What is the acceptable spontaneous tidal volume (VT) in mL/kg?

The acceptable spontaneous tidal volume is typically greater than 5 mL/kg. This parameter is crucial in mechanical ventilation because adequate tidal volume is essential to ensure sufficient ventilation and gas exchange in patients. A tidal volume in this range helps prevent hypoventilation and ensures that the alveoli are adequately filled with air, facilitating effective oxygenation and carbon dioxide removal.

When evaluating the options, a tidal volume of 8 mL/kg is often considered towards the higher end of the acceptable range and may be acceptable in certain circumstances, but generally, a value exceeding 5 mL/kg is preferred for spontaneous ventilation in most clinical contexts.

This emphasizes the need to evaluate the individual patient's condition, including their lung mechanics and overall respiratory status, when determining ideal settings for mechanical ventilation. In practice, a tidal volume greater than 5 mL/kg supports better ventilation while minimizing the risk of ventilator-induced lung injury, assuming lung compliance is adequate.