Fluid, electrolyte and acid-base imbalances

48 NCLEX-RN practice questions on Fluid, electrolyte and acid-base imbalances, part of Physiological Adaptation. The first 25 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

1. Question 1 · Medium · Matrix

   For each finding, indicate whether it suggests fluid volume deficit or fluid volume excess.

   For each row, choose: Fluid volume deficit / Fluid volume excess

   1. Third heart sound (S3)
   2. Urine specific gravity of 1.035
   3. Flat neck veins with the client at 45 degrees
   4. Bounding peripheral pulse
   5. Weight down 2 kg in two days
   6. Haematocrit lower than yesterday with no bleeding

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   Answer:

   • Third heart sound (S3): Fluid volume excess
   • Urine specific gravity of 1.035: Fluid volume deficit
   • Flat neck veins with the client at 45 degrees: Fluid volume deficit
   • Bounding peripheral pulse: Fluid volume excess
   • Weight down 2 kg in two days: Fluid volume deficit
   • Haematocrit lower than yesterday with no bleeding: Fluid volume excess

   Analyse cues: a deficit concentrates the blood and urine and empties the veins; an excess dilutes the blood, fills the veins and backs up into the lungs. Weight change is the most sensitive single measure.

   • Third heart sound (S3): An S3 reflects rapid filling of an overloaded ventricle.
   • Urine specific gravity of 1.035: The kidney conserves water and concentrates the urine.
   • Flat neck veins with the client at 45 degrees: Empty neck veins show low venous volume.
   • Bounding peripheral pulse: A full circulation gives a strong, bounding pulse.
   • Weight down 2 kg in two days: Rapid weight loss is fluid loss.
   • Haematocrit lower than yesterday with no bleeding: Extra plasma water dilutes the red cells.

2. Question 2 · Hard · Select all that apply

   A client has had nasogastric suction for 3 days. ABG: pH 7.52, PaCO2 46 mm Hg, HCO3- 34 mEq/L; potassium 3.0 mEq/L. Which actions should the nurse anticipate?

   1. AIV 0.9% sodium chloride to replace the losses
   2. BPotassium chloride replacement
   3. CIrrigation of the tube with plain water
   4. DContinuous cardiac monitoring
   5. EUnlimited ice chips by mouth
   6. FIV sodium bicarbonate

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   Answer: A, B, D

   Generate solutions: gastric suction removes hydrogen and chloride ions and causes metabolic alkalosis with hypokalaemia. Treatment replaces chloride and volume with saline and replaces potassium under cardiac monitoring. Plain water irrigation and unlimited ice chips wash more electrolytes out through the tube.

   • C: Water draws electrolytes into the stomach for removal; use saline.
   • E: Melted ice is suctioned out with more electrolytes.
   • F: Bicarbonate would worsen the alkalosis.

3. Question 3 · Medium · Select all that apply

   A client with heart failure has a serum potassium of 5.8 mEq/L (reference 3.5-5.0 mEq/L). Which of the client's medications can raise potassium?

   1. ASpironolactone
   2. BLisinopril
   3. CHydrochlorothiazide
   4. DAlbuterol
   5. EFurosemide
   6. FTrimethoprim-sulfamethoxazole

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   Answer: A, B, F

   Analyse cues: potassium-sparing diuretics, ACE inhibitors and trimethoprim all reduce potassium excretion by the kidney. Loop and thiazide diuretics waste potassium, and albuterol moves potassium into cells, so they lower the level.

   • C: Thiazides increase potassium loss in the urine.
   • D: Beta-2 agonists shift potassium into cells and lower the serum level.
   • E: Loop diuretics cause potassium loss.

4. Question 4 · Medium · Select all that apply

   A client is receiving IV magnesium sulfate for severe hypomagnesaemia. Which findings should the nurse report before the infusion continues?

   1. AClient says the arm feels warm
   2. BPatellar reflexes are now absent
   3. CUrine output of 20 mL/h for 2 hours
   4. DSerum magnesium now 2.0 mEq/L
   5. ERespiratory rate of 10/min

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   Answer: B, C, E

   Take action: magnesium is cleared by the kidney and depresses nerves and the respiratory centre. Lost reflexes, slow breathing and low urine output signal toxicity or accumulation; stop the infusion and report. A normal level and a warm feeling are expected.

   • A: Mild warmth during infusion is an expected effect.
   • D: This is within the reference range and shows the replacement is working.

5. Question 5 · Medium · Select all that apply

   A client with alcohol use disorder has a serum magnesium of 1.1 mEq/L (reference 1.5-2.5 mEq/L). Which findings should the nurse expect?

