Effects of Three Endotracheal Tube Cuff Pressure Control on Microaspiration of Gastric Contents: a Randomized Controlled Trial
Phase: NA
Conditions: Mechanical Ventilation Complication, Ventilator Associated Pneumonia, Nursing Caries, Aspiration, Respiratory
Sponsor: Afyonkarahisar Health Sciences University

Effects of Endotracheal Tube Cuff Pressure Control on Microaspiration of Gastric 
Contents  
 
Trial registration: ClinicalTrials.gov Identifier, Number NCT04061083. Registered in 2019. 
 
Study Protocol  
Aim 
The aim of this randomized controlled trial was to determine the effect of three different ETT 
cuff pressure controls used in ICU patients receiving mechanical ventilator support using an 
ETT on preventing microaspiration of gastric content and on VAP development within 48 hours 
after intubation. 
Study design 
This is a single-blind randomized controlled trial that compares finger palpation of the pilot 
balloon, intermittent and continuous ETT cuff pressure used to prevent microaspiration of 
gastric content for ICU patients. 
Study population 
The population of the study consists of the patients hospitalized in the Internal Medicine, 
Neurology, Neurosurgery, General Surgery, Anesthesia, Isolation and Diseases ICU of 
University Hospital. Inclusion criteria for the sampling of the study are as follows: being 18 
years and above, voluntariness of the patients or their relatives, and having a need of mechanical 
ventilator support with an ETT for 48 hours. The criteria of exclusion from the sample are as 
follows: having contraindication of semi-sitting position, having a contraindication to enteral 
nutrition, patients who have spent more than 48 hours on a mechanical ventilator at the initial 
assessment, having tracheostomy, gastroesophageal reflux disease (GERD), aspiration 
pneumonia or any suspicion of it, and nasal ETT intubation. Power analysis was done to 
determine the number of patients to be distributed to Group 1, Group 2, and the control groups. 
The power analysis was done using GPower 1.3.9.2 software. Thus, the significance level was 
α=0.05 (%5), the effect size was d=0.5, and the number of patients in each group was 51 for the 
power at 1-β=0.80. Missing, bad or lost data (in case patients were exitus) were considered and 
the number of patients was designed to be 56 for each group 
Intervention and Assessment 
The appropriateness of patients who have received mechanical ventilator support using an ETT 
in the ICUs will be evaluated based on the inclusion and exclusion criteria. The patients who 
have been included in the study will be evaluated in terms of age, gender, height, weight, body 
mass index, medical diagnosis, chronic diseases, consciousness, presence of nasogastric (NG) 
tube, position, the reason for intubation, type of nutrition, drugs used (antibiotics, stress ulcer 
prophylaxis and sedative agents), Ramsay Sedation Score (RSS), transport and transfusion 
status, ventilator, respiration and hemodynamic values. 
The cuff pressure of the patients in all groups will be controlled every eight hours. Smart cuff 
manager will be attached to the patients in study group 2. Samples will be taken from the 

patients through open aspiration. The first deep tracheal secretion sample to be used to 
determine pepsin I level will be taken four hours after intubation. A sampling of the tracheal 
secretion samples to be used in the determination of pepsin II level will be initiated from the 
5th hour after intubation and collected by the 24th hour of the intubation. A sampling of the 
tracheal secretion samples to be used in determination of pepsin III levels will be initiated from 
the 25th hour after intubation and collected by the 48th hour of the intubation or the patient is 
discharged or exitus.  
Statistical analysis 
The data will be analyzed using Statistical Package for the Social Sciences (SPSS) for Windows 
21.0 (IBM SPSS Statistics for Windows, Version 21.0. Armonk, NY: IBM Corp.) Software. 
They will be divided into groups by ensuring homogeneity according to gender. Patients’ socio-
demographic and clinical attributes, frequencies, percentage distribution, mean, and standard 
deviation will be provided.  
Kolmogorov–Smirnov Test will be used to check the appropriateness of data to normal 
distribution. Independent two-sample t-test, one-way analysis of variance will be used for the 
relationships between the variables that fit the normal distribution, and the Mann Whitney U 
test will be used for the variables that do not fit the normal distribution. Pearson Chi-square 
significance test and Fisher Exact will be applied in the analysis of categorical data. All p values 
lower than 0.05 will be taken as significant in all results (p<0.05).