What are the key parameters for implementing invasive respiratory support (intubation) in ventilator management, in terms of ventilator usage parameters, such as Positive End-Expiratory Pressure (PEEP), Fraction of Inspired Oxygen (FiO2), and Tidal Volume (TV)?

From the Guidelines

Implementing invasive respiratory support through intubation requires careful management of several key ventilator parameters, with a strong recommendation for mechanical ventilation using lower tidal volumes (4–8 ml/kg predicted body weight) and lower inspiratory pressures (plateau pressure < 30 cm H2O) to optimize patient outcomes, as suggested by the American Thoracic Society/European Society of Intensive Care Medicine/Society of Critical Care Medicine clinical practice guideline 1. When initiating mechanical ventilation, begin with a tidal volume of 6-8 mL/kg of ideal body weight to prevent ventilator-induced lung injury, particularly in patients with acute respiratory distress syndrome. Set the respiratory rate between 12-20 breaths per minute, adjusting based on the patient's minute ventilation needs and acid-base status. The fraction of inspired oxygen (FiO2) should initially be set at 100% during intubation, then rapidly titrated down to maintain oxygen saturation between 88-95%, minimizing oxygen toxicity. Positive end-expiratory pressure (PEEP) typically starts at 5 cmH2O and is adjusted upward (5-20 cmH2O) based on oxygenation requirements and lung compliance. For most patients, pressure support ventilation or volume-controlled ventilation modes are appropriate initial choices, with consideration for pressure-controlled ventilation in patients with poor lung compliance. Some key points to consider in ventilator management include:

• Low tidal volume ventilation
• Recruitment maneuvers before PEEP selection
• PEEP selection based on gas exchange, hemodynamic status, lung recruitability, end-expiratory transpulmonary pressure, driving pressure
• Consideration of esophageal pressure measurement
• Maintenance of plateau pressures < 30 cmH2O and driving pressure < 15 cmH2O, as recommended by recent studies 1
• Sedation is essential during mechanical ventilation, commonly using propofol, midazolam, or dexmedetomidine, often combined with fentanyl or morphine for analgesia, as part of a comprehensive approach to minimize complications and improve patient outcomes, as discussed in expert opinions 1. Regular assessment of ventilator synchrony, arterial blood gases, and patient response to ventilation is crucial for ongoing management, with the goal of maintaining PaO2 within a normal range (e.g., between 70 and 90 mmHg) or SaO2 between 92 and 97%, as suggested by recent evidence 1. This approach balances the need for adequate gas exchange while minimizing complications such as barotrauma, volutrauma, and oxygen toxicity, ultimately prioritizing morbidity, mortality, and quality of life as the primary outcomes in ventilator management.

From the Research

Parameters of Ventilator Usage

The implementation of invasive respiratory support, such as intubation, in ventilator management involves various parameters. These parameters are crucial in determining the optimal timing and method of intubation. Some of the key parameters include:

• The ratio of arterial oxygen tension to fraction of inspired oxygen (PaO2/FiO2) 2
• The level of positive end-expiratory pressure (PEEP) and inspired oxygen fraction (F(IO2)) 3
• The use of noninvasive respiratory support (NIRS) techniques, such as high-flow nasal cannula (HFNC) and noninvasive ventilation (NIV) 4, 5, 6
• The patient's body mass index (BMI) 5
• The presence of severe hypoxemic respiratory failure 5, 2

Respiratory Support Techniques

Different respiratory support techniques can be used to avoid desaturation in critically ill patients requiring endotracheal intubation. These techniques include:

• Apneic oxygenation (ApOx) 4
• High-flow nasal cannula (HFNC) 4, 6
• Noninvasive ventilation (NIV) 4, 5, 6
• Bag-valve mask ventilation 4
• Positive end-expiratory pressure (PEEP) and inspired oxygen fraction (F(IO2)) titration tables 3

Timing of Intubation

The optimal timing of intubation in acute hypoxaemic respiratory failure is uncertain and depends on various parameters. Some of the factors that can influence the decision to intubate include:

• The severity of respiratory failure 2
• The presence of comorbidities 6
• The patient's response to noninvasive respiratory support 5, 6
• The risk of ventilator-associated lung injury and other complications 3, 2

Noninvasive Respiratory Support

Noninvasive respiratory support (NIRS) can be used as a potential treatment strategy for COVID-19 patients. The use of NIRS can help prevent intubation in patients with mild respiratory disease and reduce the risk of ventilator-associated complications. However, the use of NIRS also carries risks, such as aerosolization and self-inflicted lung injury 6. The decision to use NIRS should be based on careful patient selection and monitoring, as well as consideration of the potential benefits and risks 6.