# A nurse is caring for a patient with septic shock who has a pulmonary artery catheter in place. > source: MyMerci (mymerci.kr) > url: https://mymerci.kr/pages/nclex_q.php?qn_id=540280 > language: ko > subject: Adult Health ## 문제 A nurse is caring for a patient with septic shock who has a pulmonary artery catheter in place. The patient's cardiac output is 4.0 L/min, cardiac index is 2.2 L/min/m², and pulmonary capillary wedge pressure (PCWP) is 18 mmHg. ## 보기 1. Increase the IV fluid rate to improve preload 2. Prepare to administer inotropic medications as ordered **✔ 정답** 3. Position the patient in Trendelenburg position 4. Encourage deep breathing exercises to improve oxygenation **정답: 2** ## 해설 In septic shock with a pulmonary artery catheter, inotropic medications may be used to support cardiac output if myocardial dysfunction is present. The explanation should focus on septic shock management, not cardiogenic shock. ## 심화 해설 Understanding the Question This question asks you to identify the assessment finding that most directly indicates worsening cardiac function in a patient with septic shock who has a pulmonary artery (PA) catheter. To answer this, you must understand the hemodynamic parameters measured by a PA catheter and how they reflect the pathophysiology of sepsis-induced cardiomyopathy (SICM). Analyzing the Hemodynamic Profile in Septic Shock Septic shock is a form of distributive shock characterized by profound vasodilation and, in many cases, myocardial depression. The PA catheter provides direct and indirect measurements of cardiac performance and vascular tone. The hallmark of SICM, as described in the provided literature, is a global, reversible myocardial depression leading to biventricular dilatation and a reduced ejection fraction [3, 4]. Let's analyze each option in the context of this pathophysiology. - **Systemic vascular resistance (SVR) of 1,000 dynes/sec/cm⁵** SVR reflects the afterload, or the resistance the left ventricle must overcome to eject blood. In septic shock, a defining feature is massive vasodilation due to inflammatory mediators, leading to a pathologically *low* SVR. A normal SVR is roughly 800-1200 dynes/sec/cm⁵. A value of 1,000 is within normal limits. While a "normal" SVR in a septic patient who should have low SVR might suggest vasopressor effect or a different phase of shock, it is not a direct indicator of cardiac muscle function. It reflects vascular tone, not myocardial contractility. - **Cardiac output (CO) of 4.5 L/min** Cardiac output is the volume of blood pumped by the heart per minute. A normal resting CO is approximately 4-8 L/min. In the hyperdynamic phase of septic shock, CO is typically elevated as a compensatory response to low SVR, despite underlying myocardial depression [3]. A CO of 4.5 L/min is low-normal. While a falling CO in a previously hyperdynamic patient is concerning, a single value in the normal range does not definitively isolate the problem to worsening *cardiac* function; it could be influenced by inadequate preload or other factors. - **Central venous pressure (CVP) of 4 mm Hg** CVP approximates the right atrial pressure and reflects right ventricular preload. A normal CVP is 2-8 mm Hg. A CVP of 4 mm Hg is normal. While a very high CVP could indicate right ventricular failure or fluid overload, a normal value does not signal worsening cardiac function. It is more useful for guiding fluid resuscitation. - **Pulmonary artery wedge pressure (PAWP) of 22 mm Hg** PAWP, also known as pulmonary capillary wedge pressure (PCWP), is a critical measurement. By inflating a balloon at the catheter tip, the catheter "wedges" in a small pulmonary artery branch, creating a static fluid column that reflects the pressure in the left atrium and, during diastole, the left ventricular end-diastolic pressure (LVEDP). This is a direct assessment of left ventricular preload. A normal PAWP is 8-12 mm Hg. A PAWP of 22 mm Hg is significantly elevated. In the context of septic shock, this is a critical finding. The literature explains that SICM causes global hypokinesia and increased left ventricular end-diastolic volume [1, 3]. As the failing left ventricle becomes less compliant and cannot effectively pump blood forward, pressure backs up into the left atrium and pulmonary vasculature, causing a sharp rise in PAWP. This elevated pressure can lead to pulmonary edema. Therefore, a high PAWP is a direct hemodynamic sign of left ventricular dysfunction and worsening pump failure. Connecting the Finding to the Pathophysiology The provided evidence clearly establishes that myocardial depression is a core component of septic shock. The study by Parrillo et al. [4] demonstrated that a circulating myocardial depressant substance in patients