The patient has a history of Chronic Obstructive Pulmonary Disease (COPD) and is severely hypoxic. Which of the following signs and symptoms/conditions occur in hypoxic patients? Select 2 answers.

Severe hypoxia produces two key physiological consequences reflected in these answer choices. First, when tissue oxygen delivery is critically reduced, cells cannot sustain aerobic metabolism. Mitochondrial oxidative phosphorylation fails and anaerobic glycolysis takes over as the only available means of ATP production. This process is highly inefficient and generates lactic acid as a byproduct, leading to metabolic lactic acidosis — making the statement about anaerobic metabolism and lactic acid formation correct. Second, clinically visible signs of hypoxia include cyanosis of mucous membranes such as the lips and nail beds, which appears when deoxygenated hemoglobin in capillary blood exceeds approximately 5 g/dL. Cerebral hypoxia also causes neurological manifestations ranging from restlessness and anxiety to confusion and eventual coma. The statement about decreased RBC production is incorrect because hypoxia actually stimulates increased erythropoietin release from renal peritubular cells, which drives increased RBC production — the opposite of what is described. An SpO2 greater than 95% by pulse oximetry is inconsistent with severe hypoxia; pulse oximetry in hypoxic patients typically reads well below 90%, often below 85% in severe cases. A COPD patient with this degree of hypoxia would demonstrate both the clinical signs described and the metabolic derangement from anaerobic metabolism.