A Comparison of Positional Stability: the EZ-blocker Versus Left Sided Double Lumen Tube in Adult Patients for Thoracic Surgery
Phase: NA
Conditions: Thoracic Injuries
Sponsor: Wake Forest University Health Sciences

 
1 
 
 IRB00038220 
 
A comparison of positional stability: the EZ-blocker versus Left Sided Double Lumen Tube in adult 
patients for thoracic surgery 
 
 
NCT03403192 
 
14MAR2019 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
2 
 
 
 
 
 
Study Title: A comparison of positional stability: the EZ-blocker versus Left Sided Double Lumen Tube 
in adult patients for thoracic surgery.  
 
Principal Investigator, Co-investigator(s): T. Wesley Templeton M.D., Ben Morris M.D., Rhett Hadley 
M.D., Eduardo Goenaga-Diaz M.D., Dan Forest M.D., Jeff Gardner M.D., Jerry Clark M.D., Chandrika 
Garner, M.D.  
 
Sponsor or funding source: Wake Forest Department of Anesthesia 
 
Background, Rationale and Context 
 
One lung ventilation (OLV) is commonly used in thoracic surgery to improve surgical exposure and 
improve operative conditions. At this time, there are two approaches to OLV in routine use in adult 
thoracic surgery. One approach is to use of a double lumen tube (DLT). The other approach is to use a 
bronchial blocker (BB). Currently there are several different types of bronchial BBs on the market. 
 
The EZ-Blocker is a bronchial blocker with a 7-Fr shaft with two separate occlusive balloons “Y” 
configuration designed to rest on the carina. Once secured in place, the operator can choose to inflate one 
of the two occlusive balloons to isolate either mainstem bronchus (1). 
 
Studies have been performed comparing BBs to DLTs looking at time and ease of placement, differences 
in quality of lung isolation, and incidence of sore throat, hoarseness, and other morbidity associated with 
placement [2-4]. A recent meta-analysis published by Clayton-Smith et al found that BBs are associated 
with fewer airway injuries when compared to DLTs (5). They found the quality of isolation to be 
equivalent between BBs and DLTs. While quality of isolation over all may be comparable, it has been 
demonstrated in several studies that positional stability of bronchial blockers such as the Arndt or Cohen, 
is frequently inferior to that of a DLT (2,4).     
 
At this time, there are a small number of trials looking at the use of the EZ-blocker in adult patients. In 
one study published in 2013 the EZ-blocker was compared to the Cohen Flex-Tip blocker. In this study 
they found that time to place the EZ-blocker was in fact shorter and that overall the number of 
repositioning required was less with the EZ-blocker (6). In 2013, a study was published by Mourisse et al 
which compared DLT to the EZ-blocker (7). In this study they found initial malposition of both devices to 
be fairly equivalent, and time to placement was longer with the EZ-blocker. They also found more 
tracheal and bronchial injuries in the DLT group, but importantly they found that positional stability was 
equivalent. In both of these studies however they did not design their studies to effectively differentiate 
between right and left sided procedures when quantifying the need for BB repositioning. Because the take 
off of the right upper lobe bronchus is sometimes adjacent to, or even proximal to the carina, it can 
impede effective isolation with a BB.  Therefore, claims of positional stability may rely heavily on the 
laterality of the procedure, with right sided isolation being significantly more labile than left sided 
especially with respect to isolation using a BB.      
 
 
 
In conclusion then, we feel that the potential morbidity of a DLT in terms of the potential for airway 
injury when compared to a BB suggests that further exploration of the possibility of equivalent positional 

 
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stability between these devices is necessary. We feel it is necessary to delineates the impact of laterality 
on the effectiveness of one technique for isolation versus the other. 
 
In addition to this if there is a difference in stability in cases where right sided isolation via the EZ-
blocker fails in the setting of multiple repositions or out and out failure we would like to examine the 
preoperative CT data to determine if there are anatomic measurement which could potentially inform the 
appropriateness or inappropriateness of choosing a DLT over an EZ-blocker.   
 
