A nurse is caring for a patient with acute kidney injury (AK… | 마이메르시 MyMerci
Adult Health
문제

A nurse is caring for a patient with acute kidney injury (AKI) who has been receiving continuous renal replacement therapy (CRRT) for 48 hours. Which assessment finding would require the most immediate nursing intervention?

해설
Air bubbles in the CRRT circuit pose an immediate risk of air embolism, a life-threatening emergency requiring urgent intervention. Other findings (oliguria, hypotension, hyperkalemia) are concerning but manageable with standard monitoring and CRRT therapy.

심화 해설

Core Nursing Explanation Key Concept Analysis: This question assesses the nurse's ability to prioritize patient safety during a complex therapy like Continuous Renal Replacement Therapy (CRRT). The core theme is recognizing a life-threatening, therapy-related complication that requires immediate action to prevent harm, versus expected or manageable complications of the underlying condition (Acute Kidney Injury (AKI)).

Answer Rationale: Key Point! The correct answer is ④ Air bubbles visible in the CRRT circuit tubing. This is a critical safety event. Air in the extracorporeal circuit of any hemodialysis or CRRT machine can lead to an Air embolism if it enters the patient's bloodstream. An air embolism can cause sudden cardiovascular collapse (e.g., hypotension, dyspnea, chest pain), neurological deficits, or cardiac arrest. The nursing intervention is immediate: clamp the venous line to prevent air from entering the patient, stop the blood pump, and notify the physician or dialysis team. This action cannot be delayed.

Distractor Analysis:
• Watch out for confusion! ① Urine output of 15 mL/hour for the past 4 hours: This is Oliguria, a classic and expected finding in AKI. While it requires monitoring and reporting, it is not an immediate, life-threatening emergency requiring the *most immediate* intervention, especially since the patient is already on CRRT to manage fluid and solute removal.
• ② Blood pressure of 90/55 mmHg with heart rate of 110 bpm: This indicates Hypotension and compensatory Tachycardia. Hypotension is a common complication during CRRT due to fluid shifts. While it requires intervention (e.g., slowing the ultrafiltration rate, administering IV fluids per protocol), it is a monitored and expected risk, not an acute, unpredictable safety hazard like an air embolism.
• ③ Serum potassium level of 5.8 mEq/L: This is Hyperkalemia (normal serum potassium is typically 3.5-5.0 mEq/L). Hyperkalemia is a serious complication of AKI that can lead to fatal cardiac arrhythmias. However, the patient is *actively receiving CRRT*, which is the definitive treatment for removing potassium. This level is elevated but likely being corrected by the ongoing therapy. Immediate, independent nursing action for this value alone (like administering Kayexalate) is less urgent than stopping an air embolism in progress.

Related Concepts: The principle of "Safety First" is paramount in nursing. Equipment-related hazards (air, disconnections, clotting) often take priority over physiological abnormalities that the therapy is already addressing. Always assess for threats to the integrity of life-sustaining equipment.
Concept Summary • Priority Setting: Immediate physical safety threats (air embolism, hemorrhage, respiratory arrest) > serious physiological abnormalities (hyperkalemia, hypotension) > expected disease manifestations (oliguria in AKI).
• CRRT Complications: Air embolism, circuit clotting, hypotension, electrolyte imbalances, infection.
• Air Embolism Management: Clamp line (venous first), stop pump, place patient in Trendelenburg and left lateral decubitus position (if suspected embolism has occurred), administer oxygen, notify physician.
Side-by-Side Comparison!
Assessment FindingClinical SignificancePriority & Rationale
Air in CRRT circuitRisk of air embolism → cardiac/respiratory arrestHIGHEST. Requires immediate nurse action to stop therapy and secure line.
Hypotension/Tachycardia during CRRTHypovolemia, excessive ultrafiltrationHIGH. Requires prompt intervention (adjust fluids/UF rate) but is a monitored, expected risk.
Hyperkalemia in AKI on CRRTRisk of arrhythmias; but CRRT is actively correcting itMODERATE-HIGH. Monitor EKG, ensure CRRT is running effectively. Less urgent than an active equipment hazard.

