Personnel responsible for the placement of a DLT for lung isolation include an anesthesiologist, certified registered nurse anesthetist (CRNA), or certified anesthesiologist assistant (CAA). A resident physician anesthesiologist, a student nurse anesthetist or student anesthesiologist assistant may place a DLT under the supervision of an anesthesiologist.

When preparing the DLT for use, both the trachea and bronchial cuffs should be inflated to check for leaks and symmetrical cuff inflation. Consider adding water-soluble lubricant to the stylet and insert the stylet into the bronchial side, ensuring that the stylet is not protruding beyond the tube. The connector, which connects DLT to the ventilator circuit should be assembled and ready before intubation. A fiberoptic Bronchoscope should be available to confirm the position of the DLT.[12] Knowledge of the tracheobronchial anatomy is very helpful in confirming correct placement of the DLT.

There is a lack of objective guidelines in the proper selection of DLT sizes; 39-Fr and 41-Fr tubes are used for adult males while 35-Fr and 37-Fr DLTs are used for adult females. A properly-sized DLT is one in which the main body of the tube passes without resistance through the glottis and advances easily within the trachea and in which the bronchial component passes into the intended bronchus without difficulty.[13]

There are 2 techniques used for the insertion of a DLT:

• Blind insertion
• Fiberoptic guided placement

For blind insertion of a DLT, first, perform a direct laryngoscopy and visualize the vocal cords. Visualization of the vocal cords is important as these tubes are large and placement more challenging than placing an SLT. Once the vocal cords are visualized, gently advance the DLT with the tip of the bronchial concave curve facing anteriorly through the vocal cords until the bronchial cuff passes through the cords. The tube is then turned 90 degrees to the left when using a left-sided DLT, and to the right when using a right-sided DLT, and advanced until it meets resistance. Once the DLT is well positioned, inflate the tracheal cuff and ensure ventilation of both lungs by both inspection and auscultation. Verify correct placement by checking ventilation through the bronchial lumen. First, inflate the bronchial cuff 1ml at a time until leak stops. Clamp off gas flow through the tracheal lumen at the Y connector and open the tracheal sealing cap to air. Check whether you can isolate the other lung through the tracheal lumen, by clamping off the gas flow through the bronchial lumen.[14]

The DLT can also be positioned using fiberoptic bronchoscopy. Using a fiberoptic bronchoscope through the bronchial lumen and guiding the DLT over fiber-optic scope increases the accuracy of placement.

Once inserted, the DLT is connected to the ventilator circuit via the DLT connector, and the detection of ETCO2 confirms placement in the trachea after both cuffs are inflated to seal leaks. No more than 3 mL of air should be required to create a seal in the bronchial cuff. Cuff pressures should be measured to prevent airway injury. Confirmation of correct positioning of the DLT can be done by auscultation or with fiberoptic bronchoscopy. Auscultation and bilateral chest wall movement is first confirmed. On clamping the endobronchial lumen limb connector, breath sounds should be absent from the corresponding side of the lung if the endobronchial lumen is in the correct bronchus. On clamping the endotracheal limb connector and ventilating through the endobronchial lumen, breath sounds should be absent from the opposite side of the chest.

Once the DLT is in place, confirm correct placement by inserting the fiberoptic scope through the tracheal lumen to verify that the bronchial lumen is in the correct main-stem bronchus and there is no bronchial cuff herniation.[15][12]

Though the tracheal lumen confirm that:

• The endobronchial portion is in the correct main bronchus. Left-sided DLT should be in the left main bronchus, and right-sided DLT should be in the right main bronchus.
• The bronchial rings should be anterior with the longitudinal fibers posterior to help with side identification.
• The bronchial cuff should be just visible without cuff herniation over the carina when inflated.
• The right upper lobe (RUL) bronchus should be identifiable via the right main bronchus with 3 lobar branches (apical, anterior and posterior).

Next, the fiberoptic bronchoscope is advanced through the endobronchial lumen.