   1. AHyperactive deep tendon reflexes
   2. BWarm, flushed skin
   3. CTremor of the hands
   4. DProlonged QT interval
   5. EAbsent patellar reflexes

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   Answer: A, C, D

   Recognise cues: low magnesium increases neuromuscular and cardiac excitability. Expect hyperreflexia, tremor and a prolonged QT with a risk of torsades de pointes. Absent reflexes and flushing are signs of a high magnesium.

   • B: Flushing comes from vasodilation in hypermagnesaemia.
   • E: Lost reflexes are a sign of hypermagnesaemia.

6. Question 6 · Medium · Select all that apply

   A client with chronic kidney disease and a potassium of 5.6 mEq/L is learning about diet. Which items should the client limit?

   1. AOrange juice
   2. BBanana
   3. CApple slices
   4. DWhite rice
   5. ESalt substitute
   6. FBaked potato

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7. Question 7 · Hard · Matrix

   The nurse receives several results by phone. For each result, indicate whether it needs action now or routine follow-up.

   For each row, choose: Action now / Routine follow-up

   1. Magnesium 1.4 mEq/L in a stable client on telemetry with no dysrhythmia
   2. Sodium 133 mEq/L in an alert client with no symptoms
   3. Potassium 2.6 mEq/L with new runs of ventricular ectopy
   4. Potassium 6.4 mEq/L with peaked T waves
   5. Ionised calcium low with new inspiratory stridor

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8. Question 8 · Hard · Matrix

   The provider asks the nurse which clients could receive 0.45% sodium chloride. For each client, indicate whether the hypotonic solution is appropriate or contraindicated.

   For each row, choose: Appropriate / Contraindicated

   1. Burn resuscitation in the first 24 hours
   2. Serum sodium of 126 mEq/L
   3. Hypernatraemia from water loss in a client who is not in shock
   4. Rising intracranial pressure after a head injury
   5. Hypotension from acute blood loss
   6. Hyperosmolar hyperglycaemic state once BP is restored with 0.9% saline

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9. Question 9 · Medium · Select all that apply

   A client with cirrhosis has a serum albumin of 2.1 g/dL (reference 3.5-5.0 g/dL). Which findings suggest fluid has shifted out of the vessels into third spaces?

   1. ABounding peripheral pulses
   2. BIncreasing abdominal girth from ascites
   3. CUrine output of 20 mL/h
   4. DDistended neck veins at 45 degrees
   5. EPitting oedema of both legs
   6. FHeart rate 112 with BP 96/58 mm Hg

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10. Question 10 · Hard · Select all that apply

    A client's serum sodium rose from 112 to 130 mEq/L over 24 hours. Two days later, which new findings should the nurse report as possible osmotic demyelination?

    1. ASlurred speech
    2. BDifficulty swallowing
    3. CUrine output of 60 mL/h
    4. DBetter orientation than on admission
    5. ENew weakness in both legs

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11. Question 11 · Hard · Select all that apply

    A client is confused and has a serum sodium of 118 mEq/L (reference 135-145 mEq/L). The provider prescribes 3% sodium chloride. Which actions should the nurse take?

    1. ARecord intake and output strictly
    2. BCheck serum sodium every few hours as prescribed
    3. CEncourage the client to drink plenty of water
    4. DStart seizure precautions
    5. EAim to bring the sodium to 135 mEq/L within 6 hours
    6. FGive the 3% saline through an infusion pump

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12. Question 12 · Easy · Matrix

    Each finding below was noted in a client with a calcium disorder. Indicate whether it points to hypercalcaemia or hypocalcaemia.

    For each row, choose: Hypercalcaemia / Hypocalcaemia

    1. Numbness around the mouth
    2. Constipation
    3. Shortened QT interval on the ECG
    4. Carpal spasm when a BP cuff is inflated on the arm
    5. Laryngeal stridor
    6. Kidney stones

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13. Question 13 · Hard · Select all that apply

    A client who has eaten little for 3 weeks starts enteral feeding. On day 2, which results require follow-up for refeeding syndrome?

    1. AMagnesium 1.2 mEq/L (reference 1.5-2.5 mEq/L)
    2. BPhosphorus 1.6 mg/dL (reference 2.5-4.5 mg/dL)
    3. CPotassium 3.1 mEq/L (reference 3.5-5.0 mEq/L)
    4. DGlucose 135 mg/dL
    5. ESodium 139 mEq/L (reference 135-145 mEq/L)

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14. Question 14 · Medium · Matrix

    For each condition, indicate the acid-base imbalance it most often causes.

    For each row, choose: Metabolic acidosis / Metabolic alkalosis / Respiratory acidosis

    1. Diabetic ketoacidosis
    2. Severe diarrhoea
    3. Opioid overdose with slow breathing
    4. Prolonged vomiting
    5. Heavy use of baking soda as an antacid
    6. Severe COPD exacerbation

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15. Question 15 · Hard · Matrix

    For each set of arterial blood gas results, indicate the acid-base imbalance it shows.

