Effect of intubation in the lateral position under general anesthesia induction on the position of double-lumen tube placement in patients undergoing unilateral video-assisted thoracic surgery: study protocol for a randomized controlled trial.

doi:10.21203/rs.3.rs-2009149/v1

• Background

The double-lumen tube (DLT) is an essential equipment for thoracic anesthesia and the precise position of DLT placement is particularly important for anesthesia and surgery. However, the incidence of DLT malposition remains high and it leads to lung isolation failure and hypoxemia during one-lung ventilation. This trial aims to explore the clinical application and efficacy of intubation in the lateral position under general anesthesia induction to reduce the incidence of DLT malposition in patients undergoing unilateral video-assisted thoracic surgery (VATS).

• Methods

In this prospective, randomized, controlled trial, we will recruit 108 patients, aged 18–80 years, scheduled for elective unilateral VATS with DLT intubation under general anesthesia, and they will be randomly assigned to two groups: a lateral DLT intubation group (group L) and a conventional supine DLT intubation group (group C). The left-sided DLT will be used to intubate in patients of both groups. The position of DLT will be confirmed and adjusted by using the fiberoptic bronchoscopy (FOB). The primary outcome is the incidence of DLT malposition observed via the FOB, and the secondary outcomes include the time of intubation, the frequency and duration of re-adjustments of DLT placement under FOB, whether to re-intubation, intraoperative vital signs and postoperative recovery.

• Discussion

Accurate DLT positioning is particularly important in thoracic surgery, but the incidence of DLT malposition is still high in the present thoracic anesthesia. This trial aims to investigate whether lateral DLT intubation can reduce the incidence of DLT malposition, with more stable intraoperative vital signs and fewer postoperative complications.

Trial registration:

Study protocol registered at Chinese Clinical Trial Registry with ChiCTR2200060794 on June 11, 2022.

Double-lumen tube

Intratracheal intubation

Malposition

Lateral position

Video-assisted thoracic surgery

Thoracic anesthesia

Fiberoptic bronchoscopy

Title {1}	Effect of intubation in the lateral position under general anesthesia induction on the position of double-lumen tube placement in patients undergoing unilateral video-assisted thoracic surgery: study protocol for a randomized controlled trial.
Trial registration {2a and 2b}.	Chinese Clinical Trial Registry, http://www.chictr.org.cn, ID: ChiCTR2200060794. Registered on June 11, 2022.
Protocol version {3}	Protocol Version 5.0 dated 25-04-2022
Funding {4}	This trial is funded by a grant from the Medical Science and Technology Project of Zhejiang Province (grant number: 2020ZH043).
Author details {5a}	Xi Zhang (XZ)¹, Dong-Xu Wang (DXW)¹, Qin Zhang (QZ)¹, Qi-Bin Shen (QBS)², Fei Tong (FT)¹, Yong-He Hu (YHH)¹, Zhen-Duo Zhang (ZDZ)¹, Fei-Fan Liu (FFL)¹, Ya-Wen Tang (YWT)¹, Juan-Li Chen (JLC)³, He Liu (HL)¹, Si-Ping Hu (SPH)¹ ¹Department of Anesthesiology & Huzhou Key Laboratory of Basic Research and Clinical Translation for Neuromodulation, Huzhou Central Hospital \|\| The Affiliated Huzhou Hospital, Zhejiang University School of Medicine \|\| Affiliated Central Hospital Huzhou University, Huzhou, China; ² Department of Cardiothoracic Surgery, Huzhou Central Hospital \|\| The Affiliated Huzhou Hospital, Zhejiang University School of Medicine \|\| Affiliated Central Hospital Huzhou University, Huzhou, China; Huzhou, China; ³ Department of Operating Room Nursing, Huzhou Central Hospital \|\| The Affiliated Huzhou Hospital, Zhejiang University School of Medicine \|\| Affiliated Central Hospital Huzhou University, Huzhou, China; Huzhou, China; Correspondence to Si-Ping Hu or He Liu. Roles and responsibilities:* Principal investigator: SPH Study design: SPH and LH Trial coordination: SPH, JLC and QBS Collection of data: XZ, DXW, FT, YHH, ZDZ, FFL and YWT Postoperative follow-up: XZ and DXW Data analysis and interpretation: QZ Writing of the manuscript: SPH, LH and XZ
Name and contact information for the trial sponsor {5b}	Si-Ping Hu, Huzhou Central Hospital, Huzhou, China. E-mail: [email protected].
Role of sponsor {5c}	This is an investigator-initiated trial. Si-Ping Hu is the sponsor of this study, and is fully involved in planning and designing the study. The study design, data collection, data analysis, data interpretation, manuscript writing or publication decisions are conducted independently from the funding agency.

