Answer :
Final answer:
Gas entering the stomach during PPV can lead to a physiological shunt and negatively impact the ventilation/perfusion ratio due to abdominal distension, both of which interfere with effective lung ventilation and gas exchange.
Explanation:
Two ways in which gas entering the stomach via Positive Pressure Ventilation (PPV) can interfere with effective ventilation are through the development of a physiological shunt and by causing changes in the ventilation/perfusion (V/Q) ratio due to increased stomach pressure. When gas is inadvertently introduced into the stomach, it can result in abdominal distension. This distension elevates the diaphragm, compromising the lung's ability to expand, leading to decreased alveolar ventilation. Subsequently, a physiological shunt can occur if the distension affects the lung's regions prone to infection or edema, decreasing ventilation to these areas while maintaining perfusion, thereby affecting the V/Q ratio and impairing gas exchange.
