"Mucosal Injury During Nasotracheal Intubation for Dental Procedures in Children-does the Tube Design Matter?"
Phase: NA
Conditions: Epistaxis
Sponsor: Nemours Children's Clinic

Page 1 of 7 
 
 
 
 
 
 
 
Mucosal injury During Nasotracheal Intubation for Dental 
Procedures in Children-Does the Tube Design Matter? 
 
Principal Investigator: Robert B Bryskin, MD 
 
April 10, 2015 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Page 2 of 7 
 
1. Title: Mucosal injury during nasotracheal intubation for dental procedures in children -does 
the tube design matter? 
 
2. Investigators: Stefanie Schrum, MD, Robert Bryskin, MD, Matthew Bargas, MD, Bevan 
Londergan, MD, Katrin Post-Martens, MD 
 
3. Design: Prospective randomized controlled trial 
Abstract: 
Extensive dental procedures in children frequently require general anesthesia due to lack of 
cooperation. In most cases, nasotracheal intubation (NTI) is necessary to preserve an unobstructed 
surgical field for the dental surgeon and to allow alignment assessment post repair. Advancing an 
appropriately sized breathing tube through the nares can cause significant trauma to the nasal mucosa 
resulting in bleeding, swelling and postoperative congestion and pain (7). Children are uniquely 
predisposed to these complications given the presence of adenotonsillar hypertrophy, narrow sinus 
passages, and friable mucosa! layer (7,9). To our knowledge, there has not been any study investigating 
choice of nasal tracheal tube (NTT) and degree of mucosa I damage in this patient population. 
 
Background: 
 
Several techniques have been suggested to reduce trauma during NTI, some of which are now adopted 
widely. These include lubrication of the nasal mucosa (17), softening of the tracheal tube by prewarming 
(1), and induced nasal mucosaI vasoconstriction (4,5). The design of the NTT tip has been shown to 
impact the degree of trauma during NTI in the adult population (2,3,6,16). The Parker NTT (Parker Flex- 
Tip™ Tracheal Tube, Parker Medical via Mercury Medical, Clearwater, FL 33762) has a flexible distal tip 
that is mid line, curved and tapered. This shape theoretically facilitates its sliding past obstructions 
encountered in the airway such as the nasal turbinates, arytenoids and vocal cords, rather than being 
hung up on them and causing trauma (6). Use of Parker NTT in adult patients has been demonstrated to 
facilitate intubations via the fibreoptic, oral and nasotracheal pathways (2,3,6,16). While there are 
convincing studies in adults that demonstrate that the design of the NTT tip can impact the degree of 
trauma during NTI, to our knowledge no similar studies have been conducted in children. 
 
Specific Aims: 
 
To investigate the impact of NTT tip design on mucosa! injury during NTI in children undergoing dental 
procedures under GA 
 
 
 
Null Hypothesis: 
 
Choice of NTT in children requiring NTI for dental procedures has no impact on the degree of nasal 
mucosa! injury. 

Page 3 of 7 
 
Primary Outcome: 
 
Mucosa! damage as quantified by presence and severity of bleeding immediately after passage of the 
NTT through the nasopharynx. 
 
Secondary Outcomes: 
 
Presence and degree of impingement of the NTT during NTI. 
 
Postoperative epistaxis as defined as ongoing nasal bleeding in the recovery unit (PACU), presence of 
post-extubation croup in the PACU, and time to discharge from the PACU. 
 
Research Protocol: 
 
Inclusion criteria: children between the ages of 3-11, ASA 1-3, presenting to Wolfsons Children's Hospital 
(WCH) for dental procedures requiring general anesthesia with NTI. 
 
Exclusion criteria: ASA >3, known bleeding disorder, recent or ongoing treatment with blood-thinning 
medicines, frequent epistaxis, active URl/congestion/rhinorrhea, craniofacial abnormalities prohibiting 
NTI, known difficult airway, prior nasal surgery/trauma, or allergies to any of the medicines used in this 
study. 
 
Preop: eligible patients will be identified by their dentist and receive a brochure detailing the study 
during their dentist visit. Eligibility will be confirmed by one of the study investigators or selected 
research personnel (study nurse/nurse practitioner) on the day of surgery and consent obtained with 
the parents. 
 
