Optimizing Pediatric Intubation

Introduction

• Tracheal intubation failure in children can lead to critical events, including life-threatening hypoxemia and cardiac arrest. Infants and small children are at a higher risk for difficult tracheal intubation and related complications.^1,2
• In the first report from the Pediatric Difficult Intubation (PeDI) registry, more than two tracheal intubation attempts, a weight less than 10kg, short thyromental distance, and three direct laryngoscopy attempts before an indirect technique were associated with an increased risk of complications.¹
• More recently, a secondary analysis of tracheal intubations of the Neonate and Children audit of Anaesthesia pRactice IN Europe (NECTARINE) trial found a high incidence (5.8%) of difficult tracheal intubations (defined as more than two direct laryngoscopy attempts) in children younger than 60-weeks postconceptual age resulting in severe hypoxemia (SpO2 <90% for 60 seconds) in 40% of patients.³
• Therefore, every neonatal tracheal intubation should be considered a critical event.⁴ We should optimize the conditions for first attempt tracheal intubation success without adverse effects in this vulnerable population.
• Team dynamics, delegation of roles, checklists, time-outs, backup plans/personnel, and other human factors play an important role.⁴ Airway management is not limited to choosing the right device for airway instrumentation and being proficient in its use, but also includes other essential components of airway management such as oxygenation and maintenance of adequate anesthetic depth.⁴

Passive Oxygenation

• Hypoxemia related to tracheal intubation is an important cause of morbidity and mortality in children.^3,5 Reduced functional residual volume and increased oxygen consumption make small children and neonates prone to hypoxemia during laryngoscopy.
• Supplemental oxygenation is an important factor in optimizing tracheal intubation and its safety.
• Providing passive oxygenation increases the apnea tolerance time during intubation, potentially leading to a calmer, less hurried, and less traumatic intubation.⁵
• In a study involving young children undergoing general anesthesia requiring tracheal intubation for elective surgery, conventional low-flow oxygen (100% oxygen at 0.2 L/kg/min) and transnasal humidified rapid insufflation ventilator exchange (THRIVE) 100% oxygen, significantly prolonged apnea time with no significant difference between the two techniques.⁶
• A recent randomized controlled trial found that among infants undergoing endotracheal intubation, nasal high-flow oxygen during the procedure improved the likelihood of successful intubation on the first attempt.⁷
• There are several methods of providing supplemental oxygen, including conventional nasal cannula, modified nasopharyngeal airway, and a swivel adapter connecting the supraglottic airway device to the anesthesia machine circuit are some examples (Figure 2). Delivering oxygen should not obstruct the view of the laryngoscopist, and it should be delivered through a patent airway.

Proper Anesthetic Depth

• Ideally, we would have all the time required to carefully intubate a patient with no motor or airway reflexes in response to intubation. However, this is not a realistic expectation.⁴
• Adequate anesthetic depth matters and is required to prevent adverse events such as laryngospasm and improve tracheal intubation success. The choice of anesthetic technique and sedation depends on the patient’s anatomic and physiologic circumstances.⁴
• To paralyze or not to paralyze is an important decision that must be made prior to tracheal intubation.
• Whether neuromuscular blocking drugs (NMBD) are given or not, appropriate anesthetic depth must be maintained throughout the intubation attempt to avoid airway-related complications.
• A recent randomized controlled trial in which infants were allocated to high-flow oxygen vs. conventional therapy also noted that across both groups, the first attempt tracheal intubation success was lower when NMBD was not given.⁷
• Another study from the PeDI registry found that spontaneous ventilation is associated with more nonsevere complications, such as hypoxemia and laryngospasm, compared to controlled-ventilation techniques.⁸
• A study involving ten neonatal ICUs found that tracheal intubation-associated complications were higher when NMBD was not used.⁹
• A more recent PeDI study found that 27% of sedated tracheal intubation attempts in children with difficult airways needed to be converted to general anesthesia for successful tracheal intubation.¹⁰

Appropriate Devices

• Commonly used methods for endotracheal intubation are direct laryngoscopy, video laryngoscopy, and fiberoptic intubation.
• Choosing the appropriate device in the appropriate size is key. From standard direct laryngoscopy blades (Miller and Macintosh) to standard and nonstandard hyperangulated video laryngoscopes and fiberoptic scopes, the designs of airway devices have evolved to provide a range of sizes tailored to the specific anatomic needs of neonates and infants.
• It is important to choose the right equipment depending on the type of airway anticipated. For example, in a patient with severe micrognathia, a hyperangulated blade or fiberoptic intubation through a supraglottic device may assist with the “very acute” angle to the airway, with the added benefit of passive oxygenation/ventilation through the supraglottic device.⁴
• The video laryngoscopy in small infants (VISI) trial reported improved first-attempt success rate and reduced complications among anesthetized infants using video laryngoscopy with a standard blade.¹¹