Anatomy, Physiology & Pharmacology Points • Pathophysiology: AKI leads to failure of the kidneys' filtration, regulation, and excretion functions, causing fluid overload, electrolyte imbalances (hyperkalemia, hyperphosphatemia), and accumulation of waste products (azotemia).
• CRRT Mechanism: Mimics glomerular filtration by slowly and continuously removing blood, filtering it through a semipermeable membrane (hemofilter), and returning it to the patient. It is better tolerated in hemodynamically unstable patients than intermittent hemodialysis.
• Air Embolism Patho: Air in the venous circulation travels to the right heart and pulmonary artery, obstructing blood flow and causing ventilation-perfusion (V/Q) mismatch, right heart strain, and potentially paradoxical embolism if a patent foramen ovale is present.
Memory Tips • CRRT Safety Acronym: "CLAMP": Circuit check (for air/clots), Line integrity, Access site monitored, Machine alarms heeded, Patient vital signs.
• Think: "Air in the line is a crime!" It's an emergency that you must stop immediately.
High-Frequency NCLEX Topics NCLEX heavily tests priority-setting and safety. Questions involving dialysis, CRRT, or any extracorporeal circuit (like during surgery) will often have the correct answer related to equipment malfunction or breach in sterile/closed system (air, disconnection, clotting) because these pose an immediate, direct threat to life.
Watch Out for Question Variations! • Instead of "air bubbles," the question could ask about: "A disconnection in the venous blood line" (risk of massive hemorrhage) – also highest priority.
• The scenario could shift to a post-CRRT patient asking which symptom to report immediately: "Sudden onset of shortness of breath and chest pain" (suspected air embolism) would be the key answer.

임상 시나리오

Nursing Clinical Practice Guide Clinical Scenario: You are the nurse managing Mr. Chen, a 68-year-old patient with sepsis-induced AKI on day 3 of CVVH (Continuous Veno-Venous Hemofiltration, a type of CRRT). During your hourly circuit check, you see several small air bubbles traveling in the venous return line toward the patient's central venous catheter.

Nursing Intervention Strategy:
1. Immediate Action (Within seconds): Do not wait. Firmly clamp the venous line (the line returning blood TO the patient) between the air bubbles and the patient's access. This is the single most important step to prevent air entry.
2. Stop the Pump: Press the "blood pump stop" or "therapy hold" button on the CRRT machine. Do not resume until the circuit is cleared.
3. Assess Patient: Quickly check the patient's level of consciousness, respiratory status, and vital signs for signs of air embolism (dyspnea, chest pain, cough, hypotension, cyanosis).
4. Positioning (If embolism suspected): If the patient shows symptoms, place them in the Trendelenburg position (head down) and left lateral decubitus position (Durant's maneuver) to trap air in the right ventricle and prevent pulmonary artery obstruction.
5. Notify & Document: Call the physician and the dialysis nurse specialist immediately. Document the event, your actions, the patient's response, and the notification precisely.

Patient Safety and Precautions:
• Prevention is Key: Always prime the circuit thoroughly before initiation. Ensure all connections are Luer-locked and secure. Check the circuit for air at least hourly.
• Alarms: The machine's air detector alarm should activate. Never bypass or silence this alarm without resolving the cause.
• Contraindication: Never attempt to "flush" a small air bubble toward the patient. Always remove air from the circuit away from the patient.
Nursing Procedure & Medication Flow CRRT Circuit Air Management Procedure:
1. Clamp venous line immediately.
2. Stop blood pump.
3. Identify source (loose connection, empty saline bag?).
4. Remove air: Using a syringe, aspirate air from the venous drip chamber or a designated port. May require partial or full circuit re-priming by the dialysis nurse.
5. Resume therapy cautiously only after all air is cleared and the circuit is intact, following unit protocol.

Medication Note: If an air embolism is confirmed, treatment is supportive (oxygen, IV fluids). In severe cases, hyperbaric oxygen therapy may be considered.
A Word from Your Senior Nurse "In the ICU, your eyes and hands are your patient's first line of defense. A CRRT machine can look intimidating, but your fundamental nursing vigilance is what keeps it safe. That hourly circuit check isn't a chore—it's a lifesaving ritual. When you see air in the line, your brain should scream 'CLAMP!' before it even fully processes the thought. This kind of automatic, safety-first response is what separates a task-completer from a true patient guardian. On the NCLEX, they're testing if you have that guardian instinct. Look for the option that says 'something is fundamentally broken or unsafe right now.' That's almost always your answer."

핵심 개념

  • Continuous Renal Replacement Therapy — A slow, continuous blood purification therapy used for critically ill patients with acute kidney injury, often better tolerated than intermittent hemodialysis due to gentler fluid and solute removal.
  • Air Embolism — A life-threatening condition where air enters the vascular system, potentially obstructing blood flow in the heart or pulmonary circulation, leading to cardiovascular collapse.
  • Oliguria — Decreased urine output, typically defined as less than 400 mL per day or less than 0.5 mL/kg/hour, a hallmark sign of acute kidney injury.
  • Hyperkalemia — An elevated serum potassium level (>5.0 mEq/L), a dangerous electrolyte imbalance in AKI that can cause cardiac arrhythmias and arrest.
  • Trendelenburg Position — A position where the patient's head is lowered and feet are raised. Used in suspected air embolism to help trap air in the apex of the right ventricle.

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