Background and rationale {6a}

The thoracic surgery has increased drastically in recent years, especially in the light of the outbreak of coronavirus diseases 2019. Routine “passive” computed tomography of the chest screening of inpatients detects some pulmonary disease requiring thoracic surgeries timely. With the advantages of less damage, minimizing complications, and quick postoperative recovery, the video-assisted thoracic surgery (VATS) becomes the standard approach of treatment in most thoracic surgery [1]. The DLT intubation can achieve lung isolation and one-lung ventilation (OLV) which are the basis of modern thoracic anesthesia and surgery [2, 3]. The accurate position of DLT placement can effectively isolate the ventilation pathways of both lungs to ventilate separately at the bronchial level, resulting in full atrophy of the operated lung and good exposure of the operative field to facilitate surgical operations, also preventing pus, bronchial secretions or blood from the operated lung entering the healthy lung [2]. However, many reasons lead to DLT malposition which deviating from the accurate position, generally including neck flexion or extension during shifting the patient from supine to lateral position, surgical manipulation, and coughing [4-8]. Related to differences in DLT types, intubation methods, or definitions of malposition, the incidence of DLT malposition mainly varied in 26%-37% [9-11]. About 40% of DLT-related complications are due to DLT malposition, including poor lung isolation, hypoxemia during OLV, atelectasis and so on [9, 12, 13]. Thus the accurate position of DLT placement plays a particularly important role in thoracic anesthesia, and the FOB is the most effective and reliable method to confirm and adjust the DLT position [3, 14-17].

Passive neck flexion or extension movement of patients from supine to lateral position after DLT intubation are likely to lead to DLT malposition, and a recent study reported that shifting patients to lateral position increased endobronchial cuff pressure due to changes in gravity and the curvature or length of the left main bronchus [18]. Thus we envisage whether it would be possible to assist patients in the surgically required lateral position before induction of anesthesia then to DLT intubation under general anesthesia induction in patients undergoing VATS, which would directly avoid the possible adverse effects of lateral positioning. After reviewing related articles, very few references to lateral DLT intubation can be found. Martinez et al. [19] mentioned in their article that an important and unique issue for non-intubated thoracic surgery (NIVATS) was the training of lateral position intubation for emergencies, as patients in NIVATS were likely to require to DLT intubation, and lateral intubation was not difficult according to their experiences. In addition, Ajimi et al. [20] reported a case of successful left-sided DLT intubation in the right lateral position for a patient with a giant mediastinal tumor with tracheal compression, and OLV was performed safely during thoracic surgery without ventilatory failure or hypoxemia. Therefore, we design this trial to explore the clinical application and efficacy of intubation in the lateral position under general anesthesia induction to reduce the incidence of DLT malposition in patients undergoing unilateral VATS.

Objectives {7}

We will conduct a prospective, randomized, controlled clinical trial to explore the effect of intubation in the lateral position under general anesthesia induction on the position of DLT placement in patients undergoing unilateral VATS. We will study whether the DLT intubation in the lateral position under general anesthesia induction will reduce the incidence of DLT malposition comparing to the conventional supine intubation, with more stable intraoperative vital signs and fewer postoperative complications.

Trial design {8}

This study will be conducted as a prospective, single-center, single-blind, randomized, controlled trial.

Study setting {9}

The study will be conducted in patients undergoing elective unilateral VATS with DLT intubation in

Huzhou Central Hospital, Zhejiang, China, and the recruitment has begun.