Objectives 
 
The objective of this study is to evaluate the positional stability and quality of lung isolation provided by 
the EZ-blocker compared to a DLT for both right and left sided thoracic surgery. 
 
An additional objective will be to assess time to placement of both devices and other significant clinical 
differences between these two approaches to placement of the BB including airway injury and post-
operatives sore throat, post-operative hoarseness, Additionally we would like to examine the preoperative 
high resolution CT imaging data to determine if there are anatomic landmarks that may potentially inform 
the appropriateness or inappropriateness of choosing an EZ-blocker or left sided DLT.   
 
 
  
 
Methods and Measures 
 
Design 
 
Once the patient is recruited preoperatively in the PAC or within the hospital as an inpatient, this 
information will be relayed to the study investigators. On the day of surgery, the patient will then 
be randomized using a random number generator and opaque envelope method for group 
allocation to either extra-luminal placement of an EZ blocker bronchial blocker or left side double 
lumen tube. We will recruit at least 80 patients with right sided procedures: 40 EZ-Blocker and 
40 left sided DLT. We will also recruit at least 80 patients with left sided procedures: 40 EZ-
Blocker and 40 left sided DLT.   
 
We will record age, height, weight, gender, ASA status, type of surgery, side of surgery, duration 
of one lung ventilation, duration of surgery, and duration of anesthesia. 
 
An IV will be placed in the patient prior to going to the OR. Once in the OR the patient will have 
routine monitors placed. The patient will be pre-oxygenated with 100% O2 for 2 minutes and 
induced.. The patient will then be hand ventilated with 100% oxygen for 3 minutes to ensure 
relaxation.  Patients will undergo direct laryngoscopy and according to group assignment will 
have either an extraluminal EZ-blocker placed or an appropriately sized left sided double lumen 
placed under the supervision of an attending experienced in thoracic anesthesia and one lung 
ventilation.  
We will confirm endotracheal placement of the ETT or left sided DLT via ausculation and 
ETCO2. The ETT or DLT will be secured at an appropriated depth. The fiberscope will then be 
advanced into the lumen of the ETT or DLT to further adjust and confirm placement of the EZ-
blocker or DLT. Time for initial bronchial blocker placement or DLT placement will be recorded 
from the point of the DL to removal of the fiberscope after visualization of the BB with the cuff 
inflated in the correct position or the DLT with the bronchial cuff inflated.    
 

 
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Other intravascular lines such as a radial arterial line and additional peripheral IV may be placed 
at the discretion of the attending anesthesiologist. 
 
Once in the final position prior to prepping and draping the blocker or DLT in all groups will be 
checked to make sure it is still correctly placed with a FOB. The patient will be prepped and 
draped. 
 
The surgeon will be blinded to technique and queried as to the quality of isolation upon entry into 
the chest and this will be recorded. This will be queried every 60 minutes for the duration of the 
procedure. 
 
We will record any episodes of loss of isolation and details of repositioning including times and 
the issue of malposition i.e. the blocker or DLT slipped out or slipped in too far. We will record 
any episodes of ongoing desaturation which require deflation of the EZ-blocker cuff and/or 
ventilation of both lungs with a DLT.  
 
We will record the point at which the surgeon the end of OLV. The patient will be extubated 
according to normal clinical practices and will be taken to the post anesthesia care unit. The Ez-
blocker will be removed simultaneously with the ETT. In patients in the EZ-blocker group that 
remains intubated post procedure the EZ-blocker will be removed prior to going to the ICU. In 
the DLT group the DLT will be exchanged according to routine clinical practice to a single lumen 
ETT. 
  
The patient will be contacted on post-operative days 1 and 2 to assessed for hoarseness and sore 
throat via a VAS scale from 0-100: 0=No sore throat and 100=the worst sore throat imaginable. 
We will also record any significant morbidity or mortality events such as prolonged mechanical 
ventilation or cardiac arrest or stroke that may occur within the first 2 post-operative days. 
 