Preoperative anxiolysis will be at the discretion of the anesthesiologist, but should be limited to oral or 
intravenous midazolam, dexmedetomidine, or intramuscular ketamine, and not include any medicines 
administered intranasally. 
 
lntraop: cases are assigned exclusively to one of the study investigators, but may involve the presence 
of trainees (anesthesia residents, fellows or assistants). 
 
Induction: pre-oxygenation followed by mask induction using 6-8% Sevofluorane in Nitrous oxide/O2 
(60/40) followed by IV placement (22-24g), Fentanyl lmcg/kg, Propofol 1-3mcg/kg, Rocuronium 
0.6mg/kg. 
 
Nasal Prep: Oxymetazoline (Afrin, Merck Consumer Care, Inc) nasal spray, 1 pump each nostril. Using the 
smallest pediatric sized flexible fibreoptic scope, nostril patency and degree of choanal obstruction (as 
defined by adenoid size, which is known to vary by patient age (8,9,10)) will be assessed avoiding tactile 
trauma to the nasal mucosa. Unless it is deemed not patent or significantly diminished in size, the R 
nostril will be preferably selected for intubation as most standard NTT are designed in favor of R-sided 
NTI. 

Page 4 of 7 
 
NTT prep: NTT size will be chosen based on the formula 'age+16/4 -0.5' for a cuffed NTT which has been 
validated previously (12). For patients with Trisomy 21, the formula will be uniformly  adjusted to  select 
an NTT one size down from calculated to accommodate a smaller midface skeleton (13,14,15). Since 
children  with Trisomy 21 make up a large part of the dental surgery population,  it  would be impractical 
to exclude them from the study.  A simplified table is included below(*) to define starting NTT size for  
both Down syndrome and other children by age. The selected NTT will be softened in sterile warm  saline 
(1) for at least lOmin prior to insertion into the nasopharynx. Immediately prior to insertion the NTT tip 
will be lubricated with Lidocaine Hydrochloride USP 2% jelly (©Akorn, Incorporated I 1925 W. Field 
Court, Suite 300, Lake Forest, Illinois 60045). 
 
Intubation procedure: for the purpose of this study we will intubate using the glidescope (Verathon 
Medical, ULC, Burnaby, BC, Canada) to mimic the standard practice of direct laryngoscopy while allowing 
for pictures of the oropharynx and NTT tip to be saved for later analysis. The glidescope will be inserted 
and positioned midline after which the prepared NTT is advanced through the selected nostril until 
visualization in the oropharynx. Quantification of mucosaI bleeding (none, mild(blood on tracheal cuff 
only), moderate(blood on tracheal cuff and trace blood in the oropharynx),  or  severe(blood  pooling in 
the oropharynx)) will be done at the time of intubation and verified at a later time by another study 
investigator based on the pictures taken. In the event of disagreement, a third investigator will make the 
final judgment based on the input from the prior evaluators. The presence and degree of impingement  
will be noted by the person intubating as follows: none (smooth passage without hang -ups), mild (single 
interruption in passage easily overcome by gentle rotation or angle change of the NTT), moderate 
(interruption in passage requiring re-passage of the tube, or more than one interruption in passage 
requiring readjustments) or severe (necessitating NTT down-size  and/or multiple attempted re- 
passages). Tracheal intubation should then ensue using McGill forceps as necessary to guide the NTT 
through the vocal cords. 
 
Maintenance: anesthetic gas admixture at the discretion of the anesthesiologist. Additional opioids 
and/or anxiolytics at the discretion of the anesthesiologist. 
 
Postop: in the recovery unit (PACU), presence of persistent epistaxis, post-extubation croup, and the 
time to discharge from PACU will be noted. 
 
Research Plan: 
 
This will be a prospective, randomized controlled trial in children aged 3-llyrs undergoing dental 
procedures at WCH. We are looking to exclude the null hypothesis of no effect of NTT design by 
observing significant differences in the above-mentioned primary- and secondary outcome variables in 
the study-vs. control groups. A sample size of 80 patients (40 in each group) can detect the difference 
of the same magnitude between our study and control groups with a power of more than 98% at the 
level of significance of 0.05. Randomization to study (Parker NTT) vs. control (Standard NTT) will be 
computer generated and will be stratified by adenoid size. (Please refer to the Statistics Section below) 
 
Recruitment will be facilitated by brochures handed out by our participating dental surgeons, and final 
enlistment will be done on the day of surgery. 

