Technique of emergency endotracheal intubation in children

INTRODUCTION — This topic will focus on the procedure of oral endotracheal intubation (ETI) with laryngoscopy in children.

Basic pediatric airway management, rapid sequence intubation (RSI) in children, management of the difficult pediatric airway, and pediatric airway management for anesthesia are discussed separately:

●(See "Basic airway management in children".)

●(See "Rapid sequence intubation (RSI) in children for emergency medicine: Approach".)

●(See "The difficult pediatric airway for emergency medicine".)

●(See "Video laryngoscopy and other devices for difficult endotracheal intubation in children", section on 'Video laryngoscope'.)

●(See "Airway management for pediatric anesthesia" and "Management of the difficult airway for pediatric anesthesia".)

BACKGROUND — Emergency ETI may be performed in the prehospital setting, as well as in emergency departments or other critical care settings. The need for intubation may be immediately apparent, such as in cardiopulmonary arrest. In other circumstances, the decision to intubate may result from dynamic assessment based on progressive or anticipated deterioration despite maximal medical therapies and non-invasive respiratory support.

Emergency intubation is inherently more difficult to perform than planned intubation in the operating room. Patients are not prescreened and often had recent oral intake as opposed to being in the fasted state (ie, nil per os [NPO]). In addition, rapid clinical deterioration may compromise preparation time, and underlying illness or injury may make patients more susceptible to the adverse physiologic effects of this procedure.

INDICATIONS — There are numerous disease processes and clinical situations that may necessitate intubation.

In the emergency department setting, intubations may be performed on trauma and nontrauma patients [1-4]. Specific indications for intubation fall into four different categories:

●Inadequate oxygenation or ventilation – Patients who are unable to maintain adequate oxygenation or ventilation require intubation. Respiratory failure may result from primary pulmonary disease, or from other processes associated with respiratory compromise (table 1). (See "Acute respiratory distress in children: Emergency evaluation and initial stabilization", section on 'Evaluation'.)

Clinical evidence of respiratory failure includes:

•Poor or absent respiratory effort

•Poor color or cyanosis

•Obtunded mental status

Supporting data, such as noninvasive monitoring of oxygen saturation and end-tidal carbon dioxide (EtCO₂), or partial pressure of oxygen or carbon dioxide from blood gas analysis can be helpful; however, ETI should not be delayed in patients with clinical evidence of respiratory failure in order to obtain such measurements.

●Inability to maintain and/or protect the airway – Any child who cannot maintain his/her airway requires ETI. Patients in this category may exhibit the following findings:

•Inability to phonate or produce audible breath sounds despite respiratory effort (complete airway obstruction). (See "Emergency evaluation of acute upper airway obstruction in children", section on 'Signs of airway obstruction'.)

•Inspiratory, obstructive sounds with partial airway obstruction that fail to improve despite repositioning, airway maneuvers, or medical therapies. (See "Emergency evaluation of acute upper airway obstruction in children", section on 'Evaluation'.)

•Impaired mental status including head injured patients with a Glasgow Coma Score (GCS) of ≤8 [5-7] and patients with systemic illness or poisoning because of the increased risk of aspiration [8,9]. Patients with depressed mental status can be assessed clinically for loss of protective airway reflexes. In particular, determining a patient's ability to swallow and handle secretions provides the most reliable indication of adequate airway protection. Studies suggest that swallowing and airway protective reflexes may in fact be centrally integrated [10].

•Though commonly assessed, the gag reflex is a less useful indicator of airway status for several reasons: (1) The gag reflex correlates poorly with GCS [11]; (2) A gag may not be elicited in more than one third of healthy subjects [12]; (3) The absence of a gag reflex in patients with prior neurological insults does not correlate with risk of aspiration [13]; (4) Attempting to gag a patient to determine the need for intubation increases the risk of vomiting in those whose reflex remains intact.

●Potential for clinical deterioration – Children whose condition will likely deteriorate, such as those with thermal inhalation injuries or epiglottitis, require early intubation in a controlled fashion. (See "Moderate and severe thermal burns in children: Emergency management" and "Epiglottitis (supraglottitis): Management", section on 'Patient able to maintain airway'.)

Other illnesses, such as severe anaphylaxis or asthma exacerbations, may initially be treated with aggressive medical therapies. However, clinical response must be continuously assessed, with a clear endpoint and plan for airway intervention if the patient does not improve and respiratory failure is anticipated. (See "Anaphylaxis: Emergency treatment", section on 'Airway management' and "Airway management in acute severe asthma for emergency medicine and critical care", section on 'the decision to intubate'.)

Similarly, patients with sepsis may be intubated based on their anticipated course, as well as to maximize oxygen delivery and relieve energy expenditure related to increased work of breathing. (See "Septic shock in children in resource-abundant settings: Rapid recognition and initial resuscitation (first hour)", section on 'Airway and breathing'.)

●Prolonged diagnostic studies or patient transport – Control of the airway through intubation may be the safest alternative for some patients with combative or unstable conditions who require diagnostic studies that are prolonged or prevent continuous access to the patient. This is particularly true during computed tomography or magnetic resonance imaging, where assessment and support of the child's airway will be limited in the event of an acute change. Intubation is also suggested prior to transfer to another facility for any patient at risk for deterioration. Securing the airway prior to departure avoids the need for emergency advanced airway management in a less controlled setting such as an ambulance or a helicopter transport.

CONTRAINDICATIONS AND PRECAUTIONS — Assessment and management of the airway is the first priority in caring for acutely ill or injured children. Thus, there are no absolute contraindications for ETI by appropriately trained providers.

Relative contraindications are uncommon but do exist and primarily relate to the need to move to a more controlled environment or to perform a surgical approach to the airway:

●In order to preserve airway reflexes and spontaneous respiratory efforts in case of a failed intubation, rapid sequence intubation with neuromuscular blockade should be avoided in patients who are known or expected to be difficult to intubate and difficult to ventilate with bag and mask, without an appropriate back up plan in place. (See "Rapid sequence intubation (RSI) in children for emergency medicine: Approach".)

●Patients with a known or suspected laryngeal fracture should be intubated with caution because of the risk of further disrupting a partial laryngeal transection, resulting in complete loss of the airway.

●High-risk intubations (eg, epiglottitis) are most safely performed in the controlled environment of the operating room whenever delay secondary to transport will not compromise patient outcome (table 2).

●Although very rare, the unstable surgical patient (eg, penetrating trauma to the larynx or severely distorting facial trauma) deemed to require a surgical airway should not have airway efforts delayed by attempts at laryngoscopy and ETI. (See "Needle cricothyroidotomy with percutaneous transtracheal ventilation" and "Emergency cricothyrotomy (cricothyroidotomy) in adults".)

INFECTION CONTROL — For children with suspected highly contagious and virulent airborne pathogens such as early COVID-19 variants prior to the availability of effective vaccines, there is a significant risk for transmission during laryngoscopy, endotracheal intubation, and other airway management procedures. Techniques designed to improve patient care, minimize infectious risks to care providers, and decrease spread of pathogens are essential and provided separately. (See "Rapid sequence intubation (RSI) in children for emergency medicine: Approach", section on 'Infection control precautions'.)

ANATOMY — Anatomic features of the airways of infants and children that affect the approach to intubation are reviewed in detail separately. (See "Emergency airway management in children: Unique pediatric considerations".)

●Mouth and oropharynx – The lips define the entrance to the mouth. Immediately behind the lips are the teeth extruding from the gingiva. The mouth is bound superiorly by the hard and soft palate, laterally by buccal mucosa, and inferiorly by the tongue. The uvula hangs down from the roof of the mouth in the midline, and the tonsils lie laterally just behind the palatoglossal folds which define the entrance to the oropharynx (figure 1). The oropharynx extends inferiorly to the epiglottis.

