Abstract
In clinical scenarios, the insertion of double-lumen endobronchial tubes (DLTs) is usually employed as a technique of separation of lungs for treatment purposes inclusive of one-lung ventilation for the ease of thoracic surgery. However, in patients with difficult airways, the DLT intubation can be challenging, even with the aid of a fiberoptic bronchoscope (FOB). Insertion of the FOB itself into the trachea may be relatively simple, but the advancement of the DLT with the FOB enclosed in the lumen may be hindered by the abnormal or diseased laryngeal aperture. Herein, we present an alternative approach by using a 5.5-mm video FOB to monitor the DLT rather than using it to act as an introducer to overcome the difficulties often met in DLT intubation in oral cancer patients.
Keywords
fiber optic technology; bronchoscopy; double-lumen tubes; airway management: difficult airway;
1. Introduction
The use of double-lumen endobronchial tubes (DLTs) is considered as the choice technique for lung separation in most instances of thoracic surgery.1 However, their use in patients with airways that are difficult to intubate can be complicated, particularly in those mouth opening is limited. An oral fiberoptic bronchoscope (FOB) may be used to assist DLT intubation in patients with difficult airways; nevertheless, after the FOB is inserted into the trachea, the advancement of the DLT through the glottis is blind, and is sometimes hindered. Herein, we present an alternative technique by combining the use of a DLT and a 5.5-mm video FOB for use in patients in whom difficult tracheal intubation is anticipated owing to a limited mouth opening and encumbered neck movement.
2. Case report
A 52-year-old man with a history of left buccal cancer post-operation with radiotherapy was admitted because of dyspnea and chest pain; he weighed 45 kg and stood 160 cm. Chest computed tomography showed a suspected pleural malignancy, possibly a nodularity by metastatic tumor seeding. A chest surgeon was consulted, and decortication of the left pleura was arranged.
Pre-operative airway evaluation revealed a limited mouth opening (of approximately 2 cm) and a stiff neck with limited extension because of the sequela of radiotherapy, and difficult intubation was therefore contemplated. A cart carrying an FOB, a cricothyroidotomy kit and other essential life-saving instruments for difficult airways was available in the operating room during intubation, and the patient was monitored on electrocardiogram, peripheral oxygen saturation, and noninvasive arterial blood pressure. 100% oxygen by means of a facemask was given for 5 min before induction of anesthesia.
In anticipation of a potentially difficult intubation, we chose to intubate the patient awake, by oral FOB with a 35F DLT. After counseling the patient with regard to the necessity of awake intubation, he complied with our suggestion. The patient was pre-medicated intravenously with 0.5 mg atropine and 2.5 mg midazolam, and 10% lidocaine was sprayed onto the oral pharynx. Transtracheal blocking was performed with 3 mL of 4% lidocaine. A 3.4-mm FOB (FI-10P2, Pentax medical company, Montvale, NJ, USA) was inserted through the endobronchial lumen to guide the DLT towards the trachea by means of the oral route. The vocal cords were observed through the FOB, and the FOB was then advanced into the trachea as a guider. However, resistance was felt during advancement of the DLT through the vocal cords with the FOB as the sliding rail. In order not to damage the airway and the FOB, the DLT was retracted 1–2 cm, and then rotated 90 degrees counterclockwise, and re-advanced, but this manipulation did not materialize a success, and it was suspected that advancement of the DLT might have been obstructed by the arytenoid cartilages, the interarytenoid notch, or the epiglottis. Furthermore, the DLT might have migrated into the esophageal inlet, because the FOB could have been too fine and soft to act as an introducer.
The use of a Glidescope® to ascertain the cause of obstruction of the DLT advancement was considered; however, the Glidescope® could not be placed into the patient’s oral cavity because of the limited mouth opening and narrow oral space. Subsequently, after several failed intubations, we considered that the use of a 5.5-mm video FOB with a monitor screen (EB-1570K, Pentax medical company) might help the intubation. Thus the 5.5-mm video FOB was passed through the left nostril to the pharynx, and the epiglottis and vocal cords were clearly seen on the monitor screen. With the DLT being shaped like a “hockey-stick” configuration by bending the enclosed stylet to 90-degree at 6 cm from the distal end (Fig. 1) the anesthesiologist manipulated the advancement of the DLT by observing the process on the monitor screen of the 5.5-mm video FOB, the DLT was passed through the vocal cords into the trachea (Fig. 2) without resistance. When the DLT was advanced some 2 cm, it was held steadily for removal of the stylet. When the tracheal cuff had successfully passed the vocal cords, 200 mg pentothal and 50 mg rocuronium were administered to the patient. The DLT was then rotated 90 degrees counterclockwise and advanced into the left mainstem bronchus. Later, we used a 3.4-mm FOB to confirm the proper positioning of the DLT. The operation proceeded uneventfully with good lung isolation.