    For each row, choose: Respiratory acidosis / Metabolic acidosis / Metabolic alkalosis

    1. pH 7.47, PaCO2 48 mm Hg, HCO3- 34 mEq/L
    2. pH 7.29, PaCO2 38 mm Hg, HCO3- 17 mEq/L
    3. pH 7.50, PaCO2 44 mm Hg, HCO3- 33 mEq/L
    4. pH 7.33, PaCO2 30 mm Hg, HCO3- 15 mEq/L
    5. pH 7.31, PaCO2 52 mm Hg, HCO3- 25 mEq/L

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16. Question 16 · Easy · Select all that apply

    A client has a serum potassium of 2.9 mEq/L (reference 3.5-5.0 mEq/L). Which findings should the nurse expect?

    1. ATall, peaked T waves
    2. BHypoactive bowel sounds and constipation
    3. CDiarrhoea with intestinal cramping
    4. DLeg cramps
    5. EFlattened T waves with prominent U waves
    6. FGeneralised muscle weakness

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17. Question 17 · Medium · Select all that apply

    A client has fluid volume excess with 2+ ankle oedema and crackles at both bases. Which actions should the nurse include in the plan?

    1. ACheck the sacrum for dependent oedema
    2. BRestrict dietary sodium as prescribed
    3. CPlace the client in semi-Fowler's position
    4. DAuscultate the lungs every few hours
    5. EWeigh daily at the same time on the same scale
    6. FEncourage 3 L of oral fluid a day

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18. Question 18 · Hard · Matrix

    For each set of arterial blood gas results, indicate the degree of compensation.

    For each row, choose: Uncompensated / Partly compensated / Fully compensated

    1. pH 7.44, PaCO2 48 mm Hg, HCO3- 32 mEq/L
    2. pH 7.52, PaCO2 41 mm Hg, HCO3- 33 mEq/L
    3. pH 7.25, PaCO2 60 mm Hg, HCO3- 24 mEq/L
    4. pH 7.33, PaCO2 58 mm Hg, HCO3- 31 mEq/L
    5. pH 7.37, PaCO2 55 mm Hg, HCO3- 32 mEq/L

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19. Question 19 · Easy

    A client with heart failure has gained 1 kg (2.2 lb) since yesterday's weight. The nurse estimates that the client has retained about:

    1. A1 L of fluid
    2. B500 mL of fluid
    3. C2 L of fluid
    4. D250 mL of fluid

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20. Question 20 · Medium

    Which ECG change does the nurse associate with hypocalcemia?

    1. AA prolonged QT interval
    2. BTall, peaked T waves
    3. CProminent U waves
    4. DA shortened QT interval

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21. Question 21 · Medium

    A client taking furosemide is taught to eat potassium-rich foods. Which meal choice shows that the teaching was understood?

    1. ACottage cheese with saltine crackers
    2. BCucumber slices on white bread
    3. CWhite rice with a glass of apple juice
    4. DA baked potato with skin and a sliced banana

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22. Question 22 · Easy

    A client with chronic kidney disease has been taking a magnesium hydroxide laxative every day. The nurse should assess for:

    1. ADiminished deep tendon reflexes
    2. BTachycardia with hypertension
    3. CA positive Chvostek sign
    4. DMuscle twitching and tetany

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23. Question 23 · Medium

    A client with gastroenteritis has replaced losses by drinking only plain water. The serum sodium is 124 mEq/L (reference 135-145 mEq/L), and the client has a headache and is newly confused. Which action belongs in the plan of care?

    1. AStart seizure precautions
    2. BEncourage more free water
    3. CInfuse D5W at 125 mL/h
    4. DRestrict dietary sodium

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24. Question 24 · Hard

    Six hours after abdominal surgery: HR 114/min, BP 96/58 mm Hg (preoperative 132/80), urine output 20 mL/h for the past 2 hours, urine specific gravity 1.032, dressing dry, bladder not distended. What should the nurse do?

    1. AEncourage sips of water and recheck at the shift's end
    2. BReport the findings and expect an isotonic fluid bolus
    3. CFlush the urinary catheter with sterile saline
    4. DGive the prescribed furosemide to raise the urine output

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25. Question 25 · Medium

    A client has had profuse diarrhea for three days. ABG results: pH 7.30, PaCO2 30 mm Hg, HCO3- 16 mEq/L. The nurse interprets this as:

    1. AMetabolic alkalosis, partially compensated
    2. BRespiratory acidosis, uncompensated
    3. CMetabolic acidosis, partially compensated
    4. DMetabolic acidosis, fully compensated

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