Double Lumen Tube

• Lung isolation and one  Lung Ventilation ( OLV )  are used to facilitate surgery on the lungs, thoracic aorta, thoracic spine, esophagus and during minimally invasive cardiac surgery.  They are also used to manage air leak (Bronchopleural fistula) and preventing contamination of healthy lung by blood or infected material.

• It can be achieved by double lumen tracheal tube, bronchial blocker or advancing single lumen tracheal tube into a main bronchus. 

• Modern day DLT are single use, made of PVC. They have a white or clear tracheal lumen and blue bronchial lumen. When correctly inserted tracheal lumen terminates in the distal trachea and the bronchial lumen terminates in the distal main bronchus. When initiating OLV, the connector to the operative lung is clamped and the lumen opened to air, allowing ventilation of the non-operative lung and deflation of the operative lung.

Right sided DLT

Left Sided DLT

Size

• Male : 41 Fr, Small stature :37 Fr
• Female :35

Procedure

Video

Complication

• Hoarsness of throat
• Sore throat
• Trauma to Arytenoids, vocal cord tears and airway rupture

Reference 

• Double-lumen tubes and bronchial blockers Patel, M. et al. BJA Education, Volume 23, Issue 11, 416 - 424 .

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