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3. Discussion
One-lung ventilation can be achieved in three ways, i.e. using DLT, bronchial blocker, or single-lumen endobronchial tube (SLT). DLTs are used most widely because they are easily manipulated and relatively cheaper than bronchial blockers. However, in patients with extremely difficult airways, DLT intubation may be challenging or even impossible, and in such cases awake fiberoptic intubation is the recommended technique for airway management.2 In patients with a limited mouth opening, a wire-guided endobronchial blocker (Arndt blocker) appears to be a better choice, as it can be placed coaxially through a nasal endotracheal tube.3 Nonetheless, the small diameter of the suction channel increases the time required for the lung to collapse and could increase the possibility of occlusion in patients with empyema, and that was the reason why we chose to use a DLT rather than an Arndt blocker in the first instance. However, should the DLT insertion fail, the use of an Arndt blocker as an alternative must be kept in mind.
Oral FOB intubation is a promising technique in most patients but it may be difficult to achieve in those with a distorted airway anatomy or with a limited oral space. Resistance may be encountered when advancing a tracheal tube over a FOB, especially when a large-sized tracheal tube is used, and force must not be exerted during the attempt to advance a tracheal tube. The essential sites at which the passage of a tracheal tube may be obstructed are the arytenoid cartilages and epiglottis.4 A laryngoscope or Glidescope® (Saturn Biomedical System Inc, Burnaby, BC, Canada) can be used to observe the vocal cord area to ascertain the cause of the obstruction; however, in patients with a limited mouth opening, the use of a laryngoscope or Glidescope® by means of the oral cavity is difficult or impossible. We therefore considered the use of a 5.5-mm video FOB to monitor the passage of the DLT as a reasonable method of solving this problem in our case.
There are some benefits of using a 5.5-mm video FOB by means of the nostril to assist the insertion of DLTs. First, the 5.5-mm video FOB can be used to evaluate the laryngeal anatomy before intubation and avoid shooting in a forced manner when the advancement of the DLT into the vocal cord becomes difficult. Second, both the operator and assistants can view the glottis and the DLT tip on the monitor, and can therefore cooperate to achieve DLT intubation into the glottis. However, a limitation of the 5.5-mm video FOB remains still, because it is also easily affected by secretions or blood, as it happens with the use of a conventional oral FOB.
Other devices can also be used to facilitate the insertion of a DLT in circumstances of difficult intubation, such as a Glidescope® or Trachlight® (Laerdal Medical Corporation, Wappingers Falls, NY, USA).
Chen et al. described the use of a Glidescope® to assist DLT placement in a patient with an unanticipated difficult airway.5 It is known that a Glidescope® can reduce the Cormack and Lehane grade when difficult intubation is encountered,6, 7 but the use of a Glidescope® does have limitations, particularly when the mouth opening is less than 1.8 cm, which is the lower margin for blade insertion. Furthermore, in some patients with a limited mouth opening, a Glidescope® may cause soft-palate injury during endotracheal tube intubation.8, 9, 10 Owing to the limited mouth opening and the large size of the DLT, Glidescope® was not suitable for use in our case as described above.
The Trachlight® has been advocated for use in patients who are unable to be intubated by direct laryngoscopy. In our experience, a Trachlight® can be used to assist DLT intubation in patients with difficult airways,11 and in clinical settings in which direct visualization is difficult, the Trachlight® is a good alternative. Nonetheless, in patients with tumor or abscess around the vocal cords or pharyngeal area, this blind intubation method may be contraindicated.
In this report, a 5.5-mm video FOB was used in a way that differed from those to which we are accustomed. This method is a feasible and reasonable alternative technique for tracheal intubation when direct laryngoscopy proves difficult. With the assistance of video FOB, difficult DLT intubation can be made easier in certain circumstances.