A Randomized Controlled Study Compare Lung Ultrasonography to Fiberoptic Bronchoscopy Confirming Double Lumen Tube Positioning for Thoracic Surgery.
Phase: NA
Conditions: Lung Diseases, Ultrasonography, Fiberoptic Bronchoscopy, One Lung Ventilation, Thoracic Surgery, Lung Collapse
Sponsor: Mahidol University

A randomized controlled study compares lung ultrasonography to fiberoptic bronchoscopy 
confirming double lumen tube positioning for thoracic surgery  
 
Study Protocol 
NCT03314519 
Version Mar, 10th  2020 
 
Sawita Kanavitoon, MDa,  
aDepartment of Anesthesiology, Faculty of Medicine Siriraj hospital, Mahidol university, 
Bangkok, Thailand 
Kasana Raksamani, MDa,  
aDepartment of Anesthesiology, Faculty of Medicine Siriraj hospital, Mahidol university, 
Bangkok, Thailand 
Aphichat Suphathamwit, MDa,  
aDepartment of Anesthesiology, Faculty of Medicine Siriraj hospital, Mahidol university, 
Bangkok, Thailand 
Punnarerk Thongchareon, MDb ,  
bDepartment of Surgery, Faculty of Medicine Siriraj hospital, Mahidol University, Bangkok, 
Thailand 
Sirilak Suksompong, MDa 
aDepartment of Anesthesiology, Faculty of Medicine Siriraj hospital, Mahidol university, 
Bangkok, Thailand 
 
Study Protocol 
Background 
Double-lumen endobronchial tubes is one of well-known technique for one-lung ventilation 
due to simplicity and high success rate of lung separation compare with bronchial blocker(1). 
The Blind technique is a current popular method for lung separation compare with the 
fiberoptic-guided method due to simplicity and a shorter period time to apply(2). Because 
blind intubation for double lumen tube is still more popular, evaluation for tube position is an 
essential part of the practice. The sensitivity of clinical guided for good lung collapse was 
84.5% and specificity 41.1%(3) and even lower in an older study(4, 5), which was unreliable 
and vary due to subjective skills. Recently, evidence nowadays recommended the use of 
clinical and fiberoptic-guided check for the proper position(6). 
 
Currently, fiberoptic bronchoscopy for evaluation for the position of DLT was 
considered as the gold standard. Not only evaluation for positioning, but also an adjustment 
for tube position(7). Though, proper tube positioning is not equal lung collapse. And in some 
patients with abnormal anatomy or secretion or bleeding in the airway, fiberoptic 
bronchoscopy is difficult or even impossible.  
Instead, lung ultrasonography is a novel, safe and easy way to detect lung collapse, 
which has high sensitivity and specificity(5). There is also a study report 88% of accuracy of 
lung ultrasound in the diagnosis of anesthesia-induced atelectasis in children(8,9). The recent 
study also reports superior  lung ultrasonography over clinical methods. Meanwhile, the 
misplacement of DLT in both groups could not be ensured(3). Therefore, this method might 
be useful for caring for thoracic patients. However, due to its new method, lung 
ultrasonography needs some practice and learning curve(10).  

 
Objectives: This study aimed to demonstrate that using lung ultrasonography to 
confirm lung collapse resulted from proper positioning of the double lumen tube (DLT) is a 
comparable method to using fiberoptic bronchoscopy to confirm the DLT position.  
Design: a non-inferiority randomized controlled study 
Setting: A tertiary care university hospital, single institution 
Participants: Two-hundreds patients with ASA classification 1-3 scheduled for 
elective thoracic surgery who require a left-side double lumen tube were enrolled and 
randomized into 2 groups. Five patients were dropped out from the protocol deviation. 
Interventions:   
In group FOB (n=98), standard fiberoptic bronchoscope was used to confirm the position of 
the DLT and adjusted the tube to proper position, while in group US (n=97), lung ultrasound 
was scanned in 4 zones including upper and lower lobe at flank and back of patient at the 
side of surgery to confirm the lung collapse resulted from proper positioning of the DLT and 
used to aid repositioning of the DLT if required.  
Outcome Measurements:  The degree of lung collapse was determined by visual 
grading by surgeon.  Time used to adjust the DLT position was recorded.  
  
