Nokea
A nurse in the neurologic ICU has orders to infuse a hypertonic solution into a patient with increased intracranial pressure. This solution will increase the number of dissolved particles in the patients blood, creating pressure for fluids in the tissues to shift into the capillaries and increase the blood volume. This process is best described as which of the following?
- A. Hydrostatic pressure
- B. Osmosis and osmolality
- C. Diffusion
- D. Active transport
Correct Answer: B
Rationale: Osmosis is the movement of fluid from a region of low solute concentration to a region of high solute concentration across a semipermeable membrane. Hydrostatic pressure refers to changes in water or volume related to water pressure. Diffusion is the movement of solutes from an area of greater concentration to lesser concentration; the solutes in an intact vascular system are unable to move so diffusion normally should not be taking place. Active transport is the movement of molecules against the concentration gradient and requires adenosine triphosphate (ATP) as an energy source; this process typically takes place at the cellular level and is not involved in vascular volume changes.
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You are caring for a patient who has a diagnosis of syndrome of inappropriate antidiuretic hormone secretion (SIADH). Your patients plan of care includes assessment of specific gravity every 4 hours. The results of this test will allow the nurse to assess what aspect of the patients health?
- A. Nutritional status
- B. Potassium balance
- C. Calcium balance
- D. Fluid volume status
Correct Answer: D
Rationale: A specific gravity will detect if the patient has a fluid volume deficit or fluid volume excess. Nutrition, potassium, and calcium levels are not directly indicated.
A patient who is being treated for pneumonia starts complaining of sudden shortness of breath. An arterial blood gas (ABG) is drawn. The ABG has the following values: pH 7.21, PaCO2 64 mm Hg, HCO3=24 mm Hg. What does the ABG reflect?
- A. Respiratory acidosis
- B. Metabolic alkalosis
- C. Respiratory alkalosis
- D. Metabolic acidosis
Correct Answer: A
Rationale: The pH is below 7.40, PaCO2 is greater than 40, and the HCO3 is normal; therefore, it is a respiratory acidosis, and compensation by the kidneys has not begun, which indicates this was probably an acute event. The HCO3 of 24 is within the normal range so it is not metabolic alkalosis. The pH of 7.21 indicates an acidosis, not alkalosis. The pH of 7.21 indicates it is an acidosis but the HCO3 of 24 is within the normal range, ruling out metabolic acidosis.
A 73-year-old man comes into the emergency department (ED) by ambulance after slipping on a small carpet in his home. The patient fell on his hip with a resultant fracture. He is alert and oriented; his pupils are equal and reactive to light and accommodation. His heart rate is elevated, he is anxious and thirsty, a Foley catheter is placed, and 40 mL of urine is present. What is the nurses most likely explanation for the low urine output?
- A. The man urinated prior to his arrival to the ED and will probably not need to have the Foley catheter kept in place.
- B. The man likely has a traumatic brain injury, lacks antidiuretic hormone (ADH), and needs vasopressin.
- C. The man is experiencing symptoms of heart failure and is releasing atrial natriuretic peptide that results in decreased urine output.
- D. The man is having a sympathetic reaction, which has stimulated the reninangiotensinaldosterone system that results in diminished urine output.
Correct Answer: D
Rationale: Renin is released by the juxtaglomerular cells of the kidneys in response to decreased renal perfusion. Angiotensin-converting enzyme converts angiotensin I to angiotensin II. Angiotensin II, with its vasoconstrictor properties, increases arterial perfusion pressure and stimulates thirst. As the sympathetic nervous system is stimulated, aldosterone is released in response to an increased release of renin, which decreases urine production. Based on the nursing assessment and mechanism of injury, this is the most likely causing the lower urine output. The man urinating prior to his arrival to the ED is unlikely; the fall and hip injury would make his ability to urinate difficult. No assessment information indicates he has a head injury or heart failure.
A nurse is planning care for a nephrology patient with a new nursing graduate. The nurse states, A patient in renal failure partially loses the ability to regulate changes in pH. What is the cause of this partial inability?
- A. The kidneys regulate and reabsorb carbonic acid to change and maintain pH.
- B. The kidneys buffer acids through electrolyte changes.
- C. The kidneys regenerate and reabsorb bicarbonate to maintain a stable pH.
- D. The kidneys combine carbonic acid and bicarbonate to maintain a stable pH.
Correct Answer: C
Rationale: The kidneys regulate the bicarbonate level in the ECF; they can regenerate bicarbonate ions as well as reabsorb them from the renal tubular cells. In respiratory acidosis and most cases of metabolic acidosis, the kidneys excrete hydrogen ions and conserve bicarbonate ions to help restore balance. The lungs regulate and reabsorb carbonic acid to change and maintain pH. The kidneys do not buffer acids through electrolyte changes; buffering occurs in reaction to changes in pH. Carbonic acid works as the chemical medium to exchange O2 and CO2 in the lungs to maintain a stable pH whereas the kidneys use bicarbonate as the chemical medium to maintain a stable pH by moving and eliminating H+.
You are caring for a patient with a diagnosis of pancreatitis. The patient was admitted from a homeless shelter and is a vague historian. The patient appears malnourished and on day 3 of the patients admission total parenteral nutrition (TPN) has been started. Why would you know to start the infusion of TPN slowly?
- A. Patients receiving TPN are at risk for hypercalcemia if calories are started too rapidly.
- B. Malnourished patients receiving parenteral nutrition are at risk for hypophosphatemia if calories are started too aggressively.
- C. Malnourished patients who receive fluids too rapidly are at risk for hypernatremia.
- D. Patients receiving TPN need a slow initiation of treatment to allow digestive enzymes to accumulate.
Correct Answer: B
Rationale: The nurse identifies patients who are at risk for hypophosphatemia and monitors them. Because malnourished patients receiving parenteral nutrition are at risk when calories are introduced too aggressively, preventive measures involve gradually introducing the solution to avoid rapid shifts of phosphorus into the cells. Patients receiving TPN are not at risk for hypercalcemia or hypernatremia if calories or fluids are started too rapidly. Digestive enzymes are not a relevant consideration.