ATI Fluid and Electrolyte Exam

Correct answer D: Hypokalemia

Explanation:

Loop diuretics, such as furosemide (Lasix), promote the excretion of sodium, potassium, and water. They are particularly known to cause potassium loss through the urine, leading to hypokalemia (low potassium levels in the blood). Additionally, gastric suctioning can further contribute to potassium loss as the stomach contents are removed, which may also result in a depletion of electrolytes like potassium. Potassium is crucial for normal muscle and heart function, and its depletion can lead to muscle weakness, fatigue, and life-threatening arrhythmias.

Why the other options are incorrect:

A) Hypocalcemia

Although loop diuretics can have an effect on calcium balance, they are more commonly associated with hypokalemia and hyponatremia. Hypocalcemia can occur in some cases due to the effects of diuretics, but it is not as directly linked to loop diuretics and gastric suctioning as hypokalemia is.

B) Hyponatremia

While loop diuretics can lead to hyponatremia (low sodium levels) due to excessive sodium loss through urine, the primary risk for the patient described here, given the loop diuretic use and gastric suctioning, would be hypokalemia, which is the most common electrolyte disturbance with these interventions.

C) Hypomagnesemia

Hypomagnesemia (low magnesium levels) can also occur with the use of loop diuretics, but it is not as common or as significant a concern as hypokalemia. Magnesium depletion can occur over time with chronic use, but potassium loss remains the primary concern in this scenario.

Summary:

The patient is at high risk for hypokalemia due to the combined effects of loop diuretics, which promote potassium excretion, and gastric suctioning, which can lead to further potassium loss. Monitoring potassium levels is essential to prevent dangerous complications like arrhythmias.

The correct answer is C: Glomerular endothelium.

Explanation of the correct answer:

C. Glomerular endothelium

The glomerular endothelium is the innermost layer of the filtration membrane, and it is closest to the plasma. It consists of endothelial cells that line the glomerular capillaries. These endothelial cells have fenestrations (tiny pores), which allow the passage of water, small solutes, and waste products from the blood into the glomerular filtrate, but they prevent the passage of larger molecules, such as proteins and blood cells. This layer is the first barrier that blood plasma must pass through in the filtration process.

Why the other options are incorrect:

A. Macula densa cells

The macula densa is part of the juxtaglomerular apparatus, located at the junction of the distal convoluted tubule and the afferent arteriole. These cells monitor the concentration of sodium in the filtrate and help regulate the glomerular filtration rate (GFR) through feedback mechanisms. However, they are not part of the filtration membrane and are not directly involved in the filtration process.

B. The basement membrane

The basement membrane is a thin layer of extracellular matrix located between the glomerular endothelium and the podocytes. It serves as a filtration barrier, preventing the passage of large proteins and helping to maintain selective permeability. However, it is not the layer closest to the plasma; it lies beneath the endothelium.

D. Outer layer of the glomerular capsule

The outer layer of the glomerular capsule (also called Bowman's capsule) is the outermost layer of the filtration membrane. It surrounds the glomerulus and collects the filtrate as it passes through the filtration barrier. While it is important in the filtration process, it is farthest from the plasma and does not directly interact with it.

E. Podocytes

Podocytes are specialized epithelial cells that cover the glomerular capillaries. They have foot processes that wrap around the capillaries and form filtration slits, which further regulate the filtration of small molecules. Although podocytes are an important component of the filtration membrane, they are not closest to the plasma; they are situated outside the glomerular endothelium.

Summary:

The glomerular endothelium is closest to the plasma, as it lines the glomerular capillaries and is the first layer that blood must pass through during filtration. The other layers, such as the basement membrane and podocytes, provide further filtration barriers but are not as close to the plasma as the endothelium.

Correct answer B: an implanted central venous access device (CVAD)

Explanation:

For a patient undergoing chemotherapy, an implanted central venous access device (CVAD) is most likely to meet their needs. Chemotherapy often requires the administration of strong, irritant drugs over a long period, which can be harmful to smaller veins or peripheral access. CVADs, which are inserted into large central veins, allow for long-term, safe, and effective administration of chemotherapy drugs. They also provide reliable access for blood draws and minimize the need for repeated venipunctures, which can be difficult for patients undergoing repeated treatments.

