ATI Fluid and Electrolyte Exam

The correct answer is A: The newly licensed nurse is using a bag of normal saline to prime the administration set before connecting it to the blood product.

Explanation of the correct answer:

A. The newly licensed nurse is using a bag of normal saline to prime the administration set before connecting it to the blood product

This action is inappropriate and requires intervention. While 0.9% sodium chloride (normal saline) is the only IV fluid compatible with blood products, the tubing should not be pre-primed with normal saline from a separate IV fluid bag before spiking the blood product. Priming the tubing with saline first can lead to hemodilution of the blood product and contamination risk. Instead, the Y-type blood administration set should be primed directly with the blood product itself, or if necessary, only using the normal saline port on the Y-set, not a separate saline bag. This avoids introducing an incompatible or unnecessary solution and maintains sterility and blood integrity.

Why the other options are incorrect:

B. The newly licensed nurse is verifying the client's identity using two identifiers before starting the transfusion

This is correct practice and aligns with safety protocols for blood transfusions. Verification using two identifiers (e.g., name and date of birth) and matching them with the blood product and crossmatch documentation is critical to prevent ABO incompatibility errors.

C. The newly licensed nurse is using a Y-type administration set to infuse the blood product

This is the appropriate equipment for blood transfusions. The Y-type set allows one limb to connect to the blood bag and the other to normal saline, ensuring compatibility and enabling flushing if needed. This is standard and does not require intervention.

D. The newly licensed nurse is monitoring the client for adverse reactions during the first 15 minutes of the transfusion

This is evidence-based best practice. Most transfusion reactions occur within the first 15 minutes, so close monitoring during this period is crucial for early detection and intervention. This action is appropriate and should be continued.

Summary:

The charge nurse should intervene when the newly licensed nurse uses a separate bag of normal saline to prime the blood administration tubing. Blood transfusions require strict adherence to protocols to avoid contamination, dilution, or incompatibility. All other actions reflect proper transfusion practices and do not require correction.

The correct answer is B: Secondary active transport.

Explanation of the correct answer:

B. Secondary active transport

Glucose and amino acids are reabsorbed from the glomerular filtrate in the proximal convoluted tubule (PCT) of the nephron through secondary active transport. This process utilizes the sodium gradient, which is established by the Na+/K+ ATPase pump (a primary active transport mechanism) on the basolateral membrane of tubular cells. Sodium (Na+) ions are actively pumped out of the cell into the interstitial space, creating a sodium gradient. This gradient then drives the co-transport of glucose and amino acids into the cells via sodium-dependent symporters (e.g., SGLT for glucose and Na+/amino acid symporters for amino acids). This process is secondary active transport because it relies on the energy created by the primary active transport of sodium.

Why the other options are incorrect:

A. Osmosis

Osmosis refers to the movement of water from an area of low solute concentration to an area of high solute concentration. While water is reabsorbed by osmosis in the kidneys, glucose and amino acids are not reabsorbed via osmosis. They require transport mechanisms, not simple diffusion of water.

C. Secondary passive transport

Secondary transport can be passive in some cases (e.g., for ions or small molecules like chloride), but glucose and amino acids require active transport, meaning that energy (through the sodium gradient) is used to facilitate their movement into the cell. Hence, it is secondary active transport, not passive.

D. Primary passive transport

Primary transport refers to the direct use of energy (like ATP) to move molecules, while passive transport refers to movement of molecules along a concentration gradient without energy input. In the case of glucose and amino acid reabsorption, while the sodium gradient is established using primary active transport, the movement of glucose and amino acids into the cell is through secondary active transport, which uses the gradient to power the process.

E. Primary active transport

Primary active transport involves the direct use of energy (usually from ATP) to move substances against their concentration gradient, as seen with the Na+/K+ ATPase pump. However, glucose and amino acids do not move against their concentration gradient directly using ATP; instead, they move with the sodium gradient established by the primary active transport of sodium. Therefore, secondary active transport is the correct term.