Page 5 of 7 
 
Statistics Description: 
 
Power and Sample Size Justification: The primary aim of the study is to compare the proportion of 
patients with the presence of at least mild {as defined in the intubation procedure section) bleeding 
between Parker NTT {study) and Standard NTT {control) groups. To our knowledge, no studies reported 
conducting research to assess the impact of mucosaI injury in pediatric patients. A pediatric study {ref: 
EI-Seify et al) reported a significant difference in the proportion of patients with the presence of  
bleeding between the control group {27.5%} and a similar method of our study group {7.5%). A sample 
size of 80 patients {40 in each group) can detect the difference of the same magnitude between our 
study and control groups with a power of more than 98% at the level of significance of  0.05. 
Randomization will be stratified by adenoid size. 
 
Data Analysis: Collected data will be summarized by two groups. Categorical variables will be 
summarized by frequencies and percentages. Quantitative variables are summarized by mean and 
standard error of mean {SEM} or median and inter-quartile range, whichever is appropriate. A Chi- 
squared test or Fisher exact test will be used to compare the distribution of categorical variables, while 
two-sample t test or non-parametric Mann-Whitney U test will be used to compare the  mean or median 
of quantitative variables. In addition to Chi-square/Fisher exact test, a logistic regression model will be 
used to compare the proportion of patients with the presence of at least mild bleeding between two 
groups. The analysis will be adjusted for  the degree of obstruction and for  other influential covariates in 
a multivariable logistic regression model. In addition, an ordinal logistic regression will be used to 
compare the severity of bleeding between two groups as long as the assumption of proportional odds 
met. Otherwise, a multinomial logistic regression model will be used for this purpose. The same 
analytical procedures will be used to compare the  presence and the degree of impingement between 
two groups. Once again, univariable and multivariable logistic regressions will be used to compare 
Postoperative epistaxis and the presence of the extubation croup between two groups. Kaplan Meier 
survival plot and log rank test will be used to compare the distribution of time to discharge  from the 
PACU. All tests are two -tailed at the level of significance of 0.05. The statistical software SAS, version 
9.3 will be used for analyses. 
 
Possible Discomforts and Risks: None beyond those incurred by standard practice 
 
Possible Benefits: Identifying an easily implementable measure to reduce mucosa! trauma and pain in 
children requiring NTL 
 
Conflict of interest: Nothing to disclose 
 
References: 
 
1)  Thermosoftening treatment of the nasotracheal tube before intubation can reduce epistaxis and nasal damage.Kim YC1, 
Lee SH, Noh GJ, Cho SY, Yeom JH, Shin WJ, Lee DH, Ryu JS, Park YS, Cha KJ, Lee SC. Anesth Analg. 2000 Sep;91(3):698-701. 
 
2) A silicone-bas ed wire-reinf orc ed tracheal tube with a hemispheric al bevel reduces nasal morbidit y for nasotrac heal 
intubation.Kihara S1, Komatsuzak i T, Brimacombe JR, Yaquchi Y, Taguchi N, Watanabe S. Anesth Analg. 2003 Nov;97(5):1488- 
91. 

Page 6 of 7 
 
3) Pathways through the nose for nasal intubation: a comparison of three endotracheal tubes.Ahmed-N us rat h A1 , Tong JL, 
Smith JE. Br J Anaesth. 2008 Feb;100(2): 269-7 4. Epub 2007 Dec 14. 
 
4) A comparison of cocaine vs. lidocaine with oxymetazoline for use in nasal procedures. Tarv er CP1, Noorily AD, Sakai CS. 
Otolaryngol Head Neck Surg. 1993 Oct;109(4): 653-9. 
 
5) Xylometazoline pretreatment reduces nasotracheal intubation-related epistaxis in paediatric dental  surgery.EI-Seify  ZA1 , 
Khattab AM, Shaaban AA, Metwalli OS, Hassan HE, Aiioub LF. Br J Anaesth. 2010 Oct;105(4):501-5. doi: 10.1093/bja/aeq205. 
Epub 2010 Aug 3. 
 
