LPN Interpreting Lab Values and Nursing Actions 2 — Questions and Answers
Question 1: A patient's serum potassium is 6.2 mEq/L. Which assessment finding is most concerning?
- Muscle weakness and peaked T waves on ECG (Correct answer)
- Polyuria and polydipsia
- Hypertension and headache
- Dry mucous membranes and poor skin turgor
Correct answer: Muscle weakness and peaked T waves on ECG
Hyperkalemia (>5.0 mEq/L) causes cardiac dysrhythmias with peaked T waves and muscle weakness, requiring immediate intervention.
Question 2: A patient's INR is 4.8 while on warfarin therapy. What is the priority nursing action?
- Hold the next warfarin dose and notify the provider (Correct answer)
- Administer the scheduled warfarin dose as ordered
- Increase dietary vitamin K intake
- Apply compression stockings
Correct answer: Hold the next warfarin dose and notify the provider
An INR of 4.8 is supratherapeutic (therapeutic range 2-3), placing the patient at high bleeding risk; hold warfarin and notify the provider immediately.
Question 3: A patient with chronic kidney disease has a serum phosphorus of 6.8 mg/dL. Which dietary teaching is appropriate?
- Limit dairy products, nuts, and processed foods (Correct answer)
- Increase consumption of whole grains and legumes
- Encourage high-protein foods like red meat
- Increase dairy intake to balance calcium levels
Correct answer: Limit dairy products, nuts, and processed foods
Hyperphosphatemia in CKD requires restricting phosphorus-rich foods such as dairy, nuts, and processed items to prevent renal osteodystrophy.
Question 4: A patient's arterial blood gas shows pH 7.30, PaCO2 28 mmHg, HCO3 13 mEq/L. How should the LPN interpret this?
- Metabolic acidosis with respiratory compensation (Correct answer)
- Respiratory alkalosis with metabolic compensation
- Metabolic alkalosis
- Respiratory acidosis
Correct answer: Metabolic acidosis with respiratory compensation
Low pH with low HCO3 indicates metabolic acidosis; the low PaCO2 reflects respiratory compensation (hyperventilation).
Question 5: A patient has a serum sodium of 128 mEq/L. Which symptom would the LPN expect?
- Headache, confusion, and nausea (Correct answer)
- Extreme thirst and dry mouth
- Bradycardia and hypertension
- Muscle cramps and peaked T waves
Correct answer: Headache, confusion, and nausea
Hyponatremia (<135 mEq/L) causes neurological symptoms including headache, confusion, and nausea due to cerebral edema.
Question 6: A patient's troponin I level is markedly elevated at 2.8 ng/mL. What condition does this most strongly indicate?
- Acute myocardial infarction (Correct answer)
- Pulmonary embolism
- Deep vein thrombosis
- Pericarditis
Correct answer: Acute myocardial infarction
Markedly elevated troponin I is the most specific biomarker for myocardial cell necrosis, indicating an acute MI.
Question 7: A patient on heparin therapy has an aPTT of 120 seconds (normal 25-35 sec). What is the correct nursing action?
- Hold heparin and notify the provider immediately (Correct answer)
- Continue the infusion at the current rate
- Increase the heparin infusion rate
- Administer protamine sulfate without an order
Correct answer: Hold heparin and notify the provider immediately
An aPTT of 120 seconds is dangerously supratherapeutic (goal typically 60-100 sec); heparin should be held and the provider notified.
LPN Interpreting Lab Values and Nursing Actions 2
A patient's serum potassium is 6.2 mEq/L.
Which assessment finding is most concerning?