Summary:

Glucose and amino acids are reabsorbed by the kidneys through secondary active transport, utilizing the sodium gradient established by the Na+/K+ ATPase pump. This allows the transport of glucose and amino acids against their concentration gradients with the help of sodium.

The correct answer is B: glucose.

Explanation of the correct answer:

B. Glucose

Glucose is considered an osmotic diuretic because it can increase urine output by drawing water into the urine through osmosis. When there is a high concentration of glucose in the blood (as seen in uncontrolled diabetes mellitus), it can exceed the renal threshold for glucose reabsorption in the proximal convoluted tubule (PCT). As a result, glucose is excreted in the urine, and water follows due to osmosis, leading to increased urine volume. This effect is also called osmotic diuresis, where the osmotic gradient created by the presence of glucose causes more water to be filtered into the urine.

Why the other options are incorrect:

A. Alcohol

While alcohol can have a diuretic effect, it does not work through an osmotic mechanism. Instead, alcohol inhibits the release of antidiuretic hormone (ADH), which normally helps the kidneys conserve water. By inhibiting ADH, alcohol prevents the kidneys from reabsorbing water, leading to increased urine output. This effect is not caused by an osmotic gradient but by hormonal interference.

C. Caffeine

Caffeine also has a diuretic effect, but it does not function as an osmotic diuretic. Caffeine primarily works by inhibiting sodium reabsorption in the renal tubules, leading to increased water excretion. Although it has diuretic effects, caffeine's action is not due to osmosis, but rather through a renal tubular effect.

D. ALL are osmotic diuretics

This statement is incorrect because alcohol and caffeine are not osmotic diuretics. They have diuretic effects but do not work by the osmotic mechanism like glucose.

Summary:

Glucose is the correct answer because it directly causes osmotic diuresis, where its presence in the urine draws water into the tubules and increases urine output. Alcohol and caffeine have diuretic effects but do not function through the osmotic mechanism.

The correct answer is C: Intracellular.

Explanation of the correct answer:

C. Intracellular The intracellular fluid compartment contains the most fluid in the body. It accounts for about two-thirds (2/3) of the body's total water. This fluid is inside the cells and is essential for various cellular processes such as nutrient exchange, waste removal, and maintaining cell structure and function. Therefore, the intracellular compartment has the greatest volume of fluid.

Why the other options are incorrect:

A. Interstitial The interstitial fluid is part of the extracellular fluid compartment and lies between the cells and outside the blood vessels. Although it makes up a significant portion of extracellular fluid, it is still smaller in volume compared to the intracellular compartment. The interstitial fluid accounts for about two-thirds of the extracellular fluid, which itself only makes up one-third of the total body water.

B. Extracellular The extracellular fluid includes interstitial fluid, plasma, and other small compartments like synovial fluid and cerebrospinal fluid. While it makes up one-third of the total body water, it is less than the intracellular fluid in terms of volume. The extracellular fluid is important for transporting nutrients and waste products but does not contain as much fluid as the intracellular compartment.

D. Plasma Plasma is the liquid component of blood and constitutes about 20% of the extracellular fluid. Although it is essential for transporting blood cells, nutrients, and gases, its volume is significantly smaller compared to the intracellular and interstitial fluid compartments.

Summary: 

The intracellular fluid compartment contains the most fluid in the body, representing about two-thirds of total body water. The extracellular fluid compartment, which includes interstitial fluid and plasma, makes up the remaining one-third, with plasma comprising a smaller proportion of the extracellular fluid.

The correct answer is B: Cardiac rhythm.

Explanation of the correct answer:

B. Cardiac rhythm

Calcium plays a crucial role in the regulation of the cardiac muscle and the conduction system of the heart. A serum calcium level of 8.1 mg/dL is considered to be low (normal calcium levels range from 8.6 to 10.2 mg/dL). Hypocalcemia can lead to cardiac arrhythmias, as calcium is essential for normal cardiac muscle contraction and electrical conduction. Therefore, it is the priority for the nurse to assess the cardiac rhythm, as arrhythmias can be life-threatening if not identified and addressed promptly.

