What is the normal sodium concentration in RL?

Appeared in: NORCET 2 - 2021 (shift-1)

Explanation

Ringer's Lactate (RL) is an isotonic crystalloid solution formulated to have an electrolyte concentration similar to blood plasma.
According to standard formulations, RL contains 130 mEq/L of sodium (Na+).
It also contains other electrolytes like potassium (4 mEq/L), calcium (3 mEq/L), and chloride (109 mEq/L).
The solution includes lactate (28 mEq/L), which the liver converts to bicarbonate, acting as a buffer against acidosis.

Option A: This is the sodium concentration found in 0.9% Sodium Chloride, also known as Normal Saline (NS), not Ringer's Lactate.
Option B: This value (139 mEq/L) does not correspond to the standard sodium concentration of Ringer's Lactate or any other common IV fluid. It falls between the values for RL and NS.
Option D: This value (123 mEq/L) is too low for an isotonic solution like Ringer's Lactate. It is closer to a hypotonic solution.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Composition of Intravenous Fluids (Ringer's Lactate) as background academic context rather than a clinical decision trigger.
Nurses must know the composition of IV fluids to administer them safely. Using RL instead of NS can help prevent hyperchloremic metabolic acidosis during large-volume resuscitation.
It is crucial to assess for contraindications before administering RL, such as checking liver function and potassium levels. Administering RL to a patient with liver failure can worsen lactic acidosis.
RL should not be administered in the same line as blood products because the calcium in RL can bind to the citrate anticoagulant in the blood, leading to clot formation.

How to Approach the Question

This is a factual recall question.
First, identify the key terms in the question: 'sodium concentration' and 'RL' (Ringer's Lactate).
Recall the standard composition of common intravenous fluids.
Specifically, remember the sodium content of Ringer's Lactate.
Compare the recalled value (130 mEq/L) with the given options.
Select the option that matches the correct value.

Concept Tested & Keywords

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E6 Nursing Brunner Adult Health 3SA Vol 1 Part 1 p. 142-144

E6 Gynecology Williams p. 50-74

Practise the full NORCET 2 - 2021 (shift-1)

Attempt every question from this paper in a timed mock, then review the full solution for each one.