Endotracheal Tube Clip for Prevention of Post Intubation Laryngeal Symptoms
Phase: NA
Conditions: Sore-throat, Dysphonia, Dysphagia, Intubation Complication, Anesthesia Intubation Complication, Anesthesia Morbidity, Anesthesia Complication, Anesthesia; Adverse Effect, Anesthesia; Reaction, Throat Disorder, Throat; Wound, Throat Injury
Sponsor: University of California, San Diego

Title: No Post Intubation Laryngeal Symptoms (No-PILS) 
NCT05383417 
Date: April 12, 2023 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Study Protocol 
 
Description: 
 
Single center randomized controlled trial with 100 subjects who will be intubated for already 
planned surgeries. The participants will be randomized into the control group or the clip group. 
The clip group will have a small clip (the endotracheal tube support device, also known as 
EndoClip) placed on the endotracheal tube to reduce the pressure on the vocal cords and larynx. 
This endotracheal tube support device is made from a FDA approved biocompatible material. The 
University of California San Diego Institutional Review Board (“IRB”) approved this study (IRB 
#800842). 
 
The control group subjects will undergo their planned procedure with no intervention during 
intubation. The clip group will undergo their planned procedure as normal but with the EndoClip 
placed on the endotracheal tube by the assigned anesthesia attending physician or trained 
clinician. The EndoClip is placed once the tube is secured and the ventilator circuit is connected. 
While extubating the patient, the endotracheal tube will be removed with the EndoClip attached 
and a picture of the tube will be taken to record the clip location. 
 
Before the planned procedure, the investigators will survey the participants to get a baseline for 
any pre-existing laryngeal symptoms. The same survey will be administered after the procedure 
when the participants are awake and alert (‘Day 0’), 24 hours (‘Day 1), 48 hours (‘Day 2’), and 1 
week (‘Day 7’) after the procedure. The survey will ask the participant to indicate "yes" or "no" for 
whether they are experiencing a sore throat, throat pain, oral pain, difficulty speaking, difficulty 
swallowing, changes in their voice, pain while speaking, and pain while swallowing. If they have 
indicated "yes" for any of the symptoms, the participants will also be asked to rate the severity on 
scale from 0 (no pain/difficulty) to 10 (severe pain/difficulty). If they indicate “no”, this will be 
considered a score of 0 for the respective outcome variable. 
 
Other data points will also be collected in this study that are related to the intubation and 
participant's airway. The investigators will record the total time of the procedure and the length of 
time the clip is placed on the endotracheal tube. For each participant in the clip group, the 
investigators will also record the time it takes to place the clip on the endotracheal tube. Each 
participant's airway will be evaluated, and the investigators will record the thyromental distance, 
Mallampati score, history of difficult intubation, and the size of the endotracheal tube used. Lastly, 
data from each participant's intubation will be collected including number of attempts before 
successful intubation, incidence of dental injury, incidence of lip injury, laryngeal view on Cormack-
Lehane scale, and any noted trauma upon extubation. 
 
At any point during the study, the participant can withdraw from the study. All study participants 
will be identified according to a number assigned at the beginning of the study, using key code.  
 
Study Design: 
 
Study Type:  Interventional 
Primary Purpose:  Prevention 
Study Phase:  Closed 
Interventional Study Model:  Parallel Assignment 

2 arm parallel trial where one group will receive the 
endotracheal tube clip (EndoClip) during general endotracheal 
anesthesia and the other group will not (control) 
Number of Arms:  2 
Masking:  Double (Participant, Outcomes Assessor) 
Patient will not be aware of their treatment arm. Investigator 
and Care Provider will be aware of treatment arm but data 
analysis (outcomes assessor) will be blinded to treatment 
groups. 
Allocation:  Randomized 
Enrollment:  100 [Actual] 
 
Arms and Interventions: 
 
 
Outcome Measures: 
 
Primary Outcome Measure: 
 
1. Sore throat on a scale from 0 (no sore throat) to 10 (worst possible sore throat). Subjects 
will indicate whether they are experiencing a sore throat or throat discomfort on a 
questionnaire. If they indicate 'yes' they will be asked to mark the severity of their 
symptoms on a scale ranging from 0 (no sore throat) to 10 (worst possible sore throat). 
Participants will be asked to report on their symptoms prior to intubation, after intubation 
on the day of discharge, 24 hours after intubation, 48 hours after intubation, and 1 week 
after intubation. 
[Time Frame: Baseline to 1 week after intervention] 
 
