Common Adult Ventilator Settings

1. Tidal Volume (VT):

• Amount of air delivered with each breath.
• Usually set between 6 to 8 milliliters per kilogram of ideal body weight.

2. Respiratory Rate (RR):

• Number of breaths delivered per minute by the ventilator.
• Typically set based on the patient's condition and blood gas analysis.
• Commonly set between 12 to 20 breaths per minute.

3. Fraction of Inspired Oxygen (FiO2):

• Percentage of oxygen delivered by the ventilator.
• Adjusted to maintain adequate oxygenation, usually starting at 100% and weaning down as tolerated.
• Aim to keep SpO2 (oxygen saturation) >90% or PaO2 (partial pressure of oxygen) between 60-100 mmHg.

4. Positive End-Expiratory Pressure (PEEP):

• Pressure applied to the airways at the end of exhalation to prevent alveolar collapse.
• Helps maintain lung recruitment and improve oxygenation.
• Commonly set between 5 to 10 cmH2O.

5. Peak Inspiratory Pressure (PIP):

• Maximum pressure applied during inhalation.
• Should be monitored to prevent lung injury.
• Generally, keep PIP below 30 cmH2O to minimize risk of barotrauma.

6. Flow Rate:

• Rate at which gas is delivered to the patient during inspiration.
• Typical initial settings are 40-60 liters per minute.
• Higher flow rates may improve ventilation but can increase the risk of barotrauma.

7. Trigger Sensitivity:

• Determines how sensitive the ventilator is to the patient's efforts to breathe.
• Commonly set to -1 to -2 cmH2O for pressure triggers or 2-3 liters per minute for flow triggers.
• Adjusted to avoid patient-ventilator asynchrony.

Modes of Ventilation

1. Assist-Control (AC) Mode:

• The ventilator delivers a set number of breaths per minute (respiratory rate).
• Each breath can be triggered by the patient's effort or delivered by the ventilator at the set rate.
• Delivers a full tidal volume with each breath.
• Commonly used for patients who are unable to breathe adequately on their own or require full ventilatory support.

2. Synchronized Intermittent Mandatory Ventilation (SIMV) Mode:

• The ventilator delivers a set number of mandatory breaths per minute.
• Patients can initiate spontaneous breaths between the mandatory breaths.
• Spontaneous breaths may be augmented by pressure support.
• Often used for patients who have some respiratory drive but may require assistance.

3. Pressure Support (PS) Mode:

• The ventilator delivers a preset level of positive pressure to support each spontaneous breath initiated by the patient.
• Helps reduce the work of breathing.
• Commonly used for patients who are breathing spontaneously but require assistance.

4. Continuous Positive Airway Pressure (CPAP) Mode:

• The ventilator delivers a constant positive pressure throughout the respiratory cycle.
• Used to maintain airway patency and improve oxygenation.
• Often used in patients with sleep apnea or acute respiratory failure who can maintain their own ventilation.

5. Volume-Controlled Ventilation (VCV) Mode:

• The ventilator delivers a preset tidal volume with each breath.
• Ensures consistent delivery of tidal volume.
• Commonly used in patients with acute respiratory failure.

6. Pressure-Controlled Ventilation (PCV) Mode:

• The ventilator delivers breaths at a preset pressure level.
• Allows for variable tidal volumes based on changes in lung compliance and airway resistance.
• Often used in patients with acute respiratory distress syndrome (ARDS) or conditions requiring lung-protective ventilation strategies.

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