In patients where isolation is troublesome requiring multiple repositioning we will evaluate their 
preoperative CT scan to determine if there are any anatomical findings on CT which maybe 
predictive of failure. We will compare these to an equivalent number of control patients from this 
study population in which isolation was successful. We will attempt to match these patients for 
size and diagnosis. 
The study will be performed at Wake Forest Baptist Medical Center a tertiary academic medical 
center. 
 
Subjects selection criteria 
 
Adult patients scheduled for thoracosopic surgery or thoracotomy requiring lung isolation in which both 
an EZ-blocker or double lumen tube would be considered an appropriate choice for lung isolation will be 
recruited. 
. 
 
 
 
Inclusion Criteria 
 
Patients greater than 18 years of age scheduled for thoracoscopic surgery or thoracotomy 
requiring lung isolation 
Patient presenting as an outpatient for elective thoracic surgery 
Inpatients scheduled for thoracic surgery. 
 

 
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 
Exclusion Criteria 
 
History of difficult airway/intubation 
Patients suspected to have a difficult airway.  
Morbid obesity BMI >39 
Pregnancy 
Emergency status of surgery 
Thoracic surgery requiring a right sided double lumen tube 
 
 
Sample Size 
 
Assuming a power of 80% and a type 1 error of 5% and a rate of repositioning in the DLT 
group to be approximately 0.3 repositioning/hour from our experience and a projected rate of 
repositionings using an EZ-blocker of 0.5 with a standard deviation of 0.3 we estimate a 
sample size of 36 patients in each arm to demonstrate non-equivalence and so we anticipate 
enrolling 40 patients in each device in both the left and right sided arm bringing our total 
enrollment to 160 patients. This is not a multisite study.  
 
 
Interventions and Interactions 
 
Interventions and interactions for the patient should be fairly reasonable. The largest overall commitment 
of time from the patient will be in the PAC at the time of recruitment or in their room as an inpatient. One 
of the PAC attendings, or investigators, or study personnel will interview the patient explain the study and 
attempt to recruit the patient if they are eligible. The study participant will have their questions answered 
and will be consented. 
On the day of surgery, the patient will be identified in the holding area and a study representative will 
make sure that he or she has not changed their mind about participation and will answer any questions the 
study subject may have thought of since the interview in PAC. If the patient is still in agreement to 
participate in the study they will be taken to the OR and care will proceed as it would otherwise with the 
induction of general anesthesia and placement of the EZ-blocker or DLT per the protocol depending on 
which group the patient has been randomized to. In some cases, in which the patient is an inpatient or 
does not go to the PAC a member of the study team may approach them to participate either the day 
before or on the day of surgery. After the surgery, a study representative will contact the patient to 
evaluate for any postoperative issues such as a sore throat or increase hoarseness on post-operative days 1 
and 2. This will be the last interaction of the patient with the study. 

 
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Patient 
identified 
in PAC. 
Patient 
approached 
in PAC and 
questions 
answered 
about. 
Patient to 
sign consent 
for study 
participation 
here.  
Confirmation 
and 
randomization 
on day of 
surgery 
Bronchial 
Blocker 
placed 
intraluminally 
or 
extraluminally 
. Data 
collected 
about 
placement 
Patient 
will 
undergo 
surgery. 
Intra-
operative 
events 
related 
to 
blocker 
position 
will be 
recorded 
At the 
end of 
surgery 
BB or 
DLT will 
be 
removed, 
and the 
patient 
will 
extubated, 
and  
patient 
taken to 
PACU or 
ICU 
Patient 
interviewed 
on post-op 
days 1 and 
2 to 
evaluate 
sore throat. 
Time 
required 
of 
Patient 
0 min 
20 min 
5 min 
10 min 
Depends 
on 
surgical 
duration. 
 
