clinical circumstances where airway diameter may change over the course of treatment (e.g., inhalational injury, angioedema), as a protective measure for children at risk for aspiration, and in any child in whom underlying lung disease may necessitate high ventilator pressures (e.g., bronchiolitis, status asthmaticus, chronic lung disease) The risk associated with the use of cuffed ETTs is excessive cuff pressures, which could lead to ischemia of the tracheal mucosa Various recommendations suggest that pressures higher than 20 to 30 cm H2 should be avoided Measurement of cuff pressure can be achieved either through listening for an air leak while applying positive pressure through the ETT, or by using an ETT cuff manometer The practice of “feeling” the cuff balloon has been demonstrated to be inaccurate in assessing the cuff pressure ETT sizes are reported based on the internal diameter, measured in millimeters (mm) Available sizes range from 2.0 mm (suitable for a preterm infant) to adult sizes of 7.0 mm or more Resistance to airflow as well as risk of tube obstruction is increased in smaller tubes Tube selection in pediatrics therefore aims to balance these factors associated with smaller tubes, with the need to select a tube that will pass easily through the vocal cords and not create excessive pressure on the tracheal wall Methods of selecting the appropriate tube size include use of a length-based resuscitation tape, pediatric sizing programs available online or on mobile devices, and use of an age-based formula Each has been shown to be effective, though inclusion of options for cuffed tube sizing is not offered in each 3.0- or 3.5-mm uncuffed ETTs are normally used for term newborns Smaller tubes are used for premature newborns For older children, the uncuffed ETT sizing age-based formula: + (age in years/4) has been shown to be accurate until adult sizes of 7.0 (most females) to 8.0 (most males) For newer, low-profile cuffed ETTs, selecting a tube one-half size smaller is recommended: 3.5 + (age in years/4) Regardless of the method chosen in selecting the initial tube size, it is important to have additional tubes available, one size smaller in the event that tube passage is difficult and one size larger if a large air leak results in inadequate ventilation, despite inflation of the cuff where appropriate ETT stylets provide rigidity and shape to the ETT, facilitating tube guidance through the glottic opening Stylets have become particularly important with the growing use of videolaryngoscopy (VL), during which tube passage is often done indirectly, requiring manipulation around the curve of the tongue and then into the glottic opening Various stylet sizes exist to accommodate both pediatric and adult-sized ETTs The stylet should not project past the tip of the tube or through the Murphy eye side hole Bending the stylet over the adapter at the proximal end of the tube prevents inadvertent movement during intubation FIGURE 8.1 Approach to the difficult airway SGA, supraglottic airway; NMBA, neuromuscular-blocking agents; BVM, bag-valve mask Direct Laryngoscopes There are two components to traditional direct laryngoscopes, the handle and the blade Smaller diameter handles tend to be favored with smaller blades, though selection is ultimately based on clinician preference Laryngoscope blades are either curved or straight The choice is based on the experience and preference of the clinician Curved blades are designed to follow the base of the tongue into the vallecula They often have a beaded tip to allow pressure against the hypoepiglottic ligament which helps to elevate the epiglottis They also have a large flange which facilitates displacement of the tongue Straight blades allow direct lifting of the epiglottis to expose the glottic opening This type of blade may be preferred in infants and younger children in whom the epiglottis is often larger and more likely to fall into the line of sight Selecting the appropriate laryngoscope blades size allows the clinician to control the tongue and reach the glottic structures Age-based guidelines, lengthbased resuscitation tapes, anatomic landmarks, and electronic applications, can be used to select an appropriate size Although size 00 and blades are used in neonatology, blades smaller than a size are rarely required in emergency medicine Size blades can be used in patients less than years of age Size blades are commonly used in children starting at years of age Size blades are commonly used beginning around 10 to 12 years of age Selecting a laryngoscope blade that approximates the distance between the upper incisors and the angle of the mandible can be used as a guide in patients whose age is not known or when the anatomy appears incongruous with the proposed blade