What is one common risk factor for altered gas exchange in cancer patients?

Obstruction is a common risk factor for altered gas exchange in cancer patients due to the potential for tumors to grow within or around the respiratory tract, leading to physical blockages. These obstructions can impair airflow, reduce effective ventilation, and ultimately hinder proper gas exchange in the lungs. For instance, lung tumors or metastases can infiltrate bronchial passages, causing narrowing or blockage, which directly affects the patient's ability to inhale oxygen and exhale carbon dioxide efficiently.

While emotional distress can affect overall respiratory patterns, it is not a direct anatomical barrier to gas exchange. Weight loss, which can occur with cancer, may impact muscle strength and respiratory function, but again, it does not create a physical obstruction. Excessive hydration can lead to fluid overload, potentially causing pulmonary edema, but this is more of a consequence rather than a direct obstruction of air passages. The concept of obstruction specifically highlights a mechanical issue that significantly alters ventilation and gas exchange, making it a key risk factor in these patients.