What are the anesthesia considerations for pediatric vs adult patients with respiration issues?

Anesthesia Considerations for Pediatric vs Adult Patients with Respiratory Issues

Pediatric patients with respiratory compromise require fundamentally different airway management strategies than adults, with the most critical distinction being their rapid desaturation (younger children desaturate below 94% SpO2 within seconds due to higher metabolic oxygen consumption and lower functional residual capacity), necessitating meticulous preoxygenation, positioning modifications (shoulder roll for infants <2 years vs neutral positioning for older children), and preferential use of cuffed endotracheal tubes with strict cuff pressure monitoring (≤20 cm H2O). 1, 2, 3

Anatomical and Physiological Differences

Oxygen Reserve and Desaturation Risk

• Pediatric patients have a critically narrow safety margin during airway management due to higher metabolic oxygen consumption and reduced functional residual capacity, causing rapid desaturation below 94% SpO2 1, 2, 3
• Adults maintain oxygen reserves longer, allowing more time for airway interventions before critical hypoxemia develops 3
• Apneic oxygenation techniques are essential in pediatrics to prolong safe apnea time and reduce desaturation incidence during intubation 3

Airway Positioning Requirements

• Infants under 2 years require a shoulder roll to achieve neck flexion with head extension (the "sniffing" position) for optimal airway visualization 2
• Children over 2 years and adults require only neutral head positioning without shoulder elevation 2
• These anatomical differences between age groups necessitate distinct positioning strategies that directly impact intubation success 2

Intubation Equipment and Technique

Endotracheal Tube Selection

• Use cuffed endotracheal tubes in pediatric patients with cuff pressure maintained ≤20 cm H2O to reduce re-intubation rates without increasing laryngeal complications 1, 2, 4
• This recommendation contradicts older practice of using uncuffed tubes in children, as meta-analyses demonstrate cuffed tubes reduce re-intubation for excessive leakage without increasing post-extubation complications 1
• Adult endotracheal tubes follow the same cuff pressure principle (≤20 cm H2O), though adults have lower baseline risk of re-intubation 1

Laryngoscopy Attempt Limitations

• Limit direct laryngoscopy to maximum 2 attempts by the most senior practitioner in both pediatric and adult patients, with adequate anesthesia depth, optimal head positioning, gastric decompression, and CPAP application before each attempt 2, 4
• After 2 failed attempts, immediately proceed to supraglottic airway insertion (maximum 3 attempts) while maintaining oxygenation 1, 2
• Videolaryngoscopy should be used as first-line for anticipated difficult intubation or after failed direct laryngoscopy in both populations 1, 4

Difficult Airway Management Algorithms

Pediatric-Specific Rescue Strategies

When facing inadequate ventilation in children (SpO2 <90%), follow this stepwise approach:

1. First step: Continue oxygenation attempts 1

   • FiO2 100%
   • Optimize head position and jaw thrust
   • Insert oral/nasopharyngeal airway or supraglottic airway
   • Ventilate manually
   • Decompress stomach with NG tube

2. Second step: Consider awakening if SpO2 >80% 1

   • If rocuronium or vecuronium used, administer sugammadex 16 mg/kg
   • Prepare rescue techniques if deterioration continues

3. Third step: Rescue technique if SpO2 <80% and/or decreasing heart rate 1, 2

   • Call for experienced ENT surgeon
   • Consider emergency tracheostomy or rigid bronchoscopy with jet ventilation
   • WARNING: All cricothyroid approaches carry major risk of failure and complications in children <8 years old; catheter cricothyrotomy is NOT recommended in this age group 1

Adult Difficult Airway Differences

• Adults have more established cricothyrotomy options as rescue techniques compared to the pediatric population where this is contraindicated under age 8 1
• Adult algorithms emphasize maintaining oxygenation through face mask ventilation and supraglottic airways, with similar stepwise escalation but different anatomical rescue options 1