with septic shock directly impairs cardiac myocyte contractility, leading to a reduced ejection fraction and ventricular dilatation. Court et al. [3] further clarify that this dysfunction manifests as biventricular dilatation despite a fluid-resuscitated hyperdynamic state. The dilated, failing ventricle has an increased end-diastolic volume and pressure, which is precisely what an elevated PAWP measures. An SVR of 1,000 dynes/sec/cm⁵ and a CVP of 4 mm Hg are normal values that do not indicate a problem, while a CO of 4.5 L/min is a non-specific finding. The markedly elevated PAWP of 22 mm Hg is the finding that directly corresponds to the pathophysiological hallmark of SICM: a failing left ventricle with rising filling pressures [1, 3].References (research sources) - [3]Clinical review: Myocardial depression in sepsis and septic shock.Research articleOlivier Court, Aseem Kumar, Joseph E. Parrillo, Anand Kumar (2002) · DOI: 10.1186/cc1822 - [4]A circulating myocardial depressant substance in humans with septic shock. Septic shock patients with a reduced ejection fraction have a circulating factor that depresses in vitro myocardial cell performance.Research articleJoseph E. Parrillo, Cynthia Burch, James H. Shelhamer, Margaret M. Parker, Charles Natanson, R. Schuette (1985) · DOI: 10.1172/jci112135 ## 임상 시나리오 Clinical Practice Guide: Interpreting Hemodynamics in Septic Shock Clinical Scenario A patient with septic shock has a pulmonary artery catheter in place. The cardiac output (CO) is 4.0 L/min, cardiac index (CI) is 2.2 L/min/m², and pulmonary capillary wedge pressure (PCWP) is 18 mmHg. The nurse must determine the priority intervention. Hemodynamic Interpretation - **Normal Values:** CI 2.5–4.0 L/min/m²; PCWP 8–12 mmHg. - **Current Profile:** Low-normal CI with elevated PCWP indicates adequate preload but impaired myocardial contractility. - **Clinical Pearl:** In sepsis, myocardial depression is common due to circulating inflammatory mediators. A PCWP >12 mmHg suggests fluid is not the primary deficit. Nursing Actions & Priorities - **Recognize the pattern:** Low CI + high PCWP = pump problem, not volume problem. - **Avoid fluid boluses:** Additional IV fluids will further elevate PCWP, increasing the risk of hydrostatic pulmonary edema without significantly improving CO. - **Anticipate inotropic therapy:** Prepare to administer dobutamine or milrinone as ordered. Dobutamine is often first-line for septic cardiomyopathy to improve contractility and CO. - **Monitor response:** Titrate inotropes to achieve a CI >2.5 L/min/m² and clear lactate. Continuously monitor MAP, HR, and urine output. - **Positioning:** Keep the patient in a semi-Fowler's position to optimize ventilation-perfusion matching; Trendelenburg is not recommended for shock management. Supporting Evidence - Surviving Sepsis Campaign guidelines recommend dobutamine for patients with persistent hypoperfusion despite adequate fluid resuscitation and MAP. - Fluid resuscitation should target dynamic measures (e.g., passive leg raise, stroke volume variation) rather than static pressures like PCWP. NCLEX-RN Focus: Differentiate fluid-responsive vs. inotrope-requiring shock states using invasive hemodynamic data. ## 핵심 개념 - **Cardiac Index (CI)** — Cardiac output adjusted for body surface area; normal range is 2.5–4.0 L/min/m². - **Pulmonary Capillary Wedge Pressure (PCWP)** — An indirect measure of left ventricular end-diastolic pressure; normal range is 8–12 mmHg. - **Inotropic Medications** — Agents like dobutamine that increase myocardial contractility, used when cardiac output is low despite adequate preload. - **Septic Shock** — A subset of sepsis with profound circulatory and cellular metabolism abnormalities, often causing myocardial depression. ## 같은 주제 문제 - [A nurse is caring for a patient with cardiogenic shock who has a pulmonary artery catheter…](https://mymerci.kr/pages/nclex_q.php?qn_id=540274) - [A nurse is caring for a patient with septic shock who has a pulmonary artery catheter in p…](https://mymerci.kr/pages/nclex_q.php?qn_id=540275) - [A nurse is caring for a patient with acute decompensated heart failure who has a pulmonary…](https://mymerci.kr/pages/nclex_q.php?qn_id=540276) - [A nurse is caring for a patient in cardiogenic shock who has an intra-aortic balloon pump …](https://mymerci.kr/pages/nclex_q.php?qn_id=540277) - [A nurse is caring for a patient in cardiogenic shock who has an intra-aortic balloon pump.…](https://mymerci.kr/pages/nclex_q.php?qn_id=540278) - [A patient in cardiogenic shock has a pulmonary artery catheter inserted for hemodynamic mo…](https://mymerci.kr/pages/nclex_q.php?qn_id=540279) --- More free questions: [기출문제](https://mymerci.kr/) _학습 참고용입니다. 실제 임상은 최신 지침과 소속 기관 프로토콜을 따르세요._