3 Fluid and Electrolyte Management Free Online FlashCards

Which trends can be more informative than a single fluid-status observation?

Daily weights and intake/output trends often reveal fluid-balance changes more clearly than a single observation.

What does serum sodium primarily reflect?

Serum sodium reflects water balance relative to sodium, not total-body sodium alone; excess water can lower the concentration even when total-body sodium is increased.

Which electrolyte should be checked when hypokalemia is hard to correct?

Low magnesium can make hypokalemia difficult to correct, so magnesium should be checked when potassium remains low despite treatment.

How can alkalosis affect ionized calcium?

Alkalosis increases protein binding of calcium, lowering ionized calcium.

What pH thresholds define acidemia and alkalemia?

Acidemia means blood pH below $7.35$; alkalemia means blood pH above $7.45$.

Which complications can prompt urgent dialysis consideration?

Urgent dialysis may be considered for refractory hyperkalemia, severe acidosis, pulmonary edema or fluid overload, and uremic complications such as encephalopathy or pericarditis.

What findings can indicate volume depletion?

Volume depletion may cause thirst, dry mucous membranes, tachycardia, orthostatic hypotension, and reduced urine output.

What defines hyponatremia?

Hyponatremia is serum sodium below $135\ \text{mmol/L}$; it often reflects excess water relative to sodium.

What does hypernatremia usually indicate?

Hypernatremia is serum sodium above $145\ \text{mmol/L}$ and usually indicates a water deficit relative to sodium.

What should be considered with a high potassium result from a hemolyzed sample?

Hemolysis can falsely elevate potassium. If hyperkalemia remains plausible, obtain an ECG and review kidney function and medicines.

What distinguishes a metabolic from a respiratory primary disturbance?

A primary acid–base disturbance is metabolic, involving bicarbonate $(\mathrm{HCO_3^-})$, or respiratory, involving carbon dioxide $(\mathrm{PaCO_2})$.

How is the anion gap calculated, and what can a raised gap suggest?

Calculate the anion gap as $\mathrm{AG} = \mathrm{Na^+} - (\mathrm{Cl^-} + \mathrm{HCO_3^-})$. A raised gap suggests added unmeasured acids.