Choice A rationale:
Metabolic alkalosis is a condition characterized by an increase in the pH of the blood due to an excess of bicarbonate (HCO3-) in the body. It is not typically caused by severe diarrhea. In fact, diarrhea can often lead to a loss of bicarbonate, which can contribute to metabolic acidosis.
Causes of metabolic alkalosis include: excessive vomiting, use of diuretics, and excessive intake of alkali such as antacids. Clinical manifestations of metabolic alkalosis include: muscle twitching, paresthesias, seizures, confusion, and lethargy.
Choice B rationale:
Respiratory alkalosis is a condition characterized by a decrease in the partial pressure of carbon dioxide (PaCO2) in the blood, leading to an increase in blood pH. It is caused by hyperventilation, which removes excess CO2 from the body. Severe diarrhea does not typically cause hyperventilation.
Causes of respiratory alkalosis include: anxiety, hyperventilation syndrome, high altitude sickness, and pulmonary embolism. Clinical manifestations of respiratory alkalosis include: lightheadedness, dizziness, paresthesias, palpitations, and tetany.
Choice C rationale:
Respiratory acidosis is a condition characterized by an increase in the partial pressure of carbon dioxide (PaCO2) in the blood, leading to a decrease in blood pH. It is caused by hypoventilation, which prevents the body from removing enough CO2. Severe diarrhea does not typically cause hypoventilation.
Causes of respiratory acidosis include: chronic obstructive pulmonary disease (COPD), pneumonia, asthma, and neuromuscular disorders.
Clinical manifestations of respiratory acidosis include: headache, confusion, somnolence, and coma.
Choice D rationale:
Metabolic acidosis is a condition characterized by a decrease in the pH of the blood due to an excess of acid in the body or a loss of bicarbonate. Severe diarrhea can lead to metabolic acidosis through several mechanisms:
Loss of bicarbonate in the stool: Diarrhea often contains a significant amount of bicarbonate, which can be lost from the body in large amounts during severe diarrheal episodes. This loss of bicarbonate can lead to a decrease in the blood's pH, resulting in metabolic acidosis.
Dehydration: Severe diarrhea can also lead to dehydration, which can concentrate acids in the blood and contribute to metabolic acidosis.
Lactic acidosis: In some cases, severe diarrhea can also cause lactic acidosis, a type of metabolic acidosis that occurs when there is a buildup of lactic acid in the body. This can happen due to impaired circulation or tissue hypoxia, which can occur as a complication of severe diarrhea.

Choice A rationale:
Tolerance to the opiate medication is developing. This is the most likely explanation for why the client's pain is no longer being controlled by the same dose of medication. Tolerance is a physiological adaptation that occurs with repeated exposure to opioids, leading to a decrease in their effectiveness over time. This means that the client's body is becoming less responsive to the medication, and a higher dose is needed to achieve the same level of pain relief.
Choice B rationale:
There is likely a history of addiction. While it is possible that the client has a history of addiction, this is not the most likely explanation for why the medication is no longer controlling the pain. Addiction is a complex condition that is characterized by compulsive drug seeking and use, despite negative consequences. It is not simply a matter of tolerance developing.
Choice C rationale:
The client is opiate naive. This means that the client has not previously been exposed to opioids. While opiate-naive clients may be more sensitive to the effects of opioids, they are also more likely to experience side effects, such as nausea and vomiting. The fact that the client has been receiving the same dose of medication for 2 days without experiencing side effects suggests that they are not opiate naive.
Choice D rationale:
Physical dependence. Physical dependence is a state of adaptation that occurs with repeated exposure to opioids, leading to withdrawal symptoms if the medication is abruptly stopped. However, physical dependence does not necessarily mean that the medication is no longer effective in controlling pain.