# A nurse is preparing to initiate a weight-based continuous IV unfractionated heparin infusion with bolus for an adult client newly diagnosed with pulmonary embolism. Which actions reflect safe heparin administration practice? Select all that apply.

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> language: en  
> subject: Adverse Effects/Contraindications/Interactions  
> category: PPT

## Question

A nurse is preparing to initiate a weight-based continuous IV unfractionated heparin infusion with bolus for an adult client newly diagnosed with pulmonary embolism. Which actions reflect safe heparin administration practice? Select all that apply.

1

Verify the order, weight-based dose calculation, concentration, and pump settings independently with a second licensed nurse before starting the infusion

2

Connect the heparin infusion to the same Y-site as another continuous medication without first verifying Y-site compatibility, solely to conserve venous access

3

Obtain a baseline aPTT, platelet count, hemoglobin, and hematocrit before initiating the infusion

4

If aPTT is critically prolonged or the client develops major bleeding, hold heparin and administer intramuscular vitamin K as the heparin antidote

5

Recheck aPTT approximately every 6 hours initially and adjust the heparin infusion rate using the institution's weight-based titration nomogram

6

Monitor platelet count for a 50% drop from baseline or new thrombosis between days 5 and 14 to detect heparin-induced thrombocytopenia (HIT)

## Explanation

Unfractionated heparin is a high-alert medication. An independent check of the order, weight-based calculation, concentration, and pump settings according to institutional policy is a standard safety practice before initiation (Choice 1). Baseline aPTT, platelet count, hemoglobin, and hematocrit establish a reference for anticoagulant effect and bleeding risk (Choice 3). Rechecking aPTT about every 6 hours initially and titrating with the institution's weight-based nomogram is appropriate until the result is therapeutic, after which the interval may be extended per protocol (Choice 5). A platelet decrease greater than 50% from baseline or new thrombosis, typically 5–14 days after exposure, raises concern for HIT and requires prompt evaluation and discontinuation of all heparin when HIT is suspected (Choice 6). Do not share a Y-site with another continuous medication without confirmed compatibility and an appropriate line-management plan (Choice 2). Protamine sulfate, not vitamin K, reverses unfractionated heparin (Choice 4).

## In-depth explanation

Heparin = High-Alert Med
Independent double-check of order, dose, concentration, and pump before start.

Monitoring Standard
- Baseline: aPTT, platelets, H/H
- aPTT q6h until therapeutic (typically 1.5-2.5× control or 60-80 sec), then q24h
- Platelets at baseline and at days 4, 7, 10, 14 to screen for HIT

Antidote
Protamine sulfate for heparin reversal — 1 mg neutralizes ~100 units heparin given in last 2-3 hours.
Vitamin K reverses warfarin, NOT heparin.

Memory Tip
"PHaT": Protamine antidote, HIT 5-14 days, aPTT q6h, Two nurses double-check.

## Clinical scenario

Scenario
Adult client, new pulmonary embolism. Order: heparin 80 units/kg IV bolus, then 18 units/kg/hr infusion, weight-based protocol with q6h aPTT.

Pre-Infusion Checklist
- Order verified, dose recalculated against weight
- 2-nurse independent check
- Baseline labs drawn (aPTT, plt, H/H)
- Dedicated IV line, no incompatible co-infusion
- Smart pump with heparin guardrails

Ongoing Monitoring
- Bleeding signs: gums, hematuria, melena, headache, neuro changes
- aPTT q6h, titrate per nomogram
- Platelet count days 4, 7, 10, 14 → HIT surveillance
- Reverse with protamine sulfate if needed

## Key concepts

- **High-alert medication** — Drug with heightened risk of significant patient harm if used in error. Heparin, insulin, opioids, and concentrated electrolytes top ISMP's list. Independent double-check by 2 licensed nurses required before administration.
- **Heparin antidote: protamine sulfate** — Protamine sulfate is the specific reversal agent for heparin. Each 1 mg of protamine neutralizes approximately 100 units of heparin administered in the previous 2-3 hours. Vitamin K reverses warfarin, andexanet alfa reverses apixaban/rivaroxaban — these are not interchangeable.
- **Heparin-induced thrombocytopenia (HIT)** — Type II HIT is an immune-mediated reaction occurring 5-14 days after heparin exposure (sooner with prior exposure). Hallmarks: >50% platelet drop or new thrombosis. Treatment: stop ALL heparin (including flushes), use a non-heparin anticoagulant (argatroban, bivalirudin) for ongoing anticoagulation needs.

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