●Hypopharynx – Below the oropharynx is the hypopharynx which extends from the epiglottis to the cricoid cartilage. The epiglottis attaches to the anterior aspect of the hypopharynx and drapes over the glottis. The anatomic space at the junction of the base of the tongue and the epiglottis is the vallecula. At the base of the vallecula lies the hyoepiglottic ligament, which connects the epiglottis to the hyoid bone anteriorly, covered by the median glossoepiglottic fold (figure 2). The larynx lies in the anterior portion of the hypopharynx, bounded laterally by the piriform recesses. Posteriorly lies the origination of the esophagus. Distinguishing the esophagus from the glottis is crucial during ETI. The esophageal opening has a puckered or ill-defined shape, and has smooth, homogeneous soft tissue structures surrounding it (picture 1).

●Larynx – The larynx is defined anteriorly by the hyoid bone, the thyroid cartilage, the cricothyroid membrane, and the cricoid cartilage. The arytenoid cartilages (cuneiform and corniculate) make up the posterior aspect of the laryngeal inlet. These posterior cartilages are important landmarks as they are the first structures visualized as the epiglottis is lifted during laryngoscopy and may be the only portion of the glottis visualized in some patients. The aryepiglottic folds, which connect the arytenoids to the epiglottis, make up the lateral borders of the laryngeal inlet. The true vocal cords originate below the epiglottic tubercle anteriorly and connect with the arytenoids posteriorly. The vocal cords cover the entrance to the trachea. An optimal laryngoscopic view will allow visualization of the entire length of both vocal cords (picture 2).

●Trachea – The trachea begins at the base of the cricoid cartilage, and ends inferiorly at the carina, which defines the bifurcation to the right and left mainstem bronchus.

PREPARATION — Success in airway management depends on careful patient assessment, implementation of an appropriate ETI plan, and gathering and testing of all necessary equipment prior to performing the procedure.

Pre-intubation checklists — We support the active use of intubation checklists, customized to the setting, that include items on patient assessment, appropriate personnel and role assignments, required equipment, and medications as a means to reduce errors during emergency ETI (figure 3) [14].

Rapid assessment — The clinician should perform a focused assessment of the child's history and physical findings to identify conditions and clinical features that will impact bag-mask ventilation, laryngoscopy, and/or ETI. Examples include:

●Congenital abnormalities associated with airway difficulties (eg, Pierre-Robin, Treacher-Collins) (table 3) (see "The difficult pediatric airway for emergency medicine", section on 'Causes of the difficult pediatric airway')

●Known difficult ETI in the past

●Anatomic characteristics associated with difficult airway management, such as poor mouth opening, large tongue or tonsils, small chin, short mandible, or decreased neck mobility (see "The difficult pediatric airway for emergency medicine", section on 'Identification of the difficult pediatric airway')

Some clinicians advocate for the use of the Mallampati score (figure 4) or LEMON approach (table 4), although their use has not been validated in children (see "The difficult pediatric airway for emergency medicine", section on 'Identification of the difficult pediatric airway')

●Evidence of partial upper airway obstruction from infectious, traumatic, or inflammatory etiologies (table 5)

Intubation plan — Rapid sequence intubation (RSI) has been shown to be safe and effective in children and should be planned for most emergency pediatric intubations [2,3,15]. (See "Rapid sequence intubation (RSI) in children for emergency medicine: Approach".)

However, in any child in whom laryngoscopy and intubation may be more difficult (table 5), an alternative plan that involves assistance from specialists (anesthesiologists, otolaryngologists) and/or intubation with sedation but without paralysis should be employed.

A contingency plan in the event of a failed intubation must be developed for all patients, ideally before rapid sequence intubation is attempted. (See "The difficult pediatric airway for emergency medicine", section on 'Techniques'.)

The clinician in charge should clearly assign roles to each health care provider, including an assistant to the person performing ETI. (See 'Materials, equipment, and personnel' below.)

Patient counseling/informed consent — In most circumstances, emergency ETI is performed for life-threatening circumstances, and thus, consent is implied. Whenever possible, the procedure should be explained to both the parents/primary caregivers and the child prior to intubation with emphasis on the indications for intubation and benefits of the procedure (eg, correction of hypoxemia or protection of the airway to prevent aspiration).

Key components of the discussion that should be included:

●Medications will provide sedation and pain control throughout the procedure.

●ETI may not be successful.

●The subsequent planned actions if the child cannot be successfully intubated.

Urgency of this procedure often precludes extensive discussion about minor risks, including the possibility of oral or dental trauma and post-extubation throat discomfort.

Materials, equipment, and personnel — Functioning airway equipment in a full range of sizes from neonate to adolescent/adult should be readily available wherever critically ill or injured children receive medical care (table 6). Equipment should always be checked prior to performing this procedure.

Preintubation supplies

●Personnel – Ideally, at least three practitioners are present during emergency intubation. In addition to the laryngoscopist/intubator, an assistant can be utilized to perform external laryngeal manipulation, hand equipment to the intubator, and monitor vital signs, and an additional provider can be assigned to infuse medications when RSI is utilized. When possible, the resuscitation leader should not be the provider performing the intubation. A respiratory therapist, when available, can function as the assistant during intubation, and is particularly helpful to assist with ventilator management after intubation.

●Monitoring equipment – Any patient undergoing ETI should be placed on continuous monitoring equipment including heart rate, respiratory rate, blood pressure, and continuous oxygen saturation monitoring. Capnography should be employed when available. (See "Carbon dioxide monitoring (capnography)", section on 'Clinical applications for intubated patients'.)

●Oxygen supply – Supplemental oxygen must be available, either from a wall source or a portable tank with a flow meter that allows at least 10 L/min.

●Suction – Wall suction or portable devices should be available. Pressures should be limited to 80 to 120 mmHg to decrease the risk of trauma to airway mucosa. Yankauer or wide-bore tonsil tip catheters are most appropriate for suctioning particulate matter (eg, thick secretions and vomitus). Flexible suction catheters can be used for thin secretions in the nose, mouth, and hypopharynx, as well as for deep suctioning through the endotracheal tube (ETT).

●Bag and mask – Selecting an appropriately sized bag and mask for bag-mask ventilation (BMV) is discussed separately. (See "Basic airway management in children", section on 'Bag-mask ventilation'.)

BMV can provide a temporizing means for oxygenation and ventilation while preparing for intubation in the child in respiratory failure. In addition, children desaturate more quickly than adults during RSI and may require assisted ventilation after administration of sedatives or neuromuscular blockade agents and prior to laryngoscopy and ETI. (See "Emergency airway management in children: Unique pediatric considerations".)

BMV is as effective as ventilation following ETI for providing immediate respiratory support. For example, a randomized controlled trial of prehospital BMV versus ETI in 820 pediatric patients found no difference in survival to hospital discharge or good neurologic outcomes between the two groups. Median scene and transport times were 15 minutes in the BMV group and 17 minutes in the ETI group, suggesting that BMV was equivalent to ETI for short-term airway and ventilatory support among paramedics [16].

However, BMV does not provide a secure airway and may result in gastric insufflation, which increases the risk for vomiting and aspiration. In addition, resultant abdominal distension may limit diaphragmatic excursion and compromise ventilation. Thus, any child requiring prolonged respiratory support is best managed with ETI, especially when performed by appropriately trained providers in the emergency department or other critical care settings.

●Oro- and nasopharyngeal airways – Oro- and nasopharyngeal airways should be available to facilitate bag-mask ventilation in case it is necessary during the process of intubation, or in the event that an ETT cannot be passed successfully. (See "Basic airway management in children" and "Basic airway management in adults".)

