What should be increased in a 4 kg infant receiving volume control ventilation who appears tachypneic?

Increasing the set tidal volume in a 4 kg infant receiving volume control ventilation who appears tachypneic addresses the underlying issue of inadequate ventilation that may be contributing to the rapid respiratory rate. In volume control ventilation, a specific tidal volume is delivered with each breath, and if the infant is tachypneic, it may indicate that the current tidal volume is insufficient for the infant's needs, leading to increased work of breathing and respiratory distress.

Tachypnea can be a sign of hypoventilation, where the infant is unable to achieve adequate gas exchange with the current setup. By increasing the set tidal volume, the clinician can help improve the patient's minute ventilation and ensure that the infant receives enough oxygen and clears carbon dioxide effectively, potentially resolving the tachypnea.

Adjusting other parameters like respiratory rate, PEEP, or FiO2 may not directly address the problem of inadequate tidal volume. While increasing the respiratory rate may provide more breaths, it doesn't increase the volume of air delivered with each breath, which is crucial in this situation. Increasing PEEP might help with oxygenation but can also cause decreased cardiac output and should be adjusted cautiously. Increasing FiO2 may improve oxygen saturation but does not resolve issues related to ventilation. Thus,