Non-Invasive Cardiac Output Monitoring (NICOM) CHEETAH Non-Invasive Cardiac Output Monitoring (NICOM) Kanisha Belt Kristine Krukar JP Millete John Ward

Objectives What is CHEETAH NICOM? Fluid Optimization Differential Diagnosis Drug Titration How to run the test Research Questions

What is CHEETAH NICOM? CHEETAH NICOM is a device that provides continuous, non-invasive, hemodynamic insight, delivering real time tracking of cardiac output and other key hemodynamic parameters. The hemodynamic feedback provided by CHEETAH NICOM assists healthcare workers with making decisions regarding drug and fluid management and with determining clinical diagnoses.

Settings Where NICOM is Used ICU CCU Anesthesia Peri-Operative Step Down Emergency Department Hemodynamic compromise: Shock due to hypovolemia, sepsis, trauma, heart failure, neurogenic shock, acute MI with cardiogenic shock Increased metabolic demands, requiring increased blood-flow and perfusion: Sepsis, burns, major surgery (pre, intra, and post-operative) These situations call for efficient clinical decision making in the face of rapid hemodynamic fluctuations. In dealing with these emergent scenarios the clinician needs to make, revisit and modify decisions on fluid resuscitation and administering vasopressor medications These decisions have a major impact on the incidence of complications, duration of ventilation, requirement for interventions such as hemodialysis and CRRT, length of hospital stay and ultimate survival.

Clinical Applications Fluid optimization Hemodynamic differential diagnosis Drug titration management Fluid Optimization Determinaton of fluid responsiveness Hemodynamic Differential Diagnosis Hypovolemic Shock Septic Shock Cardiogenic Shock SOB Acute Renal Failure Drug Titration Empower decisions on drug selection involving pressors and cardiac inotropes Fine tuning of dosage

Fluid Optimization Tailor fluid management to optimize resuscitation Hemodynamic monitoring gives nurses information about the patient’s cardiac status and organ perfusion. This allows for the proper fluid intervention(restriction or resuscitation) to be taken. It aids in making sure that the optimal amount of fluids are being received. -Suboptimal fluid resuscitation may lead to low perfusion state. -Overly-aggressive fluid resuscitation can lead to volume overload and heart failure exacerbation. Tailor Fluid Management to Optimize Resuscitation Hemodynamic monitoring gives healthcare providers information about the patient’s cardiac status and organ perfusion. This allows for the proper fluid intervention to be taken. The tailored approach allows better oxygenation to the tissues for patients who are in need of fluids, and makes it so that patients with excess fluids and edema are restricted from fluids.   It aids in making sure that the optimal amount of fluids are being received. -Suboptimal fluid resuscitation may lead to low perfusion state. -Overly-aggressive fluid resuscitation can lead to volume overload and heart failure exacerbation. Passive Leg Raising -Passive leg raising is done at the bedside and it mobilizes approximately 250 ml of blood from the calf veins back to the heart. It is quick, safe and reversible. It provides information that very quickly helps to guide therapy. A positive PLR test (increase of ≥10% in Stroke Volume Index or Cardiac Index) implies that there is sufficient cardiac reserve to pump the increased preload forward meaning the patient is fluid responsive.

Drug Titration Inotropes and vasopressors require continuous monitoring. With NICOM, ongoing monitoring in conjunction with repetitive fluid challenges or Passive Leg Raising maneuvers enables objective, tailored management of the patient allowing for the drug dose and type to be changed according to the resulting effects.

