Final Answer:
B) Inverse ratio ventilation (IRV), Inverse ratio ventilation (IRV) is the ventilatory support strategy least likely to result in auto-positive end-expiratory pressure (auto-PEEP).
Step-by-step explanation:
Auto-PEEP occurs when there is insufficient time for complete exhalation before the next breath, leading to the accumulation of positive pressure in the lungs. IRV, characterized by a prolonged inspiratory phase, can exacerbate this phenomenon by limiting the time available for expiration.
In contrast, continuous mandatory ventilation (CMV) assist-control, low-rate intermittent mandatory ventilation, and low inspiratory flows are more prone to causing auto-PEEP.
Continuous mandatory ventilation (CMV) assist-control (Option A) delivers breaths at a preset rate, which may not allow sufficient time for complete exhalation in some cases.
Low-rate intermittent mandatory ventilation (Option C) and low inspiratory flows (Option D) also contribute to auto-PEEP by impeding the full expiration of air before the next breath. These methods can lead to a gradual increase in lung volume over successive breaths.
In summary, recognizing the impact of ventilatory support strategies on auto-PEEP is crucial for managing patients with respiratory distress. Avoiding inverse ratio ventilation (IRV) is advisable when aiming to minimize the risk of auto-PEEP, as it allows for a more balanced inspiratory and expiratory time, facilitating adequate lung emptying and preventing complications associated with elevated end-expiratory pressures.