What are the steps to set up a ventilator for a patient?

How to Set Up a Ventilator

For surgical patients requiring invasive mechanical ventilation, set 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

Initial Ventilator Settings

Tidal Volume and Pressure Targets

• Set tidal volume to 6-8 mL/kg predicted body weight (PBW), not actual body weight 1, 2
• Target plateau pressure ≤30 cmH2O to prevent barotrauma and ventilator-induced lung injury 2, 3
• For ARDS patients specifically, use the lower end of this range (4-8 mL/kg PBW) with strict plateau pressure limits <30 cmH2O 2

PEEP Settings

• Start with PEEP of 5 cmH2O as the initial setting 1
• After initial setup, titrate PEEP to avoid increases in driving pressure (plateau pressure minus PEEP) while maintaining low tidal volume 1
• For moderate to severe ARDS, use higher PEEP (typically 10-15 cmH2O) 2
• For COPD patients requiring invasive ventilation, set PEEP between 4-8 cmH2O to offset intrinsic PEEP and improve triggering 2, 4

FiO2 and Oxygenation

• Set initial FiO2 to 0.4 (40%), then titrate to the lowest possible FiO2 to achieve SpO2 ≥94% 1
• For most ICU patients, target oxygen saturation of 88-92% to avoid oxygen toxicity while maintaining adequate oxygenation 2
• For COPD patients specifically, maintain target saturation of 88-92% to avoid worsening hypercapnia 4

Respiratory Rate and Timing

• For COPD patients on invasive ventilation, set initial respiratory rate between 10-14 breaths/min 4
• Allow adequate expiratory time with I:E ratio of approximately 1:2 or 1:3 to prevent air trapping, especially in obstructive lung diseases 2, 4
• The inspiratory time should be of sufficient length to achieve adequate volume 1

Mode Selection

Pressure vs. Volume Control

• No specific mode of controlled mechanical ventilation is universally superior 1
• Pressure-targeted ventilation has advantages including constant pressure delivery, compensation for air leaks, and positive pressure throughout expiration 1
• Volume-targeted ventilation offers the safety of pre-set tidal volume and minute ventilation 5
• In pressure-targeted mode, set inspiratory pressure (IPAP) and expiratory pressure (EPAP), with the difference between them being the level of ventilatory assistance 1

Spontaneous vs. Timed Modes

• In Spontaneous (S) mode, the ventilator delivers assisted breaths in response to patient inspiratory effort 1
• In Timed (T) mode, the ventilator delivers breaths at a set rate regardless of patient effort 1
• Spontaneous/Timed mode provides backup rate if patient has inadequate respiratory drive 4

Non-Invasive Ventilation Setup (When Applicable)

Patient Selection and Preparation

• Before attempting NIV, decide on the management plan if NIV fails and document this in the notes 1
• Determine appropriate location (ICU, HDU, or respiratory ward) based on severity of illness 1
• Explain the procedure to the patient before initiating 1

Interface Selection and Fitting

• Select a full-face mask (FFM) as the most suitable interface, as mouth breathing predominates in acute hypercapnic respiratory failure 1
• Have a range of mask shapes and sizes available to accommodate facial diversity 1
• Hold the mask in place initially to familiarize the patient before securing with straps 1

NIV Ventilator Settings for COPD

• Use bi-level pressure support with initial IPAP of 10-15 cmH2O and EPAP of 4-8 cmH2O 2, 4
• Maintain a pressure difference between IPAP and EPAP of at least 5 cmH2O 2, 4
• Set backup respiratory rate of 10-14 breaths/min 2, 4
• Set inspiratory time to achieve I:E ratio of approximately 1:2 (30% IPAP time) to allow adequate exhalation 4

Monitoring and Oxygen Titration

• Attach pulse oximeter before commencing NIV 1
• Add supplemental oxygen if SpO2 <85% initially 1
• For COPD patients, target SpO2 of 88-92% to avoid worsening hypercapnia 4

Monitoring and Reassessment

Initial Assessment Period

• Reassess the patient after a few minutes of ventilation and adjust settings as needed 1
• Check arterial blood gases at 1-2 hours after initiating ventilation 1, 4
• Recheck ABGs after 30-60 minutes or if clinical deterioration occurs 2, 4

Criteria for Escalation

• For NIV, institute alternative management plan if PaCO2 and pH have deteriorated after 1-2 hours on optimal settings 1
• If no improvement in PaCO2 and pH by 4-6 hours of NIV, escalate to invasive ventilation 1, 4
• Consider intubation for worsening ABGs and/or pH in 1-2 hours or lack of improvement after 4 hours of NIV 4

Ongoing Monitoring Parameters

• Assess plateau pressure to ensure lung-protective ventilator settings 3
• Document tidal volume as mL/kg predicted body weight 3
• Assess PEEP and auto-PEEP regularly 3
• Monitor driving pressure to prevent ventilator-induced injury 3
• Assess cuff pressure of artificial airways using a manometer 3

Common Pitfalls to Avoid

Ventilator Setting Errors

• Avoid excessive tidal volumes (>8 mL/kg PBW) which increase risk of ventilator-induced lung injury 4
• Do not use zero end-expiratory pressure (ZEEP), as appropriate PEEP prevents atelectasis 1
• Avoid inadequate expiratory time causing dynamic hyperinflation and auto-PEEP, especially in obstructive lung diseases 2, 4

Oxygenation Errors

• Avoid excessive oxygen therapy leading to worsening hypercapnia in COPD patients 2, 4
• Do not target normal oxygen saturations in COPD patients; maintain 88-92% 4

Monitoring Failures

• Do not delay escalation to invasive ventilation when NIV is failing; monitor closely for worsening ABGs 2, 4
• Avoid insufficient PEEP leading to atelectasis and worsening V/Q mismatch 4

Staffing and Training Considerations

Personnel Capable of Setup

• Trained ICU staff, doctors, physiotherapists, lung function technicians, and nurses can all successfully set up and maintain ventilation 1
• When establishing an acute NIV service, nursing staff should be trained to initiate and run NIV 1
• Outside ICU or HDU, nurses or physiotherapists will likely need to be involved for after-hours setup 1