From the Guidelines
Ventilators should be used with a lung protective strategy, including low tidal volumes (4-8 ml/kg predicted body weight) and lower inspiratory pressures (plateau pressure < 30 cm H2O), as recommended by the most recent guidelines 1. When using a ventilator, it is essential to follow specific guidelines to ensure patient safety and effective respiratory support. The ventilator settings should be based on the patient's condition, including mode selection, tidal volume, respiratory rate, FiO2, and PEEP. Key considerations for ventilator settings include:
- Tidal volume: 4-8 ml/kg predicted body weight, with a target of 6 ml/kg for adults and 5-8 ml/kg for children 1
- Plateau pressure: < 30 cm H2O 1
- PEEP: should be guided by the Fraction of Inspired Oxygen (FiO2) required to achieve a desired arterial oxygen saturation (SpO2) 1
- Respiratory rate: 10 breaths/min for adults, 20 to 30 breaths/min for infants and children, and 30 breaths/min for neonates 1 Regular monitoring is crucial, including vital signs, oxygen saturation, end-tidal CO2, ventilator parameters, and patient comfort. Proper airway management is also vital, with endotracheal tube positioning at 21-23 cm at the teeth for adults, securing the tube, and performing oral care every 2-4 hours. Infection prevention measures, such as hand hygiene, sterile suctioning techniques, and ventilator circuit maintenance, should be implemented. Sedation and analgesia should be provided as needed, using medications like propofol, midazolam, fentanyl, or dexmedetomidine. Daily spontaneous breathing trials should be performed to assess readiness for extubation when clinically appropriate. These guidelines are crucial because mechanical ventilation, while life-saving, carries risks including ventilator-associated pneumonia, barotrauma, volutrauma, and hemodynamic compromise if not properly managed 1.
From the Research
Guidelines for Using a Ventilator
- The lung-protective mechanical ventilation strategy is recommended as an initial approach to mechanical ventilation in both perioperative and critical care settings 2.
- Principles of lung-protective ventilation include:
- Prevention of volutrauma (tidal volume 4 to 8 ml/kg predicted body weight with plateau pressure < 30 cmH2O)
- Prevention of atelectasis (positive end-expiratory pressure ≥ 5 cmH2O, as needed recruitment maneuvers)
- Adequate ventilation (respiratory rate 20 to 35 breaths per minute)
- Prevention of hyperoxia (titrate inspired oxygen concentration to peripheral oxygen saturation (SpO2) levels of 88 to 95%) 2
- Lung-protective ventilation strategies using low tidal volumes and moderate levels of PEEP have been recommended as strategies to prevent tidal alveolar collapse and overdistension in patients with ALI/ARDS, and may also be beneficial in patients with normal lungs 3.
- Other lung protective ventilation strategies include:
- Moderate to high positive-end expiratory pressure
- Recruitment manoeuvres
- High frequency oscillatory ventilation
- Airway pressure release ventilation 3
- The relative contributions of the magnitude and frequency of mechanical stress and the end-expiratory pressure to the development of VILI is unknown, and it is uncertain whether the risk of VILI is best quantified in terms of tidal volume, driving pressure, or mechanical power 4.
- Variations in tidal volume, driving pressure, and mechanical power are associated with increased mortality in trials of lung-protective ventilation strategies in adult subjects with ARDS 4.