Practical Use of a Bronchial Blocker in Combination with a Double-Lumen Endotracheal Tube

Abstract

Lung separation is an essential component of many thoracic and mediastinal procedures. This is achieved most commonly with the use of a double-lumen endotracheal tube (DLT) [1,2], a single-lumen tube with a bronchial blocker, endobronchial intubation with a long single-lumen tube, or the Univent[trade mark sign] tube (Fuji Systems Corporation, Tokyo, Japan), which has an incorporated movable endobronchial blocker [3-5]. A DLT allows relatively easy collapse of the nonventilated lung and the ability to suction each lung independently. A main disadvantage is the limited size range (i.e., 28, 35, 37, 39, and 41F). A vascular embolectomy catheter may be used as a bronchial blocker when placed either outside or within the lumen of a single-lumen tube. Placement down the left mainstem bronchus can be challenging because of its greater takeoff angle and smaller diameter; complete isolation of the right lung can be impossible in some situations, depending on the takeoff of the right upper lobe bronchus. Absolute indications for lung separation include prevention of spillage and contamination of a healthy lung with blood or purulent material; unilateral bronchoalveolar lavage; and bronchopleural fistula. Relative indications include facilitation of surgical exposure at thoracotomy or during certain cardiac operations (e.g., transmyocardial revascularization, minimally invasive direct coronary artery bypass). We describe a patient who presented for thoracotomy and whose left mainstem bronchus was too small to accept the bronchial lumen of a 35F left-sided DLT. Case Report A 55-yr-old woman (60 kg, 159 cm) with a history of severe acid reflux and distal esophageal stricture presented for Collis-Belsey repair of a recurrent hiatal hernia after a failed Nissen fundoplication. Her medical history was otherwise unremarkable. Her surgical history included esophageal dilation, laparoscopic cholecystectomy, tubal ligation, and tonsillectomy and adenoidectomy. All preoperative laboratory values, chest radiographs, and electrocardiograms were within normal limits. Medications included lansoprazole 30 mg TID. In the operating room, routine monitors, a radial arterial catheter, and a lumbar epidural catheter were placed. The patient underwent rapid-sequence induction of anesthesia with IV thiopental, fentanyl, midazolam, and succinylcholine. The first attempt at endotracheal intubation was with a 37F left-sided DLT (Broncho-Cath[registered sign]; Mallinckrodt Medical, Inc., St. Louis, MO), which was too large. With cricoid pressure held at all times, a 35F left-sided DLT was easily advanced into the trachea; however, the bronchial lumen entered the right mainstem bronchus. Several attempts were made at repositioning the tube by retracting it to the level of the carina and trying to advance it directly into the left bronchus with the aid of a pediatric fiberoptic bronchoscope (FOB) (Figure 1).Figure 1: Improperly positioned left-sided double-lumen tube. With the fiberoptic bronchoscope (FOB) in the bronchial lumen of the double-lumen tube and exiting into the left main bronchus, each attempt at advancing the tube over the scope resulted in a right-sided tube placement. It soon became apparent that the tip of the FOB was indeed in the left bronchus, whereas the more proximal part of the scope holding the tube had folded itself into the right bronchus. Note bend in FOB (exaggerated for illustrative purposes) giving the false impression that tube is being guided down correct side.Because the surgeon needed complete lung collapse and because of our concerns over further instrumentation of the airway (with consequent development of edema), we believed that reintubation with a right-sided DLT or a single-lumen tube with a bronchial blocker would be a poor option, not to mention the fact that the patient would be placed at further risk of acid aspiration. Alternatively, a size 8/14F, 80-cm Fogarty embolectomy catheter (Baxter Healthcare Corporation, Irvine, CA) was passed down the bronchial lumen after the tube was positioned at the origin of the left main bronchus and advanced gently no more than a few millimeters (any further attempt at advancement would cause the tube to "pop" back into the right bronchus) (Figure 2).Figure 2: Left, Because the Fogarty catheter had to be passed blindly, it had to be measured against a clean tube (without a connector) to estimate how much of it would have to exit the bronchial end. A marking placed on the catheter could then be lined up with the "blue" (shaded) end of the double-lumen tube where the connector inserts. Right, Left-sided double-lumen tube with Fogarty catheter in place. The catheter was introduced through a hole made in the connector cap and advanced through the tube until the marking lined up accordingly. At that point, the catheter balloon was filled with air until no breath sounds could be heard on the left. The fiberoptic bronchoscope was, then passed down the tracheal lumen to verify tube position and to ensure that there was no balloon herniation.The surgical procedure proceeded uneventfully with excellent visualization of the operative field. The lung was easily and completely collapsed and reinflated as needed. Discussion DLTs are commonly used in cardiothoracic anesthesia and, in experienced hands, can be placed with relative ease. There are situations, however, when even the most experienced operator may encounter difficult or impossible tube placement. DLT size selection is often based on personal experience and preference. Several methods have been described for selecting an appropriately sized left-sided DLT. Hannallah et al. [6] measured the width of the left mainstem bronchus on the posteroanterior chest radiograph and looked for a correlation with patient age, gender, and size; in female patients, there was no significant correlation of these variables with bronchial diameter. Furthermore, the left main bronchial outline could only be visualized in 50% of the radiographs, thereby limiting this method. Hannallah et al. [7] also measured left mainstem bronchial diameter from computed tomographic (CT) scans of the chest, and although these measurements successfully guided the choice of left-sided DLT size for individual patients, not all patients presenting for intrathoracic procedures undergo preoperative CT scanning. Brodsky et al. [8] found a significant correlation between tracheal and bronchial measurements and use this as a guideline to predict left-sided DLT size. We describe a patient in whom unanticipated anatomical constraints prevented the advancement of a left-sided DLT into the left mainstem bronchus. Because of concerns over airway edema and the possibility of gastric acid aspiration, it was deemed more prudent not to reintubate the patient a third time. Careful placement of a Fogarty catheter down the bronchial lumen of a left-sided DLT provided excellent lung separation and obviated the need to reintubate the patient. Advantages of placing a Fogarty catheter within a DLT include complete lung separation; ability to deflate/inflate a lung on the operative side; ability to suction lungs independently (a long suction catheter will fit alongside the blocker); and easy and rapid insertion. Disadvantages include cost; potential for blocker dislodgment during surgical manipulation; inability to precisely verify position with a bronchoscope (auscultation and visual inspection at thoracotomy are the only reliable methods for confirming lung separation); and potential for an allergic reaction to latex in the Fogarty catheter. Although the use of a bronchial blocker in combination with a DLT should not be considered a routine practice, it can be useful for troubleshooting an improperly fitting tube, as in this case.