Eligibility criteria {10}

The inclusion and exclusion criteria for participants in this study are as follows:

Inclusion criteria:

Preformed the unilateral VATS with left-sided DLT intubation under general anesthesia;
American Society of Anesthesiologists (ASA) score of I to III;
Age 18-80 years and clear consciousness;
Agree to participate in this study and sign informed consent;

Exclusion criteria:

Difficulty in intubation at preoperative assessment (body mass index > 30 kg/m², limited neck movement, mouth opening < 3 cm or Mallampati III-IV grades);
Failure of multiple attempts to DLT intubate;
Severe mental illness and difficulty communicating;
Without informed consent;
History of pulmonary surgery;

Who will take informed consent? {26a}

Appropriate participants will be jointly identified by the chief physician of anesthesia and cardiothoracic surgery at our hospital. We will give the participants sufficient time to consider and voluntarily choose to participate in the study, then will obtain written informed consent day before surgery from each study participant.

Additional consent provisions for collection and use of participant data and biological specimens {26b}

Before obtaining the participants' informed consent, we will explain the methods of lateral and supine DLT intubation, and account for the preoperative, intraoperative and postoperative data needing to be collected. The specific content of methods and data will also be listed in the informed consent form. There is not involve in collecting biological specimens in this study.

Interventions

Explanation for the choice of comparators {6b}

With the special nature of thoracic surgery, the patients often need to be shifted to the surgical position after anesthesia and intubation. In thoracic anesthesia, the patients are placed conventionally in the supine position for induction and intubation, then be moved to the lateral position after completing the DLT positioning. Therefore, we chose the supine intubation as the comparator.

Intervention description {11a}
Preparing

All participants are routinely fasted for 8 hours before surgery and routinely monitored with a 5-lead electrocardiogram, non-invasive blood pressure or invasive arterial blood pressure, and oxygen saturation in the operation room.

Grouping

The investigator will take a sequentially numbered sequence in a sealed, opaque envelope, and after the participant enters the operation room it will be opened to obtain a random number to determine the grouping: an odd number for lateral DLT intubation group (group L) and an even number for conventional supine DLT intubation group (group C). Then the investigator will inform the participant of the specific grouping and assist the participant in lateral or supine position.

Description for Intervention

Both groups will be induction and maintenance with total intravenous anesthesia, followed by the left-sided DLT (Broncho-Cath®, Mallinckrodt Medical Ltd., Hampshire, Ireland) intubation to mechanical assisted ventilation. Group L: investigators assist the participant to a comfortable and surgically required lateral position before induction, and intubate DLT with a video laryngoscope after induction, then confirm and adjust the DLT position using the FOB to complete the positioning of DLT. Group C: investigators intubate DLT with a video laryngoscope after induction in the conventional supine position, then confirm and adjust the DLT position using the FOB to complete the positioning of DLT, and use the FOB again to confirm the DLT position after lateral positioning.

Introduction for investigators

This study will be completed with the joint participation of the Department of Anesthesiology, the Department of Cardiothoracic Surgery and the Department of Operating Room Nursing. For anesthesia, the investigator has extensive experience in thoracic anesthesia, and has specially trained in lateral intubation.

Criteria for discontinuing or modifying allocated interventions {11b}

The investigator will terminate the experiment for this participant if one of the following occurs during the experiment:

Participants in the operating room not accept the intervention after learning about their grouping.
Attempting DLT intubation in lateral position ≥ 3 times or intubation time ≥ 3 minutes.
Switch to supine DLT intubation after unsuccessful attempts to lateral intubation.
Postoperative follow-up could not be completed due to various reasons.

Strategies to improve adherence to interventions {11c}

The principal investigator (SPH) will conduct the pre-anesthesia evaluation day before surgery, strictly following the exclusion and inclusion criteria. During obtaining informed consent from participants, SPH will explain the content of the study and the need for cooperation in detail for participants. Furthermore, another investigator will administer a brief questionnaire to participants for 3-5 minutes at 24h postoperative without excessively affecting the rest time of participants.

Relevant concomitant care permitted or prohibited during the trial {11d}

All study participants will receive standard postoperative care in the operating room, the postanesthesia care unit (PACU), the intensive care unit (ICU) or the ward.

Provisions for post-trial care {30}

At the end of the intervention and surgery, participants will be extubated the DLT in the operating room and sent to the PACU for observation (or to the ICU with the DLT if the patient is in poor condition), and then sent back to the ward. There are risks associated with thoracic surgery and DLT intubation. Regardless of the reason for any adverse events, our department and the hospital will offer care.

Outcomes {12}

Primary outcome

The incidence of DLT malposition observed via the FOB in lateral and supine intubation groups. The definition of DLT malposition is that the DLT is moved to correct its position by more than 1.0 cm [9].

