Client 1's (pneumonia) airways are completely blocked, so oxygen cannot get through, while Client 2's (pulmonary embolism) airways are open

Client 2 (pulmonary embolism) has too much blood flow and not enough at while Client 1 (pneumonia) has too much air and not enough blood flow

Client 1 (pneumonia) has only partially blocked airways while Client 2 (pulmonary embolism) has a blockage of blood flow, preventing the blood from picking up oxygen

Client 1 (pneumonia) has a higher cardiac output then Client 2 (pulmonary embolism), leading to increased thoracic pressure and peripheral vascular resistance