The placement of a Double Lumen Tube (DLT), often referred to as the DLB procedure, is a specialized airway management technique used in anesthesia and critical care. This technique allows for the selective ventilation of a single lung, effectively isolating it from the other. The primary purpose of this separation is either to protect the healthy lung from contamination or to provide a still, deflated lung for surgical access. Highly trained clinicians, such as anesthesiologists, perform this intervention to manage the patient’s breathing during specific surgical and medical situations.
What is a Double Lumen Tube
A Double Lumen Tube (DLT) is a modified endotracheal tube featuring a unique, dual-channel design. It consists of two parallel tubes fused together, each leading to a distinct passage, or lumen, with its own connection port. The shorter, wider tracheal lumen rests in the windpipe above the main airway split. The longer, narrower bronchial lumen is advanced into either the left or right main bronchus.
Each lumen has a separate inflatable cuff to create a seal within the airway. The tracheal cuff seals the windpipe, while the bronchial cuff seals the main bronchus. This dual-cuff system allows the clinician to completely seal off the two lungs. By selectively clamping one port, oxygen can be provided to only one lung while the other remains collapsed.
Medical Situations Requiring Lung Isolation
Lung isolation is necessary for two main medical reasons: protection and surgical exposure. Anatomical lung isolation prevents fluids, such as pus or blood, from a diseased lung from spilling into and contaminating the healthy lung. For example, separation is required to protect the unaffected side if a patient experiences massive hemorrhage or has a large lung abscess.
Physiological lung isolation is commonly used in thoracic surgeries, which involve the chest cavity, such as lung resection, esophageal surgery, or repair of a thoracic aortic aneurysm. Collapsing one lung provides the surgeon with a non-moving, clear surgical field, optimizing visibility and access to the internal structures of the chest. Isolation is also used in cases of severe unilateral lung disease, like a major bronchial trauma, where ventilation needs to be precisely controlled for each lung independently.
How the DLB Procedure is Performed
The placement of the Double Lumen Tube is a precise, multi-step process performed after the patient receives general anesthesia and muscle relaxants. The tube is first inserted into the mouth and passed through the vocal cords into the trachea, similar to a standard intubation. Once in the trachea, the clinician advances it further, using specialized maneuvers to guide the bronchial tip into the desired main bronchus.
For a left-sided tube, which is used most often, the tube is rotated approximately 90 degrees counter-clockwise until the tip seats within the left main bronchus. After positioning, the tracheal cuff is inflated to secure the tube, and the bronchial cuff is inflated to seal the bronchus. Correct placement is confirmed using a fiberoptic bronchoscope.
The bronchoscope is a thin, flexible camera inserted down the lumens to visually confirm the tube’s position relative to the carina, the main airway split. The clinician first looks through the tracheal lumen to ensure the bronchial cuff is visible just beyond the carina, in the correct main bronchus. They then pass the bronchoscope down the bronchial lumen to confirm a clear view into the distal lung segments, ensuring no critical branches are obstructed.
Patient Care After DLB Placement
Once the Double Lumen Tube is correctly positioned and verified, the patient is often positioned for surgery, usually on their side. Continuous monitoring of the patient’s oxygenation and ventilation status is maintained, as breathing occurs through only one lung. The anesthesiologist adjusts the ventilator settings to safely deliver oxygen and remove carbon dioxide from the single ventilated lung.
Throughout the procedure, the patient’s position is closely monitored, as slight movements can cause the DLT to shift, potentially leading to airway obstruction or isolation failure. After the surgical need for lung isolation ends, the collapsed lung is carefully re-expanded using specific lung recruitment maneuvers. The DLT is usually exchanged for a standard single-lumen tube or removed entirely if the patient is ready to breathe without assistance.