Secondary outcomes

The time of intubation. Defined as the time from the use of the video-laryngoscope to confirm the correct position of the DLT by using the FOB.
The frequency and duration of re-adjustments under FOB.
Whether to re-intubation.
Intraoperative vital signs. Including heart rate, blood pressure and oxygen saturation.
Postoperative recovery. Including early postoperative complications and the Quality of Recovery-15 (QoR-15) questionnaire at 24 hours after surgery.

Participant timeline {13}

The participant timeline is shown in Fig.1.

Sample size {14}

This trial focuses on whether intubation in the lateral position under general anesthesia will reduce the DLT malposition rate observed via the FOB in patients proposed for unilateral VATS, therefore the expected sample size is calculated based on the current DLT malposition rate. According to previous studies, the incidence of DLT malposition is about 30% [9]. Expecting a 50% reduction in malposition rate to be considered an effective intervention, we chose α=0.05 and test efficacy β=80%, which is calculated to yield 48 cases in each group by using PASS 15.0 software. Considering a 10% shedding rate, the final sample size is derived as at least 54 cases per group, with a total of 108 patients included.

Recruitment {15}

Study participants will be recruited from patients undergoing unilateral VATS at Huzhou Central Hospital. The research team including anesthesiologists and thoracic surgeons will involve in the recruitment process. There is an adequate source of patients to ensure the number of enrollment, and 4 months is enough to complete the enrollment of 108 eligible participants.

Assignment of interventions: allocation

Sequence generation {16a}

The computerized random number generator is used to generate random sequences on a 1:1 basis, and the random sequence will be put into a sealed, opaque and sequentially numbered envelope by the investigator. When the participant is admitted to the operating room the investigator will open the envelope to obtain a random sequence to determine the grouping: an odd number for group L and an even number for group C. The study participant’s name and assigned group will be recorded in the randomisation list.

Concealment mechanism {16b}

The study number and group allocation of participant will be typed onto separate pages and be collected to store confidentially. The randomisation process will be performed by investigators who are not involved in postoperative follow-up and data analysis.

Implementation {16c}

The randomisation stated above will decide the allocation of intubation position (lateral versus supine). The principal investigator will prepare the envelope with random sequence for allocation.

Assignment of interventions: Blinding

Who will be blinded {17a}

This study will be a single-blinded clinical trial. It is not possible to blind participants, anesthesiologists, and surgical team when the intervention is implemented in this trial, so we will blind the followers and data analysts.

Procedure for unblinding if needed {17b}

Unblinding will not occur because this study blind only to the followers and data analysts.
Data collection and management

Plans for assessment and collection of outcomes {18a}

Data will be collected at three time points (preoperative, intraoperative and postoperative) and recorded on the case record form (CRF). The principal investigator (SPH) will conduct the pre-anesthesia evaluation and obtain informed consent from the participant day before surgery. Two anesthesiologists belonging to research team will implement the intervention, record intraoperative data, and complete the anesthesia in the operating room, with SPH as the emergency contact and involved in mentoring. Postoperative followers and data analysts will not be involved in the intervention or anesthesia process, and will not know the grouping of participant.

The preoperative CRF will be completed by SPH on the day before surgery, and consist mainly of basic patient information, airway assessment, and past medical history. The intraoperative CRF mainly records DLT malposition (time and measures of each malposition), vital signs, number of times and reasons for using FOB, etc. We define the DLT malposition as moving the DLT by more than 1.0 cm to correct its position [9]. The criteria for correct DLT position is defined via the FOB as follows: an unobstructed view into the left upper and lower lobe bronchus through the endobronchial lumen with the bronchial cuff directly below the carina and just visible in the main left bronchus through the tracheal lumen [14]. The postoperative CRF will be completed by the investigator not involved in the intervention and anesthesia process at 24h postoperative and the day of discharging from hospital, and focus on recording early postoperative complications and the QoR-15 score [21].

Plans to promote participant retention and complete follow-up {18b}

Considering that the intervention may not have long-term effects on participants, we will only perform the follow-up at 24h postoperative. When obtaining informed consent, we will explain to the participant that there will be a brief questionnaire for 3-5 minutes and stress the importance of this.

Data management {19}

All data in the study, without the participants' random sequence and grouping, will be recorded in CRFs and managed by data analysts in secrecy. The randomisation list with all participants' random sequences and groupings will be archived by SPH.