6) Parker flex-tip and standard-tip endotracheal tubes: a comparison during nasotracheal intubation.Prior S1 , Heaton J, 
Jatanq KR, Rashid RG. Anesth Prog. 2010 Spring;57(1):18-24. doi: 10.2344/0003-3006-57.1. 18. 
 
7) Nasotracheal intubation for head and neck surgery.Hall CE1, Shutt LE. Anaesthesia. 2003 Mar;58(3):249-56. 
 
8) Proposed definitive grading system tool for the assessment of adenoid hyperplasia.J os ephson GD1, Duckworth L, Hossain 
,l. Laryngoscope. 2011 Jan;121(1):187-93. doi: 10.1002/lary.21215. 
 
9) Age-specific size of the upper airway structures in children during development.Songu M1, Adibelli ZH, Tuncyurek 0, 
Adibelli H.) Ann Otol Rhino! Laryngol. 2010 Aug;119(8):541-6. 
 
10) Age-specific size of the normal adenoid pad on magnetic resonance imaging.Vogler RC1, !lLL Pilaram TK. Clin 
Otolaryngol Allied Sci. 2000 Oct;25(5):392-5. 
 
11) Which nostril should be used for nasotracheal intubation: the right or left? A randomized clinical trial.Baku A1, 
Hanamoto H2, Hirose Y3 , Kudo C2, Morimoto Y2 , Sugimura M2, Niwa H2. J Clin Anesth. 2014 Aug;26(5):390-4. doi: 
10.1016/j.jclinane.2014.01.016. Epub 2014 Aug 10. 
 
12) Endotrac heal tube selection in children: a comparis on of four methods. King BR1, Baker MD, Braitm an LE, Seidl-F riedm an 
,l, Schreiner MS. Ann Emerg Med. 1993 Mar;22(3):530-4. 
 
13) Otolaryngologic manifestations of Down syndrome.Kanamori G1, Witter M, Brown J, Williams-Smith L. Otolaryngol Clin 
North Am. 2000 Dec;33(6):1285-92. 
 
14) Down syndrom e: analysis of airway size and a guide for appropriat e intubation. Shott SR1. Larvngos c ope. 2000 
Apr;110(4): 585-92. 
 
15) Magnetic resonance imaging of the upper airway in children with Down syndrome.U ong EC1, McDonough JM, Tayag-Kier 
CE, Zhao H, Haselgrove J, Mahboubi S, Schwab RJ, Pack Al, Arens R. Am J Respir Crit Care Med. 2001 Mar;163(3 Pt 1):731-6. 
 
16) Nasotracheal fibreoptic intubation: a randomised controlled trial comparing the GlideRite® (Parker -Flex® Tip) nasal 
tracheal tube with a standard pre-rotated nasal RAE™ tracheal tube.Lomax SL1 , Johnston KD, Marfin AG, Yentis SM, 
KathawarQQ.S, Popat MT. ) Anaesthesia. 2011 Mar;66(3):180-4. doi: 10.1111/j.1365-2044. 2011.06621.x. 
 
17) EFFECTS ON POSTOPERATIVE SORE THROATS OF TWO ANALGESIC AGENTS AND LUBRICANTS USED WITH 
ENDOTRACHEAL TUBES.LUND_L\/ll, DAOS FG. Anesthesiology. 1965 Sep-Oct;26:681-3. -need full text article to confirm 

Page 7 of 7 
 
(*) 
Cuffed NTT size selection chart based on the formula (age+16)/4- 0.5 (rounded to nearest size) with 
exceptions for children with Trisomy 21 (tube down-sized by 1), and in the case of severe impingement 
(tube down-sized by 0.5) 
 
 
 
 
 
 
 
 
 
 
Patient age 
(yrs) 
NTT size, 
cuffed 
NTT size, cuffed, 
children with Trisomy 
21 
NTT size, cuffed, in 
case of severe 
impingement 
NTT size, cuffed, in 
children with Trisomy 21, 
in case of severe 
impingement 
3-4 
4.5 
4.0 
4.0 
3.5 
5-6 
5.0 
4.5 
4.5 
4.0 
7-8 
5.5 
5.0 
5.0 
4.5 
9-10 
6.0 
5.5 
5.5 
5.0 
11 
6.5 
6.0 
6.0 
5.5