A postoperative abdominal surgery patient has been receiving…

A pоstоperаtive аbdоminаl surgery patient has been receiving incentive spirometry every 2 hours. Over the past two days, her inspiratory capacity has progressively declined. Breath sounds at the lung bases are diminished with faint crackles, and a chest radiograph shows plate-like, thin-layered opacities in the lower lobes. Which condition is most likely present?