Abstract

One-lung ventilation is routinely used to facilitate exposure for thoracic surgical procedures and can be achieved via several lung isolation techniques. The optimal method for lung isolation depends on a number of factors that include (1) the indication for lung isolation, (2) anatomic features of the upper and lower airway, (3) availability of equipment and devices, and (4) the anesthesiologist’s proficiency and preferences. Though double-lumen endobronchial tubes (DLTs) are most commonly utilized to achieve lung isolation, the use of endobronchial blockers offer advantages in patients with challenging airway anatomy. Anesthesiologists should be familiar with existing alternatives to the DLT for lung isolation and alternative techniques for DLT placement in the patient with a difficult airway. Newer technologies such as videolaryngoscopy with or without adjunctive fiberoptic bronchoscopy may facilitate intubation and lung isolation in difficult airway management.

Objective: To compare the efficacy and adverse effects of
using bronchial blockers (BBs) and double-lumen endobronchial
tubes (DLTs).
Design: Systematic review and meta-analysis of randomized
controlled trials (RCTs) comparing BBs and DLTs.
Setting: Hospital units undertaking thoracic surgery
Participants: Patients undergoing thoracic surgery requiring
lung isolation.
Interventions: BBs and DLTs.
Measurements and Main Results: A systematic literature
search was conducted for RCTs comparing BBs and DLTs
using Google Scholar, Ovid Medline, and Cochrane library
databases up to October 2013. Inclusion criteria were RCTs
comparing BBs and DLTs, intubation carried out by qualified
anesthesiologists or trainee specialists, outcome measures
relating to either efficacy or adverse effects. Studies that
were inaccessible in English were excluded. MantelHaenszel
fixed-effect meta-analysis of recurring outcome
measures was performed using RevMan 5 software. The
search produced 39 RCTs published between 1996 and 2013.
DLTs were quicker to place (mean difference: 51 seconds,
95% confidence intervals [CI] 8-94 seconds; p ¼ 0.02) and
less likely to be incorrectly positioned (odds ratio [OR] 2.70;
95% CI 1.18-6.18, p ¼ 0.02) than BBs. BBs were associated
with fewer patients having a postoperative sore throat (OR
0.39, 95% CI: 0.23-0.68, p ¼ 0.0009), less hoarseness (OR:
0.43,95%, CI 0.24-0.75, p ¼ 0.003), and fewer airway injuries
(OR 0.40, 95% CI 0.21-0.75, p ¼ 0.005) than DLTs.
Conclusion: While BBs are associated with a lower incidence
of airway injury and a lower severity of injury, DLTs
can be placed quicker and more reliably.
& 2015 Elsevier Inc. All rights reserved.
KEY WORDS: bronchial blocker, double-lumen endobronchial
tube, lung isolation, one-lung ventilation, thoracic surgery,
efficacy, adverse effects

Purpose
Due to its anatomical complexity, a tracheal bronchus has important clinical implications for one-lung ventilation (OLV). We present a case of successful OLV in a patient with a high a type I (i.e., high take-off) tracheal bronchus. This anomaly presented unusual fibreoptic bronchoscopic (FOB) views that were difficult to discern from the normal carinal bifurcation.
Clinical features
A 35-yr-old male presented for posterior basal segmentectomy of the left lower lobe under video-assisted thoracoscopy. The preoperative chest radiography was reported as normal, but a computed tomography scan of the chest revealed a right upper lobe tracheal bronchus. The inlet of the tracheal bronchus was located high above the carina, and the distal trachea had significant narrowing. Because the main trachea was divided into a tracheal bronchus and a distal trachea with similar diameters and with an acute angle of divergence, FOB views of the tracheal bronchus take-off appeared similar to the normal carinal bifurcation. Moreover, the actual carina had an atypical appearance with the main bronchi shifted laterally and a blunted carinal ridge. As a result of this atypical tracheobronchial anatomy, we used an Arndt endobronchial blocker system instead of a double-lumen tube (DLT) for right-sided OLV. One-lung ventilation was satisfactory throughout the uncomplicated operation.
Conclusion
Careful preoperative assessment of tracheobronchial anatomy is imperative in order to choose an appropriate method of OLV and prevent potential complications. In a type I tracheal bronchus with a narrowed distal trachea, a bronchial blocker may have advantages over the conventional DLT in achieving OLV.

