elsewhere which were reported as essentially normal.  However this was not in keeping with her symptoms and signs of significant left hip pain and disability.

I felt this was a combination of trochanteric bursitis/gluteal tendonosis and a internal hip derangement.  After a talk that I thought there were two problems, without prophesying about what was the chicken or egg, we decided to organise MRI and perform a diagnostic/therapeutic trochantric bursa injection.   lefthip

There was only slight benefit to the injection for the patient with a persistence of the deep and positional left hip ache.  MRI demonstrated significant chondral loss, fissuring and bone oedema, out of keeping with the radiograph and CT.  There was no identified labral injury.  Now I feel this is a right gluteal and tensor fasciae latae tendonosis as a sequelae to left hip chondral loss.

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The value of a normal test result

This week I had a infrequent patient in, last seen in 2014, generally fit and well, non-smoking 35year old male.  He presented with left sided sharp chest pain that had come on suddenly while walking on the beach 36hours prior.  He rated the pain as 5/10, worse with deep inspiration and cough, relieved by lying down. There were no fever, sweats, productive cough or other infection symptoms. On examination normal RR, HR, BP, SpO2 and chest clear to auscultation and percussion. He is a tall, skinny man and with the other normal findings and history, a spontaneous small pneumothorax is a differential. Previously I would have sent this man for an erect CXR but with ultrasound there in the room we can look directly.

alines
Normal A-Line Lung ultrasound profile between two anterior rib spaces, the Bat Wing sign. Normal pleural sliding on video “ants marching”

So reassured about an absence of pneumothorax there was reassurance, assumption this was chest wall/intercostal muscle pain and a safety net plan for follow up if needed.

I called the patient 48hours post their consultations and all symptoms had resolved.

By having US available in the room, the patient was saved a trip to the radiologist, Medicare saved the cost of a radiograph and I was saved time following up the result.  Ruling out of pneumothorax with POCUS is one of the uses that has the highest specificity with sensitivity 86–98% and specificity 97–99%.

Recent gppocus medical press articles – increasing interest?

 

ministry

GP POCUS is coming of age with recent articles in two Australian medical papers – not peer reviewed journals, more of the trade papers with updates and news. The first was in the RACGP Good Practice magazine in September, available as a pdf here.

The other recent one was in the Australian Doctor magazine with a good interview with a GP from Norway who trained with US there and then moved to Australia. There is then a unfortunately dismissive radiologist interview. Have you seen any other articles about?

 

SMACCDUB talk – How US makes you better

usmakes

How Ultrasound Makes You Better

well worth lesson, this is a presentation at SMACCDUB from Resa Lewiss, a real promotor of POCUS through her work with WINFOCUS and PURE

If you want more, she also talks in this Jellybean podcast with Doug Lloyd (only on Soundcloud, no download)

 

Lung POCUS and the zone wars

Probe positioning is very well defined for echocardiograpy, FAST and vascular scanning.  However with the thorax there is a lot of real estate, and a lot of lung.  Is there  an agreed plan and language for scanning the lungs?

First a surface anatomy refresher:

09fig_lunglobes
from http://imbus.anwresidency.com/txtbook/03_lung.html

For lung ultrasound assessment for assessment of interstial oedema there seems to be two  main methods, following Volpicelli (Italy)or Lichenstein (France).  Great slides by Lichenstein here.

First I present the 4 lung zones for each hemithorax described by Volpicelli from 2006:

zones_volpicelli
from https://www.youtube.com/watch?v=VzgX9ihnmec

With two zones anteriorly and two under inferior to the axilla.  Different articles seem to variously place the horizontal line at the 3rd or 5th intercostal space.

And the three zones of Lichenstein and the BLUE (Bedside Lung Ultrasound In Emergency) protocol (really six as they divide the three zones into upper and lower, without setting out anatomical borders for upper/lower) from 2008.

lungpocuszoneslichenstein
https://com-anest.sites.medinfo.ufl.edu/files/2015/11/The-Blue-Protocol.pdf

In 2008 there were also two of the Italian workers Copetti & Cattarossi who described POCUS zones for paediatric lung infections were “The probe was placed perpendicular, oblique and parallel to the ribs in the anterior, lateral and posterior (lower and upper) thorax.”, creating six zones on each hemithorax, they don’t provide any guiding images.

