Final answer:
When a patient is positioned 'good lung' down, it allows for better ventilation and gas exchange. However, there are situations where it may not be indicated.
Step-by-step explanation:
When a patient is positioned 'good lung' down, it means that the healthier lung is facing downwards. This position is preferred because the lung that is facing downwards will have better ventilation and gas exchange. Gravity helps to distribute air and blood more evenly in the lung, allowing for improved oxygenation and removal of carbon dioxide.
However, there are situations where it may not be indicated to position a patient 'good lung' down. For example, if a patient has a known injury or condition affecting the lung that is supposed to be positioned 'good lung' down, it may be contraindicated. Additionally, certain medical procedures or surgeries may require a different positioning of the patient for optimal access or outcomes.