2. Change in voice on a scale from 0 (no voice change) to 10 (most severe voice change). 
Subjects will indicate whether they are experiencing a change in voice (i.e. deep and/or 
hoarse voice, worse than their usual voice quality) on a questionnaire. If they indicate 
'yes' they will be asked to mark the severity of their symptoms on a scale ranging from 0 
(no voice change) to 10 (most severe voice change). Participants will be asked to report 
Arms 
Assigned Interventions 
Experimental: EndoClip 
Clip applied to endotracheal tube. 
Device: EndoClip  
Clip attached to mid portion of the endotracheal tube. 
Other Names: 
• 
Endotracheal tube clip 
• 
Endotracheal tube support clop 
• 
Endotracheal tube support device 
No Intervention: No Clip 
No clip applied to endotracheal 
tube. 
 

on their symptoms prior to intubation, after intubation on the day of discharge, 24 hours 
after intubation, 48 hours after intubation, and 1 week after intubation. 
[Time Frame: Baseline to 1 week after intervention] 
 
3. Difficulty swallowing on a scale from 0 (no difficulty swallowing) to 10 (complete inability 
to swallow). Subjects will indicate whether they are experiencing difficulty swallowing on 
a questionnaire. If they indicate 'yes' they will be asked to mark the severity of their 
symptoms on a scale ranging from 0 (no difficulty swallowing) to 10 (complete inability to 
swallow). Participants will be asked to report on their symptoms prior to intubation, after 
intubation on the day of discharge, 24 hours after intubation, 48 hours after intubation, 
and 1 week after intubation. 
[Time Frame: Baseline to 1 week after intervention] 
 
4. Pain in the mouth on a scale from 0 (no mouth pain) to 10 (worst possible mouth pain). 
Subjects will indicate whether they are experiencing mouth pain on a questionnaire. If 
they indicate 'yes' they will be asked to mark the severity of their symptoms on a scale 
ranging from 0 (no mouth pain) to 10 (worst possible mouth pain). Participants will be 
asked to report on their symptoms prior to intubation, after intubation on the day of 
discharge, 24 hours after intubation, 48 hours after intubation, and 1 week after 
intubation. 
[Time Frame: Baseline to 1 week after intervention] 
 
5. Difficulty talking on a scale from 0 (no difficulty talking) to 10 (complete inability to talk). 
Subjects will indicate whether they are experiencing difficulty talking on a questionnaire. 
If they indicate 'yes' they will be asked to mark the severity of their symptoms on a scale 
ranging from 0 (no difficulty talking) to 10 (complete inability to talk). Participants will be 
asked to report on their symptoms prior to intubation, after intubation on the day of 
discharge, 24 hours after intubation, 48 hours after intubation, and 1 week after 
intubation. 
[Time Frame: Baseline to 1 week after intervention] 
 
6. Pain in the neck/chest on scale from 0 (no neck/chest pain) to 10 (worst possible 
neck/chest pain). Subjects will indicate whether they are experiencing pain in the 
anterior or low region of the neck and/or chest on a questionnaire. If they indicate 'yes' 
they will be asked to mark the severity of their symptoms on a scale ranging from 0 (no 
neck/chest pain) to 10 (worst possible neck/chest pain). Participants will be asked to 
report on their symptoms prior to intubation, after intubation on the day of discharge, 24 
hours after intubation, 48 hours after intubation, and 1 week after intubation. 
[Time Frame: Baseline to 1 week after intervention] 
 
Eligibility: 
 
Minimum Age:  
18 Years   
Maximum Age:  
  
Sex:  
All   
Gender Based:  
No   
Accepts Healthy Volunteers:  Yes   
Criteria:  
Inclusion Criteria: 
• 
Patient undergoing general endotracheal anesthesia 
with an endotracheal tube 

• 
Patient is not undergoing a procedure in the head and 
neck region 
Exclusion Criteria: 
• 
Patient with pre-existing severe sore throat, voice 
change, or trouble swallowing 
• 
Patient undergoing surgery in the head and neck 
region 
 
Statistical Analysis Plan 
 
Our statistical plan is outlined below.  
• 
●  Null Hypothesis:  
NH1) Reducing the force on the vocal cords will not change the laryngeal symptoms in 
participants who underwent Endotracheal Intubation 
NH2) Reducing the force on the vocal cords will not change the duration of laryngeal symptoms 
in participants who underwent Endotracheal Intubation 
• 
●  Alternate Hypothesis:  
AH1) Reducing the force on the vocal cords will change the laryngeal symptoms in participants 
who underwent Endotracheal Intubation 
AH2) Reducing the force on the vocal cords will change the duration of laryngeal symptoms in 
participants who underwent Endotracheal Intubation 
 
We will use IBM SPSS Statistics, version 28.0.1.1 (14). Student’s t-test will be used to compare 
symptom severity at each time point while Pearson’s chi-square test will be used to compare the 
incidence of throat symptoms across groups. Multiple regression analysis will be used to 
evaluate demographic and anesthesia variables as predictors of throat symptoms. The odds 
ratio (OR) and their 95% confidence interval (CI) will be reported for each covariate included in 
the model. The level of significance (p) to be considered is 0.05.