Determining Optimal Cuff Volume in Pediatric Patients
Condition: Cuff; Airway Edema; Children, Only; Tracheal Intubation Morbidity
Study type: Observational [Patient Registry]

Summary: 
      Background and Aim: Cuffed endotracheal tubes with appropriate size, good cuff design and
      cuff pressure monitoring in pediatric patients can be used safely without increasing airway
      morbidity. Inflating the endotracheal tube cuff with more than normal volume may lead to
      decreased capillary blood flow and mucosal damage, while inflating the endotracheal tube cuff
      with less than normal volume may lead to an increase in the risk of inadequate ventilation
      and pulmonary aspiration. In this study, we aimed to determine an optimal cuff inflation
      volume to achieve safe cuff pressure (20-25 cm H2O) in cuffed endotracheal tubes with an
      inner diameter of 4.5, 5.0, 5.5 mm, which are commonly used in pediatric anesthesia clinical
      practice.
    

Detailed description: 
      Design:

      This is a prospective, single blinded, observational study. In case of 2 independent
      variables in the multiple linear regression analysis, the required sample size was calculated
      as at least 40 in order to determine the large effect width (f2=0.35) at 0.80 power and 0.05
      error levels. Since the study will be carried out with 3 different tube diameters, the sample
      size has been determined as 120 in total (G*Power software 3.1.9). In the Bland and Altman
      method, it was stated that when there are at least 100 observations, the 95% confidence level
      can be determined in the range of ±0.34s (where "s" is the standard deviation of the
      differences between the two measurements). For this reason, it is seen that the determined
      sample number of 120 is also sufficient for the Bland&Altman method. Power analysis was made
      with G*Power 3.1.9.7 statistical package program; group=3, n=127 (n1=42, n2=43, n3=42),
      α=0.05, Effect Size (f)=0.34; power = 93%.

      Methods: Pediatric patients younger than 18 yr old who will be operated in our hospital and
      intubated with cuffed tubes numbered 4.5, 5.0, and 5.5 under general anesthesia will be
      included in this prospective observational study. After standard monitoring in the supine
      position, anesthesia will be induced with a mixture of O2 / air (50/50%) and 8% Sevoflurane,
      and then vascular access will be established. Intravenous (IV) 2-3 mg/kg propofol and 1
      μgr/kg fentanyl will be administered to patients with IV access. For muscle relaxation after
      loss of consciousness, 0.5 mg/kg rocuronium will be given IV. After the patients are
      paralyzed, a 3 cm roll pad will be placed under their shoulders and airway ultrasonography
      imaging will be performed with the head slightly extended and in the supine-neutral position.
      The linear probe will be placed transversely in the anterior neck of the patients and moved
      in a cefo-caudal direction to view the cricoid cartilage. The cricoid cartilage appears as a
      hypoechoic round structure with hyperechoic margins. At this level, the transverse diameter
      of the subglottic air column will be measured in millimeters (mm) on the USG image. The
      formulas in the literature and the subglottic transverse trachea diameter measured by
      ultrasound will be used to select the most appropriate endotracheal tube for the pediatric
      patients. After the appropriate cuffed tube is attached to the patient, the cuff will be
      inflated with air through a 5 milliliter (ml) injector, and cuff pressure will be measured
      with a cuff manometer. The optimal cuff volume will be determined by giving or withdrawing
      the 0.2 ml volume to ensure optimum cuff pressure (20-25 cmH2O) and this value will be
      recorded. Demographic data of the patients, subglottic transverse airway diameter measured by
      ultrasonography, endotracheal tube number placed in the patient, given cuff volume, measured
      cuff pressure value, tube change requirement, peak airway pressure, operation time and
      postoperative airway complications (sore throat, desaturation, stridor, hoarseness, cough)
      will be recorded.
    

Intervention name(s): Group I (The patients intubated with cuffed ETT of ID number 4.5); Group II (The patients intubated with cuffed ETT of ID number 5.0); Group III ( The patients intubated with cuffed ETT of ID number 5.5)
Intervention type(s): Other; Other; Other
Intervention description(s): Groups are classified according to endotracheal tube ID numbers. Inflating the endotracheal tube cuff with more than normal volume leads to decreased capillary blood flow and mucosal damage, while inflating the endotracheal tube cuff with less than normal volume leads to insufficient ventilation of the patient and an increase in the risk of pulmonary aspiration. The cuff pressure safety range is recommended between 20-30 cmH2O to prevent gas leakage and the risk of aspiration. We aimed to determine the optimal cuff volume that ensures airway safety in pediatric patients intubated with a 4.5 size inner diameter (ID) endotracheal cuff tube. Choosing the appropriate tube for endotracheal intubation is of great importance, especially in children. In our study, the transverse diameter of the subglottic airway will be measured by USG for the selection of the appropriate ETT to be used for each patient (the formulas for the selection of ETT in the literature will be used); Groups are classified according to endotracheal tube ID numbers. Inflating the endotracheal tube cuff with more than normal volume leads to decreased capillary blood flow and mucosal damage, while inflating the endotracheal tube cuff with less than normal volume leads to insufficient ventilation of the patient and an increase in the risk of pulmonary aspiration. The cuff pressure safety range is recommended between 20-30 cmH2O to prevent gas leakage and the risk of aspiration. We aimed to determine the optimal cuff volume that ensures airway safety in pediatric patients intubated with a 5.0 size inner diameter (ID) endotracheal cuff tube. Choosing the appropriate tube for endotracheal intubation is of great importance, especially in children. In our study, the transverse diameter of the subglottic airway will be measured by USG for the selection of the appropriate ETT to be used for each patient (the formulas for the selection of ETT in the literature will be used); Groups are classified according to endotracheal tube ID numbers. Inflating the endotracheal tube cuff with more than normal volume leads to decreased capillary blood flow and mucosal damage, while inflating the endotracheal tube cuff with less than normal volume leads to insufficient ventilation of the patient and an increase in the risk of pulmonary aspiration. The cuff pressure safety range is recommended between 20-30 cmH2O to prevent gas leakage and the risk of aspiration. We aimed to determine the optimal cuff volume that ensures airway safety in pediatric patients intubated with a 5.5 size inner diameter (ID) endotracheal cuff tube. Choosing the appropriate tube for endotracheal intubation is of great importance, especially in children. In our study, the transverse diameter of the subglottic airway will be measured by USG for the selection of the appropriate ETT to be used for each patient (the formulas for the selection of ETT in the literature will be used)
Observational model: Cohort
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        Pediatric patients younger than 18 yr old who will be operated in our hospital and
        intubated with cuffed tubes numbered 4.5, 5.0, and 5.5 under general anesthesia
      
Keywords: Airway ultrasound; Cuffed endotracheal tube; Cuff volume; Cuff pressure; Children