size based on other available references Video Laryngoscopes VL utilizes video camera technology to further facilitate TI Traditional direct laryngoscopy (DL) requires the creation of a direct line of sight through the mouth to the glottic opening This is achieved by positioning the patient in the sniffing position to align the oral, pharyngeal, and tracheal axes and then lifting the tongue and soft tissue anteriorly using a laryngoscope VL provides a vantage point from behind the base of the tongue, through a camera chip built into the device As such, operators can view the glottis on a monitor screen around the natural curvature of the upper airway, obviating the need to align the axes or displace the tongue Data support that videolaryngoscopes commonly offer improved laryngeal views over DL, and may be particularly valuable in cases where creating a direct line of sight may be challenging (e.g., cervical spine collars, macroglossia, micrognathia) Some studies suggest that intubation success rates are higher with VL compared to DL, though benefits may not be noted in routine cases performed by experienced providers, in whom DL success rates are high Data regarding time to successful intubation using VL are varied in pediatric populations Advantages of VL are most notable in (1) novice clinicians who may not have developed intrinsic skill with DL, and (2) patients with difficult airways where the ability to gain an adequate view is favored by a video- enhanced approach An additional advantage of VL is the ability for multiple practitioners to view the procedure simultaneously This allows for real-time guidance and supervision during TI Oftentimes in emergency medicine, patients require rapid airway management without the benefit of prescreening or comprehensive airway assessments, and by providers who have less frequent occasions to perform invasive airway procedures Therefore, the recognized advantages of VL may be underestimated in research studies A number of VL devices are available for use in pediatrics, varying in their cost, design, reusability, and technique for use ( e-Table 8.1 ) Currently, only a limited number offer sizing that allows for use across the entire spectrum of ages, from neonates through to adolescents The GlideScope and the Storz C-MAC are currently the two most popular products in use in pediatric emergency medicine The GlideScope utilizes a J-shaped baton in conjunction with a hyperangulated blade and a styletted ETT Alternative GlideScope blades that enable DI are currently available in adult but not pediatric sizes The Storz C-MAC utilizes more conventional blade geometry which closely mimics DI Nonetheless, the vantage point from the camera at the distal tip of the blade offers improved views over those available directly In addition, the C-MAC now has a pediatric and adult hyperangulaged “D” blade that may be advantageous for patients in whom a direct line of sight is likely to be challenging, as described above King Vision devices are newer videolaryngoscopes that also utilize a baton with disposable single-use blades The size blade is unchanneled and requires concurrent use of a styletted ETT The pediatric and adult blades (sizes and 3) come with either channeled or unchanneled blades The cost is significantly lower than the C-MAC and GlideScope systems There are other subtle differences that are beyond the scope of this chapter and products in this market are constantly evolving to improve PREOXYGENATION Given the risk of rapid desaturation in children, efforts should be made to maximize preoxygenation Preoxygenation in children in the ED is traditionally performed using a nonrebreather mask, which can be supplemented with a nasal cannula Flush rate oxygen delivery through a nonrebreather can limit entrainment of room air during preoxygenation in adults, although it is not clear if increasing flow beyond 15 liters per minute (L/min) is beneficial in younger pediatric patients with smaller minute ventilation Bag mask ventilation can be used to increase the delivered FiO2 with positive pressure breaths Spontaneously breathing infants and young children may not have the inspiratory force to open ... GlideScope and the Storz C-MAC are currently the two most popular products in use in pediatric emergency medicine The GlideScope utilizes a J-shaped baton in conjunction with a hyperangulated... simultaneously This allows for real-time guidance and supervision during TI Oftentimes in emergency medicine, patients require rapid airway management without the benefit of prescreening or comprehensive... size 00 and blades are used in neonatology, blades smaller than a size are rarely required in emergency medicine Size blades can be used in patients less than years of age Size blades are commonly