A nurse is caring for an 80\text{ kg} adult client experiencing status epilepticus. The he… — NCLEX-RN

A nurse is caring for an $80\text{ kg}$ adult client experiencing status epilepticus. The healthcare provider prescribes a loading dose of intravenous (IV) phenytoin at $15\text{ mg/kg}$ . The client currently has a continuous infusion of $5\%\text{ dextrose in water (D5W)}$ running at $50\text{ mL/hr}$ via a 22-gauge peripheral IV catheter in the right dorsal hand. Based on the pharmacological properties of phenytoin, which of the following is the most appropriate action by the nurse?

A
Prioritize rapid termination of the seizure by administering the medication undiluted via IV push over 5 minutes to quickly achieve therapeutic serum levels.
B
Dilute the medication in $250\text{ mL}$ of $5\%\text{ dextrose in water (D5W)}$ and administer via a secondary infusion over 45 minutes.
Establish a new 18-gauge IV access in a large proximal vein, dilute the dose in $0.9\%\text{ sodium chloride}$ , and infuse over at least 30 minutes.Answer
D
Pause the D5W infusion, flush the existing 22-gauge IV catheter with $0.9\%\text{ sodium chloride}$ , and administer the dose via IV push over 15 minutes.

Answer

Establish a new 18-gauge IV access in a large proximal vein, dilute the dose in

0.9\%\text{ sodium chloride}

, and infuse over at least 30 minutes.

Intravenous phenytoin requires strict adherence to multiple safety parameters. The total dose is

1200\text{ mg}

(

80\text{ kg} \times 15\text{ mg/kg}

). Because the maximum safe administration rate is

50\text{ mg/min}

, the absolute minimum infusion time is 24 minutes. Infusing over 30 minutes achieves a safe rate of

40\text{ mg/min}

. Furthermore, phenytoin precipitates in dextrose and requires dilution in

0.9\%\text{ sodium chloride}

. Because it is a known vesicant that can cause 'purple glove syndrome' (severe localized ischemia and edema), it must be administered through a large-bore catheter (18- or 20-gauge) in a large proximal vein, avoiding small distal veins like those in the hand.

Step-by-Step Solution

Calculate the total required dose based on the client's weight.

80\text{ kg} \times 15\text{ mg/kg} = 1200\text{ mg}

of phenytoin.

Accurate weight-based dosing is critical for determining the total medication volume and subsequent infusion parameters.

Determine the minimum safe infusion time based on the maximum allowable rate.

1200\text{ mg} \div 50\text{ mg/min} = 24\text{ minutes}

Phenytoin has a strict maximum administration rate of

50\text{ mg/min}

in adults to prevent severe hypotension and lethal dysrhythmias.

Evaluate the current IV access and fluid compatibility.

The current 22-gauge IV is too small for a vesicant, and the continuous D5W infusion is incompatible with phenytoin.

Phenytoin precipitates in dextrose and is highly irritating to veins, risking purple glove syndrome if given in small distal veins.

Select the intervention that meets all safety criteria: dose rate, compatibility, and vascular access.

Inserting a new 18-gauge IV in a large vein, diluting with normal saline, and infusing over 30 minutes (

40\text{ mg/min}

) is the only completely safe option.

This comprehensively addresses the pharmacological constraints and safety requirements for IV phenytoin administration.

Key Concept

Safe administration of intravenous phenytoin requires synthesis of weight-based dosing, rate calculation (max

50\text{ mg/min}

), fluid compatibility (only

0.9\%\text{ NaCl}

), and vesicant precautions.

Question

Answer

Step-by-Step Solution

Key Concept

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