Objective: To compare performance of right- versus leftsided
double-lumen tubes (DLTs) among infrequent users by
evaluating the incidence and severity of hypoxemia, hypercapnia,
and high airway pressures.
Design: A retrospective, cohort study.
Setting: A university hospital.
Participants: Ninety-eight patients undergoing left-sided
DLT placement (53.9
21.2 years old) and 98 patients
undergoing right-sided DLT placement (62.3
20.6 years
old). Cases performed by thoracic anesthesia specialists
were excluded.
Interventions: The authors retrospectively reviewed electronic
anesthetic records from a 2-year period to determine
the incidence and severity of hypoxia (SpO2 < 90%), hypercapnia (end-tidal carbon dioxide > 45 mmHg) and high airway
pressures (peak inspiratory pressure >35 cmH2O) during
one-lung ventilation via right and left DLTs.
Measurements and Main Results: Right-sided (n  98)
DLTs were almost exclusively used on the side contralateral
to surgery by infrequent users, whereas left-sided
(n  98) DLTs were used for ipsilateral surgery one third of
the time. Hypoxia lasted longer in left versus right DLTs,
but the frequency of hypoxia was the same for each tube
type among infrequent users. Hypercapnia and high airway
pressures occurred more frequently with left-sided
DLTs.
Conclusions: Left-sided DLTs are perceived to be safer
because they may be less prone to malpositioning during
lung isolation. However, the supposition that left-sided
DLTs are safer than right-sided DLTs when intraoperative
hypoxia, hypercapnia, and high airway pressures are used as
criteria, even when these tubes are used by infrequent users,
is not supported by the data.

Placement of the PLMA was achieved by threading a gum elastic bougie (Portex-SIMS; Hythe, Kent, UK) into the drain tube, and, under gentle direct laryngoscopy, its distal end was introduced into the esophagus. Positive-pressure ventilation was instituted and, via the multiport adaptor, the BB was passed into the left mainstem bronchus under bronchoscopic guidance, carefully avoiding the tracheal mass. A gastric drainage tube was gently inserted via the drainage port to drain the stomach. Adequate one-lung ventilation (OLV) was achieved after inflation of the BB cuff in the lateral decubitus position. Throughout the period of OLV, peak inspiratory pressures ranged from 30 to 35 cmH2O on pressure-controlled ventilation with tidal volumes of 400 to 450 mL, a respiratory rate of 12, and end-tidal CO2 of 45 to 48 mmHg. Surgical exposure was good, and surgery proceeded uneventfully. Postprocedure bronchoscopy did not reveal any evidence of aspiration in the larynx or tracheobronchial tree.

The patient had a friable tracheal mass close to the vocal cords that precluded the placement of an endotracheal tube and had the potential for tumor trauma. We used a supraglottic airway to mitigate this and chose the PLMA in view of the patient’s aspiration risk, taking advantage of the probable added protection of a gastric drainage tube. Although a reduction in aspiration risk with the PLMA (compared with the CLMA) has not been shown, the drainage tube successfully vented regurgitated fluid and protected against aspiration. 2 In more than 2,000 PLMA placements, there were 12 cases of clinically apparent regurgitation with no clinical or bronchoscopic evidence of aspiration. 2

The measured peak airway pressures of 30 to 35 cmH2O were high probably because of reduced lung compliance. These pressures are within the appropriate “lung-protective ventilation” strategy of limiting the peak inspiratory pressure to <35 cmH2O during OLV. 3 The reported improved seal of the PLMA as compared with the CLMA was to our advantage. Median seal pressures with PLMA are reported to be approximately 30 cmH2O, 4 with pressures exceeding 40 cmH2O in 20% of cases. 5 The airway seal with CLMA is reported to exceed 30 cmH2O in only 4% of cases. 5 Our approach was an effective strategy in the management of this uncommon yet challenging scenario. We suggest that it be considered as part of the armamentarium for such cases requiring lung separation.

BACKGROUND: There is no consensus on the best technique for lung isolation for thoracic surgery. In this study, we compared the clinical performance of three bronchial blockers (BBs) available in North America with left-sided double-lumen tubes (DLTs) for lung isolation in patients undergoing left-sided thoracic surgery.

METHODS: One hundred four patients undergoing left-sided thoracotomy or video-assisted thoracoscopic surgery were randomly assigned to one of the four lung isolation groups (n = 26/group). Lung isolation was with an Arndt(R) wire-guided BB (Cook(R) Critical Care, Bloomington, IN), a Cohen Flexi-tip(R) BB (Cook Critical Care) or a Fuji Uni-blocker(R) (Fuji Systems, Tokyo) or with a left-sided DLT (Mallinckrodt Medical, Cornamadde, Athlone, Westmeath, Ireland). Anesthetic management and lung isolation were performed according to a standardized protocol. Each group was randomly subdivided into two subgroups (n = 13/subgroup): immediate suction (at the time of insertion of the lung isolation device) (Subgroup I) or delayed suction (20 min after insertion of the lung separation device) (Subgroup D) according to when suction was applied to the BB suction channel or the bronchial lumen of the DLT. Using a verbal analog scale, lung collapse was assessed by the surgeons, who were blinded to the lung isolation technique.

RESULTS: There was no difference among the lung isolation devices in lung collapse scores at 0 (P = 0.66), 10 (P = 0.78), or 20 min (P = 0.51) after pleural opening. The time to initial lung isolation was less for DLTs (93 +/- 62 s) than BBs (203 +/- 132) (P = 0.0001). There were no differences among the BBs in the time to lung isolation (P = 0.78). There were significantly more repositions after initial placement of the lung isolation device with BBs (35 incidents) than with DLTs (two incidents) (P = 0.009). The Arndt BB required repositioning more frequently (16 incidents) than the Cohen BB (8) or the Fuji BB (11) (P = 0.032).