Endotracheal tube

Cuffed versus uncuffed — Beyond the newborn period, cuffed ETTs are equally as safe as uncuffed tubes, and are favored in most clinical circumstances [17-20], especially:

●Children at risk for aspiration [21]

●Burn victims [22]

●Children with severe lung disease who may require high ventilator pressures (eg, bronchiolitis, status asthmaticus, chronic lung disease) [23,24]

Cuffed ETTs also improve accuracy of capnography and decrease need for ETT changes. The clinician should test the balloon integrity prior to intubation by briefly inflating the cuff and then deflating completely. After intubation with cuffed tubes, care must be taken to avoid cuff pressures greater than 20 to 25 cm H₂O, which can increase the risk of tracheal mucosal ischemia. Clinical estimation of cuff pressure is often inaccurate, therefore an endotracheal cuff manometer or assessment of air leak should be considered in any patient requiring prolonged intubation [25,26].

Historically, uncuffed ETTs have been recommended for infants and young children to prevent pressure-induced ischemic damage to tracheal mucosa from a cuffed tube. Functional narrowing of the airway at the subglottis in children can create an effective anatomic seal without the need for a cuffed ETT in some patients. (See "Emergency airway management in children: Unique pediatric considerations".)

However, ETTs with low-pressure, high-volume cuffs in sizes suitable for infants and children have been shown to be safe and effective. Observational studies and two randomized controlled trials have demonstrated that cuffed tubes are more likely to result in placement of a correctly sized tube on the first attempt and provide better tidal volumes and less leakage during ventilation without causing an increase in acute postextubation respiratory complications (ie, postextubation stridor and/or need for racemic epinephrine) or long-term complications such as subglottic stenosis [18,19,24,27-30]. The ability to adjust cuff inflation for excessive air leak also results in less frequent need for tube change secondary to inappropriate sizing. Thus, cuffed ETTs may avoid the need for repeat intubation in critically ill children in whom air leak compromises the ability to oxygenate or ventilate effectively.

Endotracheal tube size — The ETT size for children outside of the neonatal period can be estimated based upon age (table 7) (calculator 1). For neonates, initial ETT size is based on gestational age or weight (table 8).

The size of the ETT is determined by the internal diameter, measured in millimeters (mm). Available sizes range from 2.5 mm (suitable for a preterm infant) to adult sizes of 7.0 mm or more. The appropriate size ETT for any given patient should be small enough to pass easily through the vocal cords but large enough to minimize resistance to air flow through the tube. Uncuffed tubes should fit snugly in the subglottic trachea to minimize air leak, while cuffed tubes allow for some adjustment through cuff inflation to provide appropriate endotracheal fit.

For uncuffed ETT sizing, the age-based formula 4 + (age in years/4) has been shown to be effective and accurate in children [31]. When using a cuffed ETT, selecting a tube one full size smaller than determined by the above formula was accurate 99 percent of the time [32], though with the development of newer, lower profile, thinner walled cuffed ETTs, using a tube one half size smaller than the age-based calculation is recommended (table 7) [23,33].

Other methods that have been proposed for estimating the best size uncuffed ETT in children include comparison of the outer ETT diameter width with the child's fifth finger or the width of the child's fifth fingernail with inner ETT diameter, and a derivation based on the child's length [31]. Of these methods, derivation based on the child's length is best.

Utilizing a length-based resuscitation tape (eg, Broselow-Luten tape), is as effective as age-based formulae for determining the appropriate ETT size in children with normal growth [34], as well as those with short stature [35]. Early versions, however, may not include sizing for cuffed ETTs below 5.5 mm.

Regardless of the method chosen in selecting ETT size, it is important to have available additional tubes, one size larger and one size smaller than expected, to permit rapid replacement of any poorly fitting tube.

Stylet — The clinician should generally use a stylet during emergency ETI to reinforce the rigidity of the ETT and allow the operator to direct the tube into the glottic opening.

The largest diameter stylet that fits through the ETT should be used. Tubes greater than 5.5 mm usually accommodate a larger diameter (ie, adult) stylet. Two small (pediatric) stylets may improve rigidity in smaller tubes if a single small stylet is inadequate. If the stylet does not have a friction reducing surface coating, the provider should lubricate it with water soluble lubricant to facilitate removal. Bending the styletted ETT into a hockey stick configuration enhances the ability to direct the ETT anteriorly through the glottis (picture 3) [36,37].

To avoid injury to the tracheal mucosa, care must be taken to ensure that the tip of the stylet does not pass beyond the distal end or through the Murphy's eye of the ETT. Bending the proximal end of the stylet over the adapter at the proximal end of the tube prevents inadvertent movement during intubation.

Laryngoscope handle and blade — There are two components to the laryngoscope, the handle, and the blade. Pediatric and adult sized handles are available that differ in diameter and length, though either size can be used depending on the clinician's preference. Standard geometry laryngoscope blades are either curved or straight. The choice of curved or straight blade is best made based on the experience and preference of the laryngoscopist. Curved blades have a large flange which facilitates displacement of the tongue, and a curve that promotes easy placement in the vallecula (figure 5). A straight blade permits direct lifting of the epiglottis to expose the glottic opening, which may be preferred in infants and children younger than two years of age in whom the epiglottis is often larger, floppier, and more acutely angled (figure 6). (See "Emergency airway management in children: Unique pediatric considerations".)

A straight blade may also be preferred in patients in whom cervical spine injury is suspected because laryngoscopy with a straight blade may result in less motion of the cervical spine [38].

●Laryngoscope blades range in size from 00 for the extremely premature infant to 4 for large adults. The appropriate size blade for a given patient is one that is large enough to control the tongue and to reach the glottic structures (table 9). Generally, size 0 or 1 blades are used in average-sized newborns, and size 1 blades for most infants beyond the immediate newborn period. The Wis-Hipple is available in a 1.5 size, which is convenient for children one to three years of age. The phrase "switch to size 2 at age two (years)" helps to remember this important changeover point for laryngoscope blade sizing.

●Anatomic landmarks also help identify the appropriate laryngoscope blade size. In a prospective observational study, intubation was more consistently successful on the first attempt when the length of the blade used for laryngoscopy was within one centimeter of the distance between the upper incisors and the angle of the mandible [39].

Video laryngoscope — Video laryngoscopes display the glottic view on a video monitor during endotracheal intubation. The video laryngoscope can be categorized according to the shape of the blade (acute angle [hyperangulated] versus standard geometry [ie, Macintosh or Miller type]) and whether or not they have channels that hold and guide tracheal tube advancement. (See "Video laryngoscopy and other devices for difficult endotracheal intubation in children", section on 'Video laryngoscope'.)

Postintubation and alternative airway supplies

●Confirmation devices

•Colorimetric end-tidal carbon dioxide (EtCO₂) devices or capnographic monitors are the most accurate means for confirming endotracheal intubation in patients who are not in cardiac arrest. EtCO₂ detecting devices should be available for ETT placement confirmation in any setting in which intubation is performed. (See "Carbon dioxide monitoring (capnography)", section on 'Verification of ETT placement'.)

Disposable qualitative devices use colorimetric methods to detect CO₂ in the ETT. Once the trachea is intubated and the colorimetric detector is attached, six positive pressure breaths are delivered. The device will change color (typically from purple to yellow) during exhalation when CO₂ is present. This confirms placement of the ETT in the tracheo-bronchial tree if the patient has a perfusing cardiac rhythm. Waveform EtCO₂ has also shown high sensitivity for confirming endotracheal placement in patients who are receiving effective cardiopulmonary resuscitation. (See "Carbon dioxide monitoring (capnography)", section on 'Clinical applications for intubated patients'.)

