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Syllabus

Fluid, Electrolyte & Acid-Base

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12 testable areas · 7 questions · 0 covered, 3 building, 9 thin

acid-base imbalance

building3 questions
    • Loop diuretics deplete potassium.
    • Watch for muscle weakness, diminished reflexes, reduced GI motility, and flattened T waves with U waves.
    • Peaked T waves point to the opposite problem - hyperkalemia.
    • Low potassium means weak everything: flaccid muscles, ileus, flat T waves with U waves.
    • And it makes digoxin toxic at an ordinary level.
  • Metabolic acidosis: low pH, low bicarbonate, Kussmaul respirations, drowsiness, warm flushed skin and hyperkalemia — which falls again as you correct it.

Hypokalemia is most often caused by gastrointestinal loss through vomiting, diarrhea or nasogastric suction, by loop and thiazide diuretics, by corticosteroids, by insulin administration and by alkalosis, which shifts potassium intracellularly. Manifestations follow impaired membrane excitability: skeletal muscle weakness beginning in the lower limbs and ascending, with severe depletion threatening respiratory muscles; diminished deep tendon reflexes; smooth muscle effects producing reduced bowel sounds, constipation and paralytic ileus; and cardiac effects including flattened or inverted T waves, ST depression, prominent U waves, premature beats and increased risk of serious dysrhythmia. Potassium potentiates digoxin toxicity at ordinary serum drug levels, which matters because the drugs causing hypokalemia are frequently co-prescribed with it. Replacement is oral where possible; intravenous potassium is always diluted, never given as a bolus or by push, is infused at a controlled rate with cardiac monitoring for higher rates, and requires adequate urine output. Magnesium is checked alongside, since hypokalemia is refractory to correction while magnesium remains low.

Metabolic acidosis is compensated by respiratory carbon dioxide elimination and shifts potassium out of cells, raising the serum level.

How they trap you here (2)
  • Both incorrect options belong to a different electrolyte disturbance and each is a mirror of a correct finding, so the item tests directional knowledge rather than recall. The peaked-T-wave option is the more dangerous confusion because the two conditions are treated in opposite directions and both present with weakness.
  • Option (e) gives the alkalosis picture, which is the standard paired-condition trap. The potassium shift in (c) is the clinically consequential item, because the level moves again during treatment.
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hypokalemia

building3 questions
    • Loop diuretics deplete potassium.
    • Watch for muscle weakness, diminished reflexes, reduced GI motility, and flattened T waves with U waves.
    • Peaked T waves point to the opposite problem - hyperkalemia.
    • Potassium will not correct while magnesium is low.
    • Replace the magnesium first.
    • Loop diuretics waste both.
    • Low potassium means weak everything: flaccid muscles, ileus, flat T waves with U waves.
    • And it makes digoxin toxic at an ordinary level.

Hypomagnesemia causes renal potassium wasting and refractory hypokalemia and hypocalcemia.

Hypokalemia is most often caused by gastrointestinal loss through vomiting, diarrhea or nasogastric suction, by loop and thiazide diuretics, by corticosteroids, by insulin administration and by alkalosis, which shifts potassium intracellularly. Manifestations follow impaired membrane excitability: skeletal muscle weakness beginning in the lower limbs and ascending, with severe depletion threatening respiratory muscles; diminished deep tendon reflexes; smooth muscle effects producing reduced bowel sounds, constipation and paralytic ileus; and cardiac effects including flattened or inverted T waves, ST depression, prominent U waves, premature beats and increased risk of serious dysrhythmia. Potassium potentiates digoxin toxicity at ordinary serum drug levels, which matters because the drugs causing hypokalemia are frequently co-prescribed with it. Replacement is oral where possible; intravenous potassium is always diluted, never given as a bolus or by push, is infused at a controlled rate with cardiac monitoring for higher rates, and requires adequate urine output. Magnesium is checked alongside, since hypokalemia is refractory to correction while magnesium remains low.

How they trap you here (2)
  • Each distractor proposes a plausible-sounding electrolyte relationship that does not exist.
  • Both incorrect options belong to a different electrolyte disturbance and each is a mirror of a correct finding, so the item tests directional knowledge rather than recall. The peaked-T-wave option is the more dangerous confusion because the two conditions are treated in opposite directions and both present with weakness.
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fluid volume excess

building2 questions
    • Excess: bounding, distended, crackles, edema.
    • Deficit: thready, flat, dry, concentrated.
    • Weight tracks both — a kilogram is a liter.
    • Deficit: low output, concentrated urine, orthostatic drop, raised hematocrit, flat neck veins, weight loss.
    • Weight is the most sensitive measure — 1 kg is about 1 liter.

Fluid volume excess produces vascular and interstitial congestion detectable as bounding pulse, venous distension and crackles.

Fluid volume deficit reduces circulating volume, producing compensatory tachycardia, renal conservation and hemoconcentration.

