Nasotracheal tube stenting by Nelaton catheter in paediatric dental surgery

Background : Nasotracheal intubation is associated with many complications such as epistaxis and nasal cavity injury. Stenting the endotracheal tube with appropriate sized nelaton catheter may decrease these complications. In this study we compared stenting the endotracheal tube by nelaton catheter with ordinary intubation technique. Methods: Eighty paediatric patients who were scheduled for elective dental surgery (restoration surgery) were randomly divided into two groups according to the nasotracheal intubation technique. In the first group endotracheal tube was stented with appropriate size nelaton catheter which was removed immediately after tube passage to the oropharynx. In the second group nasotracheal intubation was done by the ordinary technique without tube stenting. Evaluation of the resistance during nasal intubation, incidence and severity of epistaxis and nasal cavity injury were done. Results: Nasotracheal intubation was smooth in 80% of patients with stented tube compared to 40% in the non-stented tube. Epistaxis was found in 22.5% of patients with stented tubes compared to 85% of patients with non-stented tubes. Histopathology of tube contents after extubation showed blood cells in 32.5% in stented tubes and 92% in the non-stented ones. Adenoid tissue was found in5% of patients with stented tubes and 37.5% of patients with non-stented tubes. Conclusion: Stenting the endotracheal tube with nelaton catheter facilitates nasotracheal intubation and decreases the incidence and severity of epistaxis and nasal cavity injury.

Nasotracheal tube stenting by Nelaton catheter in paediatric dental surgery Amin Mohammed Alansary 1* , Randa Ali Shoukry 2 University, Egypt. , Ain Shams 2 thesia s e a n A rofessor of P , Assistant * 1 Lecturer Background: Nasotracheal intubation is associated with many complications such as epistaxis and nasal cavity injury. Stenting the endotracheal tube with appropriate sized nelaton catheter may decrease these complications. In this study we compared stenting the endotracheal tube by nelaton catheter with ordinary intubation technique.

Methods:
Eighty paediatric patients who were scheduled for elective dental surgery (restoration surgery) were randomly divided into two groups according to the nasotracheal intubation technique. In the first group endotracheal tube was stented with appropriate size nelaton catheter which was removed immediately after tube passage to the oropharynx. In the second group nasotracheal intubation was done by the ordinary technique without tube stenting. Evaluation of the resistance during nasal intubation, incidence and severity of epistaxis and nasal cavity injury were done.

Introduction
Nasotracheal intubation is the commonest intubation technique indicated in paediatric dental surgery to secure and maintain the airway. 1,2 This technique may be accompanied by many complications such as epistaxis, avulsed adenoids, fractured turbinate, avulsed nasal polyps, mucosal injury and consequent sub mucosal tube passage. 3 Impaction of avulsed tissues in the tube and delivering it inside the trachea and lung effects ventilation and predisposes to postoperative chest infection. 4 Many manoeuvers, including tube thermo softening, vasoconstrictor use, telescoping catheter technique, tube sheathing have been used to facilitate easy tube passage and reduce epistaxis associated with nasal intubation. 5,6 We hypothesized that the above-mentioned complications might be decreased or prevented and passage of the tube through the nasal cavity might be smoother by using an appropriate sized nelaton catheter as a stent in the endotracheal tube. Accordingly, this study was conducted to compare incidence of complications using nelaton catheter as endotracheal tube stent and ordinary non-stented tube.

Patients and methods
After approval by the ethical committee at Faculty of Medicine, Ain-Shams University, Egypt the study was conducted in the Department of dental paediatrics. 80 children, aged 2-9 years with ASA physical status class I or II, scheduled for dental procedures under general anaesthesia were chosen. Exclusion criteria included patients with a history of recurrent epistaxis, coagulopathy, previous nasal surgery, history of nasal trauma.
In the operating room standard monitors were applied. Patients were randomly allocated into two groups, according to the nasotracheal intubation technique: Group 1 -Intubation done after stenting the tube by an appropriate size nelaton catheter ( Figure 1).  In both groups the tube size was determined by the equation (age/4+4). The bevel of the tube to be directed laterally with gentle rotation until it appears in the oropharynx. Induction of general anesthesia for all cases was standardized. During induction the patient's nasal cavity was lubricated with 2% lidocaine jelly and cotton swabs with local vasoconstrictor applied in both nostrils. After nasotracheal intubation, a throat pack was inserted. At the end of surgery extubation was done after oral suctioning and removal of throat pack.
An independent anaesthesiologist who did not observe the tube insertion assessed the severity of epistaxis and presence of avulsed tissues using a laryngoscope, immediately after the tube was passed through trachea. Assessment of the resistance of tube passage through the nasal cavity during intubation was done using three grades 1- Smooth (no resistance).

3-
Large resistance (sense of tissue resistance and avulsion).
EpistaEpistaxis was evaluated using four grades: 1-No epistaxis, no blood observed on either tube surface or the posterior pharyngeal wall.

2-
Mild epistaxis, blood apparent on tube surface or posterior pharyngeal wall, partial staining of small gauze.