Confidentiality {27}

The randomisation list and CRFs will be stored by relevant investigators and locked in the cabinet, with accessible to the authorised personnel only. Any subsequent publications will not include any patient identification information. For the purposes of monitoring, audits, and inspections, direct access to source documents will be granted.

Plans for collection, laboratory evaluation and storage of biological specimens for genetic or molecular analysis in this trial/future use {33}

Not applicable, there will be no biological specimens collected.

Statistical methods

Statistical methods for primary and secondary outcomes {20a}

The SPSS statistical software version 26.0 (IBM) will be used for statistical analysis. Primary and secondary outcomes will be analysed as follows: Use Kolmogorov-Smirnov test to determine whether continuous data follows normal distribution. Continuous data following a normal distribution are expressed as mean ± standard deviation (`x ± s), while nonnormal distributions are expressed as median (quartile spacing). The independent samples t test will be used for comparison between groups of normally distributed continuous data. The Mann-Whitney U test will be used for comparison of non-normally distributed continuous data. Count data are expressed as number of cases (rate) and tested by chi-square test or Fisher's exact test. If subsequent multi-factor analysis will be required, multiple linear regression or logistic regression models are selected according to continuous-type or sub-type dependent variables. The data analysis of this study adopts the principle of intentional analysis. Multiple interpolation will be used for the analysis of missing data, and sensitivity analysis will be performed. Probability values < 0.05 will be considered significant.

Interim analyses {21b}

Not applicable, no interim analyses are planned.

Methods for additional analyses (e.g. subgroup analyses) {20b}

Not applicable, no additional analyses are planned.

Methods in analysis to handle protocol non-adherence and any statistical methods to handle missing data {20c}

Given that we will explain the intervention in detail and emphasize cooperation matters to the patient during pre-anesthesia evaluation and obtaining informed consent, we guess that few patients will protocol non-adherence. If needed, multiple interpolation will be used for the analysis of missing data, and sensitivity analysis will be performed.

Plans to give access to the full protocol, participant level-data and statistical code {31c}

This is a principal investigator-initiated trial. Access to the full protocol and participant level data will be considered upon submission of a reasonable request and consent of the principal investigator.

Oversight and monitoring

Composition of the coordinating centre and trial steering committee {5d}

This is a single-center trial. No steering committee will be formed. Weekly group meetings will be initiated by the principal investigator to discuss the progress of the study.

Composition of the data monitoring committee, its role and reporting structure {21a}

We expect the rapidly inclusion of 108 participants and plan to complete the trial within 4 months, therefore no data monitoring committee will be formed.

Adverse event reporting and harms {22}

Adverse events that occur in this trial will be recorded on the CRF and reported to the principal investigator.

Each adverse event will be assessed for the character (expected vs unexpected), severity (serious vs non-serious) and relevance to the intervention (relevant vs irrelevant). Serious and unexpected adverse events will be reported to the Ethics Committee. The principal investigator will conduct regular cumulative reviews of all adverse events and convene investigator meeting as necessary.

Frequency and plans for auditing trial conduct {23}

A research nurse who is not involved in the current trial will act as an independent reviewer for the duration of the trial. The audit process will include a review of CRFs, registries, missing data, duplicate data, and informed consent documentation.

Plans for communicating important protocol amendments to relevant parties (e.g. trial participants, ethical committees) {25}

The Ethics Committee of Huzhou Central Hospital has reviewed the protocol and agreed to conduct the trial as the protocol. No protocol amendments will be made unless permitted by the Ethics Committee.

Dissemination plans {31a}

Following statistical analysis of the trial, every endeavour will be made to publish the results in peer-reviewed journals related to clinical anesthesia and thoracic surgery.