How they trap you here (2)
  • Fluid volume deficit is the mirror image and the option a student picks if they read 'volume problem' without reading the direction.
  • Both distractors are the mirror-image findings of fluid volume excess. The item cannot be answered by recognizing abnormal fluid status, only by knowing which direction each finding moves in — which is the discrimination that matters at the bedside.
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blood transfusion

thin1 question
  • The first 15 minutes of a transfusion belong to the registered nurse — that's when a hemolytic reaction shows itself.

Scope decisions turn on the risk of the specific moment rather than on the procedure in general. Most of a blood transfusion is routine monitoring, but an acute hemolytic reaction — fever, chills, flank or back pain, dark urine, hypotension — declares itself in the opening minutes and requires immediate recognition, cessation and management. That window therefore requires the registered nurse's presence and judgment, while established maintenance infusions, fluid balance totals and scheduled set changes sit within the practical nurse's remit. Exact boundaries are set by jurisdiction and facility policy.

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cardiac medications

thin1 question
    • Loop diuretics deplete potassium.
    • Watch for muscle weakness, diminished reflexes, reduced GI motility, and flattened T waves with U waves.
    • Peaked T waves point to the opposite problem - hyperkalemia.

No written explainer yet — the rule above comes from the question itself.

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cardiac rhythm interpretation

thin1 question
    • Loop diuretics deplete potassium.
    • Watch for muscle weakness, diminished reflexes, reduced GI motility, and flattened T waves with U waves.
    • Peaked T waves point to the opposite problem - hyperkalemia.

No written explainer yet — the rule above comes from the question itself.

Practice this →

diabetic ketoacidosis

thin1 question
  • Metabolic acidosis: low pH, low bicarbonate, Kussmaul respirations, drowsiness, warm flushed skin and hyperkalemia — which falls again as you correct it.

Metabolic acidosis is compensated by respiratory carbon dioxide elimination and shifts potassium out of cells, raising the serum level.

How they trap you here (1)
  • Option (e) gives the alkalosis picture, which is the standard paired-condition trap. The potassium shift in (c) is the clinically consequential item, because the level moves again during treatment.
Practice this →

fluid volume deficit

thin1 question
    • Deficit: low output, concentrated urine, orthostatic drop, raised hematocrit, flat neck veins, weight loss.
    • Weight is the most sensitive measure — 1 kg is about 1 liter.

Fluid volume deficit reduces circulating volume, producing compensatory tachycardia, renal conservation and hemoconcentration.

How they trap you here (1)
  • Both distractors are the mirror-image findings of fluid volume excess. The item cannot be answered by recognizing abnormal fluid status, only by knowing which direction each finding moves in — which is the discrimination that matters at the bedside.
Practice this →

hyperkalemia

thin1 question
  • Metabolic acidosis: low pH, low bicarbonate, Kussmaul respirations, drowsiness, warm flushed skin and hyperkalemia — which falls again as you correct it.

Metabolic acidosis is compensated by respiratory carbon dioxide elimination and shifts potassium out of cells, raising the serum level.

How they trap you here (1)
  • Option (e) gives the alkalosis picture, which is the standard paired-condition trap. The potassium shift in (c) is the clinically consequential item, because the level moves again during treatment.
Practice this →

intravenous therapy

thin1 question
  • The first 15 minutes of a transfusion belong to the registered nurse — that's when a hemolytic reaction shows itself.

Scope decisions turn on the risk of the specific moment rather than on the procedure in general. Most of a blood transfusion is routine monitoring, but an acute hemolytic reaction — fever, chills, flank or back pain, dark urine, hypotension — declares itself in the opening minutes and requires immediate recognition, cessation and management. That window therefore requires the registered nurse's presence and judgment, while established maintenance infusions, fluid balance totals and scheduled set changes sit within the practical nurse's remit. Exact boundaries are set by jurisdiction and facility policy.

Practice this →

magnesium imbalance

thin1 question
    • Potassium will not correct while magnesium is low.
    • Replace the magnesium first.
    • Loop diuretics waste both.

Hypomagnesemia causes renal potassium wasting and refractory hypokalemia and hypocalcemia.

How they trap you here (1)
  • Each distractor proposes a plausible-sounding electrolyte relationship that does not exist.
Practice this →

scope of practice

thin1 question
  • The first 15 minutes of a transfusion belong to the registered nurse — that's when a hemolytic reaction shows itself.

Scope decisions turn on the risk of the specific moment rather than on the procedure in general. Most of a blood transfusion is routine monitoring, but an acute hemolytic reaction — fever, chills, flank or back pain, dark urine, hypotension — declares itself in the opening minutes and requires immediate recognition, cessation and management. That window therefore requires the registered nurse's presence and judgment, while established maintenance infusions, fluid balance totals and scheduled set changes sit within the practical nurse's remit. Exact boundaries are set by jurisdiction and facility policy.

Practice this →