FALLS Protocol

FALLS (Fluid Administration Limited by Lung Sonography) protocol is an ultrasound approach done at admission, facilitating causal diagnosis of acute circulatory failures with no obvious cause through seven step.

• Step 1 : Pericardial tamponade
• Step 2 : Look for Right ventricle enlargement ( Pulmonary Embolism )
• Step 3: Look for Lung sliding (Pneumothorax)

• Step 1-3 : Rules out Obstructive Shock

• Step 4: Look for B-Profile of Blue protocol ( Acute Hemodynamic Pulmonary Edema ) (Cardiogenic Shock). B lines between two ribs symmetrically distributed anteriorly and assosciated with lung sliding. 

• Step 5 (FALLS- Profile): Applied when A profile is seen ( Anterior A-lines mostly, with lung sliding). The B-Line appears from pulmonary artery occlusion pressure of 18 mmHg. A lines indicate that PAOP < 18 mmHg and fluids can be administered.  The idea is to partially treat both remaining causes of shock (hypovolemic, distributive), while promptly detecting the transformation from A-lines to B-lines under fluid therapy, a change called the FALLS-profile

• Step 6(Round Falls Protocol):  Here fluid is administrated using traditional rules or until FALLS profile occurs (To correct hypovolemia). If patient responds to fluid he is in hypovolemic shock, whereas there will be no improvement in distributive shock (Septic shock) . FALLS profile indicates need for addition of other measures like vasopressors. 

A FALLS Profile indicates a septal edema (Interstitial edema) which precedes alveolar edema. Intersitial AHPE is a silent development with moderate or no effect on gas exchange.

Limitation

•  A patient presenting with B lines on admission can have no transformation from A lines to B lines.

Reference

• Lichtenstein, D.A., Bar, S. Lung ultrasound for causal diagnosis of shock (FALLS-protocol), a tool helping to guide fluid therapy while approaching fluid tolerance. Some comments on its accuracy. Ann. Intensive Care 14, 88 (2024). https://doi.org/10.1186/s13613-024-01329-8