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THE use of endobronchial blockers to provide one-lung isolation during anesthesia for thoracic surgery has been previously described. 1Based on clinical experience, the primary disadvantage of this technique is the potential for the endobronchial blocker to become dislodged and obstruct the trachea. 2This is especially true when the blocker is placed in the right mainstem bronchus. We present our experience with a double endobronchial blocker (DEB) technique that effectively deals with this problem.
A 69-yr-old man weighing 92 kg with carcinoma of the esophagus was scheduled to undergo flexible esophagoscopy and bronchoscopy, followed by an Ivor-Lewis esophagectomy through laparotomy and right thoracotomy incisions. It is our practice to provide early postoperative ventilatory support for such patients. Therefore, use of a double-lumen endotracheal tube (DLT) would require that we exchange the DLT with a single-lumen tube again at the end of surgery. This procedure involves a risk, albeit small, of aspiration. Therefore, a decision was made to use an endobronchial blocker placed externally to the single lumen endotracheal tube to avoid further airway manipulation before and after the operation.
Anesthesia was induced using sodium thiopental, fentanyl, and succinylcholine and maintained with isoflurane in oxygen, fentanyl, and pancuronium. The patient’s trachea was intubated with an 8/14-French Fogarty Occlusion Catheter (Baxter Healthcare Co., Irvine, CA) and then with an 8.0-mm-ID standard endotracheal tube. After bronchoscopy and esophagoscopy, the surgeon decided to enter the thorax before entering the abdomen because the trachea seemed to be compressed by the esophageal carcinoma, possibly rendering the patient unresectable. This approach would spare the need for the abdominal incision. With the aid of a 4.1-mm-OD fiberscope (Olympus LF-GP; Olympus Optical Co., Ltd., Tokyo, Japan) the Fogarty catheter was positioned in the right mainstem bronchus and later inflated under direct vision with 5 ml air at the start of the right thoracotomy. When the lung was visualized through the surgical incision, it was obvious that there was unsatisfactory one-lung isolation with full lung expansion. Multiple attempts to position the endobronchial blocker in the right mainstem bronchus to occlude the right upper lobe orifice were unsuccessful. It was then decided to advance the endobronchial blocker into the bronchus intermedius and inflate the balloon with 4 ml air. A Cook airway adapter (Cook Critical Care, Bloomington, IN) was used to introduce a second 8/14-French Fogarty catheter through the endotracheal tube and position it in the orifice of the right upper bronchus without difficulty and inflate the balloon with 3 ml air (figs. 1A, 1B, and 2A). One-lung isolation was accomplished, and surgery proceeded without further interruption. Unfortunately, the carcinoma was contiguous with the aorta, and further attempts to resect were abandoned. The remainder of the patient’s anesthetic procedure and recovery were uneventful.
After the initial experience with this patient, we have used the DEB technique in eight patients undergoing esophageal or pulmonary resection. Lung isolation was accomplished without difficulty in all patients. We subsequently modified our approach in six other patients undergoing thoracic surgery. We tested the feasibility of inserting both endobronchial blockers through an 8.0- or 9.0-mm-ID single-lumen standard endotracheal tube, as shown in figure 2B. One of these patients required an awake fiberoptic intubation for a history of difficult intubation. We measured airway peak and plateau pressures in this patient whose trachea was intubated with an 8.0-mm-ID standard endotracheal tube: 24 and 15 cm H2O at baseline, 30 and 18 cm H2O with both endobronchial blockers in place, and 42 and 22 cm H2O with both blockers and a 4.1-mm-OD Olympus LF-GP fiberscope placed intraluminally, respectively. None of the patients had difficult ventilation or oxygenation due to the presence of both endobronchial blockers.
