Two hours before major surgery is to begin, the patient experiences 'jitters,' an elevated heart rate and blood pressure. These symptoms are the result of

Correct Answer: A

Rationale: The correct answer is A) sympathetic activation. Two hours before major surgery, the patient experiencing 'jitters,' an elevated heart rate, and blood pressure is a classic physiological response to stress, known as the fight-or-flight response. This response is mediated by the sympathetic nervous system, which releases stress hormones like epinephrine and norepinephrine, leading to increased heart rate and blood pressure to prepare the body for perceived danger. Option B) decreased levels of epinephrine in the blood is incorrect because in times of stress, epinephrine levels actually increase to mobilize the body's resources for action. Option C) decreased activity of sympathetic centers in the hypothalamus is incorrect because decreased activity in these centers would result in a blunted sympathetic response, not the heightened response seen in the patient. Option D) increased parasympathetic activity is incorrect because parasympathetic activity is responsible for rest and digest functions, not the fight-or-flight response seen in this scenario. In an educational context, understanding the autonomic nervous system's role in stress responses is crucial in healthcare settings, especially in preoperative care. Recognizing and managing stress responses can help healthcare professionals provide optimal care and ensure patient safety during high-stress situations like surgery. This knowledge also highlights the importance of a holistic approach to patient care, considering not only the physical aspects but also the psychological and emotional well-being of patients.

Correct Answer: A

Rationale: The correct answer is A) potassium. Potassium is particularly affected by diuretics because some diuretics, such as potassium-sparing diuretics like spironolactone, help retain potassium in the body, while others, like loop diuretics, lead to potassium excretion. This differential impact on potassium levels distinguishes diuretics in terms of their effect on this specific electrolyte. Option B) calcium, option C) magnesium, and option D) sodium are not the primary electrolytes affected by diuretics in the same distinctive manner as potassium. While diuretics may have some impact on these electrolytes, it is not as pronounced or specific as the effect on potassium. Calcium and magnesium levels can be influenced by certain diuretics, but the effect is not as well-defined or characteristic as the relationship between diuretics and potassium levels. Sodium, on the other hand, is commonly affected by most diuretics, unlike potassium which shows a more varied response depending on the type of diuretic used. Understanding the specific impact of diuretics on electrolytes is crucial for healthcare professionals, especially in managing conditions like hypertension and heart failure where diuretics are commonly prescribed. Knowledge of how different diuretics affect electrolyte balance can help in monitoring patients for potential imbalances and adjusting treatment accordingly to prevent adverse effects such as arrhythmias or muscle weakness. This knowledge also underscores the importance of individualizing treatment plans based on the patient's electrolyte profile to optimize therapeutic outcomes and minimize risks associated with diuretic therapy.

Correct Answer: A

Rationale: The use of isotonic IV fluids can cause problems because they can lead to fluid overload, especially in patients with impaired kidney function or heart failure. This can result in symptoms such as swelling, shortness of breath, and increased blood pressure. Additionally, isotonic IV fluids can also cause electrolyte imbalances, such as hyponatremia or hypernatremia, which can have detrimental effects on the body's functioning. Therefore, it is important to carefully monitor the administration of isotonic IV fluids and adjust the dosage according to the patient's specific needs.

Correct Answer: B

Rationale: Urine promotion helps to clear K+ because the kidneys are responsible for filtering waste products, including potassium, from the blood and excreting them in urine. By promoting urine production, the kidneys remove excess potassium, maintaining a healthy balance. This is especially important in renal failure, where potassium clearance is impaired, contrary to option C.

Correct Answer: A

Rationale: PTH is released when Ca++ is at a low level. This hormone helps to regulate calcium levels in the blood by stimulating the release of calcium from bones and increasing calcium reabsorption in the kidneys. Therefore, when the calcium level is below the normal range, the parathyroid glands release PTH to restore the balance.