How do you increase oxygen saturation in a patient on a ventilator in Assist-Control (AC) mode?

From the Guidelines

To increase oxygen saturation in a patient on AC mode ventilation, first increase the fraction of inspired oxygen (FiO2) to 1.0 as needed, as this is the most direct and effective method to improve oxygenation. This recommendation is based on the most recent and highest quality study available, which suggests adjusting ventilator settings to improve oxygenation while minimizing the risk of complications 1.

Key Considerations

• Increasing FiO2 to 1.0 is a straightforward approach to increase oxygen saturation, and it is recommended to adjust this setting first before considering other interventions.
• After adjusting FiO2, consider optimizing tidal volume to 4-6 mL/kg of ideal body weight for adults and neonates, and 5-8 mL/kg for children, as this can help improve oxygenation while preventing lung injury 1.
• Adjusting positive end-expiratory pressure (PEEP) may also be necessary to balance lung volumes and venous return, but this should be done with caution and while monitoring hemodynamics.
• Ensuring proper endotracheal tube positioning and clearing any secretions through suctioning are also crucial steps in maintaining adequate oxygenation.

Additional Interventions

• If the patient remains hypoxemic despite these measures, consider recruitment maneuvers or adjusting ventilator settings to deliver full breaths with asynchronous chest compressions, as these interventions can help improve oxygenation in severe cases 1.
• It is also important to continuously monitor oxygen saturation, blood pressure, and ventilator parameters to ensure the patient tolerates the changes and to prevent complications like barotrauma or hemodynamic compromise.
• The goal of these interventions is to maintain an arterial oxyhemoglobin saturation of at least 94%, while avoiding hyperoxia and ensuring adequate oxygen delivery 1.

From the FDA Drug Label

INOmax appears to increase the partial pressure of arterial oxygen (PaO2) by dilating pulmonary vessels in better ventilated areas of the lung, redistributing pulmonary blood flow away from lung regions with low ventilation/perfusion (V/Q) ratios toward regions with normal ratios.

To increase oxygen saturation in a patient on a ventilator in Assist-Control (AC) mode, consider the following:

• Administering nitric oxide: Nitric oxide can help improve oxygenation by dilating pulmonary vessels and redistributing blood flow to better-ventilated areas of the lung.
• Monitoring and adjusting ventilator settings: Ensure that the ventilator settings are optimized for the patient's specific needs, including tidal volume, respiratory rate, and positive end-expiratory pressure (PEEP).
• Maintaining adequate oxygen levels: Ensure that the patient is receiving an adequate fraction of inspired oxygen (FiO2) to meet their oxygenation needs.

Note: The FDA drug label does not provide specific guidance on adjusting ventilator settings or managing patients on Assist-Control (AC) mode. The above suggestions are based on general clinical principles and may require consultation with a healthcare professional for implementation. 2 2 2

From the Research

Increasing Oxygen Saturation in Patients on Ventilators

To increase oxygen saturation in a patient on a ventilator in Assist-Control (AC) mode, several strategies can be employed:

• Adjusting the positive end-expiratory pressure (PEEP) and fractional inspired oxygen (FIO2) settings to optimize oxygenation, as suggested by studies 3, 4, 5
• Using recruitment maneuvers to promote alveolar recruitment, as mentioned in 6 and 3
• Implementing prone positioning to improve oxygenation, as discussed in 6, 3, 7
• Considering the use of inhaled vasodilators or nontraditional ventilator modes to improve oxygenation, although evidence for improved outcomes is weak 3
• Using an oxygenation advisor to provide guidance on setting PEEP and FIO2, as described in 4

Ventilator Settings

Specific ventilator settings that may help increase oxygen saturation include:

• Setting the tidal volume to 4 to 8 mL/kg predicted body weight (PBW), with a plateau pressure (Pplat) ≤ 30 cm H2O, as recommended in 3
• Initializing PEEP at 10 to 12 cm H2O and increasing it in increments of 2 to 3 cm H2O, provided that Pplat remains ≤ 30 cm H2O and driving pressure does not increase, as suggested in 3
• Adjusting FIO2 to achieve a target oxygen saturation goal, such as SpO2 ≥ 88 and ≤ 95%, as mentioned in 4

Additional Therapies

In cases of severe hypoxemic respiratory failure, additional therapies may be considered, including:

• Extracorporeal membrane oxygenation (ECMO) for patients with profound refractory hypoxemia, as discussed in 6, 3, 7
• Neuromuscular blockade to facilitate ventilation and improve oxygenation, as mentioned in 3