A patient in cardiogenic shock is receiving dopamine at 10 m… | 마이메르시 MyMerci
마이메르시 — 문제와 상세 해설까지 전부 무료 무료로 시작하기
Adult Health
문제

A patient in cardiogenic shock is receiving dopamine at 10 mcg/kg/min and has a central venous pressure of 18 mmHg. To prevent further cardiovascular collapse, which intervention should the nurse prioritize to manage the patient's fluid volume and preload?

해설
In cardiogenic shock with elevated CVP (18 mmHg), the priority is reducing preload to decrease cardiac workload while maintaining adequate perfusion pressure.

This question evaluates critical thinking about priority nursing interventions for a patient in cardiogenic shock. The patient shows fluid overload and cardiac pump failure, which are typical signs of cardiogenic shock.

Analyzing the patient's clinical picture, the central venous pressure (CVP) is elevated at 18 mmHg (normal 2–8 mmHg). This indicates fluid overload and right heart failure. At the same time, blood pressure is low at 85/50 mmHg, and urine output has decreased to 15 mL/hr over the past 2 hours (normal >30 mL/hr). This reflects decreased organ perfusion.

Pathophysiologically, the heart cannot pump effectively, causing blood to pool in the venous system, which raises CVP while simultaneously causing hypotension and decreased organ perfusion. The elevated CVP means the heart is already volume overloaded and cannot effectively handle the current preload.

The reason furosemide administration is the priority is that it promotes diuresis to reduce preload. This decreases venous return and lessens the burden on the failing heart. Loop diuretics block sodium and chloride reabsorption in the ascending loop of Henle, promoting rapid diuresis.

The core of critical thinking is recognizing that in cardiogenic shock with elevated CVP, the problem is not inadequate volume but that the heart cannot handle the existing volume load. The nursing priority is to reduce this volume burden while monitoring for signs of improved cardiac output and organ perfusion.
같은 주제 다음 문제A nurse is caring for a patient in the emergency department who presents with signs of dis…

심화 해설

Clinical Context and Priority Assessment

In cardiogenic shock, the heart's pumping capacity is severely compromised, leading to inadequate tissue perfusion despite sufficient or even excessive intravascular volume. The patient's central venous pressure (CVP) of 18 mmHg is markedly elevated, indicating high right-sided filling pressures and significant congestion. While the dopamine infusion at 10 mcg/kg/min is intended to provide inotropic support, the primary immediate threat identified by this hemodynamic profile is volume overload exacerbating ventricular wall stress and pulmonary congestion. The nurse must prioritize an intervention that directly reduces this excessive preload to optimize cardiac function and prevent further decompensation.

Rationale for Correct Answer: Administer Furosemide

Administering furosemide 40 mg IV push is the correct priority action. The core pathophysiological principle here is preload reduction. In the failing heart, the relationship between preload and stroke volume is altered; beyond a critical point, further increases in filling pressure do not augment cardiac output but instead cause pulmonary and systemic congestion [4]. A CVP of 18 mmHg is well above the normal range (typically 2-6 mmHg) and signifies a state of volume overload where the ventricle is operating on the flat, inefficient portion of the Frank-Starling curve. Furosemide, a loop diuretic, induces rapid venodilation and diuresis, which immediately reduces venous return and central venous pressure. This pharmacological preload reduction decreases ventricular wall tension and myocardial oxygen demand, potentially breaking the cycle of worsening pump failure [4]. The goal is not simply to remove fluid but to move the patient's hemodynamic status to a more optimal point on the cardiac function curve where contractility can be more effective.

Analysis of Incorrect Options

Option 2: Increase the dopamine infusion rate to 15 mcg/kg/min
While dopamine is an inotrope used in cardiogenic shock, simply escalating the dose is inappropriate and potentially harmful in this scenario. At higher doses, dopamine exerts more pronounced alpha-adrenergic effects, causing significant vasoconstriction. This increases afterload, which a failing left ventricle must work against, thereby increasing myocardial oxygen consumption and potentially worsening the shock state. Current evidence emphasizes that pharmacological management in cardiogenic shock must be carefully titrated, and norepinephrine is often recommended as a first-line vasopressor over dopamine due to a more favorable hemodynamic profile and lower risk of arrhythmias . The immediate problem is not inadequate vasoconstriction but excessive preload; increasing the dopamine dose does not address this and could precipitate a malignant arrhythmia.

Option 3: Position the patient in Trendelenburg position
The Trendelenburg position is a historical intervention intended to promote venous return and increase preload. In a patient with cardiogenic shock and a CVP already at 18 mmHg, this action is contraindicated. It would further increase venous return to a heart that is already volume-overloaded and failing to pump effectively, acutely worsening pulmonary congestion and right ventricular strain. Modern critical care interprets CVP not as a simple marker of volume responsiveness but as a measure of the interaction between volume and cardiac function . A high CVP in this context is a warning sign of right ventricular dysfunction or severe congestion, making any maneuver that increases preload dangerous .

Option 4: Prepare for immediate intubation and mechanical ventilation
While respiratory failure is a common consequence of cardiogenic shock, preparing for intubation is not the most immediate, nurse-driven intervention to address the underlying hemodynamic problem of volume overload. Positive pressure ventilation can actually have complex and sometimes beneficial effects on preload and afterload, but it is an invasive procedure with its own risks, including the potential for hypotension upon induction. The priority is to first administer a rapid-acting pharmacological agent like furosemide to directly reduce the elevated preload. This may improve gas exchange by reducing pulmonary edema and could potentially avert the immediate need for intubation. Hemodynamic monitoring in shock requires a multimodal approach, and the CVP value here guides the nurse to a targeted volume management strategy before escalating to more invasive ventilatory support [1,2].
References (research sources)
  • [4]
    Preload Reduction Therapies in Heart Failure.Research articleKhan MS, Paracha AA, Biegus J, Espriella R, Núñez J, Santos-Gallego CG, Yaranov D, Fudim M. (2024) · DOI: 10.1016/j.hfc.2023.05.004

임상 시나리오

Cardiogenic Shock with Elevated CVPPrioritizing Preload Reduction

In cardiogenic shock, a central venous pressure (CVP) of 18 mmHg (normal: 2-6 mmHg) indicates severe volume overload and right ventricular congestion. The failing heart operates on the flat portion of the Frank-Starling curve, where increasing preload does not improve stroke volume but worsens pulmonary edema and wall stress.

The priority intervention is to administer an IV loop diuretic like furosemide. This provides dual benefit: immediate venodilation reduces venous return, and subsequent diuresis decreases total circulating volume, directly lowering the elevated filling pressures.

Caution

Avoid interventions that increase preload, such as the Trendelenburg position or aggressive fluid boluses. Also, escalating inotropes like dopamine without addressing volume status can increase myocardial oxygen consumption and provoke arrhythmias.

핵심 개념

Merci NCLEX-RN Question Bank 3,445 문제 · 로그인 없이 바로 볼 수 있어요

마이메르시로 국가고시 완벽 대비

기출문제와 상세 해설을 무료로. 내 약점을 분석하고 진도를 관리하며 더 똑똑하게 공부하세요.

무료로 시작하기

학습 참고용입니다. 실제 임상은 최신 지침과 소속 기관 프로토콜을 따르세요.