• For a left-sided DLT, identify the origins of the left upper and lower bronchi (confirm that the tip of the endobronchial orifice is not occluding the left upper or lower bronchi).
• For a right-sided DLT, identify good alignment between the opening slot of the endobronchial lumen relative to the takeoff of the right upper lobe bronchus (to allow ventilation of the right upper lobe bronchus).
• Identify the bronchus intermedius and the right lower lobe bronchus distally.

Fiberoptic bronchoscopy is the gold standard for confirmation of correct placement of a DLT. Auscultation alone is unreliable as an indicator of proper DLT placement.[16]

Troubleshooting techniques for DLT insertion include:

• Using a bronchoscope to cannulate the bronchus and railroading the tube over the scope. Always place the scope in the bronchial (longer) lumen.
• A stylet should be used when placing a DLT.
• Always check placement when changes to the patient's position have been made, or changes have been made between normal ventilation and isolated lung ventilation.
• To assist in cannulating the bronchus, rotate tube toward bronchus that is to be cannulated, turn the patient's head to the opposite side and gently slide the tube down until resistance is felt.

To initiate one-lung ventilation, the bronchial cuff is inflated, the lung to be isolated is clamped off at the corresponding connector, the connector is then opened to the atmosphere to allow lung collapse. Lung collapse is most rapid if initiated at end expiration.

Intraoperatively the bronchial cuff should be kept deflated (unless needed to avoid the spread of blood or infection) and should be inflated only during the time of lung isolation to minimize bronchial mucosal injury.

The most lethal complication arising from the use of a DLT is airway rupture from traumatic placement.[17][18] Injury to tongue, lips, and teeth may also occur from laryngoscopy. A majority of airway injuries were associated with undersized DLTs, particularly in females who received a 35-Fr or 37-Fr DLT.[19] Undersized DLTs tend to migrate too far distally into the main stem bronchus, or that the endobronchial cuff requires a larger amount of air when smaller tubes are used predisposing to mucosal ischemia.

Other complications include hypoxemia due to tube malposition, displacement, tube occlusion from secretions or blood. Inadvertent entrapment of the DLT in suture lines during procedures have also been reported.

Malposition of the DLT can lead to life-threatening consequences. Ventilation can be severely impaired, leading to hypoxia, gas trapping, tension pneumothorax, cross-contamination of lung contents, and interference with surgical procedures.[20]

Factors predisposing to airway injury include: 

• Inserting a DLT too forcefully
• Placing undersized DLTs
• Overdistention of the endobronchial cuff 
• Reposition of the DLT with the cuffs inflated 
• Preexisting pathology of the airway including tumors

Double lumen tubes play a crucial role in:

• Airway management during thoracic surgery
• Anatomical lung separation or isolating normal from the diseased lung in situations such as:
  • Massive hemorrhage from one lung
  • Whole lung lavage in patients with pulmonary alveolar proteinosis
  • Avoiding spillage of purulent secretions from one lung to another
• Differential lung protective ventilation in case of lung transplantation patients 

Double-lumen tubes are used for multiple complex surgical procedures and lung isolation in some non-surgical patients. Since malposition and displacement of these tubes can lead to life-threatening consequences, an interprofessional education is an essential component to avoid morbidity and mortality. Everyone involved in the care of patients requiring DLT placement including anesthesiologists, intensivists, resident physicians, CRNAs, AAs, nurses, and respiratory therapists in the intensive care unit must know the indications for placement, identify correct placement, confirm the position, and be able to troubleshoot complications from the placement of DLT. Daily chest x-ray and auscultation to confirm placement and bronchoscopy should be immediately available if malposition is suspected. Respiratory status should be monitored continuously, and caution should be used during the positioning and transport of patients. The need for continued placement should be addressed daily as these tubes have the potential for airway injury and should be changed to SLTs if mechanical ventilation is still needed, but lung isolation is no longer indicated.