A nurse is assessing a client who has respiratory failure. Which of the following manifestations should the nurse identify as indicative of severe hypercapnia?

A. Respiratory acidosis: Clients with COPD have chronic difficulty exhaling carbon dioxide due to airflow obstruction, leading to CO₂ retention. This accumulation of carbon dioxide causes a drop in blood pH, resulting in respiratory acidosis, a common acid-base imbalance in COPD patients.
B. Metabolic acidosis: Metabolic acidosis results from increased acid production or loss of bicarbonate through the kidneys or gastrointestinal tract, such as in diabetic ketoacidosis or severe diarrhea. It is not typically associated with impaired ventilation or chronic lung disease like COPD.
C. Respiratory alkalosis: Respiratory alkalosis occurs when there is excessive loss of carbon dioxide due to hyperventilation. Clients with COPD generally hypoventilate rather than hyperventilate, making this acid-base imbalance unlikely in this case.
D. Metabolic alkalosis: Metabolic alkalosis is typically caused by loss of hydrogen ions through vomiting or diuretic use, or excessive bicarbonate intake. It is unrelated to the impaired gas exchange and CO₂ retention seen in clients with COPD.

A. The liver releases glucagon to regulate blood glucose levels: The liver does release glucagon, but glucagon's role is to stimulate the liver to release glucose into the bloodstream, not to regulate blood glucose directly. Glucagon is released in response to low blood glucose levels to raise them, but the adrenal glands play a larger role in regulating glucose in the short term.
B. The adrenal glands release epinephrine and norepinephrine to respond to low blood glucose: When blood glucose levels drop, the adrenal glands release epinephrine (adrenaline) and norepinephrine. These hormones stimulate glucose release from the liver and promote glucose production to help increase blood sugar levels. This is the correct response to hypoglycemia, as these hormones help combat low blood sugar quickly.
C. Glycogenesis occurs in the pancreas when blood glucose levels fall: Glycogenesis refers to the process of glucose being stored as glycogen, primarily in the liver and muscles, and not the pancreas. When blood glucose levels fall, glycogenolysis (the breakdown of glycogen into glucose) occurs, not glycogenesis, to raise glucose levels. The pancreas releases insulin and glucagon, but not for storing glucose.
D. The brain uses protein for energy if glucose levels fall too low: While the brain primarily uses glucose for energy, when glucose levels are critically low, it will use ketones, not protein, for energy. Protein breakdown for energy is typically a later response, and the body generally tries to prevent using protein for energy as long as possible due to its importance in cellular functions.