Capnography confirms ventilation by producing a continuous tracing of CO₂ levels. The presence of a regular waveform indicates successful ventilation. It is the most accurate method for confirming ETT placement. (See "Carbon dioxide monitoring (capnography)", section on 'Clinical applications for intubated patients'.)

•In patients in cardiac arrest, gas exchange in the lungs is markedly reduced and CO₂ may not be detectable, despite proper positioning of the ETT. In such situations, an esophageal bulb may be used to confirm tracheal placement in children who weigh more than 20 kg [23,40]. It relies on the principle that the esophagus is collapsible under negative pressure, whereas the trachea (which is rigid) is not. The bulb is deflated and then placed on the end of the ETT following intubation. When the grip on the bulb is released, it will remain deflated when the ETT is in the esophagus but will reinflate with gas from the trachea and lungs when the ETT is correctly positioned in the non-collapsible trachea.

•Based upon small observational studies and a systematic review, bedside ultrasound (eg, direct visualization of the ETT in the trachea, lung sliding, and diaphragmatic ultrasound) has promise as an alternative means for rapid confirmation of ETT placement [41-47]. Depending upon the method used, the sensitivity for correct tube placement relative to chest radiograph or capnography varied from 91 to 100 percent and overall accuracy was 89 to 98 percent. In some studies, confirmation of correct endotracheal position was obtained as quickly as 17 seconds using a curvilinear probe. However, confirmation was more difficult in patients who had short necks or were wearing cervical collars. The use of ultrasound as an adjunct for confirmation of ETT placement warrants further validation.

●Alternative airway supplies – Alternative strategies and appropriate equipment for providing oxygenation and ventilation must be considered for the child who may be difficult to intubate with direct laryngoscopy. These techniques may be temporizing (such as laryngeal mask airway, Combitube, or a surgical airway) or provide alternative approaches to endotracheal intubation (as with fiberoptic intubation, gum elastic bougie, a lighted stylet, or a video laryngoscope). (See "The difficult pediatric airway for emergency medicine", section on 'Techniques' and "Video laryngoscopy and other devices for difficult endotracheal intubation in children".)

●Miscellaneous supplies

•Tape or a commercial holder to secure the ETT.

•Tincture of benzoin to enhance the holding power of the tape.

•Gauze or cotton-tipped applicator for benzoin application.

•5 to 10 mL syringe for cuff inflation.

•A nasogastric or orogastric tube to decompress the stomach following intubation. Insufflated air from BMV or residual gastric contents should be removed to decrease the risk of aspiration and improve diaphragmatic excursion.

PROCEDURE — Direct laryngoscopy and ETI are complex processes. Developing a systematic and reproducible approach to this procedure will improve success.

A mnemonic (SOAP ME) has been developed to help practitioners remember the preparatory tools and steps for ETI (see 'Preparation' above):

●S: Suction

●O: Oxygen

●A: Airway equipment (laryngoscope blades, handles, tubes, stylet, oral and nasal airways)

●P: Pharmacopeia/positioning

●M: Monitoring

●E: Equipment (with end-tidal carbon dioxide [EtCO₂])

Monitoring — Continuous cardiorespiratory monitoring and pulse oximetry prior to intubation are essential. Capnography should be utilized to confirm and monitor endotracheal tube (ETT) position after intubation. Patients requiring emergency ETI may have significant cardiovascular or respiratory compromise. In addition, profound physiologic changes may occur as a result of medication delivery, the mechanical stimulation from laryngoscopy and/or ETI, and the physiologic change from spontaneous (negative pressure) to assisted (positive pressure) ventilation.

Preoxygenation — Preoxygenation with the maximal possible fraction of inspired oxygen creates an oxygen reservoir, primarily by washing nitrogen out of the functional residual capacity of the lungs and replacing it with oxygen. This increased lung store of oxygen, in combination with the improved oxygen delivery within the circulation and body tissues, serves to delay or avoid hypoxemia resulting from prolonged apneic periods during ETI. Thus, preoxygenation should be performed even in patients with normal oxygen saturation.

Patients without spontaneous respirations require immediate institution of bag-mask ventilation (BMV) with maximal possible fraction of inspired oxygen.

Preoxygenation has traditionally included administration of oxygen using a nonrebreather mask for three to five minutes in the spontaneously breathing patient. Although two minutes may be sufficient in healthy children [48,49], emergency intubations are often performed in patients with compromised pulmonary function or respiratory effort who may benefit from more prolonged oxygen delivery prior to the procedure. In general, children have less functional residual capacity and higher oxygen utilization and, thus, will become hypoxic more quickly than adults, regardless of the method of preoxygenation. (See "Emergency airway management in children: Unique pediatric considerations", section on 'Lower functional residual capacity'.)

Rarely, children with gastric distension after bag-mask ventilation have restricted lung excursion on inhalation and are difficult to preoxygenate. Placement of a gastric tube in these patients is warranted prior to ETI despite the risk of vomiting. Venting of a gastric or gastrostomy tube, when present, also relieves gastric distension without adding any additional risk of emesis.

Suction — Two suction devices (eg, Yankauer or wide-bore tonsil tip catheters) should be immediately available at the bedside and attached to a wall unit suction that is turned on and limited to a maximum of 120 mmHg. (See 'Materials, equipment, and personnel' above.)

Positioning — Proper positioning aligns the pharyngeal, tracheal, and oral axes into the "sniffing position" (picture 4). This maintains the patency of the airway once the child becomes unconscious, as well as facilitates visualization of laryngeal structures during subsequent intubation.

●To align the pharyngeal and tracheal axes, the chin is moved anteriorly with respect to the shoulders, such that the external auditory canal is anterior to the shoulder and aligned with the sternal notch. This may be accomplished in older children by placing a towel roll under the occiput. In infants, because of a prominent occiput, the towel should be placed under the shoulders to achieve this position (picture 5). (See "Emergency airway management in children: Unique pediatric considerations".)

●To align the oral axis with the pharyngeal and tracheal axes, the head is then extended on the neck, such that the nose and mouth are pointing toward the ceiling. This may be accomplished by placing the palm of the right hand on the patient's forehead with the fingers extending onto the occiput, cupping the head and gently rotating the head posteriorly (figure 7). This maneuver also opens the patient's mouth, facilitating insertion of the laryngoscope.

Cervical spine immobilization — For the child with a suspected cervical spine injury, neck movement must be minimal during positioning and laryngoscopy. Initially, the airway can be opened with the jaw thrust maneuver (figure 8). If a cervical collar is in place, the front should be opened to allow complete mouth opening and displacement of the chin and mandible [50]. Manual in-line stabilization should be maintained by an assistant during laryngoscopy and intubation (figure 9) [7,23].

Pediatric-specific data from a simulator-based study support the protective effects of inline stabilization [51]. However, the practice of inline stabilization has been challenged on grounds that it increases laryngoscopic force [52], compromises view and intubation success [53], and inconsistently decreases cervical spine movement. Thus, the balance between minimizing neck movement must be weighed against the possibility of insufficient glottic visualization and an unsuccessful intubation attempt. The safest practice is to provide the minimum amount of force and movement necessary to allow for successful completion of endotracheal intubation. (See "Pediatric cervical spinal motion restriction", section on 'Motion restriction during airway management'.)

Induction (sedation) and neuromuscular blockade — Rapid sequence intubation (RSI) typically achieves optimal conditions for laryngoscopy in children requiring emergency intubation (table 10). RSI involves the delivery of a sedative and neuromuscular blocking agent to sedate and pharmacologically paralyze so that movement and protective airway reflexes do not interfere with ETI. (See "Rapid sequence intubation (RSI) in children for emergency medicine: Approach".)

