Mandatory minute volume. A new concept in weaning from mechanical ventilation

Area of Science:

• Respiratory Physiology
• Mechanical Ventilation
• Critical Care Medicine

Background:

• Spontaneous breathing in mechanically ventilated patients presents challenges in controlling gas exchange.
• Existing systems like Intermittent Mandatory Ventilation (IMV) have limitations in precise CO2 regulation.
• The need for a ventilation strategy that guarantees a stable minute volume despite patient effort is recognized.

Purpose of the Study:

• To introduce and describe the novel Mandatory Minute Volume (MMV) ventilation system.
• To present the apparatus designed for MMV, including PEEP/CPAP capabilities.
• To compare the control over PaCO2 offered by MMV versus IMV.

Main Methods:

• Description of the MMV system, where a preset minute volume is provided, with spontaneous breathing supplemented by a ventilator.
• Construction and testing of the MMV apparatus, incorporating Positive End-Expiratory Pressure (PEEP) and/or Continuous Positive Airway Pressure (CPAP) up to 15 cmH2O.
• Evaluation of MMV's ability to maintain a constant fresh gas volume delivered to the patient.

Main Results:

• The MMV system ensures a constant minute volume of fresh gas to the patient, irrespective of spontaneous breathing variations.
• The apparatus allows for simpler and more direct control over the patient's PaCO2 compared to the IMV system.
• The system was successfully used with two common ventilators, demonstrating its practical application.

Conclusions:

• Mandatory Minute Volume (MMV) represents a new concept in mechanical ventilation.
• MMV offers improved control over ventilation and gas exchange compared to IMV.
• The MMV system is adaptable and can be integrated into future artificial ventilator designs.