Basic Pediatric Tracheostomy
Tracheostomy has been increasing performed in the pediatric population. Although there are similarities between an adult and pediatric tracheostomy, there are key distinctions. Considerations include anatomy, the tracheostomy procedure, and tracheostomy tubes.
According to the Agency for Healthcare Research and Quality, there are over 100,000 tracheostomy procedures performed per year in the United States, with over 4,000 of those performed on pediatric patients (2017). Tracheostomy tube placement in the pediatric population is much less common, with less known about current practice and consensus guidelines. Here we will review the indications for pediatric tracheostomy, the differences in adult and pediatric airways, pediatric tracheostomy procedure, and pediatric tracheostomy tubes.
Indications for Pediatric Tracheosotmy
The indications for tracheostomy have evolved over the years. The main indication for tracheostomy in the pediatric population was for viral and bacterial infections such as croup, diptheria and epiglottitis. However, with widespread vaccinations, these indications have changed. Increased survival rates of premature infants due to improved neontal care has increased the incidence of tracheostomy placement. During the late 1900’s there has been an increase in the use of endotracheal intubation in this population for respiratory compromise and airway obstruction (Watters, K., 2017). Tracheostomy is now more frequently performed.
There are three main reasons for tracheostomy in the pediatric population:
- Fixed upper airway obstruction- the tracheostomy tube would be used to bypass the airway obstruction. Examples include subglottic stenosis, bilateral vocal fold paraysis, and tumors. Congenital airway malformations and syndromes such as Pierre Robin Sequence are other examples.
- Anticipated long term ventilatory support
- Pulmonary toilet due to poor secretion management- a tracheostomy tube can allow for tracheal suctioning to allow for easier management and removal of secretions.
Differences in Adult and Pediatric Airways
There are some considerations when performing a tracheostomy for a pediatric in comparison to an adult.
- The pediatric airway is smaller in diameter and shorter in length compared to the adult. The smaller and more pliable trachea can be difficult to palpate.
- The tongue takes up a large proportion of the oral cavity.
- The infant hyoid bone and larynx are situated higher in the pharynx at the level of the third or fourth cervical vertebrae. The larynx starts to descend at 2 years of age.
- The epiglottis is short and omega shaped.
- Pediatrics are obligate nose breathers.
Pediatric Tracheostomy Procedure
There are some considerations when performing a tracheostomy for a pediatric in comparison to an adult. Pediatric tracheostomy are typically surgically placed. Although percutaneous and hybrid have been performed, there are concerns over the safety in young children and infants. The procedure is typically planned in pediatric patients, often after prolonged hospitalization. The procedure is typically performed within the first year of life because of the increased survival of premature infants.
In a pediatric tracheostomy, a vertical incision is typically made. Due to the small airway, it is very important to have the tube placed precisely. Stay sutures are used on either side of the vertical incision to allow for the lumen to stay open in case of emergency, before the first planned tracheostomy. Stoma maturation sutures are used to make sure that the stoma is secure. The sutures allow for safe tracheostomy tube changes even the next day after the surgery.
A child’s initial tracheostomy tube should be changed within 5-7 days if inserted surgically to establish a mature tract (Mitchell et al., 2012).
Pediatric Tracheostomy Tubes
Pediatric tracheostomy tubes come in the same basic components when compared to adult tracheostomy tubes. Pediatric tracheostomy tubes are manufactured in standard neonatal and pediatric sizes. The neonatal tracheostomy tubes are generally for children under 5kg. Neonatal tubes are shorter in length than pediatric tubes. However, the diameters are the same for neonatal and pediatric and range from 2.5mm to 6.5mm.
Pediatric tracheostomy tubes differ from adult tracheostomy tubes in a few ways. Due to the small size of the tracheostomy tube, pediatric tracheostomy tubes are single lumen tubes, so there is no inner cannula. An inner cannula would further reduce the inner diameter of the tracheostomy tube. There are also no fenestrated tracheostomy tubes available for the pediatric population.
Another difference is that most pediatric tracheostomy tubes are cuffless due to the small diameter of their airways. However, cuffed tracheostomy tubes are also available. Cuffed tracheostomy tubes are used if high ventilatory pressures are needed or the patient is not ventilating adequately with a cuffless tube. Inability to manage secretions with a high aspiration risk may also be an indication. (Although the cuff does not prevent aspiration, the cuff and tube can bypass the secretions).
As a child grows, he or she will require a progressively larger tracheostomy tube.
Tracheostomy Tube Materials
Prior to the 1960’s, adult and pediatric tracheostomy tubes were made out of stainless steel or silver. Today, most tubes are made from plastic (polyvinyl chloride) or silicone. The Clinical Consensus Guideline indicates that plastic tracheostomy tubes should be used for the initial tracheostomy tube placement for both adults and pediatrics (2012).
Pediatric Tracheostomy Tube Selection
Plastic tracheostomy tubes should be used for the initial pediatric tracheostomy tube placement. The size of the tracheostomy tube should be selected based on lung mechanics, upper airway resistance and airway clearance, ventilation and communication needs and indications for the procedure. Both the diameter and length of the tube should be considered. “The tracheostomy tube size, shape, and diameter should be determined based on the need for the tube to fit the airway without undue pressure on the tracheal wall but also to satisfy the functional needs of the patient, including speech and airway clearance requirements” (Mitchell et al., 2012).
In most cases the selected tracheostomy tube should extend at least 2 cm beyond the stoma, and no closer than 1–2 cm to the carina. Flexible tracheoscopy is used to determine the appropriate length where the scope is inserted through the tube to assess the position in relation to the carina. Curvature recommendations are that the distal portion of the in situ tracheostomy tube should be concentric and colinear with the trachea (ATS, 1999). Assessment of appropriate curvature requires neck/chest radiographs or flexible bronchoscopy.
Pediatric Cuffed Tracheostomy Tubes
Pediatric tracheostomy tubes are typically cuffless to prevent damage to the trachea. Uncuffed tubes are preferred over cuffed tracheostomy tubes in the pediatric population (ATS, 1999). However, cuffed pediatric tracheostomy tubes are available and may be used in certain circumstances. Cuffed tracheostomy tubes may be used for those on high ventilatory pressures or those who are not ventilating adequately with a cuffless tracheostomy tube. Another reason for a cuffed tracheostomy tube is for patients at risk of gross aspiration.
There are low pressure/high-volume cuffs and high pressure/low-volume cuffs. ATS guidelines indicate that cuff pressures below 20cmH2O are generally well tolerated and that cuff pressure should be monitored (1999). Some tubes require air to be inserted, while others require water. Manufacturer recommendations should be followed.
Calculating Pediatric Tracheostomy Tube Size
An age-appropriate tracheostomy tube size can be estimated by using the endotracheal tube (ETT) formula for children >1 y of age: (age in years/4) +4 mm = internal diameter of ETT. This can then be converted to the appropriately sized tracheostomy tube
Custom Pediatric Tracheostomy Tubes
Custom pediatric tracheostomy tubes are available and can be made to order for a range of options based on the patient’s anatomy. Options include swivel versus fixed connector, standard or hyperflex silicone shaft, curvature size, length, cuff design, cuff position, and flange.
Pediatric tracheostomy has key differences in comparison to adult tracheostomy. Airway management is typically more difficulty in pediatric tracheostomy due to the high incidence of upper airway anomolies. Healthcare professionals who care for individuals with tracheostomy should be aware of these differences and receive training in routine and emergent tracheostomy care. Tracheostomy in children also requires intense support from parents and caregivers, who also need to be appropriately trained.