From the Guidelines
Mechanical ventilation should be used to support patients who cannot breathe adequately on their own, with a focus on lung-protective strategies to prevent ventilator-induced lung injury, as recommended by the American Thoracic Society and the American College of Chest Physicians 1.
Indications for Mechanical Ventilation
The primary indications for mechanical ventilation include:
- Respiratory failure
- Airway protection
- Respiratory muscle fatigue
- To reduce the work of breathing during critical illness
Ventilator Modes and Settings
Common ventilator modes include:
- Volume-controlled ventilation (VCV)
- Pressure-controlled ventilation (PCV)
- Pressure support ventilation (PSV) Initial ventilator settings typically include:
- A tidal volume of 6-8 mL/kg of ideal body weight
- Respiratory rate of 12-20 breaths per minute
- PEEP (positive end-expiratory pressure) of 5-10 cmH2O
- FiO2 (fraction of inspired oxygen) starting at 100% and titrated down based on oxygen saturation goals
Importance of Lung-Protective Strategies
Lung-protective strategies are essential to prevent ventilator-induced lung injury, particularly in patients with ARDS, as highlighted in a systematic review of ECMO use in adult patients with acute respiratory failure 1.
Assessment of Readiness for Weaning
Regular assessment of readiness for weaning is important, with spontaneous breathing trials conducted when patients meet criteria, as outlined in the official executive summary of an American Thoracic Society/American College of Chest Physicians clinical practice guideline 1.
Complications of Mechanical Ventilation
Complications of mechanical ventilation include:
- Ventilator-associated pneumonia
- Barotrauma
- Volutrauma
- Oxygen toxicity
- Diaphragmatic weakness These complications necessitate vigilant monitoring and prompt intervention when issues arise, to minimize morbidity, mortality, and improve quality of life.
From the Research
Mechanical Ventilation Overview
- Mechanical ventilation is a cornerstone in the management of acute respiratory failure, used to prevent catastrophe of hypoxemia and hypercapnia 2.
- However, mechanical ventilation can cause lung injury, accelerating disease progression, and alternative strategies like extracorporeal membrane oxygenation (ECMO) can be employed to rescue patients with severe respiratory failure 2.
Ventilation Modes
- Both volume-targeted and pressure-targeted ventilations are used in mechanical ventilation, with pressure-targeted modes being increasingly used 3.
- A systematic review and meta-analysis found no difference in outcomes between pressure control-continuous mandatory ventilation (PC-CMV) and volume control-continuous mandatory ventilation (VC-CMV) in terms of compliance, gas exchange, hemodynamics, work of breathing, and clinical outcomes 3.
- Noninvasive mechanical ventilation (NMV) can be delivered using volume-controlled or pressure-controlled devices, with the majority of patients with chronic respiratory failure being adequately maintained with pressure-controlled ventilation 4.
Ventilation Strategies
- Protective ventilation strategies with low tidal volume, high positive end-expiratory pressure, and prone positioning can provide benefits on mortality outcome 2.
- Awake and spontaneous breathing for patients undergoing ECMO is thought to be beneficial in terms of rehabilitation 2.
- Patient-ventilator synchrony, air trapping and auto-positive end-expiratory pressure, and airway pressures are key principles to consider when managing patients with severe obstructive lung disease 5.
Noninvasive Ventilation
- Noninvasive ventilation is a lifesaving therapy for critically ill patients with respiratory failure, but its administration requires careful consideration of indications and contraindications 6.
- The effect of the ventilator on kidney function is an important consideration in the management of respiratory failure 6.