Two methods are available to achieve one-lung ventilation (OLV), the double-lumen endotracheal tube (DLT) and the bronchial blockers (BBs). Both of them will allow anatomic isolation of the lungs. The absolute indication for OLV is to protect the healthy lung from ipsilateral diseased lung or secretions such as blood, pus, or fluid used for pulmonary lavage (as in alveolar proteinosis). In addition, lung separation is required during bronchopleural fistula to prevent loss of tidal volume, and during resection of giant unilateral bullae. The relative indication for OLV is to provide an optimal and quiet surgical field during various types of thoracic surgeries such as pneumonectomies, repair of thoracic aortic aneurysms, and esophageal surgery.¹ The disadvantages of DLTs are difficulty in achieving the accurate position and size restriction, because they are available in specific sizes only (28, 35, 37, 39, 41), which makes placement difficult in small patients (pediatric population) or in patients with difficult airway anatomy. DLTs require replacement with a single-lumen ET at the end of surgery if the patient requires postoperative ventilation, a procedure that can be complicated and hazardous, especially in patients with difficult airway and/or prolonged surgery resulting in massive fluid shifts with airway edema.²

BBs may be used to provide lung isolation in conjunction with single-lumen endotracheal tube (ETT), eliminating the requirement to change the ETT at the end of the procedure. BBs are especially indicated in patients with difficult airway or abnormal airway (postsurgery or postradiation) or during prolonged surgery with large-scale fluid shifts resulting in airway edema, as well as in patients who are already are intubated with single-lumen ETT before coming to surgery. BBs may be placed through or alongside the single-lumen ETT, and a 7.0-mm ETT can easily allow the passage of a 4.0 fiberoptic bronchoscope with a BB.¹ The following are the most commonly used types of BBs:

There is scant evidence supporting one method of OLV as clearly superior to the other, so it is ultimately left to the anesthesiologist to select which method of OLV he/she is comfortable with (See also chapter 45). The practitioner must understand the fundamental advantages and disadvantages of each technique in various circumstances, to assure the optimal use and the least possible intra-/postoperative complications. In a study conducted by Campos and Kernstine3 in 2003, the authors demonstrated that not only did DLT intubation require less time to place but also lung collapse was accomplished significantly faster than BBs (DLT took an average of 2:08 minutes as compared with 3:34 minutes for the Arndt blocker). However, the ability to use BBs across a wide range of patient populations makes these devices increasingly popular and practical devices.