What are the ideal ventilator settings for a 10 kg child with severe bronchitis and asthma?

Ideal Ventilator Settings for a 10 kg Child with Severe Bronchitis Asthma

For a 10 kg child with severe bronchitis asthma, use pressure-controlled ventilation with peak inspiratory pressure ≤30 cmH2O, PEEP 5-8 cmH2O, tidal volume ≤10 mL/kg (100 mL), longer expiratory times (I:E ratio ≥1:3), and lower respiratory rates to allow complete exhalation and prevent air trapping. 1

Mode Selection

• Use pressure-controlled ventilation as the initial ventilatory mode for obstructive airway disease 1, 2
• Target patient-ventilator synchrony to reduce work of breathing and prevent asynchrony 3, 1
• Consider pressure-controlled ventilation over volume-controlled ventilation as it may allow for more uniform ventilation in severe asthma 2

Pressure Settings

• Keep peak inspiratory pressure (PIP) ≤30 cmH2O for obstructive airway disease to prevent barotrauma 3, 1
• Set plateau pressure (Pplat) target at 25-30 cmH2O, as elevated plateau pressures usually reflect dynamic hyperinflation in asthma 4
• Use PEEP of 5-8 cmH2O as baseline 3, 1
• Add PEEP in obstructive airway disease when there is air-trapping to facilitate triggering 3
• Consider PEEP titration based on flow-time scalar observation to optimize expiratory flow 3, 1

Volume and Flow Settings

• Target tidal volume ≤10 mL/kg ideal body weight (approximately 100 mL for a 10 kg child) 3, 1
• Set inspiratory time based on respiratory system mechanics using time constant and flow-time scalar observation 3
• Use longer expiratory times (I:E ratio of 1:3 or greater) to accommodate prolonged expiration in asthma 1, 5
• Use lower respiratory rates to allow for complete exhalation and prevent air trapping 1, 4

Oxygenation and CO2 Management

• Target SpO2 ≤97% for obstructive airway disease 3, 1
• Accept higher PCO2 levels (permissive hypercapnia) unless contraindicated 3, 5
• Target pH >7.20 rather than normal PCO2 3, 1
• Avoid rapid correction of hypercarbia and respiratory acidosis 4, 5
• Monitor SpO2 continuously in all ventilated children 3, 1

Monitoring Parameters

• Measure peak inspiratory pressure, plateau pressure, mean airway pressure, and PEEP 3, 1
• Monitor pressure-time and flow-time scalars to assess for air trapping 3, 1
• Measure PCO2 in arterial or capillary blood samples 3
• Consider measuring intrinsic PEEP (PEEPi) with an expiratory hold maneuver 4
• Measure flow near the Y-piece of the patient circuit for children <10 kg to improve trigger sensitivity 3

Supportive Measures

• Use humidification 3, 1
• Maintain head of bed elevated 30-45° 3, 1
• Use cuffed endotracheal tube with cuff pressure ≤20 cmH2O 3, 1
• Do not perform endotracheal suctioning routinely, only on indication 3
• Minimize dead space by reducing added components 3
• Use double-limb circuits for invasive ventilation 3
• Avoid hand ventilation unless specific conditions dictate otherwise 3

Common Pitfalls to Avoid

• Using excessively high respiratory rates that don't allow complete exhalation 1, 4
• Setting inadequate expiratory times leading to air trapping and auto-PEEP 1, 5
• Failing to monitor for patient-ventilator asynchrony 1, 4
• Using high tidal volumes that may worsen air trapping 1, 5
• Excessive pulmonary hyperinflation which can cause hypotension and barotrauma 4, 5
• Rapid correction of hypercarbia which can worsen patient outcomes 4, 5

Advanced Considerations

• Consider heliox if available and compatible with the ventilator, as it may improve gas flow through obstructed airways 4
• If conventional ventilation fails despite optimal settings, consider consultation for inhaled anesthetics which are direct bronchodilators 4
• Extracorporeal membrane oxygenation (ECMO) may be considered as a rescue therapy in cases of severe air-leak syndrome or refractory hypoxemia 4, 6