Airway-related problems are the most common critical incidents in paediatric anaesthesia and are four times more common in infants than in older children. This chapter discusses anatomical and physiological differences in the paediatric airway. Straight laryngoscope blades are useful in infants up to about the age of 3 to 6 months. In contrast to the tracheal tube (TT), paediatric laryngeal mask airways (LMAs) are sized according to patient weight. There are a number of syndromes and pathologies that are known to be associated with difficult airway management. There are a number of causes, both congenital and acquired, of airway obstruction in the child. The general principles of airway management are the same regardless of underlying cause, however, there are two scenarios that deserve special attention: inhalation of a foreign body, and acute epiglottitis. Rapid sequence induction is not a standard in paediatric practice.

Tracheal intubation is an essential skill but can be difficult and may result in complications, the most serious being hypoxaemic brain damage and death. A significant lifting force, causing considerable tissue distortion but not damage, may be required in direct laryngoscopy. The Macintosh technique of laryngoscopy depends on indirect elevation of the epiglottis and is the most frequently used direct laryngoscopy technique in most centres. Direct laryngoscopy with the straight laryngoscope was the first technique to allow tracheal intubation under vision. The straight laryngoscope offers unique advantages and there is good evidence of its value. The laryngoscope is inserted to the right of the midline and passed along the paraglossal gutter to the right side of the tongue. Many alternative techniques can facilitate tracheal intubation under vision in patients in whom this is not possible with direct laryngoscopy. Nasotracheal intubation is necessary when the oral route is not available.

Airway anatomy and physiology are altered in obesity, and an understanding of these changes is key to appropriate airway management. Longitudinal studies of pulmonary function have shown reduction in pulmonary tests with obesity. The functional residual capacity (FRC) is reduced by the conduct of general anaesthesia. In the obese, the resting metabolic rate, oxygen consumption and also carbon dioxide production are all increased, compounding the reduction in FRC. In addition to acting as an oxygen store, FRC is important in splinting small airways. Respiratory mechanics are affected even in moderate obesity. Prediction of difficulty: Mallampati score and neck circumference are better predictors than body mass index (BMI) and a history of obstructive sleep apnoea (OSA), but their predictive value is not strong. Difficult mask ventilation and difficult intubation are uncommon. Awake intubation is worthwhile if difficulty is expected, because of the rapid desaturation problem.