Which of the following patients would most likely benefit from sigh breaths?

• A. 60 kg IBW Patient on 350 mL with Pplat 28
• B. 65 kg IBW Patient on 360 mL with Pplat 27
• C. 75 kg IBW Patient on 350 mL with Pplat 26
• D. 70 kg IBW Patient on 400 mL with Pplat 25

Answer: (D)

Sigh breaths are occasional, larger inflations used to reopen collapsed alveoli and maintain alveolar recruitment during protective, low-tidal-volume ventilation. The key is having enough headroom in plateau pressure to avoid overdistension when the breath is increased. The patient with the lowest plateau pressure—25 cm H2O—has the most room to accommodate a recruitment sigh without pushing Pplat toward unsafe levels. Their tidal volume is near protective ranges for their IBW, so a sigh can help recruit atelectatic units without causing excessive stress. The other patients have higher plateau pressures with less margin for safely increasing breath size, making a recruitment sigh riskier or less effective.