Differentiating Diagnoses By evaluating cardiac output, NICOM is able to aid in differentiating diagnoses with similar symptoms, such as shortness of breath seen with COPD and CHF. NICOM can help determine if the symptom is stemming from a cardiac issue or a pulmonary issue. In acute CHF there is no cardiac reserve to propel the additional preload forward therefore there is no increase in cardiac output following the hemodynamic challenge. In dyspnea due to COPD the response to the hemodynamic challenge is expected to be positive where the increase in preload causes an increase in cardiac output. In cases of shock: Monitoring only BP does not provide any advanced warning, nor does it enable differential diagnosis between hypovolemic shock, septic shock and cardiogenic shock.   With NICOM, monitoring of cardiac output and total peripheral resistance enables early detection of future hemodynamic collapse and combined with a simple bedside hemodynamic challenge such as passive leg raising or response to 250 ml fluid bolus provides an insight as to the shock etiology. Shortness of Breath Differentiating between shortness of breath due to Chronic Obstructive Pulmonary Disease, Congestive Heart Failure, or other diseases: In acute CHF there is no cardiac reserve to propel the additional preload forward and hence no increase in cardiac output following the hemodynamic challenge. In dyspnea due to COPD the response to the hemodynamic challenge is expected to be positive where the increase in preload causes an increase in cardiac output.

Why is NICOM a better option over other methods of hemodynamic monitoring? Until the development of NICOM, many hemodynamic parameters were determined via invasive methods - Pulmonary Artery Catheters allow direct measurement of the cardiac output, stroke volume, pulmonary artery pressures and the mixed venous oxygen saturation. A disadvantage is the difficulty in interpretation of the waveforms and the lack of an understanding of the relevance of each variable obtained. This can lead to inappropriate intervention and adverse results. It is associated with increased mortality (Lavdaniti, 2008). - Central Venous Pressure can determine whether a patient requires fluids or is well hydrated or even congested. It is dependent on venous return to the heart, right ventricular compliance, peripheral venous tone and posture. A disadvantage is that this method is unable to predict patient’s volume status and response to fluids. It is also invasive and requires insertion of a catheter into the patient’s large neck vein(Lavdaniti, 2008). -Pulmonary artery catheters allow direct measurement of the cardiac output, stroke volume, pulmonary artery pressures and the mixed venous oxygen saturation. It requires caution in ventilated patients as increased intrathoracic pressure falsely increases the pressure reading. A disadvantage is the difficulty in interpretation of the waveforms and the lack of an understanding of the relevance of each variable obtained. This can lead to inappropriate intervention and adverse results. It is associated with increased mortality. -Central Venous Pressure can determine whether a patient requires fluids or is well hydrated or even congested. It is dependent on venous return to the heart, right ventricular compliance, peripheral venous tone and posture. A disadvantage is that this method is unable to predict patient’s volume status and response to fluids. It is also invasive and requires insertion of a catheter into the patient’s large neck vein. - Modified Fick equation is a non-invasive method of assessing cardiac output from changes in exhaled carbon dioxide during rebreathing. Its major limitation is a time lag of ∼3 min for a physiological change to be displayed and requirement for mechanical ventilation with constant minute ventilation. The technique assumes no intrapulmonary shunt and requires a correction for estimated shunt fraction.   -Pulse contour analysis assesses changes in cardiac output according to changes in the size and shape of the arterial pressure wave. Calibration requires measurement of cardiac output by another technique. Two readily available techniques are a modification of the dye dilution technique using lithium as the indicator or thermodilution. The techniques are inaccurate in cases of aortic regurgitation, intra-aortic balloon counterpulsation, severe peripheral vascular disease and in hypothermic patients. Recalibration is needed more frequently during hemodynamic instability.

Why is NICOM a better option over other methods of hemodynamic monitoring? Modified Fick equation is an invasive method of assessing cardiac output from changes in exhaled carbon dioxide during rebreathing. Its major limitation is a time lag of ∼3 min for a physiological change to be displayed and requirement for mechanical ventilation with constant minute ventilation. The technique assumes no intrapulmonary shunt and requires a correction for estimated shunt fraction (Lavdaniti, 2008).

What are the Benefits of Using NICOM? NICOM is completely non-invasive Reduces the risk of blood borne infections Provides continuous real-time data Compact & Portable Cost Effective Can be managed by a nurse!

