When does peak lung and chest wall compliance decrease after a sternotomy?

Peak lung and chest wall compliance typically decreases within the post-operative period following a sternotomy, reflecting the impact of surgical intervention and recovery processes. The peak compliance refers to how easily the lungs and chest wall can expand during inhalation.

After a sternotomy, various factors contribute to the decrease in compliance, including pain, swelling, and restrictions due to the healing of the sternum. Generally, significant changes in compliance are observed in the first few days post-op when patients still experience immediate pain and inflammation.

By around 6 days post-surgery, compliance may show a measurable decline before starting to improve as the chest wall heals and pulmonary function is optimized through respiratory therapy and mobilization. Therefore, the choice that identifies this specific timeframe as when peak lung and chest wall compliance decreases is particularly aligned with the physiological healing process that occurs after a surgical intervention like a sternotomy. It is important to recognize that while compliance may begin to recover after a few days, it typically reaches a nadir around the 6-day mark, making this choice the most accurate reflection of the situation as outlined in the question.