Final answer:
In respiratory acidosis, laboratory values typically show decreased pH, increased PCO₂, and increased bicarbonate levels if compensation occurs. The base/acid ratio is decreased.
Step-by-step explanation:
The expected laboratory values for respiratory acidosis are a: decreased pH, increased PCO₂ (partial CO₂ pressure), and an increased Bicarbonate level if the body has time to compensate. As CO₂ accumulates, it combines with water to form carbonic acid, which dissociates into hydrogen ions (lowering the pH) and bicarbonate ions. The body may compensate by increasing renal retention or production of bicarbonate to buffer these excess hydrogen ions, attempting to restore the acid-base balance, thereby increasing the bicarbonate levels. The Base/Acid ratio would be decreased due to the initial presence of excess acid (CO₂).