Why the other options are incorrect:

A. a midline peripheral catheter:

A midline catheter is inserted into a peripheral vein but is longer than a standard peripheral catheter and is typically used for therapies that last from 1 to 4 weeks. While it can be used for certain medications, it is not ideal for chemotherapy, especially if the drugs are irritants, as it does not have the same safety and longevity as a central line.

C. a peripheral venous catheter inserted to the cephalic vein:

While this is a common option for short-term intravenous access, it is not ideal for chemotherapy because the veins in the periphery (including the cephalic vein) can become damaged over time, especially with repeated chemotherapy infusions. Peripheral venous access is not suitable for long-term, repeated use with chemotherapy.

D. a peripheral venous catheter inserted to the antecubital fossa:

This is also a peripheral venous catheter, and while it can provide access for short-term treatments, it is not appropriate for long-term chemotherapy. The antecubital fossa (the area in front of the elbow) contains larger veins, but these veins still are not ideal for long-term chemotherapy administration due to the risk of irritation, infiltration, and thrombosis.

Summary:

For long-term chemotherapy administration, an implanted central venous access device (CVAD) is the best option as it provides reliable access, reduces the risk of vein damage, and is appropriate for the strong drugs used in chemotherapy. The other options are less suitable for long-term, repeated chemotherapy treatments.

The correct answer is A: A client who has vomited four times during the last 8 hours.

Explanation of the correct answer:

A. A client who has vomited four times during the last 8 hours

Hypomagnesemia can result from gastrointestinal losses such as vomiting or diarrhea. Magnesium is primarily absorbed in the small intestine, and repeated vomiting can deplete body stores of magnesium through both direct loss and impaired absorption. Clients with prolonged or severe vomiting are at risk for electrolyte imbalances, including low magnesium levels, which can lead to neuromuscular excitability, cardiac dysrhythmias, and muscle cramps. Therefore, this client is at risk of developing hypomagnesemia and warrants further evaluation.

Why the other options are incorrect:

B. A client who requested an extra breakfast tray to eat

This behavior suggests a good appetite and adequate nutritional intake. Since dietary intake is the main source of magnesium, this client is less likely to be magnesium-deficient, assuming the food consumed is balanced. There is no indication of risk factors like GI losses or malabsorption.

C. A client who can ambulate without assistance

Ambulating independently does not provide any direct or indirect evidence of magnesium deficiency. Hypomagnesemia can cause weakness or tremors, but without symptoms or a history of conditions that cause magnesium loss, this client's ability to ambulate suggests functional strength and balance, making hypomagnesemia less likely.

D. A client who reports extreme thirst

Extreme thirst is more characteristic of hypernatremia or hyperglycemia, not hypomagnesemia. While electrolyte imbalances can sometimes overlap, thirst alone is not a hallmark symptom of low magnesium and does not strongly indicate hypomagnesemia.

Summary:

Vomiting leads to gastrointestinal loss of electrolytes, including magnesium, and is a common cause of hypomagnesemia. Among the clients described, only the one with repeated vomiting shows a clear risk factor. The other clients demonstrate no signs or behaviors that are strongly associated with magnesium deficiency.

The correct answer is D: Decrease in level of consciousness.

Explanation of the correct answer:

D. Decrease in level of consciousness

A decrease in level of consciousness (LOC) is the priority finding to report to the provider. Hypovolemia, or decreased blood volume, can lead to hypoperfusion of vital organs, including the brain. A change in LOC indicates that the brain is not receiving adequate oxygen and blood supply, which can be a serious sign of inadequate circulation and requires immediate medical intervention. This could be a sign of severe hypovolemia or shock, which requires urgent attention to prevent further complications or organ damage.

Why the other options are incorrect:

A. Dry mucous membranes

Dry mucous membranes are a common sign of hypovolemia, indicating dehydration. While this finding is concerning, it is not as critical as a decreased LOC, which suggests impaired brain function due to inadequate perfusion.

B. Decreased urine output

Decreased urine output (oliguria) is another typical sign of hypovolemia and occurs due to reduced renal perfusion. Although this finding warrants attention and intervention, it is not as immediately life-threatening as a decrease in LOC. It is important to monitor urine output, but LOC changes take priority due to their potential to indicate serious complications.