RSI may be modified in the following circumstances:

●Sedative agents may be omitted in obtunded or comatose patients.

●Neuromuscular blockade should be avoided in patients with a predicted difficult airway unless a back-up approach is available.

Once RSI medications are provided, the clinician should limit BMV because of the increased risk of vomiting and aspiration that can occur with gastric distention. However, in patients who cannot be adequately preoxygenated or who are likely to desaturate quickly, BMV with small tidal volumes and cricoid pressure to reduce gastric insufflation is preferable to intubating a hypoxic patient. BMV may also be continued in patients with severe metabolic acidosis where prolonged apnea may result in increasing pCO2, compounding the acidosis. Nasal cannula oxygen delivery to the apneic patient following administration of RSI medications can also decrease the likelihood of hypoxemia. The optimal flow of oxygen for this practice in pediatrics has not been determined. Our approach is to provide apneic oxygenation using 1 to 2 L/min per year of age (maximum flow rate, 15 L/min) via nasal cannula. Higher flow rates may be utilized when using heated, humidified nasal cannula delivery. (See "Rapid sequence intubation (RSI) in children for emergency medicine: Approach", section on 'Preoxygenation'.)

Laryngoscopy

Video versus direct laryngoscopy — Laryngeal exposure with visualization of the glottis is a key determinant of success or failure for endotracheal intubation (ETI). During emergency endotracheal intubation (ETI) in children, we suggest use of a videolaryngoscope (VL), if available, rather than traditional direct laryngoscope (DL), although some experienced clinicians continue to prefer DL based upon their expertise and which device is most immediately available [54-59]. The technique for use of video laryngoscopes equipped with standard geometry (ie, Miller- or MacIntosh-type) blades is similar to direct laryngoscopy as discussed below. (See 'Technique' below.)

Some experts refer to the use of a VL with a standard geometry laryngoscope blade as "video-assisted laryngoscopy" because it permits direct and/or indirect laryngoscopy for the primary proceduralist, with the additional benefit of a shared view that allows coaching from an experienced physician observer and a safe means of guiding less experienced proceduralists during emergency ETI for [59].

The use of VL with standard geometry blades may encompass viewing the laryngeal structures indirectly, directly, or in combination. For intubations in children with normal mouth opening and without concern for cervical spine injury, VL with standard geometry blades rather than acute angle blades permits direct and indirect laryngoscopy during ETI and easier passage of the endotracheal tube. The shape of the acute angle video laryngoscope blade permits intubation without neck movement, making it a good choice for intubation of trauma patients and those with limited cervical spine mobility. However, acute angle laryngoscopy only provides indirect visualization of the airway and delivery of the tracheal tube requires that the tube tip is bent to form a 60- to 80-degree angle with its body. (See "Video laryngoscopy and other devices for difficult endotracheal intubation in children", section on 'Acute angle blade'.)

Observational studies that compare use of a VL with a traditional DL for emergency pediatric endotracheal intubation (ETI) have found that VL is associated with either similar or reduced frequency of adverse effects; and similar or higher first attempt success rate [54-60]. For example, in a cohort study of over 1400 ETIs performed in pediatric emergency departments, use of video-assisted laryngoscopy, when compared with traditional DL, was associated with higher odds of first-attempt success (odds ratio [OR] 2.01, 95% CI 1.48-2.73) and decreased odds of severe adverse airway outcomes such as aspiration, severe hypoxia, unrecognized esophageal intubation, hypotension, or cardiac arrest (OR 0.70, 95% CI 0.58-0.85) [54]. Emergency departments with high use of video-assisted laryngoscopy (>80 percent of intubations) had higher odds of first-attempt success than sites with low use (<20 percent of intubations) even after adjusting for the type of laryngoscopy used on individual patients (adjusted OR [aOR] 2.30, 95% CI 1.79-2.95). During implementation of routine VL with standardized coaching by an attending in 10 pediatric intensive care units, over 3,500 ETIs using VL were performed, and VL during ETI increased from 30 percent (baseline) to 89 percent of ETIs. VL was associated with lower adverse events compared with DL (9 versus 15 percent, aOR 0.61, 95% CI 0.46 to 0.81) [59]. In another multicenter retrospective study of nearly 500 children undergoing ETI in pediatric emergency departments, first pass success was also similar for VL versus DL although VL was used for the entire procedure in only 35 percent of patients [60].

Additional indirect evidence from clinical trials involving children undergoing elective intubation in the operating room also supports VL rather than DL for rapid sequence induction and intubation in neonates, infants, and in older children with difficult airways (eg, limited mouth opening, cervical spine immobility, or severe micrognathia due to genetic syndromes such as Pierre Robin or Treacher Collins). These data are discussed separately. (See "Airway management for pediatric anesthesia", section on 'Choice of intubation technique' and "Management of the difficult airway for pediatric anesthesia", section on 'Alternative intubation techniques'.)

Technique — When using either a video laryngoscope with a standard geometry blade or a traditional laryngoscope and handle, direct laryngoscopy is most easily performed with the clinician standing at the patient’s head and the bed adjusted to the level of the laryngoscopist's xiphoid. The ETT, with stylet in place, and suction equipment should be easily accessible. ETTs that are one size above and below the estimated size for age (children (table 7) (calculator 1)) gestational age or weight (neonates (table 8)) should also be available. (See 'Materials, equipment, and personnel' above.)

Whenever possible, an assistant should stand to the right of the patient's head to assist with optimal positioning and to hand items to the intubator. Once the child is completely relaxed, the following steps are performed:

●Opening the mouth – The mouth is opened using either of two techniques: a scissor technique in which the thumb of the operator's right hand pushes the lower incisors (or mandibular gum) caudad while the index or middle finger (placed posterior to the thumb) pushes the upper incisors (or maxillary gum) cephalad (picture 6), or in a patient without cervical spine restrictions, extension of the head will naturally open the mouth (see 'Positioning' above). This can be augmented by applying caudad pressure on the chin using the fifth finger of the left hand (figure 6).

●Inserting the laryngoscope – The laryngoscope is held in the left hand, regardless of the practitioner's hand dominance. The most common approach is to insert the blade into the right side of the patient's mouth, taking care not to catch the lower lip against the teeth, which may lacerate the lip. Asking an assistant to retract the lip off the teeth can be helpful. Within the oral cavity, the blade is passed under direct visualization along the base of the tongue following the natural contour of the pharynx. The tongue is swept to the left as the laryngoscope is advanced into midline of the hypopharynx (figure 10). An alternative approach is to pass the blade down the midline. The advantage of this method is that it may avoid the blade getting caught on pharyngeal folds and may also permit easier identification of recognizable anatomic structures such as the epiglottis [61].

●Retracting the tongue and soft tissues – Once in the midline of the oropharynx, the laryngoscope blade should be used to lift the mandibular block. This can be accomplished by applying force away from the laryngoscopist along the long axis of the handle (figure 5). The laryngoscope should not be "rocked" backward, using the upper palate or incisors as the fulcrum for leverage. This improper technique will decrease the space within the oral cavity, making it difficult to pass the ETT under direct visualization. In addition, injury to the mouth, gingiva, or teeth can occur when the blade is levered against these structures. Keeping the wrist straight will help prevent inadvertent levering.

●Identifying glottic structures – After the tongue and soft tissues have been retracted, the aim is to identify recognizable anatomic structures within the extrathoracic airway. As the laryngoscope blade is advanced into the pharynx, the epiglottis will often come immediately into view (figure 11). This is the landmark that is most useful when identifying the remainder of the glottic structures. At this point, suction is often needed to remove saliva, blood, or debris and optimize the glottic view.

