Can you teach me about Mechanical Ventilation (MV) in the Intensive Care Unit (ICU)?

From the Guidelines

Mechanical ventilation (MV) in the intensive care unit (ICU) should be managed with the goal of liberating patients from the ventilator as soon as possible, as outlined in the American Thoracic Society (ATS) and American College of Chest Physicians (CHEST) clinical practice guidelines 1. To learn MV, it's essential to understand the basic modes, including volume-controlled ventilation (VCV) and pressure-controlled ventilation (PCV). Common initial ventilator settings include:

• FiO2 of 100% (titrated down to maintain SpO2 >92%)
• PEEP of 5 cmH2O (adjusted based on oxygenation needs)
• Respiratory rate of 12-20 breaths/minute
• I:E ratio of 1:2 For sedation during MV, medications like propofol, midazolam, or dexmedetomidine are commonly used 1. Daily spontaneous breathing trials should be conducted to assess readiness for extubation. Understanding ventilator alarms, patient-ventilator asynchrony, and complications like ventilator-associated pneumonia is crucial. MV requires hands-on training under supervision, as it involves managing complex physiology and potential life-threatening complications if performed incorrectly.

Key Considerations

• The ATS and CHEST guidelines provide evidence-based recommendations for liberating patients from mechanical ventilation 1.
• The goal of MV is to support patients until they can breathe adequately on their own, and liberation from the ventilator should be done as soon as possible to minimize complications.
• Daily spontaneous breathing trials are essential to assess readiness for extubation, and sedation should be managed carefully to avoid delaying liberation from the ventilator 1.
• Understanding ventilator alarms, patient-ventilator asynchrony, and complications like ventilator-associated pneumonia is critical to providing high-quality care for patients on MV.

Clinical Implications

• Clinicians should follow the ATS and CHEST guidelines for liberating patients from mechanical ventilation to improve outcomes and minimize complications 1.
• MV requires a multidisciplinary approach, involving critical care physicians, nurses, respiratory therapists, and other healthcare professionals.
• Hands-on training and supervision are essential for healthcare professionals to acquire the skills and knowledge needed to manage MV effectively.

From the Research

Modes of Mechanical Ventilation

• The most commonly used modes of mechanical ventilation are assist-control, synchronized intermittent mandatory ventilation, and pressure support ventilation 2
• These modes can be employed to provide effective and safe invasive mechanical ventilation through manipulation of the ventilator settings

Patient Positioning and Respiratory Mechanics

• Changes in body position can impact respiratory mechanics in mechanically ventilated ICU patients 3
• The sitting position (with thorax angulation >30° from the horizontal plane) is associated with improvement of functional residual capacity (FRC), oxygenation, and reduction of work of breathing
• The prone position also provides beneficial impact on respiratory mechanics, although its effects are complex

Virtual Patients for Mechanical Ventilation

• A digital clone model, or in-silico virtual patient, can be used to accurately predict lung mechanics in response to changes in mechanical ventilation settings 4
• The virtual patient model can capture patient-specific lung dynamics and predict lung response for changes in PEEP up to 12 cmH2O for both volume and pressure control cohorts

Use of Mechanical Ventilation Protocols

• Mechanical ventilation protocols are often recommended to improve process of care and outcomes, but their composition may be variable and penetration into clinical practice may be incomplete 5
• Factors associated with reported use of mechanical ventilation protocols include intensivist-staffing model, presence of daily multidisciplinary rounds, and presence of 24 hour/7 days per week respiratory therapist coverage

Mechanical Ventilation in ICU vs Medical Wards

• Patients mechanically ventilated in the ICU have a higher in-hospital survival rate compared to those ventilated on medical wards 6
• ICU provides better monitoring, less endotracheal tube-related complications, and more active ventilatory management compared to medical wards