From the Guidelines
Initial mechanical ventilation settings for a patient on Volume-Synchronized Intermittent Mandatory Ventilation (V-SIMV) should include a tidal volume of 4-8 mL/kg of ideal body weight, with a target plateau pressure < 30 cmH2O, as recommended by the most recent and highest quality study 1.
Key Considerations
- Tidal volume: 4-8 mL/kg of ideal body weight, with the goal of maintaining end-inspiratory plateau pressures at levels less than 30 cmH2O 1
- Respiratory rate: 10-16 breaths per minute, with adjustments based on the patient's condition and response to ventilation 1
- FiO2: starting at 100% and titrated down to maintain SpO2 > 92% 1
- PEEP: 5 cmH2O, with adjustments based on the patient's oxygenation status and underlying pathology 1
- Inspiratory flow rate: 40-60 L/min, with an I:E ratio of 1:2 to 1:3 1
Individualization of Settings
These settings should be individualized based on the patient's condition and underlying pathology, with regular assessment of the patient's response to ventilation, including monitoring of oxygen saturation, end-tidal CO2, peak and plateau pressures, and patient comfort 1.
Lung-Protective Ventilation
The use of lower tidal volumes (4-6 mL/kg) is particularly important in ARDS patients, as it helps to prevent ventilator-induced lung injury 1.
Weaning and Pressure Support
The SIMV mode delivers set mandatory breaths while allowing the patient to breathe spontaneously between these breaths, making it useful for weaning 1. Pressure support of 5-10 cmH2O should be added to spontaneous breaths to overcome the resistance of the endotracheal tube and ventilator circuit 1.
From the Research
Initial Mechanical Ventilation Settings for V-SIMV
The initial mechanical ventilation settings for a patient on Volume-Synchronized Intermittent Mandatory Ventilation (V-SIMV) depend on various factors, including the patient's respiratory status, lung mechanics, and clinical goals.
- Tidal Volume (VT): The recommended initial VT setting is 6-8 ml/kg of ideal body weight 2, 3.
- Respiratory Rate: The initial respiratory rate setting is typically 12-20 breaths per minute 4.
- Inspiratory Time: The inspiratory time setting is usually 0.5-1.5 seconds 4.
- Positive End-Expiratory Pressure (PEEP): The initial PEEP setting is typically 5-10 cm H2O 3.
- Pressure Support: Pressure support can be added to V-SIMV to reduce the patient's work of breathing and improve comfort 5, 4.
Key Considerations
When setting up V-SIMV, it is essential to consider the following:
- Ventilator-Induced Lung Injury (VILI): The risk of VILI can be minimized by using lower VT settings and adjusting the inspiratory pressure to maintain a safe level of airway pressure 6, 3.
- Patient-Ventilator Dyssynchrony: The use of adaptive pressure-control modes, such as APC, can help reduce patient-ventilator dyssynchrony and improve ventilatory efficiency 2.
- Individualized Ventilation: Mechanical ventilation settings should be personalized to each patient's clinical needs and respiratory mechanics to optimize ventilation and minimize the risk of complications 3.