Question

Lithium carbonate (Lithobid) has been ordered for a client with mania. Which finding increases the likelihood of the client developing lithium toxicity? A. Calcium level of \(8.2 \mathrm{mg} / \mathrm{dL}\) B. Potassium level of \(4.0 \mathrm{mEq} / \mathrm{L}\) C. Magnesium level of \(1.8 \mathrm{mg} / \mathrm{dL}\) D. Sodium level of \(120 \mathrm{mEq} / \mathrm{L}\)

Short answer

A. Calcium level of 8.2 mg/dL B. Potassium level of 4.0 mEq/L C. Magnesium level of 1.8 mg/dL D. Sodium level of 120 mEq/L Answer: D. Sodium level of 120 mEq/L

Step-by-step solution

Be familiar with lithium toxicity causes

Lithium toxicity occurs when the concentrations of lithium in the body become too high. Factors that can contribute to lithium toxicity include dehydration, underlying kidney dysfunction, and low sodium levels in the body. Therefore, we should find the option that is related to one of these factors.

Analyze Option A

A. Calcium level of \(8.2 \mathrm{mg}/\mathrm{dL}\): This option doesn't directly affect the risk of lithium toxicity, as calcium has no significant impact on lithium levels.

Analyze Option B

B. Potassium level of \(4.0 \mathrm{mEq}/\mathrm{L}\): Normal potassium levels range between \(3.5-5.0 \mathrm{mEq}/\mathrm{L}\). This option indicates that the potassium levels are within the normal range, and there is no significant correlation between potassium levels and lithium toxicity.

Analyze Option C

C. Magnesium level of \(1.8 \mathrm{mg}/\mathrm{dL}\): Normal magnesium levels are between \(1.7-2.2 \mathrm{mg}/\mathrm{dL}\). This option shows that the magnesium levels are within the normal range, and there is no significant correlation between magnesium levels and lithium toxicity.

Analyze Option D

D. Sodium level of \(120 \mathrm{mEq}/\mathrm{L}\): Low sodium levels in the body can cause the kidneys to retain more lithium, leading to higher lithium levels and an increased risk of toxicity. Normal sodium levels range between \(135-145 \mathrm{mEq}/\mathrm{L}\). This option indicates that the sodium levels are below the normal range, which, as mentioned earlier, increases the likelihood of developing lithium toxicity.

Select the correct answer

Based on the analysis above, we conclude that Option D (Sodium level of \(120 \mathrm{mEq}/\mathrm{L}\)) is the one that increases the likelihood of the client developing lithium toxicity when taking Lithium Carbonate (Lithobid).

Key concepts

NCLEX-PN Exam Preparation

As candidates prepare for the NCLEX-PN exam, familiarity with pharmacology concepts is essential. Lithium toxicity is a critical concept that nursing students must understand, as it can appear in questions related to psychotropic medications.

To prepare efficiently for lithium-related questions, students should focus on the indications for lithium use, commonly prescribed doses, signs of toxicity, and the client's labs to monitor. Special attention should be given to the education of clients regarding the importance of maintaining adequate hydration and not altering their sodium intake drastically, as these can influence lithium levels.

A well-prepared candidate will know that abnormal sodium levels, as in the case study provided, are a red flag for potential lithium toxicity. Engaging with practice questions that involve clinical scenarios can assist in developing critical thinking skills vital for interpreting patient data and making informed decisions on patient care, which is a fundamental aspect that NCLEX-PN evaluates.

Nursing Pharmacology

The study of nursing pharmacology involves understanding the therapeutic effects, side effects, and potential toxicity of medications like lithium carbonate. When educating students or patients about the use of lithium, it's crucial to highlight that the therapeutic range for lithium is narrow, meaning the difference between the effective dose and a toxic dose is quite small.

It's, therefore, imperative that nursing professionals comprehend the pharmacokinetics of lithium, which is heavily impacted by the sodium levels in the body due to its similarity to sodium ions and its handling by the renal system. Patients should be counseled to maintain consistent sodium intake and be cautious of any factors that may lead to dehydration or decreased renal function as these can increase lithium levels potentially leading to toxicity.

Understanding these pharmacological concepts is of great importance for nurses administering lithium and provides a basis for the education that should be extended to patients to manage their treatment effectively.

Electrolyte Imbalance

Electrolyte imbalance plays a significant role in the overall health of the body as well as in the pharmacodynamics of certain medications, such as lithium. Nurses must possess the ability to identify and manage electrolyte imbalances, as these can pose severe threats to patient safety.

In the context of the exercise, a sodium level of 120 mEq/L (Option D) is indicative of hyponatremia, an electrolyte deficiency that can jeopardize lithium excretion, thereby increasing the risk of lithium toxicity. Normal sodium levels are critical for maintaining proper fluid balance, nerve and muscle function, and are essential in the prevention of lithium accumulation.

It is critical for nursing professionals to understand how to monitor and interpret lab results such as sodium levels for the safe administration of medications and for understanding how factors like dietary changes, fluid intake, and pathological states can influence electrolyte balance. Vigilance in monitoring and ensuring electrolyte balance is a vital nursing intervention in the prevention of medication-induced toxicities.