What is the effect of rib fractures on respiratory mechanics?

Rib fractures can significantly impact respiratory mechanics, primarily leading to a reduction in lung capacity. This occurs for several reasons. Firstly, rib fractures often cause pain, which can lead to shallow breathing as the patient instinctively avoids deep inhalation due to discomfort. This shallow breathing reduces overall lung volume and hinders effective ventilation.

Moreover, the structural integrity of the chest wall is compromised with rib fractures. This can inhibit normal expansion and contraction of the thoracic cavity during respiration, contributing to the decreased lung capacity. The inability to fully engage the diaphragm and intercostal muscles due to pain further exacerbates this issue, leading to reduced tidal volumes and impaired gas exchange.

In summary, rib fractures impair the mechanics of breathing by causing pain and restricting chest wall movement, ultimately resulting in decreased lung capacity.