Several laryngoscopic adjustments can be made if the epiglottis is not seen immediately:

•The epiglottis may be lying flat against the posterior pharyngeal wall or folded on itself, making it difficult to distinguish from surrounding mucosal surfaces. Additional elevation of the mandibular block may help separate the epiglottic rim from surrounding tissue.

•The laryngoscope blade may not be midline, often as a result of challenges in sweeping the tongue from right to left. Repositioning the blade using the uvula as a midline reference point may be helpful.

•If neither the epiglottis nor the glottic structures are visible, the laryngoscope blade can be advanced fully, placing the blade tip in the esophagus. The blade is then pulled back slowly. The first structure to fall into view will be the glottis, followed by the epiglottis. Some experts recommend routine use of this approach with blind insertion beyond the larynx and locating identifiable structures as the blade is withdrawn, particularly when intubating infants [62].

●Elevating the epiglottis – After the epiglottis has been identified, it needs to be elevated to expose the underlying vocal cords and glottic opening. The technique employed varies based on the type of blade being used.

When using a straight blade, the tip of the blade is commonly positioned under the epiglottis to lift it directly (figure 6). The epiglottis is frequently large, floppy, and covered with airway secretions and therefore may easily slide off the blade. If this occurs, the blade should be repositioned beneath the epiglottis, and it should be carefully lifted again. Alternatively, the straight blade can be placed in the vallecula, and the epiglottis indirectly lifted with elevation of the mandibular block.

When using a curved blade, the tip of the blade is pressed against the deepest portion of the vallecula (median glossoepiglottic fold) to place tension on the hyoepiglottic ligament, which will help suspend the epiglottis.

Once the blade (straight or curved) is positioned correctly, force is applied upward and forward along the long axis of laryngoscope handle at approximately 45 degrees. This will lift the mandibular block and the epiglottis to expose the glottic opening (figure 5 and picture 1)

Laryngoscope blade positioning has an important impact on airway visualization. For example, in a prospective cohort study of 171 video-laryngoscopy attempts performed with either a curved or straight standard geometry laryngoscope blade in a children's hospital emergency department (first-pass success rate 83 percent), directly lifting the epiglottis compared with indirectly lifting it with the blade in the vallecula was associated with a better glottic view but not a higher overall success rate [63]. When the laryngoscope blade was placed in the vallecula, engagement of the median glossoepiglottic fold was associated with better visualization and overall procedural success.

Adjusting for suboptimal view — Ideally, with appropriate positioning and laryngoscopy, the vocal cords and glottic aperture will be quickly identified. In selected pediatric patients with poor visualization of the larynx, external laryngeal manipulation or cricoid pressure may improve the glottic view:

●External laryngeal manipulation (bimanual laryngoscopy or BURP maneuver) – If little or none of the glottic opening is visualized despite appropriate positioning of the patient and the laryngoscope blade, external laryngeal manipulation (ELM) may improve the view in some patients (eg, children with anteriorly located airways due to congenital anomalies or trauma patients undergoing intubation with cervical spinal motion restriction in place). However, routine use of ELM in children has not been associated with improved first pass success rates and may not be beneficial.

Bimanual laryngoscopy, also called ELM, entails manipulating the thyroid cartilage or hyoid bone with the right hand in order to improve the view of the glottis (picture 7) (see "Direct laryngoscopy and endotracheal intubation in adults", section on 'Bimanual laryngoscopy (external laryngeal manipulation)'):

•While holding the laryngoscope in the left hand, posterior displacement of the larynx is achieved with external pressure applied at the thyroid cartilage with the right hand.

•Once the optimal glottic view is obtained, the laryngoscopist has an assistant place their fingers in exactly the same spot on the thyroid cartilage, using the same direction and degree of force necessary to maintain the view. This can be facilitated using the shared view available with VL.

Alternatively, backward-upward-rightward pressure (BURP) is applied to the larynx by an assistant. The BURP maneuver has been demonstrated to improve glottic exposure in some patients by moving the larynx more into the line of vision [64,65]; however, it may compromise visualization when used in conjunction with traditional cricoid pressure [66].

Data regarding the use of external laryngeal manipulation in pediatric airway management are limited [67-69]. In a retrospective study using an international multicenter registry of over 7800 infants and children undergoing ETI in pediatric intensive care units, ELM was associated with lower first-pass successful intubation (unadjusted first-pass success with and without ELM 59 versus 68 percent, respectively) [69]. This lower success rate for ELM remained significant after adjusted analysis (aOR 0.93, 95% CI 0.90-0.95) although residual confounding may contribute to this finding.

●External laryngeal manipulation (Cricoid pressure) – Cricoid pressure was originally described in adults as pressure on the cricoid cartilage to occlude the posteriorly seated esophagus to prevent aspiration. This posterior pressure has also been described as a means to posteriorly displace the laryngeal structures to improve visualization. Distinguishing the cricoid cartilage from the thyroid cartilage may be challenging in young children, and both efforts can be included under the description of external laryngeal manipulation (ELM). Adjusting the location of pressure on the anterior neck may be an important part of optimizing ELM. When used, it should be applied after the sedative is administered and the patient becomes unconscious. If ELM does not improve or worsens the view, it should be removed immediately, and external laryngeal manipulation attempted [70,71].

Cricoid pressure may also help prevent gastric insufflation during bag-mask ventilation although regurgitation can still occur and is considered optional for this purpose. However, during RSI, bag-mask ventilation should be limited whenever possible (see "Rapid sequence intubation (RSI) in children for emergency medicine: Approach", section on 'Protection'). If cricoid pressure makes bag-mask ventilation more difficult due to occlusion of the airway, then it should be relaxed or removed.

Cricoid pressure has historically been proposed as a means to prevent passive regurgitation of gastric contents during laryngoscopy and intubation. However, conflicting evidence exists regarding the effectiveness of cricoid pressure for preventing regurgitation and ELM may better improve visualization of the glottis. Therefore, we prefer to use the ELM technique during RSI. (See "Rapid sequence intubation (RSI) in children for emergency medicine: Approach", section on 'Cricoid pressure' and "Rapid sequence intubation in adults for emergency medicine and critical care", section on 'Positioning and protection'.)

Passing the endotracheal tube — Once the glottic opening has been identified, the final step is passage of the ETT. While maintaining a view of the glottic opening, the intubator receives the tube in his/her right hand from a previously assigned assistant. The tube is held like a pencil, between the thumb and first two fingers (figure 12). Having an assistant place traction on the right corner of the mouth can provide improved visualization and additional room to accommodate the ETT entering the mouth (figure 13).

The tube enters the right side of the mouth and is advanced toward the larynx in a horizontal plane. Passage of the tube directly along the barrel of the laryngoscope blade will obscure visualization of the glottic opening and should be avoided. The ETT should be passed through the vocal cords under direct visualization. Once the tip has passed through the vocal cords, the tube is rotated to the upright position (figure 14). Although the tendency is for the intubator to move closer to the patient to improve view, this may compromise binocular vision and depth perception.

Depth of insertion — The ideal location for the ETT tip is at the midpoint between the thoracic inlet and the carina. There are a number of ways to guide the proper depth of insertion for the ETT in children outside of the neonatal period [72,73]:

●Placing the double line on the uncuffed ETT at the glottis

●Inserting the cuffed ETT until the cuff is just beyond the vocal cords

●Using the depth provided by the length-based resuscitation tape

●Inserting the tube until the centimeter marking at the lip is three times the size (internal diameter) of the ETT

This last calculation will result in the ETT being correctly positioned more than 80 percent of the time, when using an appropriately size ETT [74].

