What are the ideal initial ventilator settings for a 10 kg child with bronchial asthma?

Ideal Initial Ventilator Settings for a 10 kg Child with Bronchial Asthma

For a 10 kg child with bronchial asthma, the ideal initial ventilator settings should include a pressure-controlled mode with peak inspiratory pressure ≤30 cmH2O, PEEP of 5-8 cmH2O (with additional PEEP for air-trapping), tidal volume ≤10 mL/kg, and patient-ventilator synchrony as primary goals. 1

Mode Selection

• Use pressure-controlled ventilation as the initial mode for obstructive airway disease 1
• Target patient-ventilator synchrony to reduce work of breathing 1
• Consider synchronized intermittent mandatory ventilation (SIMV) to allow for more consistent tidal volumes 2

Pressure Settings

• Keep peak inspiratory pressure (PIP) ≤30 cmH2O for obstructive airway disease 1, 3
• Set PEEP at 5-8 cmH2O as baseline 1
• Add additional PEEP in obstructive airway disease when there is air-trapping to facilitate triggering 1
• Keep driving pressure (PIP minus PEEP) ≤10 cmH2O for healthy lungs, though specific recommendations for asthma are not established 1, 3

Volume Settings

• Target tidal volume ≤10 mL/kg ideal body weight (approximately 100 mL for a 10 kg child) 1
• Be aware that delivered tidal volumes may vary significantly from set volumes, especially with decreased lung compliance 4
• Set inspiratory time based on respiratory system mechanics using time constant and flow-time scalar observation 1

Rate and I:E Ratio

• Use lower respiratory rates to allow for complete exhalation and prevent air trapping 1
• Set longer expiratory times (I:E ratio of 1:3 or greater) to accommodate prolonged expiration in asthma 1
• Monitor flow-time scalar to ensure complete exhalation before next breath 1

Oxygenation Targets

• Target SpO2 ≤97% for obstructive airway disease 1
• Monitor SpO2 continuously in all ventilated children 1
• Measure arterial PO2 in moderate-to-severe disease 1

CO2 and pH Management

• Accept higher PCO2 levels (permissive hypercapnia) unless contraindicated 1
• Target pH >7.20 rather than normal PCO2 1
• Measure PCO2 in arterial or capillary blood samples 1
• Consider transcutaneous or end-tidal CO2 monitoring 1

Monitoring Parameters

• Measure peak inspiratory pressure, plateau pressure, mean airway pressure, and PEEP 1
• Monitor pressure-time and flow-time scalars to assess for air trapping 1
• Consider measuring intrinsic PEEP in severe asthma 1
• Measure flow near the Y-piece of patient circuit for children <10 kg to improve trigger sensitivity 1, 3

Supportive Measures

• Use humidification 1
• Maintain head of bed elevated 30-45° 1
• Use cuffed endotracheal tube with cuff pressure ≤20 cmH2O 1
• Use double-limb circuits for invasive ventilation 1
• Minimize dead space by reducing added components 1

Common Pitfalls to Avoid

• Using excessively high respiratory rates that don't allow complete exhalation 1
• Setting inadequate expiratory times leading to air trapping 1
• Failing to monitor for patient-ventilator asynchrony 1, 3
• Using high tidal volumes that may worsen air trapping 1
• Delaying systemic steroids and bronchodilators which should be administered concurrently with ventilation 5