Induction Techniques

Pediatric Preferences

• Inhalational induction with sevoflurane is preferred for most pediatric patients, as children typically resist IV access when awake and mask induction avoids needle insertion distress 5
• Sevoflurane has replaced halothane due to non-pungent odor, rapid onset, lack of airway irritation, and superior cardiovascular safety 5
• In children with upper respiratory infections, administer inhaled salbutamol 30 minutes before induction (reduces perioperative cough and bronchospasm by approximately 50% in children under 6 years) 5

Adult Induction Options

• Adults tolerate IV induction more readily with propofol (1-2 mg/kg) or ketamine (1-2 mg/kg) when venous access is established 5, 6
• Rapid bolus administration should be avoided in elderly, debilitated, or ASA-PS III/IV patients due to increased cardiorespiratory depression including hypotension, apnea, airway obstruction, and oxygen desaturation 6

Ventilation Strategy During Respiratory Compromise

Spontaneous Ventilation Maintenance

• For airway procedures in both populations, maintaining spontaneous ventilation with deep anesthesia provides continuous airway observation and allows assessment of dynamic airway compression 5, 7, 8
• Tubeless anesthetic techniques using total intravenous anesthesia (propofol 200-300 mcg/kg/min with remifentanil 0.06-0.2 mcg/kg/min in adults) or sevoflurane insufflation (3-6% in 4 L/min oxygen in pediatrics) maintain steady spontaneous respiration 7
• High-flow nasal oxygen (HFNO) during spontaneous ventilation reduces hypoxemia incidence and maintains adequate oxygenation by minimizing room air entrainment 3, 8

Positive Pressure Ventilation Considerations

• Positive pressure ventilation increases cardiac output depression in both populations, particularly when combined with opioid premedication 6
• General anesthesia causes decreased spontaneous minute ventilation with increased CO2 tension, requiring careful monitoring especially with concurrent opioid/sedative use 6

Extubation Planning

High-Risk Extubation Protocol

• Extubate children who were difficult to intubate when fully awake after at least 3 minutes of spontaneous ventilation with 100% O2, under full monitoring, with trained assistant and difficult intubation equipment available 1
• Use hollow airway exchange catheter (8Fr, 11Fr, or 14Fr) for suspected difficult extubation in both pediatric and adult patients 1
• These catheters are well-tolerated and facilitate re-intubation if needed, decreasing complications such as hypoxia and bradycardia 1

Post-Surgical Airway Assessment

• Perform evaluation under general anesthesia before extubation when surgery may have induced anatomical changes, head/neck edema, recurrent nerve injury, or cervical spine instability 1
• Assessment should include examination for mouth opening limitation, lingual/pharyngeal/laryngeal edema or hematoma, airway deformity, and blood clots 1
• A negative leak test (no leak with cuff deflated or leak <12% of expired volume) increases risk of laryngeal edema, post-extubation stridor, and re-intubation 1

Pharmacologic Adjuncts

• Repeated doses of IV dexamethasone before and after extubation decrease stridor and re-intubation incidence in neonates at risk for laryngeal edema, though benefit is unclear in older children 1
• Epinephrine nebulization for post-extubation stridor provides quick effect (30 minutes) but is transient (2 hours), requiring PACU or ICU monitoring 1

Critical Pitfalls to Avoid

• Never use desflurane in children with upper respiratory tract infections due to increased airway irritation 1
• Never attempt cricothyrotomy with catheter in children <8 years old due to major failure and complication risk 1
• Never use rapid bolus dosing in elderly, debilitated, or ASA-PS III/IV patients during MAC sedation or induction, as this dramatically increases cardiorespiratory depression 6
• Never exceed 3 attempts at supraglottic airway insertion before choosing alternative oxygenation technique 1
• Never delay calling for ENT assistance when facing CICO (Cannot Intubate Cannot Oxygenate) scenario in pediatric patients 1, 2