Why the other options are incorrect:

A. Deep tendon reflexes

While hypocalcemia can cause hyperreflexia (exaggerated deep tendon reflexes), this is not the priority assessment. Although important to monitor, cardiac rhythm is more immediately critical because abnormal rhythms can cause cardiac arrest, which can be fatal.

C. Peripheral sensation

Hypocalcemia can lead to paresthesias (numbness or tingling), particularly in the fingers, toes, and around the mouth, but this is not as immediately dangerous as potential cardiac arrhythmias. Therefore, assessing cardiac rhythm takes precedence.

D. Bowel sounds

Hypocalcemia can cause hypoactive bowel sounds due to its effects on smooth muscle function, but again, this is not as urgent as ensuring the client's cardiac function is stable. While important, assessing bowel sounds should not take priority over assessing cardiac rhythm.

Summary:

A serum calcium level of 8.1 mg/dL indicates hypocalcemia, which can lead to cardiac arrhythmias. The priority assessment is the cardiac rhythm because arrhythmias can lead to life-threatening complications. The other assessments, such as deep tendon reflexes, peripheral sensation, and bowel sounds, are important but are not as immediately critical as monitoring the cardiac rhythm in this scenario.

Correct answers:

A. Hct 55%,

C. Serum Sodium 150 mEq/L,

D. Urine Specific Gravity 1.035

Explanation of the correct answers:

A. Hct 55%

This hematocrit value is elevated (normal range for females is ~37–47%, for males ~42–52%). In dehydration, plasma volume is decreased, which causes hemoconcentration, leading to increased hematocrit levels. This is a classic indicator of dehydration.

C. Serum Sodium 150 mEq/L

This value is elevated (normal range: 135–145 mEq/L). Hypernatremia is a common manifestation of dehydration, especially in cases where there is more water loss than sodium loss, leading to concentrated extracellular fluid.

D. Urine Specific Gravity 1.035

This value is above the normal range (1.010–1.030), indicating concentrated urine, which is typical of dehydration. When the body is dehydrated, the kidneys conserve water, resulting in a higher concentration of solutes in the urine, thus increasing specific gravity.

Why the other options are incorrect:

B. Serum Osmolarity 260 mOsm/kg

This is below normal (normal range: 275–295 mOsm/kg). In dehydration, serum osmolality typically increases, not decreases, due to hemoconcentration and the loss of water relative to solutes. A low serum osmolality would be more consistent with overhydration or SIADH, not dehydration.

E. Serum creatinine 0.6 mg/dL

This is low-normal (normal range: ~0.6–1.3 mg/dL depending on gender and muscle mass). Dehydration usually results in increased creatinine levels due to decreased renal perfusion and reduced glomerular filtration rate. A value of 0.6 does not support dehydration.

Summary:

Signs of dehydration include elevated hematocrit (A), hypernatremia (C), and concentrated urine (D) with high specific gravity. Low serum osmolality (B) and low creatinine (E) do not support a diagnosis of dehydration and may suggest alternative conditions.

Correct answer A: water moves from an area of lower solute concentration to an area of higher solute concentration

Explanation:

A. water moves from an area of lower solute concentration to an area of higher solute concentration

Osmosis is the process where water molecules move across a semipermeable membrane from an area of lower solute concentration to an area of higher solute concentration. This movement is a response to the concentration gradient of solutes on either side of the membrane. The goal is to equalize the concentration of solutes on both sides of the membrane.

Why the other options are incorrect:

B. solutes pass through semipermeable membranes to areas of lower concentration

This describes diffusion, not osmosis. Diffusion is the movement of solutes, not water, from an area of higher concentration to an area of lower concentration, while osmosis specifically involves water moving in response to solute concentrations.

C. plasma proteins facilitate the reabsorption of fluids into the capillaries

This statement refers to colloid osmotic pressure (also known as oncotic pressure), which is the force exerted by plasma proteins like albumin to pull water back into the bloodstream. While this is related to osmotic principles, it is not the definition of osmosis itself.

