In volume controlled ventilation, which of the following factors can be adjusted to change I:E ratio?

In volume controlled ventilation, adjusting the inspiratory flow is indeed the correct way to manipulate the inspiratory to expiratory (I:E) ratio. When the inspiratory flow rate is changed, it directly affects the duration of the inspiration phase. For instance, an increase in inspiratory flow will shorten the inspiratory time, allowing more time for expiration, thereby altering the I:E ratio.

The I:E ratio is critical in ensuring adequate ventilation and oxygenation and in preventing complications such as air trapping or inadequate expiration, which can occur if the expiratory time is too short.

Other factors like tidal volume, end-expiratory volume, and PEEP level influence overall ventilation and oxygenation but do not directly enable control of the I:E ratio. While tidal volume influences the total volume delivered, it does not dictate the time spent in inspiration versus expiration. End-expiratory volume and PEEP primarily affect the baseline pressure and lung mechanics, impacting lung recruitment and functional residual capacity rather than the timing of breaths in the ventilatory cycle.