3 Electrolyte, Renal, and Metabolic Studies Free Online FlashCards

How should laboratory results be interpreted?

Laboratory reference ranges vary; interpret results with symptoms, trends, medications, fluid status, and other tests rather than in isolation.

What is a common adult potassium reference range?

A common adult reference range is $3.7\text{–}5.2\ \mathrm{mmol/L}$; use the reporting laboratory’s range.

What is the priority response to potassium of $6.4\ \mathrm{mmol/L}$ with new weakness?

Treat it as potentially urgent: assess the patient, promptly notify the clinician, and arrange cardiac monitoring or an ECG according to orders and facility protocol.

What should be done for sodium of $121\ \mathrm{mmol/L}$ with new confusion?

Promptly report the result and mental-status change, assess neurologic status and safety, and follow orders and facility protocol. Do not attempt rapid correction independently.

How should potassium of $2.9\ \mathrm{mmol/L}$ with palpitations be addressed?

Assess promptly, notify the clinician, and arrange ECG or cardiac monitoring according to protocol. Give potassium replacement only as prescribed; never give IV potassium by direct injection.

Why is a rising creatinine with falling urine output concerning?

A rise from baseline plus declining urine output is concerning. Report the trend, assess intake and output and volume status, and review medications and possible nephrotoxic exposures with the care team.

What should be done if a hypoglycemic patient cannot swallow safely?

Give nothing by mouth. Call for immediate assistance and use prescribed glucagon or IV dextrose according to protocol.

What do vomiting and deep rapid breathing with marked hyperglycemia suggest?

Escalate promptly for urgent assessment. Vomiting, abdominal pain, and deep rapid breathing with marked hyperglycemia may signal a serious metabolic emergency; glucose alone does not establish or rule out ketoacidosis.

What is the first step in interpreting an acid–base pattern?

Start with pH to identify acidemia or alkalemia, then use PaCO₂ and bicarbonate to identify the primary respiratory or metabolic component.

Interpret: pH $7.28$, PaCO₂ $58\ \mathrm{mm\ Hg}$, HCO₃⁻ $26\ \mathrm{mmol/L}$.

The low pH indicates acidemia, and elevated PaCO₂ indicates primary respiratory acidosis. Near-normal bicarbonate suggests little or no metabolic compensation.

Interpret: pH $7.29$, HCO₃⁻ $15\ \mathrm{mmol/L}$, PaCO₂ $30\ \mathrm{mm\ Hg}$.

The low pH indicates acidemia, and low bicarbonate indicates primary metabolic acidosis. The lower PaCO₂ is consistent with respiratory compensation.

Which acid–base components do PaCO₂ and HCO₃⁻ represent?

PaCO₂ is the respiratory component; bicarbonate (HCO₃⁻) is the metabolic component.