Basic Ventilator Modes Lecture Notes

Introduction

• Speaker: Eddie Watson
• Channel: ICU Advantage
• Topic: Basic ventilator modes, crucial for understanding advanced modes and ventilation techniques.

Overview of Ventilator Modes

• Ventilators primarily use positive pressure ventilation.
• Two main categories of ventilator modes:
  • Volume Control: Sets and controls the volume of air delivered.
  • Pressure Control: Sets and controls the pressure delivered.

Key Points

• Volume Control: Volume is constant, pressure varies.
• Pressure Control: Pressure is constant, volume varies.
• Understanding these differences is crucial for patient care.

Volume Control Modes

• Purpose: Ensure patients receive a set volume of breath each minute.
• Modes affect patient work of breathing.

Settings to Know

1. Tidal Volume (VT): Volume of air delivered per breath.
2. Frequency/Respiratory Rate (F or RR): Number of breaths per minute.
   • Determines timing for breath delivery.
3. Oxygen Concentration (FiO2): Fraction of inspired oxygen.
   • Expressed as a fraction/decimal (e.g., 50% = 0.5).
4. Positive End-Expiratory Pressure (PEEP): Keeps alveoli open during expiration.
   • Important for oxygenation.
5. Pressure Support (PS): Assists spontaneous breaths, similar to a gym spotter.
   • Helps overcome ET tube resistance.

Monitoring Parameters

1. Minute Ventilation (VE): Total air delivered per minute.
   • Affects CO2 clearance.
2. Peak Inspiratory Pressure (PIP): Maximum pressure during inspiration.
   • Goal: <35 to prevent lung injury.
3. Plateau Pressure (Pplat): Indicates lung compliance.
   • Goal: <30 to prevent barotrauma.

Volume Control Modes

1. Assist Control (AC/VC)

• Predetermined volume and frequency.
• Ventilator delivers full set tidal volume, even on spontaneous breaths.
• No pressure support used.
• Possible issue: Excessive ventilation leading to respiratory alkalosis.

2. Synchronized Intermittent Mandatory Ventilation (SIMV)

• Delivers set volume/frequency but allows spontaneous breaths.
• Synchronizes mandatory breaths with spontaneous breaths.
• Uses pressure support for spontaneous breaths.
• Useful for weaning patients off ventilators.

3. Pressure Support

• Technically not a volume control mode.
• Spontaneous breathing with set FiO2, PEEP, and pressure support.
• Used for weaning and spontaneous breathing trials.

Conclusion

• Ventilator modes range from most to least supportive of patient's breathing.
• Key differences lie in handling spontaneous breaths.
• Logical progression from CMV to pressure support allows for gradual reduction in support.

Final Remarks

• Encouragement to subscribe and check out additional resources.
• Mention of social media and Patreon for further learning and support.