ANATOMIC CONSIDERATIONS OF THE PEDIATRIC PATIENT
Endotracheal intubation of children may be more difficult compared with intubation of adults because of anatomical differences. A number of differences are illustrated in Figure 9–1. Children have a small mouth aperture with a hyomental distance of 1.5 cm or less in a newborn or infant and 3 cm or less in a child. Children also have impaired head and neck mobility, especially a child with Down syndrome or juvenile rheumatoid arthritis.
Children have airways that are cephalad compared with adults. Children have a larynx that is closer to the C3 spinal level, whereas the larynx in adults is at the C4 level. The higher position of the larynx in a child causes the tongue to be located higher in the airway and at a more acute angle to the larynx. This causes the larynx to appear anterior in the airway. Moreover, the larynx can be partially shielded by the hyoid superiorly.
Because children naturally have larger occiputs in comparison with their bodies, intubation of pediatric patients on backboards or other firm surfaces is often difficult. A large occiput requires the physician to position a pediatric patient differently. If the head is flexed, it may cause a collapse of the upper airway. The neck must be extended or kept in a neutral position to maintain a patent airway. Proper patient position can be achieved by using blankets or towels to support the body.
The narrowest portion of the airway in a child is at the level of the cricoid membrane, compared with the level of the vocal cords in an adult. Conventional teaching is that cuffed tubes should not be used in a child younger than 8 years. Appropriately sized uncuffed tubes seal well at the cricoid ring where the airway is the narrowest. Uncuffed tubes are preferred because cuffed tubes increase the risk of ischemic damage to the tracheal mucosa from compression between the cuff and cricoid ring. However, the design of modern endotracheal tube (ETT) has improved and this may be less of a risk than previously thought, and many practitioners use cuffed tubes in small children. ETT cuffs now are designed to be high volume and low pressure, thus producing a seal at a lower pressure. Several studies have shown no increase in postextubation stridor or reintubation rates when cuffed tubes were used in controlled settings with frequent cuff pressure monitoring. Cuffed tubes may provide some protection from aspiration. Potential benefits of ETT cuffs include facilitating ventilation with higher pressures, more consistent ventilation, and decreased need to exchange inappropriately sized tubes.
Children may have proportionally larger tongues, tonsils, and adenoids compared with adults. A large tongue is a common cause of airway obstruction, especially in children who are seizing, postictal, or obtunded. The physician should be cautious when placing a nasal airway in young infants because large adenoids and tonsils ...