C. Report of thirst

Thirst is a natural response to hypovolemia and dehydration. While it is an important subjective symptom, it is not as urgent as a decrease in LOC. Thirst can be addressed by providing fluids and hydration, but the risk of permanent brain damage or other serious outcomes due to decreased LOC is more critical.

Summary:

When caring for a client experiencing hypovolemia, the decrease in level of consciousness should be reported as the priority finding. This is an urgent sign that the brain may not be receiving sufficient oxygen and blood flow, requiring immediate intervention. Other findings such as dry mucous membranes, decreased urine output, and thirst, though concerning, do not indicate the immediate threat to organ function that a decreased LOC does.

The correct answer is C: 22-gauge.

Explanation of the correct answer:

C. 22-gauge

A #22-gauge catheter is smaller in diameter than a #20-gauge and is appropriate for clients with fragile or difficult veins, such as those who are dehydrated. Dehydration can cause peripheral veins to collapse or become less prominent, making them more challenging to cannulate. A smaller gauge catheter, such as a #22, can be inserted more easily into these narrowed veins without causing trauma, making it the most suitable choice in this situation.

Why the other options are incorrect:

A. #16-gauge

A #16-gauge catheter is significantly larger than a #20-gauge and is typically used in emergency or trauma situations where rapid fluid or blood product administration is necessary. It would be inappropriate for a dehydrated client with compromised peripheral veins because the large size would increase the risk of vein rupture or infiltration.

B. 18-gauge

While an #18-gauge catheter is commonly used for blood transfusions and rapid infusions, it is still larger than a #20-gauge. In a dehydrated client, using an #18-gauge may prove difficult or traumatic to the vein. It does not meet the requirement of being a smaller gauge than the current #20-gauge.

D. 14-gauge

A #14-gauge catheter is the largest size used in extreme emergencies like massive trauma or surgery for rapid fluid replacement. It is significantly larger than a #20-gauge and completely inappropriate for someone with dehydration, as it would be nearly impossible to insert into a narrowed or collapsed vein.

Summary:

Dehydrated clients typically have constricted or collapsed peripheral veins, necessitating the use of a smaller gauge catheter to ensure successful and less traumatic insertion. A #22-gauge catheter is smaller than a #20-gauge and is commonly used for clients with fragile or difficult veins, making it the most appropriate recommendation.

The correct answer is C: Serum potassium 3.0 mEq/L

Explanation of the correct answer:

C. Serum potassium 3.0 mEq/L

This serum potassium level is below the normal range (3.5–5.0 mEq/L), indicating hypokalemia, which is a common and serious complication during treatment for diabetic ketoacidosis (DKA). When insulin is administered, it promotes the shift of potassium into cells, further lowering serum potassium levels. If the patient already has hypokalemia (as in this case, 3.0 mEq/L), starting or continuing insulin therapy without correcting the potassium level may result in life-threatening cardiac arrhythmias or muscle weakness. Therefore, this finding must be reported immediately, and potassium replacement is typically initiated before continuing insulin infusion if hypokalemia is present.

Why the other options are incorrect:

A. Urine output of 30 mL/hr

This value is within the acceptable minimum range for adequate renal perfusion (≥30 mL/hr). It indicates that the kidneys are producing urine, which is expected and desirable in a patient with DKA. There is no need to report this finding unless urine output drops below this level or there are other concerns about renal function.

B. Blood glucose of 180 mg/dL

This glucose level reflects an improvement from likely much higher levels typically seen in DKA (usually >250 mg/dL). Once blood glucose levels drop to around 200 mg/dL, the standard practice is to adjust the insulin rate and add dextrose to the IV fluids to prevent hypoglycemia. However, this value alone does not warrant immediate reporting, as it is an expected part of DKA resolution.

D. BUN 18 mg/dL

Blood urea nitrogen (BUN) in the range of 10–20 mg/dL is normal, and 18 mg/dL does not indicate renal impairment or dehydration. This value does not indicate a critical issue and does not need to be reported unless other signs of renal compromise are present.