Additional techniques, less commonly used during emergency intubation, include deliberately advancing the ETT to create an endobronchial intubation and then withdrawing the tube 2 cm beyond the passage of the carina [75], and palpation of the tube tip at the suprasternal notch [76].

The depth of insertion in neonates, including pre-term infants, is based upon weight (table 11) or nasal-tragal length. (See "Neonatal resuscitation in the delivery room", section on 'Endotracheal intubation'.)

Initiate positive pressure ventilation — The laryngoscope can now be removed from the mouth while the tube is held securely against the roof of the mouth, or by grasping the tube using the index finger and thumb with the remaining three fingers holding the patient's face. If a cuffed tube is being used, the cuff should be inflated at this time.

Positive pressure ventilation should be initiated with 100 percent inspired oxygen via a resuscitation bag with a carbon dioxide detector attached to the ETT. The bag should initially be squeezed with enough force and volume to provide chest wall movement.

Subsequent ventilatory strategies can be made based on noninvasive measures of oxygenation and ventilation or based on results of blood gas analyses. If a large air leak is noted at this time, cuff inflation may be adjusted accordingly. However, persistent leak after cuff inflation may require the tube to be changed to a larger size.

If an uncuffed ETT is in place, then the air leak pressures should ideally occur at less than 25 cm H₂O, while still allowing for effective ventilation. Air leak pressures up to 40 cm H₂O have been shown to be safe.

Confirming tube position — Immediately following intubation, placement of the ETT in the trachea must be confirmed. Clinical assessment for appropriate tube position includes:

●Visible chest wall rise

●Auscultation of breath sounds in both axillae and not heard over the stomach

●Adequate oxygenation as demonstrated by continuous pulse oximetry

●Mist should be present in the ETT

However, because clinical evaluation is not completely accurate, confirmatory devices should be used [77].

●End-tidal carbon dioxide (EtCO₂) should be detected using either a colorimetric device or capnography and is the most definitive method of confirming that the ETT is in the tracheobronchial tree [23,78].

●A self-inflating bulb may also be used for children weighing more than 20 kg and may be particularly useful for confirming tube position in patients in cardiac arrest. (See 'Materials, equipment, and personnel' above.)

●Although use in pediatric practice is limited, bedside ultrasound can rapidly confirm intratracheal position when performed by properly trained clinicians. (See 'Postintubation and alternative airway supplies' above.)

Securing the tube — After correct position is confirmed, the ETT must be firmly secured. The most common approach is to tear longitudinally down the midline of a length of cloth or silk tape, creating a Y-shape. One segment is wrapped around the tube and the base segment is placed across the cheek (figure 15). Preparing the underlying skin with a layer of benzoin, which is allowed to air dry, can provide additional adherence. Alternatively, commercial tracheal tube holders may be utilized to secure the ETT. These devices have been shown to be rapidly applied in adults and to have reasonable resistance to extubation forces, although in most instances, tape is stronger [79]. However, commercial ETT holders have not been specifically studied in infants and young children.

Post-intubation care

●Post-intubation imaging – After immediate confirmation of ETT placement as described above, an anterior-posterior chest radiograph should be obtained to confirm the location of the tip of the ETT [80]. Optimal position is located at a minimum of one to three centimeters above the carina and below the thoracic inlet. Tube depth may be adjusted based on radiographic position. Preliminary evidence suggests that bedside ultrasound, performed by clinicians experienced with this technique, may also be useful for directly determining the position of the ETT within the trachea, or confirming appropriate position by documenting bilateral lung sliding. However, this is not common practice at this time and should not replace radiography [41-47].

●Gastric decompression – An orogastric or nasogastric tube should be placed following intubation to decompress the stomach. Gastric distension can occur secondary to crying or insufflation following BMV. In addition, because emergency intubation may be performed on non-fasted patients, residual gastric contents may be present and should be evacuated. Gastric decompression can decrease the risk of aspiration around the ETT, as well as improve diaphragmatic excursion and patient ventilation.

●Minimize head movement – Care must be taken to avoid significant head movement in patients who have been intubated. Multiple studies have demonstrated that a significant percentage of ETTs can become malpositioned with neck movement [81-83]. Flexion of the neck may result in the tube advancing into an endobronchial position with resultant limited ventilation of one lung, while neck extension can lead to unintended extubation.

●Positive pressure ventilation – Ventilation strategies vary based on underlying disease process, whether ongoing sedation and neuromuscular blockade is needed, and subsequent management plans. These details are discussed elsewhere. (See "Acute severe asthma exacerbations in children younger than 12 years: Intensive care unit management" and "Initiating mechanical ventilation in children".)

COMPLICATIONS — Acute complications from laryngoscopy and intubation can occur at multiple points during the procedure.

Before laryngoscopy/intubation

●Gastric distension – Bag-mask ventilation (BMV) may cause gastric distension, leading to diminished lung capacity and increased risk of regurgitation.

•Applying cricoid pressure (Sellick maneuver) may decrease this risk.

•If significant distension has occurred, placing an orogastric or nasogastric tube to suction can help decompress the stomach. However, gastric tube placement may also stimulate vomiting in the patient, which will increase the risk of aspiration of gastric contents.

During laryngoscopy/intubation

●Hypoxemia – Sustained periods of inadequate oxygen delivery may lead to ischemic brain injury, the most significant complication of ETI.

•Inadequate preoxygenation will shorten safe apnea time. Preoxygenation with maximal FiO₂ for a minimum of three minutes or with BMV as needed will increase the oxygen reservoir within the patient's lungs, circulation, and tissues.

•Prolonged laryngoscopy (even with adequate preoxygenation) will lead to hypoxemia. Monitoring via continuous pulse oximetry is essential to recognize inadequate oxygenation. If desaturation occurs, the intubation attempt should be discontinued. Before another attempt is initiated, the patient should receive BMV until oxyhemoglobin saturations improve. If cricoid pressure is in place, then it should be continued during BMV provided it is not compromising ventilation.

An alternative approach is to time laryngoscopy duration during the intubation attempt and discontinue it if the attempt is unsuccessful within a specific time period (eg, 30 to 45 seconds). This may prevent oxyhemoglobin desaturation during pediatric RSI but may also result in more laryngoscopy attempts. In one observational study that used video review of 114 children (median age 2.4 years) undergoing RSI in a pediatric emergency department, at least one episode of oxyhemoglobin desaturation (pulse oximetry <90 percent) occurred in 33 percent of patients [84]. Oxyhemoglobin desaturation was more common in children two years of age or younger compared with older children (59 versus 10 percent) and was strongly associated with the duration of laryngoscopy; 82 percent of patients experiencing desaturations had laryngoscopy durations of 30 seconds or longer. There was no association between the number of intubation attempts and desaturation.

●Bradycardia – Profound bradycardia can occur during laryngoscopy and intubation as follows:

•Vagal response from stimulation of the hypopharynx, lifting the epiglottis, or rarely, the use of succinylcholine can lead to bradycardia, particularly in infants and young children [85].

•Hypoxemia can also result in secondary bradycardia in infants.

•Atropine may help prevent vagal mediated bradycardia but will be ineffective in cases of hypoxemia. It may be used during emergency intubations in the following patients (see "Rapid sequence intubation (RSI) in children for emergency medicine: Approach", section on 'Pretreatment'):

-Infants younger than 1 year of age to prevent vagally-induced bradycardia

-Infants and children with septic or late-stage hypovolemic shock

-Children ≤5 years of age receiving succinylcholine and children >5 years of age receiving a second dose of succinylcholine

●Increased intracranial pressure (ICP) – Intracranial pressure may increase during laryngoscopy as a result of increased cerebral arterial pressure during laryngoscopy [86,87].