We have presented the DEB technique as an alternative method to the DLT to provide one-lung isolation. Our initial goal was to minimize the potential risk for aspiration and airway trauma at the conclusion of esophageal surgery. The patient presented in this report seemed to have a short right mainstem bronchus, a condition that may be found in approximately 10% of the population. 3In addition, 0.4–2% of patients have a right upper lobe orifice arising at or above the level of the carina. Both of these anatomic variations can account for failure of a single endobronchial blocker technique to provide complete one-lung isolation. Other examples of extensive operations in which one-lung isolation is routinely used with a DLT and commonly require a period of postoperative mechanical ventilation with a single-lumen endotracheal tube include major pulmonary resection, thoracoabdominal aortic reconstruction, and extensive thoracolumbar spine fusion. We subsequently extended our experience with the DEB technique and found that it provided satisfactory one-lung isolation in patients undergoing minimally invasive or major thoracic surgery. DLTs are frequently used to provide one-lung isolation during cardiothoracic and other surgery. However, there are situations in which the anesthesiologist may elect to place a DLT and, even with much expertise, may be forced to abandon its use in cases when it is difficult or impossible to do so because of unanticipated anatomical constraints. 4,5Also, patients requiring an awake fiberoptic intubation for a known difficult airway present a challenge for DLT placement. Use of the DEB technique in these clinical situations offers the advantage of instrumenting the airway with a smaller endotracheal tube and, if required, avoiding the need to replace the DLT at the end of surgery for any reason.
The use of selective lobar blockade in adults has been reported to improve arterial oxygenation during one-lung ventilation in some patients undergoing thoracic surgery. 6Our DEB technique could also be considered for selective lobar blockade in adults who have marginal pulmonary function reserve in which complete isolation of the left or right lung would cause hypoxemia or in situations in which the surgeon does not need more than selective lobar blockade to accomplish the desired operation. In fact, using the DEB technique for video-assisted thoracoscopy to biopsy a right lower lobe mass, we placed the distal endobronchial blocker in the bronchus intermedius and inflated its cuff while the second endobronchial blocker placed in the orifice of the right upper bronchus was not inflated but provided reduced ventilation to that lobe so that surgical conditions were satisfactory. Recently, Takahashi et al. 7reported their experience of selective lobar endobronchial blockade in children undergoing thoracic surgery. Whether the DEB technique may be used safely in children or small adults requires further study. We speculate that this will depend on the size of the trachea, the size of the endotracheal tube, and whether one can insert an appropriately sized endobronchial blocker through the endotracheal tube and another externally to it or both endobronchial blockers externally to the endotracheal tube.
Factors that might limit use of the DEB method are operator inexperience with the use of fiberoptic bronchoscopy and lack of knowledge of airway anatomy. Also, it is anticipated that that there will be a learning curve to achieve perfect results, which may translate into increased operating room time utilization. However, this increase in operating room time usage will be offset by avoiding the need to replace a DLT at the conclusion of surgery or by struggling to insert a DLT in difficult clinical situations. Similarly, the cost of two Fogarty catheters are greater than one DLT by approximately $50, and this should be weighed against the benefits of avoiding repeated airway instrumentation and risk for trauma, aspiration, or both. Common clinical practice standards at one’s own institution in conjunction with cost considerations and having the surgeon participate in discussions about which method of one-lung isolation to use are intuitive to achieve satisfactory results and to solve potential intraoperative problems related to this technique. In addition to known methods to treat severe hypoxemia during one-lung ventilation, such as positive end-expiratory pressure to the ventilated lung, intermittent ventilation of the collapsed lung, or both, the DEB technique offers the option to selectively inflate the nonoperative segment of the lung to hopefully improve oxygenation without compromising the operation. Our experience using this technique in 15 patients should not be interpreted as an efficacy trial but as a stimulus for further evaluation of its applicability and safety.
The Fogarty catheters used in this report lack suction ports and thus the ability to insufflate oxygen or to provide jet ventilation. Alternative endobronchial blockers with suction ports include the wire-guided Arndt blocker (Cook Critical Care) and the Univent tube (Vitaid Medical Products, Lewiston, NY). In contrast to the DEB technique, both of these alternatives have the same problem of dislodgement when used on the right side. 2In addition, if a patient requires extended mechanical ventilation postoperatively, the Univent tube may need to be exchanged for a standard endotracheal tube.
In conclusion, we present a novel method for one-lung isolation using a DEB technique. This method could be considered for patients undergoing major surgery or for minimally invasive procedures. We believe that the DEB method may lead to fewer airway interventions and reduce the potential for injury.