5-10 min 
 
 
 
 
 
 
 
Outcome Measure(s) 
 
We will measure the number of DLT or BB replacements, time of placement, quality of isolation at 1-
hour intervals during the operation, incidence of sore throat and/or hoarseness postoperatively. 
 
Analytical Plan 
 
Results will be analyzed initially using descriptive statistics.  Comparison between groups will be done 
using chi square tests for proportions, and t-tests or ANOVA procedures for continuous variables. Other 
inferential statistical analysis will be conducted as appropriate. 
 
Human Subjects Protection 
 
Subject Recruitment Methods 
 
Patients will be identified for participation in the Preoperative Assessment Clinic (PAC) prior to the day 
of surgery or via the OR schedule for patients who are not seen in the PAC. All patients scheduled for 
elective thoracic surgery pass through the PAC. PAC attendings will be educated by the investigators as 
to the specific inclusion and exclusion criteria. Patients will be recruited by investigators and/or the study 
coordinator with the participation and collaboration of PAC attending and other staff present in the clinic 
involved in this study. We will attempt to recruit qualified subjects in a non-biased manner. Privacy will 
be protected because subjects will be recruited in the process of a confidential preoperative evaluation in 

 
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PAC. If they choose not participate no research record will be created and as such there will be no contact 
information to destroy. In house patients will be approached to participate either the night before surgery 
or on the day of surgery. 
 
Informed Consent 
 
Signed informed consent will be obtained from each subject. Investigators, study coordinator, and PAC 
attendings involved in the study will obtain informed consent. Inpatients will be interviewed and recruited 
by either study investigators or other member of the study team. 
 
Confidentiality and Privacy 
 
Confidentiality will be protected by collecting only information needed to assess study outcomes, 
minimizing to the fullest extent possible the collection of any information that could directly identify 
subjects, and maintaining all study information in a secure manner.  To help ensure subject privacy and 
confidentiality, only a unique study identifier will appear on the data collection form.  Any collected 
patient identifying information corresponding to the unique study identifier will be maintained on a 
linkage file, store separately from the data.  The linkage file will be kept secure, with access limited to 
designated study personnel.  Following data collection subject identifying information will be destroyed 4 
years after closure of the study via shredding, consistent with data validation and study design, producing 
an anonymous analytical data set.  Data access will be limited to study staff.  Data and records will be 
kept locked and secured, with any computer data password protected.  No reference to any individual 
participant will appear in reports, presentations, or publications that may arise from the study. 
 
Data and Safety Monitoring 
The principal investigator will be responsible for the overall monitoring of the data and safety of study 
participants.  The principal investigator will be assisted by other members of the study staff. 
 
Reporting of Unanticipated Problems, Adverse Events or Deviations 
Any unanticipated problems, serious and unexpected adverse events, deviations or protocol changes will 
be promptly reported by the principal investigator or designated member of the research team to the IRB 
and sponsor or appropriate government agency if appropriate. 
 
References 
 
1. Mungroop et al. “Lung isolation with a new Y-shaped endobronchial blocking device, the EZ-
Blocker.” British Journal of Anesthesia 2010; 104: 119-120. 
2. Dumans-Nizard. “A Comparison of the deflecting-tip broncia Blocker with a wire guided blocker 
or left sided double-lumen tube.” Journal of Cardiothoracic and Vascular Anesthesia 
3. Campos JH, et al. “Devices for lung isolation used by anesthesiologist with limited thoracic 
experience: Comparison of double-lumen endotracheal tube, Univent torque control blocker, and 
Arndt wire-guided endobronchial blocker.” Anesthesiology 2006; 104: 261-266. 
4. Knoll H, et al. “Airway injuries after one-lung ventilation: A comparison between double-lumen 
tube and enobronchial blocker: A randomized, prospective, controlled trial.” Anesthesiology 
2006; 105: 471-477. 
5. Clayton-Smith Ana, et al. “A comparison of the efficacy and adverse effects of double-lumen 
endobronchial tubes and bronchial blockers in thoracic surgery: a systematic review and meta-
analysis of randomized controlled Trials.” Journal of Cardiovascular and Vascular Anesthesia 
2015; 29: 955-966. 
6. Alparsian et al. “A Comparison of the EZ-Blocker With a Cohen Flex-Tip Blocker for One-Lung 
Ventilation.” Journal of Cardiothoracic and Vascular Anesthesia 2014; 28: 896-899. 

