Hypoxemia Treatment During Lung Isolation With an Endobronchial Blocker: Continuous Positive Airway Pressure Application Should Be Common Practice

Abstract

Thoracic surgery generally requires one-lung ventilation (OLV) to facilitate surgical exposure and tissue resection. 1-4 Contemporary airway devices for lung isolation include the double-lumen endotracheal tube (DLT), endobronchial placement of a single-lumen endotracheal tube, or placement of an endobronchial blocker through a single-lumen endotracheal tube. 1-5 The DLT is the most commonly used airway device for OLV because it enables rapid deflation of the isolated lung and suctioning of the airways of the deflated lung, and further allows for the application of continuous positive airway pressure (CPAP) in the event that significant hypoxemia occurs. 1-2 Unfortunately, not all thoracic surgery patients are candidates for DLT placement, and lung isolation may require endobronchial blocker insertion through a single-lumen endotracheal tube. 1,3-5 When hypoxemia develops during OLV in the setting of an endobronchial blocker, treatment options are limited. Considering that CPAP is the best therapy for hypoxemia when a DLT is employed for OLV, this strategy should be common practice when an endobronchial blocker is placed for OLV. We report a case of significant hypoxemia during OLV with an endobronchial blocker, and its management with CPAP application. A 44-year-old man with a left lower lobe lung mass presented for a video-assisted thoracoscopic wedge resection. The patient's medical history was unremarkable otherwise. Intraoperatively, standard American Society of Anesthesiologists monitors were placed and the patient was preoxygenated. General anesthesia was induced; however, intubation with a size 8.0-mm single-lumen endotracheal tube to facilitate bronchoscopy was challenging and required 2 intubation attempts. After completion of the bronchoscopy, we decided not to exchange the single-lumen tube for a DLT for safety reasons. A 9-F Cohen tip deflecting endobronchial blocker (Cook Medical, Bloomington, IN) (Fig 1) was placed in the left mainstem

Application of Continuous Positive Airway Pressure During Video-Assisted Thoracoscopic Surgery

“…The application of CPAP with the use of the bronchial blocker is a different alternative to maintain and improve oxygenation during VATS and OLV [ 25 , 26 ]. With the use of the bronchial blocker (such as Arndt®, Cohen®, Fuji-Uniblocker® and EZ-blocker®), CPAP can easily be applied by using the center channel of the bronchial blocker and adapting a Mallinckrodt® system while applying 5 L of oxygen [ 27 ].…”

“…In a case report [ 25 ], the authors recommend that CPAP should not be applied until lung collapse has occurred. The application of CPAP immediately after lung isolation with a bronchial blocker inhibits timely deflation of the lung and makes the VATS and RATS challenging.…”

“…This belief may have also influenced the design of some studies that investigated the effectiveness of CPAP in VATS as the study designs avoided an alveolar recruitment maneuver prior to application of CPAP [ 31 , 32 ]. Evidence to support the negative effect of CPAP on surgical visualization is mixed: impediment of surgical exposure has been reported in some studies [ 32 ] and refuted in others [ 25 , 33 ]. As an alternative to CPAP, some authors have reported effective interventions for hypoxemia during VATS, such as apneic oxygen insufflation of the non-ventilated lung [ 34 ], high frequency jet ventilation [ 33 ], differential ventilation of the non-ventilated lung [ 31 ], and selective lobar oxygen insufflation of the non-ventilated lung using the suction/insufflation channel of the fiberoptic bronchoscope [ 35 ].…”

“…Reported empiric experience suggests that CPAP applied at 5–10 cm H 2 O to the non-ventilated lung in VATS impedes visualization of the operative field [ 28 ]. There is also empiric support that CPAP can be applied to the non-ventilated lung in VATS without impeding surgical exposure [ 25 ]. Evidence investigating the quality of surgical visualization and degree of CPAP applied is limited.…”