3-
Moderate epistaxis, pooling of blood on the posterior pharyngeal wall, staining of more than one of small gauze.

4-
Severe epistaxis, a large amount of blood in the pharynx impeding nasotracheal intubation and necessitating urgent orotracheal intubation.
After extubation any contents of the endotracheal tube were collected in a 5 ml syringe by using a sterile swab and sent for histopathology. Evaluation was done of the contents from the tube by microscopy and histopathology as follows: Descriptive statistics were done for quantitative data as minimum and maximum of the range as well as mean±SD (standard deviation) for quantitative normally distributed data, while it was done for qualitative data as number and percentage.
Inferential analyses were done for quantitative variables using Shapiro-Wilk test for normality testing, independent t-test in cases of two independent groups with normally distributed data.
In qualitative data, inferential analyses for independent variables were done using Chi-square test for differences between proportions and Fisher's Exact test for variables with small expected numbers. The level of significance was taken at P value < 0.050 is significant, otherwise is non-significant.

Results
A total of 80 patients were enrolled and completed the study, patients were divided blindly into two groups 40 patients for each ( Figure 2). Both groups were matched with regard to their demographic data, there were no statistically significant differences between the two groups with regard to duration of surgery, nostril side, size of used tube, type of surgery and ASA physical status (Table 1). In Group II resistance during intubation was found in 60% of patients, while smooth intubation was found in 40% of patients. In Group I, smooth intubation was found in 80% of patients while resistance during intubation was found in 20% of patients only (Table 2).
There was a statistically significant difference between the two groups regarding the incidence of epistaxis. Epistaxis was observed in 85% of patients in group II, (mild 45%, moderate 35% and severe 5%) while 15% of patients had no epistaxis during intubation. While in group I 77.5% of patients had no epistaxis and epistaxis was observed in only 22.5% of patients, of them; 17.5% mild 5% moderate and 0% severe (Table 3).  Microscopy and histopathology of tube contents revealed that there was no statistically significant difference between the two groups with regard to secretions (100% of patient had secretions in the tubes). Blood cells was seen in the contents in 92% of patients in group II and only 32% of patients in group I. 37.5% of patients of group II had tissues in their tube contents mainly adenoid tissue. In group I, about 5% of patients had tissues mainly adenoid. (Table 4).

Discussion
Epistaxis is a common complication of nasal intubation, blood in the airway can interfere with the laryngoscopy view and can lead to aspiration. 7,8,9,10 Partial or complete obstruction of the tube can occur by avulsed tissues as adenoid, plop, turbinate and blood clot. 11,12 In this study, tracheal tubes stented with appropriately sized nelaton catheter were associated with smooth intubation and minimal resistance than standard non-stented tubes, this may be due to decreasing the surface of the sharp edge of the tube which acts as a shaver. According to the smooth intubation and minimal resistance, incidence of epistaxis was lower in stented tubes rather than standard ones.
Stenting the endotracheal tube increased the value of getting smooth intubation and the efficacy was increased by about 50% compared to the nonstented tubes.
Also the value of stenting in preventing epistaxis was increased by about 62.5% with 80% efficacy compared to the non-stented group.
We suggest that the nelaton catheter acts as a trocar that prevent the friction between the tube and pharyngeal wall and makes smoother passage of the tube along the curve of the nasopharynx.
Obliteration of the distal end of the endotracheal tube with the distal end of the catheter was associated with little or no impaction of the avulsed tissues in the tube end, this finding was approved by histopathology of the collected tissues after extubation.
In agreement with our results, Morimoto et al 13 found that using a curve-tipped suction catheter to guide the nasotracheal tube passage decreased the frequency of nasal bleeding. Morimoto et al used one size of nelaton catheter and the tip of the catheter protruded from the tube end by about 10cm. In our study we used different sizes of nelaton catheters, and the catheter tip was at the same level of the distal end of the tube.
Watt et al. showed that telescoping the endotracheal tube with a red rubber catheter decreased the incidence and severity of nasal bleeding during nasotracheal intubation. 14 Suk Seo et al found that the use of oesophageal stethoscope to obturate the endotracheal tube was effective in reducing epistaxis during and after nasotracheal intubation. 15 In agreement with our results, Kazuna et al reported that a styletted tracheal tube with posterior facing bevel reduces the incidence of epistaxis during nasotracheal intubation, the only difference between the two studies is that in our study stenting the tube was done by a soft malleable nelaton catheter while in Kazuna's study a metal stylett was used to control the direction of the tube bevel during intubation. 16 In our study we found that ordinary nasal intubation is associated with more tissue trauma which may adhere to tube wall, this was proven by microscopy and histopathology of the tube contents after extubation, more blood cells and solid tissues as adenoid and turbinate was found, stenting the tube with nelaton catheter lowered tissue injury and avulsion and subsequent tube impaction. Kazuna et al studied epistaxis only, but we studied also the microscopy and histopathology of tube contents.
In conclusion, stenting the endotracheal tube with appropriate size nelaton catheter represents a simple, cheap and practical method for smooth nasotracheal intubation and decreasing the incidence and severity of nasal bleeding and injury.