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Difficulty: Very hardPharmacological Therapies

A practical nurse (PN) is reviewing the morning laboratory results and medication administration record for a client being treated for a deep vein thrombosis (DVT). The client has been receiving a continuous intravenous heparin infusion and was recently started on oral warfarin. The morning laboratory results reveal an International Normalized Ratio (INR) of 4.24.2 and a platelet count of 145,000/mm3145,000/\text{mm}^3. The provider has prescribed a scheduled dose of oral warfarin 55 mg and a new, one-time prescription for oral phytonadione 2.52.5 mg. The pharmacy has dispensed the phytonadione as a 55 mg/mL oral liquid.

Based on these findings, what is the priority sequence of actions for the practical nurse to take?

  1. A
    Withhold the scheduled oral warfarin, notify the registered nurse of the laboratory results, and measure 2.02.0 mL of the phytonadione oral liquid to address the elevated INR.
  2. B
    Independently discontinue the warfarin prescription in the medical record due to the toxic INR level, and administer the phytonadione via the intravenous (IV) route to ensure rapid reversal of anticoagulation.
  3. Withhold the scheduled oral warfarin, notify the registered nurse of the critical INR result, and prepare to administer 0.50.5 mL of the oral phytonadione after checking two distinct client identifiers.Answer
  4. D
    Measure 0.50.5 mL of the phytonadione oral liquid, scan the medication barcode on the bottle at the bedside, and immediately administer the dose because the supratherapeutic INR requires emergent intervention.

Answer

The most appropriate sequence is to withhold the scheduled oral warfarin, notify the registered nurse of the critical INR result, and prepare to administer 0.50.5 mL of the oral phytonadione after checking two distinct client identifiers.
An INR of 4.24.2 is supratherapeutic (the normal therapeutic range for DVT is typically 2.02.0 to 3.03.0), placing the client at a high risk for hemorrhage. The PN must prioritize client safety by withholding the scheduled warfarin (an oral anticoagulant) and promptly notifying the RN or provider of the critical laboratory result. Phytonadione (vitamin K) is the standard antidote utilized for warfarin toxicity. The prescribed dose is 2.52.5 mg, and the available concentration is 55 mg/mL. The correct volume to administer is calculated as: (2.52.5 mg / 55 mg/mL) * 11 mL = 0.50.5 mL. Finally, the PN must rigidly adhere to medication safety protocols by verifying two distinct client identifiers prior to administration, even in urgent clinical scenarios.

Step-by-Step Solution

1
Evaluate the laboratory results against standard therapeutic ranges for the client's condition.
The INR of 4.24.2 is identified as supratherapeutic (above the target of 2.02.0 to 3.03.0 for DVT), indicating a high risk of hemorrhage.
Recognizing critical laboratory values is a fundamental nursing responsibility prior to administering any anticoagulant therapy.
2
Determine the appropriate intervention regarding the scheduled medications.
The scheduled dose of warfarin must be withheld immediately.
Administering additional warfarin to a client with a supratherapeutic INR would dangerously prolong clotting time and precipitate bleeding.
3
Calculate the correct dosage of the prescribed antidote (phytonadione).
The required volume to administer is calculated to be 0.50.5 mL.
Using the standard formula (Desired / Have) * Volume: (2.52.5 mg / 55 mg) * 11 mL = 0.50.5 mL of the phytonadione oral liquid.
4
Identify the proper procedure for safe medication administration and interprofessional communication.
The PN must notify the RN of the critical lab value and verify two distinct client identifiers before administration.
Delegation guidelines require escalating critical findings to the RN, and safety standards universally mandate dual identifier verification, regardless of clinical urgency.

Key Concept

Pharmacological Therapies - Safe Medication Administration and PN Scope of Practice

Alternative Method

Instead of the standard Desired/Have formula, the ratio and proportion method can be utilized for the calculation: 55 mg / 11 mL = 2.52.5 mg / XX mL. Cross-multiplying yields 5X=2.55X = 2.5, which mathematically simplifies to X=0.5X = 0.5 mL.
Estimated Time:2m 0s
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Topics

Pharmacological Therapies

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