Estimating Length of Endotracheal Tube Insertion Using Gestational Age or Nasal-Tragus Length in Newborn Infants
Estimating Length of Endotracheal Tube Insertion Using Gestational Age or Nasal-Tragus Length in Newborn Infants
Endotracheal intubation is a life-saving intervention that few infants need after birth.
 Although an endotracheal tube is the most reliable way of providing positive-pressure breath,
 the critical factor that determines the maximal efficacy of positive-pressure ventilation is
 the optimal placement of the endotracheal tube tip. There are various methods available to
 determine the initial depth of endotracheal tube (ETT) that are based on the infant's birth
 weight, gestational age, anthropometric measurements, and others include vocal cord guide and
 suprasternal palpation methods.

 The Neonatal Resuscitation Program (NRP) textbook, in its 7th edition of the textbook,
 recommends a gestational age chart and nasal-tragus length method for estimating endotracheal
 tube insertion depth during cardiopulmonary resuscitation of the neonate. The evidence to
 support these two methods is, however, limited. Hence, we designed this study to determine
 the accuracy of two methods, gestational age chart and nasal-tragus length method,
 recommended by the Neonatal Resuscitation Program.
Trial Objective: To determine whether estimating ETT insertion depth using gestational age
 chart rather than nasal-tragus length method results in more correctly positioned ETT tips.

 Setting: The neonates will be recruited from multiple tertiary-level neonatal intensive care
 units in Saudi Arabia. A neonate can participate in more than one clinical trial, depending
 on the interventions being given. Parallel run trials will be discussed between the chief and
 local principal investigators whether or not joint recruitment is feasible to both parties.

 Informed Consent: We will obtain written consent after the parents have been given a full
 verbal explanation and written description. We will explain to the parents in their own
 native language. We will use a hospital-based adult interpreter wherein required. We will
 obtain deferred consent (after initial verbal assent) where prior consent is not feasible as
 the study does not involve additional risk or investigations to the participants, and the
 interventions are otherwise considered as standard practice recommendations by the NRP.

 Data Safety Monitoring Board: Any unexpected serious events (death, any life-threatening
 event, any event that will prolong the hospitalization or any event that will result in
 disability) will be reported to the data safety monitoring committee. The trial steering
 committee will receive recommendations from the data safety monitoring board if the trial
 requires early termination following the interim data analyses and evidence from relevant
 studies. The following measures were agreed to consider stopping the trial, wholly or partly
 (subgroups), after an interim analysis, that will be done after recruiting 200 participants.

 1. An absolute difference of greater than or equal to 25% in the primary outcome between
 the study groups.

 2. An absolute difference of less than 5% in the primary outcome between the study groups.

 3. A rate of less than 20% in the primary outcome in either of the groups.

 Sample Size: Our unpublished data showed using the nasal-tragus length method results in 35%
 of correctly positioned ETT tips in term and preterm infants. The data is similar to the
 randomized and non-randomized studies that showed an accuracy between 32 and 37 percent using
 the nasal-tragus length method. With 90% power and two-sided 5% significance, to detect an
 absolute increase in optimally positioned ETT tips of 15%, we will require 454 participants.
 We calculated sample size using nQuery Advisor Sample Size Calculator version 8.3.0.0.

 Statistical Analysis: We will analyze the data based on the intention-to-treat principle.
 Univariate analyses will be performed to compare baseline demographic factors between the two
 groups. A mean with standard deviation (normal data) or median with interquartile range
 (skewed data) will be obtained for continuous variables and numbers and percentages for
 categorical variables. Independent T-test (normal data) or Mann Whitney U test (skewed data)
 for continuous variables and chi-square test (or Fisher's exact test as appropriate) for
 categorical variables will be used for analyses between the groups. Statistical Analysis
 Software version 9.4 will be used for the conduct of all analyses.

 Analysis of primary outcome: Adjusted risk ratios of a successful outcome will be calculated
 along with 95% confidence intervals. Adjusted ratios will be determined by way of
 multivariable logistic regression analysis, including co-variates deemed biologically to have
 an influence on the primary outcome (gestational age, small for gestational age, and center).
 Principles of best model practices will be followed (including assessment of collinearity
 amongst included variables) as well as the determination of the predictive ability of the
 model using area under the curve.

 Analysis of secondary outcomes: Similar analyses as above will be performed for all secondary
 outcomes that are categorical variables. The risk ratios of secondary outcomes mortality,
 oxygen therapy at 28 days, pneumothorax, and bronchopulmonary dysplasia will be adjusted
 based on the following variables: gestational age, male sex, small for gestational age,
 maternal hypertension, chorioamnionitis, antenatal steroids, and center if the P-value is
 less than 0.25 on univariate analysis.
Inclusion Criteria:

 -  Infants (less than 28 days of life) between 23 weeks 0 days and 41 weeks 6 days
 gestational age

 -  Infants requiring oral intubation in the delivery room or in neonatal intensive care
 unit

 Exclusion Criteria:

 -  Infants with major chromosomal anomalies, including trisomy 13, trisomy 18, and
 trisomy 21

 -  Infants with major anomalies, including craniofacial anomalies and facial dysmorphism
 that may affect the nasal-tragus length