심방세동으로 와파린을 복용 중인 성인 환자의 아침 검사 결과를 확인하고 있습니다. 가장 최근 INR이 5.8입니다. 간호사가 가장 먼저 취해야 할 행동은 무엇입니까?

INR 5.8은 심방세동의 치료 범위(2.0–3.0)를 크게 벗어나 출혈 위험이 매우 높은 상태입니다. 가장 우선해야 할 행동은 다음 와파린 용량을 보류하고 의료진에게 보고하여 비타민 K(phytonadione) 또는 용량 조정을 받는 것입니다. 프로타민(protamine)은 헤파린의 길항제이며 와파린의 길항제는 비타민 K입니다. 비타민 K가 풍부한 채소 섭취는 장기적으로 INR을 낮출 수는 있지만 즉각적인 출혈 위험을 해소하지 못합니다. 그대로 유지하며 관찰하는 것은 두개내·소화관 출혈 위험을 방치하는 안전성 위반입니다.

Clinical Judgment
The core of this question is the bleeding risk indicated by an INR of 5.8, which greatly exceeds the therapeutic range (INR 2.0–3.0). Using the NCJMM framework: Recognize Cues (abnormal INR 5.8) → Analyze Cues (excessive warfarin effect, impending bleeding) → Prioritize (safety-first: hold the medication) → Take Action (report to provider and consider vitamin K or FFP). Any option that implements another intervention without first discontinuing the drug itself violates safety.

Memory Tip
High INR → Hold + Call. If the INR deviates from the therapeutic range by more than 1 point (especially 4 or above), always "hold + report." Warfarin antidote = Vitamin K, Heparin antidote = Protamine — do not confuse them.

KR vs US
Although the same INR target range is applied in Korea, the NCLEX frequently uses the phrase "first action." In this case, you must select the single most urgent intervention directly related to patient safety. In Korean clinical practice, it is common to observe while waiting for a physician's order change, but the NCLEX differs by clearly asking about the nurse's autonomous authority (holding medication and reporting).

Clinical Practice Guide
Warfarin monitoring is INR-based. Standard target for atrial fibrillation is INR 2.0–3.0. INR ≥4.5 sharply increases bleeding risk; for INR ≥5.0, standard practice is to immediately withhold the drug and notify the healthcare provider (ACCP Antithrombotic Therapy Guidelines). If bleeding signs are present, consider IV vitamin K + FFP/PCC.

Caution
On the NCLEX, the "first action" must be a single action that immediately ensures patient safety. "Education" or "observation" are usually lower priority. Drug-antidote pairs (warfarin↔vitamin K, heparin↔protamine, opioid↔naloxone) are tested every time, so memorize them.