D. water shifts from high-solute areas of lower solute concentration

This statement is incorrect because osmosis involves the movement of water towards higher solute concentrations, not away from them. The principle is that water moves to areas where solutes are more concentrated to balance concentrations on both sides of a membrane.

Summary:

Osmosis involves the movement of water from an area of lower solute concentration to an area of higher solute concentration. Therefore, A is the most accurate description of osmosis.

The correct answer is A: Hyperactive deep-tendon reflexes.

Explanation of the correct answer:

A. Hyperactive deep-tendon reflexes

Hypomagnesemia (low magnesium levels) often causes neuromuscular excitability. One of the clinical manifestations of hypomagnesemia is hyperactive deep tendon reflexes (DTRs). Magnesium plays a crucial role in stabilizing cell membranes and regulating neuromuscular function. When magnesium levels are low, the excitability of nerves and muscles increases, leading to signs like hyperreflexia, muscle cramps, and tremors.

Why the other options are incorrect:

B. Increased bowel sounds

Increased bowel sounds are generally associated with hypermagnesemia (high magnesium levels), not hypomagnesemia. Elevated magnesium can cause smooth muscle relaxation, leading to symptoms like decreased bowel motility or hypoactive bowel sounds. Therefore, this finding is more indicative of elevated magnesium levels rather than low levels.

C. Drowsiness

Drowsiness is more commonly seen in cases of hypermagnesemia or other conditions involving sedation or depression of the central nervous system. While hypomagnesemia can lead to irritability or agitation, it does not typically cause drowsiness. In fact, individuals with low magnesium levels are more likely to experience hyperexcitability rather than sedation.

D. Decreased blood pressure

Decreased blood pressure is not typically associated with hypomagnesemia. In fact, hypomagnesemia can sometimes contribute to vasoconstriction, which could cause increased blood pressure. However, magnesium deficiency is more likely to cause cardiac arrhythmias or muscle spasms than a direct decrease in blood pressure.

Summary:

Hyperactive deep-tendon reflexes are a key indicator of hypomagnesemia due to the increased neuromuscular excitability that occurs with low magnesium levels. The other options—increased bowel sounds, drowsiness, and decreased blood pressure—are not typical signs of hypomagnesemia and are more commonly seen with hypermagnesemia or other conditions.

The correct answer is D: Presence of Trousseau's sign

Explanation of the correct answer:

D) Presence of Trousseau's sign

A serum calcium level of 7.6 mg/dL is below the normal range (normal range is 8.6 to 10.2 mg/dL). Hypocalcemia (low calcium levels) is associated with neuromuscular irritability, and Trousseau's sign is a clinical indication of this. Trousseau's sign is elicited by inflating a blood pressure cuff above the patient's systolic pressure for a few minutes. If the patient has low calcium levels, they may develop carpopedal spasm, where the hand and fingers curl into a "claw-like" position. This is a classic sign of hypocalcemia.

Why the other options are incorrect:

A) Slurred speech

Slurred speech can occur in various conditions, but it is not typically associated with hypocalcemia. Speech issues are more likely to be related to neurological conditions or muscle weakness rather than directly to calcium imbalances.

B) Muscle weakness

While muscle weakness can be a symptom of hypocalcemia, it is not as specific or characteristic as Trousseau's sign. Muscle weakness could also be caused by many other factors, including post-surgical changes or other electrolyte imbalances.

C) Negative Chvostek's sign

Chvostek's sign is another test for hypocalcemia. It is positive when tapping on the facial nerve (just in front of the ear) causes twitching of the facial muscles. A negative Chvostek's sign would indicate normal calcium levels, and therefore, this option is inconsistent with the patient's hypocalcemia.

Summary:

The presence of Trousseau's sign is a classic and reliable finding in patients with hypocalcemia. This sign should be expected in a patient with a serum calcium level of 7.6 mg/dL, which is low. Other options like slurred speech, muscle weakness, and a negative Chvostek's sign are not as directly associated with hypocalcemia.