Ventilator Setup and Management

Initial Ventilator Settings

• The British Journal of Anaesthesia recommends setting the ventilator to deliver a tidal volume of 6-8 mL/kg predicted body weight with PEEP of 5 cmH2O initially, then individualize PEEP to avoid increases in driving pressure while maintaining low tidal volume 1
• Set tidal volume to 6-8 mL/kg predicted body weight (PBW), not actual body weight, as recommended by the British Journal of Anaesthesia 1, 2
• Target plateau pressure ≤30 cmH2O to prevent barotrauma and ventilator-induced lung injury, according to Praxis Medical Insights 2
• For ARDS patients, use the lower end of the tidal volume range (4-8 mL/kg PBW) with strict plateau pressure limits <30 cmH2O, as suggested by Praxis Medical Insights 2
• Start with PEEP of 5 cmH2O as the initial setting, as recommended by the British Journal of Anaesthesia 1
• After initial setup, titrate PEEP to avoid increases in driving pressure (plateau pressure minus PEEP) while maintaining low tidal volume, according to the British Journal of Anaesthesia 1
• For moderate to severe ARDS, use higher PEEP (typically 10-15 cmH2O), as suggested by Praxis Medical Insights 2
• For COPD patients requiring invasive ventilation, set PEEP between 4-8 cmH2O to offset intrinsic PEEP and improve triggering, according to Praxis Medical Insights 2, 3
• Set initial FiO2 to 0.4 (40%), then titrate to the lowest possible FiO2 to achieve SpO2 ≥94%, as recommended by the British Journal of Anaesthesia 1
• For most ICU patients, target oxygen saturation of 88-92% to avoid oxygen toxicity while maintaining adequate oxygenation, according to Praxis Medical Insights 2
• For COPD patients, maintain target saturation of 88-92% to avoid worsening hypercapnia, as suggested by Praxis Medical Insights 3
• For COPD patients on invasive ventilation, set initial respiratory rate between 10-14 breaths/min, according to Praxis Medical Insights 3
• Allow adequate expiratory time with I:E ratio of approximately 1:2 or 1:3 to prevent air trapping, especially in obstructive lung diseases, as recommended by Praxis Medical Insights 2, 3
• The inspiratory time should be of sufficient length to achieve adequate volume, according to Thorax 4

Mode Selection

• No specific mode of controlled mechanical ventilation is universally superior, as stated by the British Journal of Anaesthesia 1
• Pressure-targeted ventilation has advantages including constant pressure delivery, compensation for air leaks, and positive pressure throughout expiration, according to Thorax 4
• In pressure-targeted mode, set inspiratory pressure (IPAP) and expiratory pressure (EPAP), with the difference between them being the level of ventilatory assistance, as recommended by Thorax 4
• In Spontaneous (S) mode, the ventilator delivers assisted breaths in response to patient inspiratory effort, according to Thorax 4
• In Timed (T) mode, the ventilator delivers breaths at a set rate regardless of patient effort, as stated by Thorax 4
• Spontaneous/Timed mode provides backup rate if patient has inadequate respiratory drive, according to Praxis Medical Insights 3

Non-Invasive Ventilation Setup

• Before attempting NIV, decide on the management plan if NIV fails and document this in the notes, as recommended by Thorax 5, 6
• Determine appropriate location (ICU, HDU, or respiratory ward) based on severity of illness, according to Thorax 5, 6
• Explain the procedure to the patient before initiating, as suggested by Thorax 5, 6
• Select a full-face mask (FFM) as the most suitable interface, as mouth breathing predominates in acute hypercapnic respiratory failure, according to Thorax 4
• Have a range of mask shapes and sizes available to accommodate facial diversity, as recommended by Thorax 4
• Hold the mask in place initially to familiarize the patient before securing with straps, according to Thorax 5, 6
• Use bi-level pressure support with initial IPAP of 10-15 cmH2O and EPAP of 4-8 cmH2O, as suggested by Praxis Medical Insights 2, 3
• Maintain a pressure difference between IPAP and EPAP of at least 5 cmH2O, according to Praxis Medical Insights 2, 3
• Set backup respiratory rate of 10-14 breaths/min, as recommended by Praxis Medical Insights 2, 3
• Set inspiratory time to achieve I:E ratio of approximately 1:2 (30% IPAP time) to allow adequate exhalation, according to Praxis Medical Insights 3
• Attach pulse oximeter before commencing NIV, as suggested by Thorax 5, 6
• Add supplemental oxygen if SpO2 <85% initially, according to Thorax 5, 6
• For COPD patients, target SpO2 of 88-92% to avoid worsening hypercapnia, as recommended by Praxis Medical Insights 3

Monitoring and Reassessment

• Reassess the patient after a few minutes of ventilation and adjust settings as needed, as suggested by Thorax 5, 6
• Check arterial blood gases at 1-2 hours after initiating ventilation, according to Thorax 5, 6 and Praxis Medical Insights 3
• Recheck ABGs after 30-60 minutes or if clinical deterioration occurs, as recommended by Praxis Medical Insights 2, 3
• For NIV, institute alternative management plan if PaCO2 and pH have deteriorated after 1-2 hours on optimal settings, according to Thorax 5, 6
• If no improvement in PaCO2 and pH by 4-6 hours of NIV, escalate to invasive ventilation, as suggested by Thorax 5, 6 and Praxis Medical Insights 3
• Consider intubation for worsening ABGs and/or pH in 1-2 hours or lack of improvement after 4 hours of NIV, according to Praxis Medical Insights 3

Common Pitfalls to Avoid

• Avoid excessive tidal volumes (>8 mL/kg PBW) which increase risk of ventilator-induced lung injury, as recommended by Praxis Medical Insights 3
• Do not use zero end-expiratory pressure (ZEEP), as appropriate PEEP prevents atelectasis, according to the British Journal of Anaesthesia 1
• Avoid inadequate expiratory time causing dynamic hyperin