Ci Values Also Help
Apr 14, 2022, 1:37 PM(edited)
Explain the value of invasive hemodynamic monitoring, including a discussion of whether an acute, chronic, or complex-care patient is a candidate for this type of assessment. For a complex-care patient, propose an evidence-based treatment plan regarding the hemodynamic information. What are the risk factors to take into consideration for this patient?
Clinical decision-making about optimizing treatments for complex-care patients can be guided effectively by hemodynamic monitoring with a pulmonary artery catheter (PAC, also known as Swan-Ganz or right heart catheter) (Saxena et al., 2020).
Based on Ingbar & Thiele (2018), pulmonary artery catheter (PAC) use in hemodynamic monitoring is declining because clinical trials have shown no mortality advantage. However, hemodynamic data furnished by a PAC can confirm the presence and severity of cardiogenic shock (CS), involvement of the right ventricle, left-to-right shunting, pulmonary artery pressures and trans-pulmonary gradient, and the pulmonary and systemic vascular resistance. It can support recognizing acute mitral regurgitation (MR), decreased left atrial filling pressure, and secondary occult sepsis and exclude left-to-right shunts. Equalization of diastolic pressures indicates cardiac tamponade, but an echocardiogram is more definitive. The detailed hemodynamic profile can be utilized to individualize and monitor therapy and provide prognostic details, such as cardiac index and cardiac force. The AHA currently recommends using a PAC for potential utilization in diagnostic or CS management uncertainty cases or patients with severe CS who are unresponsive to initial therapy. Therapeutic options for patients in CS include inotropes and vasopressors and mechanical circulatory support (MCS) devices that pump blood from 1 vascular chamber to another to improve systemic hemodynamics.
Winehouse (2021) wrote that common PAC insertion complications include atrial and/or ventricular arrhythmias. Less commonly, catheter misplacement or knotting can happen. Perforation of a cardiac chamber and rupture of a cardiac valve or the pulmonary artery are rare complications that can be fatal. Complications of catheter use include pulmonary artery rupture, pulmonary infarction, thromboembolic events, infection, and data misinterpretation. In addition, the benefit must be balanced against risks, as with any invasive diagnostic tool. Absolute contraindications to PAC placement include infection at the insertion site, right ventricular assist device, insertion during cardiopulmonary bypass, and lack of consent. Relative contraindications include the presence of a coagulopathy (INR >1.5), thrombocytopenia (platelet count <50,000/microL), electrolyte disturbances (hypo/hyper -kalemia, -magnesemia, -natremia, -calcemia), and severe acid-base disturbances (e.g., pH <7.2 or >7.5).
Normal values and differential diagnoses for the alteration in normal readings for cardiac index.
According to Patel, Durland & Makaryus (2021), the cardiac index (CI) assesses the cardiac output value based on the patient’s size. To calculate CI, divide the cardiac output by the person’s body surface area (BSA). The normal range for CI is 2.5 to 4 L/min/m2. Cardiac output (CO) can be broken down as the product of stroke volume (SV- blood volume ejected by one heartbeat) and heart rate (HR). Notably, this measures left ventricular output and is a significant clinical indicator of left ventricular function. Therefore, conditions that affect HR or SV directly impact cardiac output. Both cardiac output and cardiac index are essential to understand if a patient’s heart pumps enough blood and delivers enough oxygen to cells. CO and CI values also help manage specific drug treatments, such as inotropics and vasopressors. Also, CI is a hemodynamic measurement used to help evaluate the different forms of shock (cardiogenic, obstructive, hypovolemic, and distributive).
- CO= stroke volume X heart rate
- CI= cardiac output/ body surface area
Differential diagnoses of an abnormal cardiac index reading include myocardial ischemia, pulmonary disease (such as COPD), and patients with sleep apnea, anxiety, and depression. In addition, patients presenting with fluid retention may complain of a leg or abdominal swelling. Other causes of edema include venous thrombosis or insufficiency, renal sodium retention, drug side effect (e.g., CCB), and cirrhosis (Colucci & Borlaug, 2021).
Colucci, W.S. & Borlaug, B.A. (March 04, 2021). Heart failure: Clinical manifestations and diagnosis in adults. UpToDate. https://www.uptodate.com/contents/heart-failure-clinical-manifestations-and-diagnosis-in-adults#H305292239
Ingbar, D.H. & Thielee, H. (2018). Cardiogenic shock and pulmonary edema. In Jameson, J.L., Kasper, D.L., Longo, D.L., Fauci, A.S., Hauser, S.L. & Loscalzo, J. (Eds). Harrison’s Principles of Internal Medicine (20th Ed, Vol.2, Part 1, Chap.298, pp.448). McGraw-Hill Education.
Patel, N., Durland, J. & Makaryus, A.N. (September 28, 2021). Physiology, Cardiac index. https://www.ncbi.nlm.nih.gov/books/NBK539905/
Saxena, A., Garan, A.R., Kapur, N.K., O’Neill, W.W., Lindenfeeeld, A., Pinney, S.P., Uriel, N., Burkoff, D. & Kern,M. (April 6, 2020). Value of hemodynamic monitoring in patients with cardiogenic shock undergoing mechanical circulatory support. https://doi.org/10.1161/CIRCULATIONAHA.119.043080/ Circulation;141:1184–1197
Weinhouse, G.L. (June 24, 2021). Pulmonary artery catheterization: Indications, contraindications, and complications in adults. UpToDate. https://www.uptodate.com/contents/pulmonary-artery-catheterization-indications-contraindications-and-complications-in-adults?search=pulmonary%20artery%20catheter&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1#H13