In designing this randomized controlled trial, we aim to explore the effect of lateral intubation after induction on the position of DLT in patients undergoing elective unilateral VATS. In order to visually and quantitatively measure the effect, the rate of DLT movement of more than 1.0 cm observed via the FOB will be compared between lateral intubation and supine intubation. This definition of DLT malposition was also used in the study by Inoue et al. as the authors indicated that Japanese patients were small and a deviation of 1.0 cm could be significant for them [9]. In China which is also in Asia, the DLT movement more than 1.0 cm is also critical for Chinese patients, so we select the deviation of 1.0 cm as the cut-off value. For information on how to measure the distance of DLT movement, we refer to Desiderio et al. [8] on the method of measuring tracheal distance. After the DLT positioning is completed, the distance from the main carina to the distal tip of the tracheal lumen is measured in centimeters using the FOB as the carina-to-tracheal distance. Specifically, it is the difference between the depth when the tip of the FOB is at the main carina minus the depth when the tip of the FOB is at the distal tip of the tracheal lumen. The carina-to-tracheal distance measured after accurate DLT positioning is taken as the base value, and then measured again after turning to the lateral position or intraoperatively, a difference of more than 1.0 cm from the base value is recorded as DLT malposition.

There are many reasons for DLT malposition in thoracic surgery, especially shifting the patient from supine to lateral position which may lead to more malposition [8]. Several innovative approaches by many researchers have shown promising results in reducing the incidence of DLT malposition during lateral positioning. For example, it has been shown that the DLT malposition rate was lower in patients who removed the headrest before lateral positioning compared to those who used the headrest all the time [22]. In addition, one study found that limiting head and neck movements with a neck brace also minimized DLT malposition during supine to lateral position [7]. Unfortunately, these effective measures did not fundamentally solve the DLT malposition caused by the patient's position change. We expect that the lateral intubation after assisting the patient to a comfortable and surgically required lateral position before induction, will thoroughly resolve the DLT malposition or other adverse effects caused by lateral positioning. Of course, there is more than one cause for the malposition. All occurrences of DLT malposition will be recorded throughout the trial, as well the time and the possible reason.

Currently, this trial is in the recruitment phase and patients will be screened strictly according to the recruitment criteria. All collected data will be analyzed after the last participant has completed the trial by investigators not involved in the trial process. Compared to conventional supine intubation, we expect that lateral intubation will reduce the risks associated with DLT malposition, post-anaesthetic position changes, and multiple uses of the FOB. Considering to ensure the safety and stability of the patient during surgery, the intraoperative vital signs and the incidence of hypoxemia will be investigated. Furthermore, we pay attention to the postoperative complications and the QoR15 score which is more in line with the concept of enhanced recovery after surgery. For anesthesiologists who have never tried or even heard of lateral DLT intubation, this procedure seems awkward and difficult. However, based on our preliminary pre-experiments, this process is not as challenging as anticipated when using flexible intubation techniques and proper DLT shaping. After intubation in the lateral position, the patient does not need to be moved again and the operation can be started directly. It reduces the need for medical staff to shift position of patient under anesthesia, which is an unsafe and labor-intensive process, so the lateral DLT intubation is well received by operating room nurses and surgeons. The results of the study, we anticipate, will provide evidence for the clinical application and efficacy of lateral intubation, pioneering a new approach to DLT intubation in thoracic surgery.

The trial is registered on the Chinese Clinical Trial Registry (http://www.chictr.org.cn) identifier: ChiCTR2200060794. The current protocol is version 5.0 of 25/04/2022. Recruitment for the trial starts in August 2022 and we are currently recruiting patients. Approximate date of recruitment completion is December 2022.

ASA score: American Society of Anesthesiologists Score

CRF: case record form

DLT: double-lumen tube

FOB: fiberoptic bronchoscopy

Group L: lateral DLT intubation group

Group C: conventional supine DLT intubation group

ICU: intensive care unit

NIVATS: non-intubated thoracic surgery

OLV: one-lung ventilation

QoR-15: Quality of Recovery-15

PACU: postanesthesia care unit

VATS: video-assisted thoracic surgery

Acknowledgements

We would like to thank our anaesthetic colleagues for their great support and help with this trial; our thoracic surgeons and operating room nurses for their cooperation and assistance; the Ethics Committee for their revision of the informed consent form. Finally, we would like to thank all participants for their willingness to participate and their cooperation in this trial.

Protocol amendments

Any important protocol modifications will be reviewed by the principal investigator who will sign the amendment, which will be submitted to the ethics committee for approval later.

Dissemination plans

The study will be published after the approval of the research team in a peer-reviewed scientific journal.