Statistical Analysis 
 
Sample size calculation was performed by Mario de Bellis et al (11)report that 
fiberoptic bronchoscopy provided a sensitivity of 95% for optimal LDLT position. Moreover, 
Parab et al(5) and Chou et al(12) report the sensitivity of lung ultrasonography to confirm 
lung collapse at 88-100%. As a result, we hypothesized that lung ultrasonography is not 
inferior to fiberoptic bronchoscopy (non-inferiority study). Non-inferiority margin equal 10% 
with significant p-value as 0.05, power 90%, the sample size each group equal 82 cases. 
Furthermore, concerning drop out about 15%, sample size of each group was 100. Sample 
size calculation was demonstrated from n4Studies as 
 
 
,     
,     
 
For a non-inferiority or superiority trial for binary data 
  Proportion in group1 (p1) = 0.950 
  Proportion in group2 (p2) = 0.950 
  Non-inferiority or superiority margin (δ) = 0.100 
  Ratio between 2 groups (k) = 1.0 
  Alpha (α) = 0.05, Z (0.950) = 1.644854 
  Beta (β) = 0.10, Z (0.900) = 1.281552 
  Sample size: n1 = 82, n2 = 82 
 
Statistical analysis was performed using SPSS version 18 for Windows (Chicago, USA). 
Continuous data were presented as the means and SD and statistical significance was 
considered when p<0.05. The positive predictive value was calculated to determine the 
effectiveness of lung ultrasound compared to fiberoptic bronchoscopy and defined as follow: 
Positive predictive value (%) = TP/(TP+FP) x100  
 

 
Figure 1: Trial profile
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
References 
1. 
Bussieres JS, Somma J, Del Castillo JL, Lemieux J, Conti M, Ugalde PA, et al. 
Bronchial blocker versus left double-lumen endotracheal tube in video-assisted thoracoscopic 
surgery: a randomized-controlled trial examining time and quality of lung deflation. Can J 
Anaesth. 2016;63(7):818-27. 
2. 
Boucek CD, Landreneau R, Freeman JA, Strollo D, Bircher NG. A comparison of 
techniques for placement of double-lumen endobronchial tubes. J Clin Anesth. 
1998;10(7):557-60. 
3. 
Alvarez-Diaz N, Amador-Garcia I, Fuentes-Hernandez M, Dorta-Guerra R. 
Comparison between transthoracic lung ultrasound and a clinical method in confirming the 
position of double-lumen tube in thoracic anaesthesia. A pilot study. Rev Esp Anestesiol 
Reanim. 2015;62(6):305-12. 
4. 
Cohen E. Double-lumen tube position should be confirmed by fiberoptic 
bronchoscopy. Curr Opin Anaesthesiol. 2004;17(1):1-6. 
5. 
Parab SY, Divatia JV, Chogle A. A prospective comparative study to evaluate the 
utility of lung ultrasonography to improve the accuracy of traditional clinical methods to 
confirm position of left sided double lumen tube in elective thoracic surgeries. Indian J 
Anaesth. 2015;59(8):476-81. 
6. 
Lohser J. Evidence-based management of one-lung ventilation. Anesthesiol Clin. 
2008;26(2):241-72, v. 
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Kitabjian L, Bordi S, Elisha S, Gabot M, Heiner J, Nagelhout J, et al. Anesthesia case 
management for video-assisted thoracoscopic surgery. AANA J. 2013;81(1):65-72. 
200 patients enrolled and randomly assigned 
100 assigned to receive lung 
ultrasonography 
97 received lung ultrasonography 
 
100 assigned to receive fiberoptic 
bronchoscopy 
98 received fiberoptic bronchoscopy 
 
97 included in analysis 
98 included in analysis 
3 switch to fiberoptic-guided LDLT insertion  
due to difficult proper position 
by blind technique 
2 switch to fiberoptic-guided LDLT insertion  
due to difficult proper position 
by blind technique  
 

8. 
Acosta CM, Maidana GA, Jacovitti D, Belaunzaran A, Cereceda S, Rae E, et al. 
Accuracy of transthoracic lung ultrasound for diagnosing anesthesia-induced atelectasis in 
children. Anesthesiology. 2014;120(6):1370-9. 
9. 
Yamaguchi Y, Moharir A, Burrier C, Tobias JD. Point-of-care lung ultrasound to 
evaluate lung isolation during one-lung ventilation in children: A case report. Saudi J 
Anaesth. 2019;13(3):243-5. 
10. 
Nam JS, Park I, Seo H, Min HG. The use of lung ultrasonography to confirm lung 
isolation in an infant who underwent emergent video-assisted thoracoscopic surgery: a case 
report. Korean J Anesthesiol. 2015;68(4):411-4. 
11. 
de Bellis M, Accardo R, Di Maio M, La Manna C, Rossi GB, Pace MC, et al. Is 
flexible bronchoscopy necessary to confirm the position of double-lumen tubes before 
thoracic surgery? Eur J Cardiothorac Surg. 2011;40(4):912-6. 
12. 
Chou EH, Dickman E, Tsou PY, Tessaro M, Tsai YM, Ma MH, et al. 
Ultrasonography for confirmation of endotracheal tube placement: a systematic review and 
meta-analysis. Resuscitation. 2015;90:97-103.