Nursing Research Background: Determining cardiac output in critically ill patients is important in “optimal diagnosis, organ support and definitive management” (Corley, Barnett, Mullany, Fraser, 2009, p. 1292). Pulmonary Artery Catheters (PAC) and the Fick equation are currently the common methods to measure CO in critical care units. PACs are associated with many risks and do not have a large body of supporting evidence. Use of non-invasive hemodynamic monitoring “has the potential to allow the bedside ICU RN to independently measure CO and act on the measures if provided with a structured algorithm to follow” (Corley, Barnett, Mullany, Fraser, 2009, p. 1292).

Nursing Research Purpose: to define the learning curve for USCOM use by a non- echocardiograpically trained ICU nurse; and to compare CO measures between USCOM (as determined by the ICU nurse with no previous training in cardiac output assessment) and PAC (as inserted by a medical team), both by thermodilution and a modified Fick equation (Corley, Barnett, Mullany, Fraser, 2009, p. 1292).

Nursing Research Methods: A 2-day training course was provided for the RN conducting the USCOM. The USCOM was conducted on 30 patients who were being evaluated for heart failure and/or pulmonary hypertension who also had a PAC. After CO was determined by PAC and the Fick equation, CO was determined by use of USCOM. The ultrasound beam was directed across either the aortic valve to monitor LV output or the pulmonary valve to measure right ventricular output (Corley, Barnett, Mullany, Fraser, 2009).

Nursing Research Results: “ICC demonstrated very good to excellent correlation for USCOM and PAC, USCOM and Fick and PAC and Fick (r= 0.848, 0.903, 0.921 respectively)” (Corley, Barnett, Mullany, Fraser, 2009, p. 1294). Learning curve: “time halved from 22 min to less than 10 min over the course of 30 examinations” (Corley, Barnett, Mullany, Fraser, 2009, p. 1294).

Nursing Research Discussion: There was an unsatisfactory signal in 20% of patients. High failure rate is attributed to “ combination of difficult acoustic environment associated with substantially altered cardiac anatomy and function and the relative inexperience of the operator” (Corley, Barnett, Mullany, Fraser, 2009, p. 1295). By the end of the study, average time to obtain USCOM CO was 10 minutes versus 45 – 120 minutes needed to insert PAC. USCOM is faster, more cost effective and carries less risk for the patient. Limitations: pilot study and small population.

Nursing Research Nursing Implications: “This study has highlighted the fact that appropriately trained ICU RNs can safely and accurately monitor changes in their patient’s CO status in a non-invasive manner with no risk to the patient” (Corley, Barnett, Mullany, Fraser, 2009, p. 1296). Increased autonomy for ICU RNs.

NICOM User’s Guide 101

Basic Equipment… NICOM system is equipped with 4 sensor pads, each of which contains an outer sensor for transmitting a signal, and an inner sensor for receiving returning signals

Quick “How to” Outline Perform hand hygiene.   Perform hand hygiene. Identify Pt with identifiers based on the hospital’s protocol. Monitor patient health status and perform pain assessment. Perform patient/family education on the machine and its purpose. Assist the patient onto his or her back, with the head of the bed slightly elevated. Place the sensors (2 on the upper thorax, 2 below the lower ribs). Activate the device Enter patient-specific characteristics, including name, height, weight, and gender Obtain hemodynamic values. Power off the machine and remove the electrodes from the patient. Clean and store the machine. Document. (Ittner, 2012)

Sensor Placement First, shave skin if necessary, wipe with alcohol Apply the 4 sensors to the patient’s torso in a box-like pattern around the patient’s heart – 2 on the upper thorax, and 2 under the lower ribs Sensors can be applied to patient’s chest OR back!

