FALLS protocol…

Below is the main content discussed at an ultrasound workshop I ran this week at the Sydney HEMS Clinical Governance Day.

Whilst the bread & butter use of prehospital ultrasound would have to be an extended-FAST scan in the setting of trauma, I decided to focus more on utility of basic ECHO & lung ultrasound in the assessment of shocked medical patients.

A lot has been written about the RUSH protocol and its role in aiding the diagnosis of undifferentiated shock/hypotension. From my own experience (in initiating patient transfers, not conducting them), a source of shock is largely defined by the time an inter-hospital retrieval takes place (ie. abdominal aortic aneurysms excluded by history, examination or ED ultrasound).

When faced with the ongoing ED-based resuscitation of shocked patients (esp. those with septic shock & refractory hypotension), I find myself using a process similar to Lichtenstein’s FALLS protocol which I believe can be carried into the arena of retrieval medicine to guide ongoing therapy (and potentially alter outcomes).

The FALLS protocol.

This is a tool proposed to assist in the management of shocked patients, mainly by the use of lung ultrasound.

Firstly, it aims to exclude obstructive shock by

  1. Cardiac ECHO.
    • ?tamponade
    • ?massive pulmonary embolism with right heart strain
  2. Lung USS.
    • ?tension pneumothorax.

The second phase aims to assess volume status by exploiting ultrasound lung-artefact to detect interstitial syndrome (suggestive of extravascular lung water).

  1. B-Profile.
    • ie. cardiogenic shock – supported by distended, non-compressing inferior vena cava & the presence of pleural effusions.
    • alternatively; signals appropriate volume replacement & a trigger to start vasopressors to maintain blood pressure.
  2. A-Profile.
    • suggestive of hypovolaemic or distributive shock.
    • triggers further fluid administration.
FALLS Protocol - Lichtenstein, 2012.
FALLS Protocol – Lichtenstein, 2012.

Below are the images & ultrasound clips used in my presentation, demonstrating the significant findings at each stage of the protocol.

[DDET Cardiac tamponade…]

Early tamponade with RV diastolic collapse.


Massive pericardial effusion with obvious tamponade. Dx: Malignant effusion 2* to NSCLC.


Massive pericardial effusion with features of tamponade.
NB. the both right atrial and right ventricular diastolic collapse.

Pulse wave doppler measuring MV inlet velocities. ~25% variation through respiratory cycle suggests tamponade physiology.
Pulse wave doppler measuring MV inlet velocities. ~25% variation through respiratory cycle suggests tamponade physiology.

For more information on features of tamponade check out “Sequential sinister sightings…” !!


[DDET Pulmonary embolism…]

Submassive PE.
Severe dyspnoea with A-a gradient > 500 !! Normotensive, but elevated serum troponin.


Massive pulmonary embolism.
Elderly male with undifferentiated shock, hypoxia and abdominal pain.

Features of right ventricular strain in PE.

  1. RV:LV (end-diastolic diameter) > 0.9 – A4C or subcostal view.
  2. RV end-diastolic diameter > 30mm – PLAX or PSAX view.
  3. Hypokinetic RV free wall
  4. Tricuspid regurgitant jet velocity > 2.6m/s
  5. Paradoxical interventricular septal motion
  6. McConnell’s sign – akinesia of the RV-mid free wall with normal motion at the RV apex.

For further discussion on the role of thrombolysis in pulmonary embolism check out “Two in two days…


[DDET Pneumothorax…]

Normal lung sliding. Comet tails + A-line artefact present.

Normal lung ultrasound. Comet-tail artefact present with obvious A-lines.
Normal lung ultrasound. Comet-tail artefact present with obvious A-lines.
M-mode image. Sandy beach sign. No pneumothorax.
M-mode image. Sandy beach sign. No pneumothorax.


Pneumothorax present. No visible comet tails, no lung sliding.

M-mode ultrasound demonstrating a 'bar-code' sign, consistent with pneumothorax.
M-mode ultrasound demonstrating a ‘bar-code’ sign, consistent with pneumothorax.



[DDET B-Profile]

Bilateral B-lines [‘lung rockets’] consistent with pulmonary oedema/interstitial syndrome.

7 criteria for B-lines.

  1. There is a comet-tail, vertical artefact.
  2. Arises from the pleural line.
  3. Moves in concert with lung sliding.
  4. Does not fade.
  5. Well-defined, laser like.
  6. Hyperechoic.
  7. Obliterates the A-lines.

In the BLUE-protocol detection of interstitial syndrome to anterior chest, bilaterally (with lung-sliding) makes the diagnosis of haemodynamic pulmonary oedema with 97% Sn & 95% Sp.

Differential diagnoses of B-lines;

  • pulmonary contusion
  • pneumonia
  • pulmonary fibrosis


[DDET A-Profile]

Bilateral A-lines with lung sliding.


The presence of A-profile in a shocked patient = a FALLS responder. This suggests a hypovolaemic or distributive contributor to shock & correlates with pulmonary artery occlusion pressures of < 18mmHg [Sp 93%, PPV 97%].

The protocol recommends further fluid boluses with serial assessment by lung-ultrasound, looking specifically for change from A-lines to B-lines. At this stage, vasopressors would be started.


[DDET The slideshow…]

[slideshare id=34888257&doc=ultrasoundupdatesforhems-140520012035-phpapp02]


[DDET References.]

FALLS protocol + lung ultrasound

  • Lichtenstein, D. A., & Mezière, G. A. (2008). Relevance of lung ultrasound in the diagnosis of acute respiratory failure: the BLUE protocol. Chest134(1), 117–125. doi:10.1378/chest.07-2800
  • Lichtenstein, D. (2013). FALLS-protocol: lung ultrasound in hemodynamic assessment of shock. Heart, lung and vessels, 5(3), 142–147.
  • Lichtenstein, D. A. (2014). Lung ultrasound in the critically ill. Annals of intensive care, 4(1), 1. doi:10.1186/2110-5820-4-1
  • Mount Sinai Emergency Medicine Ultrasound.

RUSH protocol.

ECHO for Pulmonary Embolism.

  • MD, S. D., et al. (2014). Right Ventricular Dilatation on Bedside Echocardiography Performed by Emergency Physicians Aids in the Diagnosis of Pulmonary Embolism. Annals of Emergency Medicine, 63(1), 16–24. doi:10.1016/j.annemergmed.2013.08.016
  • Rudski, L. G.., et al. (2010). Guidelines for the echocardiographic assessment of the right heart in adults: a report from the American Society of Echocardiography endorsed by the European Association of Echocardiography, a registered branch of the European Society of Cardiology, and the Canadian Society of Echocardiography. Journal of the American Society of Echocardiography : official publication of the American Society of Echocardiography, 23(7), 685–713– quiz 786–8. doi:10.1016/j.echo.2010.05.010
  • Meyer, G., Vicaut, E., Danays, T., Agnelli, G., Becattini, C., Beyer-Westendorf, J., et al. (2014). Fibrinolysis for Patients with Intermediate-Risk Pulmonary Embolism. The New England journal of medicine, 370(15), 1402–1411. doi:10.1056/NEJMoa1302097
  • Sosland, R. P., & Gupta, K. (2008). Images in cardiovascular medicine: McConnell’s Sign. Circulation, 118(15), e517–8. doi:10.1161/CIRCULATIONAHA.107.746602


For a great bibliography on the evidence available for prehospital ultrasound, check out Cliff’s Resus.me.

Special thanks to Dr Justin Bowra for his assistance & advice with putting this together.



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