Authors’ contributions {31b}

As the Principal Investigator, SPH conceived and designed the trial, wrote the initial proposal, and was ultimately responsible for the trial. HL contributed to the study design, oversaw proposal submission, and made substantial revisions to the final manuscript. XZ refined the content of the manuscript under the guidance of SPH and HL, and submitted for ethical review and clinical registration. SPH, QBS and JLC contributed to trial coordination. XZ, DXW, FT, YHH, ZDZ, FFL and YWT involved in data collection. XZ and DXW involved in postoperative follow-up. QZ contributed to data analysis and interpretation. All the authors made a significant contribution to this study and approved this final protocol. The authorship will be determined by their contributions to this trial.
Funding {4}

This trial is funded by a grant from the Medical Science and Technology Project of Zhejiang Province (grant number: 2020ZH043). The funding agency has no influence on study design, data collection, data analysis, data interpretation, manuscript writing or publication decisions.

Availability of data and materials {29}

All data during the study are available from the corresponding author upon reasonable request.

Ethics approval and consent to participate {24}

The study was approved by the Ethics Committee of Huzhou Central Hospital on May 17, 2022, Approval No: 202205005-01. The principal investigator will obtain written informed consent from each study participant.

Consent for publication {32}

The model consent form for this study is contained in additional file 3. All authors gave their consent for publication.
Competing interests {28}

The authors declare that they have no competing interests.

Authors’ information (optional)

Authors and Affiliations

Department of Anesthesiology & Huzhou Key Laboratory of Basic Research and Clinical Translation for Neuromodulation, Huzhou Central Hospital || The Affiliated Huzhou Hospital, Zhejiang University School of Medicine || Affiliated Central Hospital Huzhou University, Huzhou, China;

Xi Zhang, Dong-Xu Wang, Qin Zhang, Fei Tong, Yong-He Hu, Zhen-Duo Zhang, Fei-Fan Liu, Ya-Wen Tang, He Liu & Si-Ping Hu

Department of Cardiothoracic Surgery, Huzhou Central Hospital || The Affiliated Huzhou Hospital, Zhejiang University School of Medicine || Affiliated Central Hospital Huzhou University, Huzhou, China;

Qi-Bin Shen

Department of Operating Room Nursing, Huzhou Central Hospital || The Affiliated Huzhou Hospital, Zhejiang University School of Medicine || Affiliated Central Hospital Huzhou University, Huzhou, China;

Juan-Li Chen

Corresponding authors

Correspondence to Si-Ping Hu or He Liu.