Then there are various EM/ICU/CC/Anaesthesia protocols eFAST, RUSH, CCUS,FATE, F-LUS:

m_chest_148_4_912_fig01
CCUS – Critical Care Ultrasound, similar to Volpicelli, adds a 5th zone for dependent pleural fluid (PLAPS -Postero-Lateral Alveolar Pleural Syndrome- see also BLUE protocol) http://journal.publications.chestnet.org/article.aspx?articleid=2297756
efast
eFAST – extended Focused Assessment with Sonography in Trauma – adds two anterior high thoracic and two low lateral thoracic probe positions to the FAST scan
RUSH - Rapid Ultrasound for Shock and Hypotension, two anterior thoracic windows http://sinaiem.us/tutorials/rush/
RUSH – Rapid Ultrasound for Shock and Hypotension, two anterior thoracic windows
http://sinaiem.us/tutorials/rush/
lung portion of FATE (Focus Assessed Transthoracic Echo)
lung portion of FATE (Focus Assessed Transthoracic Echo)
m_chest_144_6_1868_fig01
F-LUS – expansion of FATE( Focused Lung Ultrasound/Focus Assessed Transthoracic Echocardiography) which the authors state is a modification of Lichenstein and Volpicelli http://journal.publications.chestnet.org/article.aspx?articleid=1728827

If you want to really wig out there is a 28 zone protocol to use:

http://handsonecho.com/sites/53072f21c97d797504000002/content_entry530f3ce3c97d79b7c2000279/5470daaac97d7945d40d6b5f/files/How_I_do_it.pdf
http://handsonecho.com/sites/53072f21c97d797504000002/content_entry530f3ce3c97d79b7c2000279/5470daaac97d7945d40d6b5f/files/How_I_do_it.pdf

 

I really just like this pragmatic approach:

wheretoputtheprobe
http://handsonecho.com/sites/53072f21c97d797504000002/content_entry530f3ce3c97d79b7c2000279/5470d878c97d7904e30d4f41/files/Semiotics_A.pdf

What will I be using in general practice? As per my positioning post, clothing access and patient positioning and room ergonomics play a large part of the scanning process for me.  The questions I want to address pneumothorax yes/no, B-lines/interstial oedema yes/no, consolidation yes/no and effusion yes/no would be well answered by any of these however the CCUS five zones (1R, 2R, 3R, 4R, 5R) modification of Volpicelli’s zones seems clear and allow me to have a re-producible note for myself in the patient record and onscreen comments for review scans. For on-referred patients (usually going to the ED for LRTI) I will still use word descriptors because we do not yet have a lingua franca for lung ultrasound zones.

I have not talked about probe selection or probe orientation (mostly perpendicular to ribs to achieve the Bat Wing sign, the FATE low pleural views are parallel to ribs to view lung/diaphragm/liver or spleen) or lung scoring systems.

Another learning point from my reading around these zones was something I have not been doing – scan low on the back to get kidney and then work up when patient is sitting. You will ensure you are low, below diaphragm and as you scan up in area 5R you give yourself the best chance of spotting the curtain sign of the diaphragm and then a dependent effusion.

 

Patient positioning and GPPOCUS

Traditional sonography has the patient on a examination couch, usually in the centre of the room with machine on the patients right.  POCUS in the ED can replicate this, or for procedures have the screen on the patients left, operator on the patients right however access around the patient on the hospital trolley bed is preserved.

In general practice we are often more constrained. Rooms can be small, beds are often fixed or too heavy to move easily and if not electric can be hard/unsafe for the elderly to climb.

Time constraints of a consultation also come into play – it can take a very long time for someone in winter layers to take everything off, lie down on the examination couch and then dress again.

So for pure reasons of anatomical access, safety, timeliness and privacy there are some scans that just need to go to the formal sonographer due to pure patient positioning reasons.

I have also been using a sitting position for lung POCUS, the patient sitting sideways on a chair without arms, allowing access to the back and infra-axillary lung windows.  This however must affect rib spacing and ?increased lower zone consolidation compared to the ideal lying down with hands behind head in a trolley. Some articles do suggest a lying or sitting position equally valid and points out that sitting is preferred for the very dyspnoeic. This is another article from a early researcher/adopter of LungPOCUS, Volpicelli, who states there is no difference in lying/sitting/standing as fluid shifts occur slowly in the lungs.