Sensor Placement (con’t) Exact sensor positioning is NOT required If possible, place the stickers outside of direct contact with ECG electrodes, drains, IV lines, and external pacemaker leads On a similar note – If performing electrical shock therapy, such as defibrillation or transcutaneous pacing, NICOM should be disconnected

Assessing Hemodynamic Status – The Passive Leg Raising Test (PLR) When performed on patients in hemodynamic compromise, passive leg raising has been shown to induce changes in cardiac output that reliably predict responsiveness to fluid administration

Performing the PLR Test – Determining a Baseline First, have the patient lay in a semi-recumbent position Perform a baseline reading After confirming baseline reading, NICOM interface will prompt user to initiate PLR challenge…

Performing the PLR Test… At this time, lay the patient flat and lift their legs above 45o. Run the PLR challenge test on the NICOM machine

Explanation of the PLR Test Lifting the legs causes 250 mL of blood from the calf veins to migrate back towards the heart If it is not possible to lift the patient’s legs, the PLR challenge test is instead performed by administering a 250 mL fluid bolus

PLR Results The PLR Test Report will supply you with valuable hemodynamic information, including… - Heart rate, BP, MAP - Cardiac Output (CO) - Cardiac Index (CI) - Stroke Volume Index (SVI) - Other hemodynamic data…

Note the SVI “ (%)”, located on the bottom line

How to Interpret PLR Test Results A positive PLR test = ≥ 10% in SVI A positive PLR test suggests that there is sufficient cardiac reserve to pump an increased preload (which would result from increased fluid administration), thus, the patient would likely be fluid responsive In such instances, hemodynamic stability could be achieved by nurses with fluid bolus administration, without the use of vasopressor medications

How to Interpret PLR Test Results If the change in SVI is less than 10%, then your patient will likely not be fluid responsive, thus, IV fluid administration will NOT be effective for increasing blood pressure!!! In the case of a negative PLR test, the nurse should be able to recognize that use of vasopressors will be necessary to maintain hemodynamic stabilization because the patient will not be responsive to fluid bolus administration.

Other Uses for NICOM - Differential Diagnosis The NICOM PLR challenge test also provides with a simple, and accurate way to help differentiate between different types of shock Hypovolemic shock Cardiogenic shock Neurogenic shock Septic shock

Patient/Family Teaching Explain the purpose of NICOM in assessing cardiac and tissue perfusion in patients Emphasize that NICOM is a painless, noninvasive procedure that can provide valuable information and help guide patient management

Conclusion Advanced hemodynamic monitoring is an important part of treatment in clinical situations where aggressive, guided hemodynamic interventions are required to stabilize the patient and optimize outcome Cardiac Output and other hemodynamic parameters play an important role in fluid optimization, drug titration, and differential diagnosis, aiding in establishing the right treatment plan and monitoring and refining it in real-time. Advanced hemodynamic monitoring is an important part of treatment in clinical situations where aggressive, yet guided hemodynamic interventions are required to stabilize the patient and optimize outcome Cardiac Output and other hemodynamic parameters play an important role in fluid optimization, drug titration, and differential diagnosis, establishing the right treatment plan and monitoring and refining it in real-time.

References Cheetah Medical (n.d.). NICOM: 100% noninvasive guided fluid management. Retrieved from: http://www.cheetah-medical.com/ Corley, A., Barnett, A.G., Mullany, D., Fraser, J.F. (2009). Nurse-determined assessment of cardiac output. Comparing a non-invasive cardiac output device and pulmonary artery catheter: A prospective observational study. International Journal of Nursing Studies, 46, 1291-1297. doi: 10.1016/j.ijnurstu2009.03.013 Doig, Drews, & Keefe (2011). Informing the design of hemodynamic monitoring displays. Computers, Informatics, Nursing, 29, 706-713. doi:10.1097/NCN.0b013e3182148eba Ittner, H. (2012). Nursing practice & skill: Cardiac output monitoing, noninvasive: Performing. Lavdaniti, M. (2008). Invasive and non-invasive methods for cardiac output measurement. International Journal of Caring Sciences, 3, 112–117.

Quiz What are some benefits of CHEETAH NICOM? What bedside maneuver is used to determine if the patient is fluid responsive? What are the three main functions of the CHEETAH?