•Increases in ICP are of little clinical significance except for patients who already have elevated pressures, and in most circumstances, the benefits of securing the airway and preventing hypoxemia are critical in these patients. Adequate use of sedatives may help attenuate increases in ICP. (See "Rapid sequence intubation (RSI) in children for emergency medicine: Approach".)

●Mechanical trauma – Soft tissue injury can occur anywhere along the extrathoracic airway.

•Laryngoscopy may cause trauma to the alveolar ridge or teeth. Use of the upper incisors or maxillary gums as a fulcrum during laryngoscopy greatly increases this risk.

•Abrasion or laceration of the lips, tonsils, or pharyngeal mucosa can occur and may lead to bleeding, which can impair visualization and lead to airway obstruction.

•The laryngoscope blade or endotracheal tube (ETT) can injure the vocal cords and lead to vocal cord paralysis. Using equipment of appropriate size and ensuring laryngoscopy and intubation are performed under direct visualization minimizes this risk.

●Aspiration – Aspiration of oral or gastric contents during laryngoscopy or intubation can occur. The severity of any subsequent pneumonitis is related to the acidity, volume, and presence of particulate matter in the aspirated material.

•In inadequately sedated patients, direct laryngoscopy may stimulate the gag reflex, which may induce vomiting.

•Based on limited data, cricoid pressure is no longer routinely indicated to prevent aspiration during ETI.

After intubation

●Hypoxemia – Inadequate oxygenation following laryngoscopy and attempted intubation will have different etiologies than those occurring during the procedure.

●Esophageal or tracheal tube malposition – Endotracheal tubes that are not properly situated within the trachea can lead to adverse clinical outcomes. Unrecognized esophageal tube position is a relatively common etiology of hypoxemia after attempted ETI [88,89]. In most cases, this can be identified with absence/loss of end-tidal carbon dioxide (EtCO₂) detection even before hypoxemia occurs [90,91].

•The ETT may be advanced too far, resulting in an endobronchial intubation, most commonly right mainstem, aerating only one lung.

•An ETT which is not advanced past the thoracic inlet is at increased risk of becoming dislodged, leading to inadequate oxygenation.

•Confirming ETT position by chest radiograph, minimizing head movement following intubation, and utilizing continuous oxygen saturation monitoring and quantitative EtCO₂ detection (where available) can help prevent complications from a malpositioned tube.

●Tube obstruction – Obstruction of an ETT can occur when the tube tip is against a mucosal surface, from intraluminal inspissated secretions, or if the tube kinks. Inadequate air flow can result in hypoxemia and hypercapnia.

•Repositioning the head may relieve distal tip obstruction or kinking.

•Deep suctioning with a flexible catheter following instillation of saline is often effective in removing secretions and restoring tube patency.

•If neither of these techniques resolves the obstruction, the tube should be removed and BMV initiated, until a new ETT can be placed.

●Barotrauma – By definition, positive pressure ventilation puts patients at risk for pulmonary barotrauma, including pneumomediastinum and pneumothorax.

•Patients with chronic lung disease and decreased lung compliance are at higher risk.

•Pneumomediastinum is self-limited and usually requires no intervention.

•Patients who develop pneumothorax while receiving positive pressure ventilation may develop tension physiology and therefore require concomitant tube thoracostomy.

●Post-obstructive pulmonary edema – When intubation is performed to relieve upper airway obstruction, the resultant changes in intrathoracic pressure can lead to pulmonary edema [92,93].

•Post-obstructive pulmonary edema, also known as negative pressure pulmonary edema, is difficult to prevent once obstruction has occurred.

•Treatment is supportive with supplemental O₂, positive pressure ventilation, and diuretics in patients who have no hemodynamic compromise.

●Adverse events from medications – Complications related to medications for sedation and neuromuscular blockade may also occur. This may include medication-specific adverse reactions as well as complications from dosing outside the therapeutic window. (See "Rapid sequence intubation (RSI) in children for emergency medicine: Approach".)

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Airway management in children".)

SUMMARY AND RECOMMENDATIONS

●Infection control precautions – For children with suspected highly contagious and virulent airborne pathogens such as early COVID-19 variants prior to the availability of effective vaccines, there is a significant risk for transmission during laryngoscopy, endotracheal intubation, and other airway management procedures. Techniques designed to improve patient care, minimize infectious risks to care providers, and decrease spread of pathogens are essential and provided separately. (See "Rapid sequence intubation (RSI) in children for emergency medicine: Approach", section on 'Infection control precautions'.)

●Indications – Specific indications for ETI fall into four different categories (see 'Indications' above):

•Inadequate oxygenation or ventilation (table 1) (see "Acute respiratory distress in children: Emergency evaluation and initial stabilization", section on 'Evaluation')

•Inability to maintain and/or protect the airway

•Potential for clinical deterioration

•Prolonged diagnostic studies or transport in an unstable patient

●Contraindications and precautions – Assessment and management of the airway is always the first priority in caring for acutely ill or injured children. Thus, there are no absolute contraindications for endotracheal intubation (ETI) by appropriately trained providers. Relative contraindications are uncommon but do exist and primarily relate to the need to move to a more controlled environment or to perform a surgical approach to the airway. (See 'Contraindications and precautions' above.)

●Anatomic features of the airways of infants and children that affect the approach to intubation are reviewed in detail separately. (See "Emergency airway management in children: Unique pediatric considerations".)

●Preparation – Success in airway management depends on careful patient assessment, implementation of an appropriate ETI plan, and gathering and testing of all necessary equipment. Use of a pre-intubation checklist (figure 3) is encouraged to avoid errors. (See 'Preparation' above and 'Pre-intubation checklists' above.)

The following mnemonic can also help practitioners remember the necessary equipment and preparatory steps for ETI (see 'Materials, equipment, and personnel' above):

•S: Suction

•O: Oxygen

•A: Airway equipment (laryngoscope blades, handles, tubes, stylet, oral and nasal airways)

•P: Pharmacopeia/positioning

•M: Monitoring

•E: Equipment (with end-tidal carbon dioxide [EtCO₂])

●Laryngoscope blade and endotracheal tube selection – Appropriate laryngoscope blade and endotracheal tube size by age are shown in the table (table 9). The ETT size for children outside of the neonatal period can also be estimated using an age-based formula (table 7) (calculator 1). Cuffed ETTs are equally as safe as uncuffed tubes and are favored in most clinical circumstances. (See 'Endotracheal tube' above and 'Depth of insertion' above.)

For neonates, initial uncuffed ETT size (table 8) and depth of insertion (table 11) are based on gestational age or weight.

●Procedure – The table provides a summary of emergency endotracheal intubation in children (table 12). During emergency endotracheal intubation in children, we suggest video laryngoscopy (VL), if available, rather than traditional direct laryngoscopy (DL) (Grade 2C). However, some experienced clinicians continue to prefer DL based upon their expertise and which device is most immediately available. A range of VL devices are available that include standard geometry and acute angle blades. Standard geometry blades permit both direct and indirect laryngoscopy and can be used in children with normal mouth opening and without concern for cervical spine injury. By contrast, acute angle blades permit only indirect laryngoscopy. (See 'Procedure' above and 'Video versus direct laryngoscopy' above.)

Immediately following intubation, placement of the endotracheal tube (ETT) in the trachea must be confirmed using an end-tidal CO₂ detector and clinical assessment. A self-inflating bulb may also be used for children weighing more than 20 kg and may be particularly useful for confirming tube position in patients with cardiac arrest. (See 'Confirming tube position' above.)