 
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7. Mourisse et al. “Efficiency, Efficacy, and Safety of EZ-Blocker Compared with Left-Sided 
Double-Lumen Tube for One Lung Ventilation.” Anesthesiology 2013; 118: 550-561. 
8. Piccioni et al. “Extraluminal EZ-Blocker Placement for One-Lung Ventilation in Pediatric 
Thoracic Surgery.” Journal of Cardiovascular and Thoracic Anesthesia 2015; December, e71-e73. 
9. Templeton TW et al. “Bending the Rules: A Novel Approach to Placement and Experience with 
the 5 French Arndt Endobronchial Blocker in Children Less than 2.” Pediatric Anesthesia 2016; 
26: 512-520 . 
 
 
Appendix 
1. Data collection form 

 
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Appendix 1 Data Sheet 
Data Form for EZ-bronchial Blocker vs. Double Lumen Study 
 
 
 
 
 
 
 
ASA: 
Weight:           Height:  
BMI: 
Gender: 
Diagnosis: 
Laterality: 
 
RIGHT  
 
LEFT 
 
EZ-Blocker 
 
DOUBLE LUMEN 
Induction Drug Doses:  
Propofol________ 
     Fentanyl_______ Rocuronium(0.8mg/kg)__________ 
Etomidate________ 
 
Ventilate/Wait 3 minutes at least. 
 
Begin Blocker or Double Lumen with DL. START TIMING:  
 
Time for placement of EZ-blocker or DLT:___________ 
 
Number of EZ-blocker or DLT Replacements During Procedure: ________________ 
 
Quality of Isolation:  1- Excellent 
 
2 – Fair 
 
3 - Poor  
Time 1 _______ 
 
Quality of Isolation T1  ________ 
Time 60 min  
Quality of Isolation 60  ________ 
Time 120 min  
Quality of Isolation 120________ 
Time 180 min  
Quality of Isolation 180________ 
Time 240 min  
Quality of Isolation 240________ 
Time 300 min  
Quality of Isolation 300________ 
(Excellent=complete collapse with perfect surgical exposure; Fair=total collapse but the lung has residual air; Poor=no collapse, 
or partial collapse with interference in surgical exposure) 
 
Incision Time:_________ 
Closure Time:_________  
Time of OLV__________ 
Patient Sticker 

 
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Sore Throat Post procedure: 
VAS score from page 3 
 
Day 1  _____ 
Day 2  _____ 
Additional Comments/Adverse Events/Other significant intra-operative events 
 
 
 
 
 
 
Blocker or Double Lumen Replacement 
 
Replacement Event: 
Time 
Brief Description of event including duration of 
replacement event 
 
 
Too Deep 
Too Proximal 
Other 
 
 
Too Deep 
Too Proximal 
Other 
 
 
Too Deep 
Too Proximal 
Other 
 
 
Too Deep 
Too Proximal 
Other 
 
 
Too Deep 
Too Proximal 
Other 
 
 
Too Deep 
Too Proximal 
Other 
 
 
Too Deep 
Too Proximal 
Other 
 

 
11 
Day 1 
 
No Sore Throat 
 
 
 
 
   Worst Sore Throat Imaginable 
            0 _______________________________________________________________ 100 
 
 

 
12 
 
 
Day 2 
 
No Sore Throat 
 
 
 
 
   Worst Sore Throat Imaginable 
            0 _______________________________________________________________ 100