CONCLUSIONS: The three BBs provided equivalent surgical exposure to left-sided DLTs during left-sided open or video-assisted thoracoscopic surgery thoracic procedures. BBs required longer to position and required intraoperative repositioning more often. The Arndt BB needed to be repositioned more often than the other BBs.

We present a simple and reliable airway assembly that can be used to provide lung isolation for lung lavage or other such procedures in small children. Essentially, two tracheal tubes are passed through the glottis, one seated endobronchially to isolate the lung to be lavaged and the second seated in the trachea. This assembly mimics commercially available double lumen bronchial tubes, considered by many to be the airway device of choice for lung isolation. The obvious advantages of this technique include effective lung isolation, the ability to collect lavage returns by gravity instead of suction, and the option of differential lung ventilation after lavage. In addition, the patient can be kept in the supine position, and fiberoptic bronchoscopy can be used to periodically ensure continued lung isolation throughout the procedure.

BACKGROUND: Left-sided double-lumen tubes are perceived to be safer than right-sided tubes, because they may be less prone to malposition. If this is true, then the incidence and severity of hypoxemia, hypercapnea, and high airway pressures should be higher for right-sided tubes during thoracic surgery than for left-sided tubes.

METHODS: We retrospectively reviewed thoracic surgical anesthetics between April 15, 2003, and December 31, 2004, using an automated anesthesia information management system. The system automatically records pulse oximetry, end-tidal carbon dioxide, and peak inspiratory pressure data every 30 s. Side of surgery and double-lumen tube placement are also documented. We compared the frequency of right- and left-sided Mallinckrodt tube use by thoracic anesthesiologists. Next, we examined the incidence, duration, and severity of hypoxemia (Spo2 <90%), hypercapnea (Etco2 >45 mm Hg) and high airway pressures (peak inspiratory pressure >35 cm H2O) for lung and chest wall surgery patients. Group counts and means were compared by standard statistical methods.

RESULTS: Right- (n = 241) and left- (n = 450) sided tubes were almost exclusively used on the side contralateral to surgery. There were no differences in the incidence or duration of hypoxemia, hypercarbia, or high airway pressures. There was a small but significant increase in Etco2 for patients having left lung ventilation.

CONCLUSIONS: The supposition that left-sided double-lumen tubes are safer than right-sided tubes when intraoperative hypoxemia, hypercapnea, and high airway pressures are used as criteria for safety is not supported by our data comparing the two types of tubes from one manufacturer.

Sample Bronchoscopy Quiz QuestionThe attached pdf. shows a bronchoscopy photo question and answer similar to the those in the Bronchoscopy Quiz. Simply click on the Bronchoscopy Quiz button at the top of the home page to take the quiz. You will receive the number of answers you get correct after completing the 16 question Quiz. After you take the Bronchoscopy Quiz you have access to the bronchoscopy Simulator. We ask that you take the Bronchoscopy Quiz again after using the simulator and becoming familiar with fiberoptic tracheo-bronchial anatomy. After you take the quiz a second time you will receive the correct answers and you can compare anonymously the number you get correct with others who have taken the test. All results are confidential. Try it its fun and educational!

Amar, David MD; Desiderio, Dawn P. MD; Heerdt, Paul M. MD, PhD; Kolker, Anne C. MD; Zhang, Hao MD; Thaler, Howard T. PhD

Institution From the Departments of Anesthesiology and Critical Care Medicine and Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center and Weill Medical College of Cornell University, New York City, New York.

Anesthesia & Analgesia. 106(2):379-383, February 2008.

Abstract BACKGROUND: Some anesthesiologists choose smaller than body size-appropriate left sided double-lumen tubes (DLTs) (“down-size”) for lung isolation in an attempt to limit the risk of airway trauma. There are few data on the effects of DLT size on intraoperative outcome measures.

METHODS: In 300 adults undergoing thoracic surgery requiring lung isolation, we conducted a prospective pilot study to evaluate whether the use of 35 FR DLT, regardless of gender and/or height (care standard of two investigators), was associated with a similar incidence of intraoperative hypoxemia, lung isolation failure, or need for DLT repositioning during surgery (noninferiority) than with the conventional goal of inserting the largest possible DLT (care standard of two other investigators). DLT insertion position was immediately confirmed with fiberoptic bronchoscopy after direct laryngoscopic placement and after lateral positioning.

RESULTS: The combined incidence of transient hypoxemia, inadequate lung isolation, or need for DLT repositioning during surgery did not differ among patients receiving 35, 37, or 39 FR DLT, regardless of gender or height. Despite the high frequency of 35 FR DLT use, 2% of patients required further down-sizing due to the inability to introduce the DLT into the left mainstem bronchus or when no inflation of the bronchial cuff was needed for lung isolation.

CONCLUSIONS: Under the conditions of this pilot study, the use of smaller than conventionally sized DLT was not associated with any differences in clinical intraoperative outcomes.