Klapper J, D'Amico TA. VATS versus open surgery for lung cancer resection: moving toward a minimally invasive approach. J Natl Compr Canc Netw. 2015;13(2):162-4.
Falzon D, Alston RP, Coley E, Montgomery K. Lung Isolation for Thoracic Surgery: From Inception to Evidence-Based. J Cardiothorac Vasc Anesth. 2017;31(2):678-93.
Brodsky JB, Lemmens HJ. Left double-lumen tubes: clinical experience with 1,170 patients. J Cardiothorac Vasc Anesth. 2003;17(3):289-98.
Saito S, Dohi S, Naito H. Alteration of double-lumen endobronchial tube position by flexion and extension of the neck. Anesthesiology. 1985;62(5):696-7.
Riley RH, Marples IL. Relocation of a double-lumen tube during patient positioning. Anesth Analg. 1992;75(6):1071.
Yazigi A, Madi-Jebara S, Haddad F, Antakly MC. Relocation of a double-lumen tube during surgical dissection. Anesth Analg. 1993;77(6):1303.
Yoon TG, Chang HW, Ryu HG, Kwon TD, Bahk JH. Use of a neck brace minimizes double-lumen tube displacement during patient positioning. Can J Anaesth. 2005;52(4):413-7.
Desiderio DP, Burt M, Kolker AC, Fischer ME, Reinsel R, Wilson RS. The effects of endobronchial cuff inflation on double-lumen endobronchial tube movement after lateral decubitus positioning. J Cardiothorac Vasc Anesth. 1997;11(5):595-8.
Inoue S, Nishimine N, Kitaguchi K, Furuya H, Taniguchi S. Double lumen tube location predicts tube malposition and hypoxaemia during one lung ventilation. Br J Anaesth. 2004;92(2):195-201.
Campos JH, Hallam EA, Van Natta T, Kernstine KH. Devices for lung isolation used by anesthesiologists with limited thoracic experience: comparison of double-lumen endotracheal tube, Univent torque control blocker, and Arndt wire-guided endobronchial blocker. Anesthesiology. 2006;104(2):261-6, discussion 5A.
Schuepbach R, Grande B, Camen G, Schmidt AR, Fischer H, Sessler DI, et al. Intubation with VivaSight or conventional left-sided double-lumen tubes: a randomized trial. Can J Anaesth. 2015;62(7):762-9.
Hurford WE, Alfille PH. A quality improvement study of the placement and complications of double-lumen endobronchial tubes. J Cardiothorac Vasc Anesth. 1993;7(5):517-20.
Brodsky JB, Shulman MS, Mark JB. Malposition of left-sided double-lumen endobronchial tubes. Anesthesiology. 1985;62(5):667-9.
Slinger PD. Fiberoptic bronchoscopic positioning of double-lumen tubes. J Cardiothorac Anesth. 1989;3(4):486-96.
Cohen E. Double-lumen tube position should be confirmed by fiberoptic bronchoscopy. Curr Opin Anaesthesiol. 2004;17(1):1-6.
Klein U, Karzai W, Bloos F, Wohlfarth M, Gottschall R, Fritz H, et al. Role of fiberoptic bronchoscopy in conjunction with the use of double-lumen tubes for thoracic anesthesia: a prospective study. Anesthesiology. 1998;88(2):346-50.
Benumof JL. The position of a double-lumen tube should be routinely determined by fiberoptic bronchoscopy. J Cardiothorac Vasc Anesth. 1993;7(5):513-4.
Kim JH, Kim E, Kim IY, Choi EJ, Byun SH. Changes in the Bronchial Cuff Pressure of Left-Sided Double-Lumen Endotracheal Tube by Lateral Positioning: A Prospective Observational Study. J Clin Med. 2021;10(8).
Navarro-Martinez J, Galiana-Ivars M, Rivera-Cogollos MJ, Galvez C, Nadal SB, Lamaignere MO, et al. Management of Intraoperative Crisis During Nonintubated Thoracic Surgery. Thorac Surg Clin. 2020;30(1):101-10.
Ajimi J, Nishiyama J, Hosoi S, Masuda R, Miura M, Suzuki T, et al. Successful Double-lumen Tube Intubation in the Lateral Position for a Patient with a Giant Superior Mediastinal Tumor. Tokai J Exp Clin Med. 2021;46(1):22-5.
Stark PA, Myles PS, Burke JA. Development and psychometric evaluation of a postoperative quality of recovery score: the QoR-15. Anesthesiology. 2013;118(6):1332-40.
Seo JH, Hong DM, Lee JM, Chung EJ, Bahk JH. Double-lumen tube placement with the patient in the supine position without a headrest minimizes displacement during lateral positioning. Can J Anaesth. 2012;59(5):437-41.

Table 1 Participant timeline

	STUDY PERIOD
	Enrollment		Surgery		Post-surgery	Close-out
TIMEPOINT	3 days before surgery	Day before surgery	Before anesthesia	During anesthesia	Day after surgery	Discharge from hospital
Enrollment
Eligibility screen	X
Pre-anesthesia evaluation		X
Informed consent		X
Randomization			X
INTERVENTIONS
Lateral DLT intubation			X
Supine DLT intubation			X
ASSESSMENTS
DLT malposition				X
Time of intubation				X
Re-adjustments of DLT				X
Whether to re-intubation				X
Vital signs			X	X
Postoperative complications					X	X
QoR-15 score					X
Length of stay and expenses						X

DLT: double-lumen tube; QoR-15: Quality of Recovery-15 questionnaire.

PreoperativeintraoperativeandpostoperativeCRFs.pdf
Additional file 1: Preoperative, intraoperative and postoperative CRFs.
QoR15score.pdf
Additional file 2: QoR-15 score.
Informedconsentform.pdf
Additional file 3: Informed consent form.

Effect of intubation in the lateral position under general anesthesia induction on the position of double-lumen tube placement in patients undergoing unilateral video-assisted thoracic surgery: study protocol for a randomized controlled trial.

Status:

Journal Publication

Version 1

Abstract

• Background

• Methods

• Discussion

Trial registration:

Administrative Information

Introduction

Methods: Participants, Interventions And Outcomes

Discussion

Trial Status

Abbreviations

Declarations

References

Table 1

Supplementary Files

Status:

Journal Publication

Version 1