Summary:

A serum potassium level of 3.0 mEq/L is critically low and can be dangerous if not corrected before or during insulin administration in DKA. Insulin further lowers serum potassium, increasing the risk of cardiac complications. Therefore, C is the priority finding to report. The other findings—urine output, improved glucose level, and normal BUN—do not indicate urgent or abnormal conditions

The correct answer is A: Magnesium

Explanation of the correct answer:

A) Magnesium:

Magnesium should be closely monitored in a patient undergoing alcohol withdrawal, as hypomagnesemia (low magnesium levels) is commonly seen in patients with chronic alcohol use. Alcohol consumption can lead to poor dietary intake, malabsorption, and renal loss of magnesium, which increases the risk of hypomagnesemia. Low magnesium levels can contribute to neurological and cardiac symptoms, including seizures, muscle cramps, and arrhythmias, all of which can complicate alcohol withdrawal and worsen the clinical condition of the patient.

Why the other options are incorrect:

B) Potassium:

While potassium imbalances (either hypokalemia or hyperkalemia) can occur during alcohol withdrawal, magnesium is typically more critical to monitor due to its influence on cardiac function and neurological health. Potassium imbalances are generally less immediately concerning in alcohol withdrawal compared to magnesium.

C) Phosphorus:

Phosphorus levels can be affected by alcohol use and withdrawal, with hypophosphatemia (low phosphorus) occurring in some cases. However, magnesium has a more direct and significant role in the symptoms and complications of alcohol withdrawal, making it the more important electrolyte to monitor.

D) Calcium:

Calcium levels can also be affected during alcohol withdrawal, especially if magnesium levels are low. Magnesium plays a key role in regulating calcium, so hypomagnesemia can lead to secondary hypocalcemia. However, magnesium imbalances tend to be more prevalent and directly problematic during alcohol withdrawal.

Summary:

Magnesium is the most important electrolyte to monitor closely in a patient undergoing alcohol withdrawal due to its critical role in neurological and cardiac function. Hypomagnesemia can exacerbate withdrawal symptoms and lead to severe complications such as seizures and arrhythmias. While potassium, phosphorus, and calcium are important, magnesium has a more direct and significant impact in this context.

The correct answer is D: An 82-year-old woman who receives all nutrition via tube feedings. Her medications include carvedilol (Coreg) and torsemide (Demadex).

Explanation of the correct answer:

D. An 82-year-old woman who receives all nutrition via tube feedings. Her medications include carvedilol (Coreg) and torsemide (Demadex).

This patient is at the highest risk for fluid and electrolyte imbalance due to several factors. The patient is 82 years old, and older adults are more susceptible to fluid and electrolyte disturbances due to changes in kidney function, decreased body water content, and less efficient compensatory mechanisms. The fact that this patient is on torsemide (Demadex), a loop diuretic, significantly increases the risk for electrolyte imbalances, particularly hypokalemia, hyponatremia, and dehydration. Additionally, patients on diuretics require careful monitoring of fluid balance, as these medications promote the excretion of water and electrolytes. The reliance on tube feedings also means that this patient’s hydration and nutrition status depend entirely on external sources, which can lead to complications if not closely managed.

Why the other options are incorrect:

A. A 45-year-old man who had a laparoscopic appendectomy 24 hours ago being advanced to a regular diet.

While this patient is recovering from surgery, a laparoscopic appendectomy is a minimally invasive procedure with a relatively quick recovery time. The patient being advanced to a regular diet 24 hours post-op indicates a smooth recovery, and there is no immediate indication of a high risk for fluid and electrolyte imbalance.

B. A 79-year-old man admitted with a diagnosis of pneumonia.

This patient is at some risk due to age and pneumonia, but there is no indication that his condition is significantly complicating fluid and electrolyte balance. Pneumonia can cause dehydration due to fever and increased respiratory rate, but the risks are less compared to the patient in option D, who is on diuretics and tube feedings.

C. A 66-year-old woman who had an open cholecystectomy with a T-tube placed that is draining 125 mL of bile per shift.

While the patient has undergone an open cholecystectomy, which is a more invasive procedure, the T-tube drainage of bile is typically managed well and does not usually lead to significant fluid and electrolyte imbalance. This patient is at moderate risk but not as high as the patient in option D.

Summary:

The 82-year-old woman in option D is at the highest risk for fluid and electrolyte imbalance due to her age, reliance on tube feedings, and the use of torsemide (a diuretic). These factors increase the likelihood of fluid imbalance and electrolyte disturbances, making her the most vulnerable among the options.