The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. M.M. is supported by the National Institute on Minority Health and Health Disparities of the National Institutes of Health under Award Number R25MD011564.
Resources for the figures, reference values, and training recommendations were adapted from Ruoss et al.30, the TnECHO teaching manual47, the Neonatal Hemodynamics Research Center (NHRC)48, and the Targeted neonatal echocardiography application49.

This protocol was approved by the institution&#39;s human research ethics committee, and written consent was obtained from the patient before the procedure.
1. Preparation
<ol>
	<li>For image acquisition, use ultrasound systems that include two-dimensional (2D), M-mode, and full Doppler capabilities, as well as simultaneous electrocardiographic tracing display ability.</li>
	<li>Ensure that multi-frequency probes, 5-6 MHz (for infants &#62;2 kg) and 8-12 MHz (for infants &#6...

The authors have nothing to disclose and no conflicts of interest.

TnECHO-guided care has been adopted in many neonatal intensive care units as an adjunct to the clinical assessment of hemodynamic instability in infants by neonatologists4. Accredited training programs have been developed in accordance with the 2011 ASE3 with a focus on a competence-based approach to training. The unique vulnerability of the immature cardiovascular system and the complexity of cardiovascular adaptation during the postnatal transition are key determinants of...

Targeted neonatal echocardiography (TnECHO) refers to the bedside use of echocardiography to longitudinally assess myocardial function, systemic and pulmonary blood flow, and intracardiac and extracardiac shunts1. When TnECHO is integrated with clinical findings, it can provide vital information in diagnosis, the guidance of therapeutic interventions, and the dynamic monitoring of response to treatments2.&#160;TnECHO is frequently performed by trained neonatologists in response to a specific clinical question with the goal of acquiring hemodynamics information that can complement and provide physiologic insights into the clinical status of the patients, resulting in precise cardiovascular care3. Over the past 10-15 years, TnECHO services have been incorporated in multiple tertiary neonatal intensive care units (NICUs) in Australia, New Zealand, Europe, and North America, especially in the management of complex high-acuity cases4,5,6,7,8.&#160;To date, there are eight centers in the USA with trained practitioners providing TnECHO services and a growing number of centers involved in neonatal hemodynamics research. Furthermore, the establishment of the neonatal hemodynamics and TnECHO special interest group (SIG) at the American Society of Echocardiography (ASE) reinforces the academic collaboration with pediatric cardiology and creates a strong political platform for further growth in the field9.
Neonatal hemodynamics training is designed to ensure that individuals who have received the training can achieve high-level imaging and provide comprehensive cardiovascular decision-making. In 2011, training recommendations for TnECHO, endorsed by European and North American professional organizations, were published3. Currently, more than 50 North American neonatologists have completed formal training in TnECHO; of note, more than 50% of hemodynamic clinicians are considered emerging academic leaders in the field, which is an unanticipated but much-needed benefit of formal training. Figure 1 summarizes hemodynamics training and accreditation.
The essential elements of a TnECHO service include access to a dedicated echocardiography machine. This ensures immediate availability for image acquisition and allows longitudinal follow-up (Figure 2 and Figure 3). The database/image archive must include the ability to provide immediate playback without video degradation, standardized reports, and long-term storage as per the recommendations of the Intersocietal Commission for the Accreditation of Echocardiography Laboratories10. A standard TnECHO includes key measurements that allow comprehensive assessments of intricate cardiovascular physiology during the neonatal period. This includes left ventricular (LV) function, right ventricular (RV) function, intracardiac shunt (atrial-level shunt and ductal-level shunt), the hemodynamic effects of patent ductus arteriosus (PDA), right ventricular systolic pressure (RVSp)/pulmonary artery (PA) pressure, systemic and pulmonary blood flow, the presence of pericardial fluid, thrombus, and central line position. Table 1 shows the commonly used echocardiographic terms utilized to acquire some of the data for these measurements. The evaluation may be performed for both symptom- and disease-based indications. Supplementary File 1 and Table 2 outline the comprehensive neonatal echocardiography assessments with recommended measurements, interpretation, and reference ranges for term neonates in the first 7 postnatal days.
The evaluation of LV systolic function is a key component as it assists in the delineation of the etiology and management of hemodynamic instability in critically ill neonates. Quantitative assessment is recommended as qualitative assessment is prone to inter-observer and intra-observer variability11. The calculation of the ejection fraction using a multi-plane method such as Simpson&#39;s biplane or the area-length method is superior to M-mode estimations, which may miss regional wall motion abnormalities and is inaccurate in the presence of septal flattening12. LV diastolic dysfunction is an emerging concept in neonatal hemodynamics. However, the data remain limited13.
An assessment of RV function is crucial in neonatal life because the RV is the dominant ventricle in transitional circulation, and many neonatal diseases are associated with right heart pathology. For a similar reason, in the assessment of LV systolic function, subjective assessment should be avoided14. However, due to the RV&#39;s unusual shape, highly trabeculated surface, and position wrapped around the LV, the measurement of RV function is more difficult. Despite this, several reliable quantitative parameters have been studied, and normative data have been published15,16. Fractional area change (FAC) and tricuspid annular plane systolic excursion (TAPSE) are two of the recommended quantitative measurements used17.
Intracardiac shunt (atrial and ductal level) is another important aspect of the comprehensive neonatal echocardiography assessment. In most situations, left atrial pressures are higher in comparison to right atrial (RA) pressures, resulting in a left-to-right shunt. However, in the neonatal period, a bidirectional shunt can still be normal. Elevated right-sided filling pressures, especially in association with pulmonary hypertension (PH), should be considered when there is right-to-left shunting at the atrial level, but this should not be used in isolation given that variation in ventricular compliance/pressure may also influence atrial pressure at various points during the cardiac cycle.
An assessment of patent ductus arteriosus (PDA) should include the determination of ductal shunt direction and the measurement of ductal pressure gradients, which are used to assist in treatment decisions. An arch-sidedness evaluation is also important, especially when there is consideration of surgical PDA ligation. PDA shunt direction is reflective of the difference between aortic and PA pressures, as well as the relative resistance of the pulmonary and systemic circulation. One factor used to adjudicate hemodynamic significance is the presence of holodiastolic retrograde flow in the descending thoracic or abdominal aorta18. Hemodynamic significance can be further assessed by quantifying the degree of volume overload by comprehensive measurements19. Scoring systems that assess the surrogate consequences of volume loading on the heart and the systemic hypoperfusion associated with PDA shunt, such as the Iowa PDA score, have been published (Table 3)19,20,21 The Iowa PDA score has been adopted clinically at the University of Iowa to enhance objectivity in determining the hemodynamic significance of a PDA shunt. A score of more than 6 is suggestive of a hemodynamically significant patent ductus arteriosus (hsPDA)19.
In the assessment of pulmonary hemodynamics, the absolute value of RVSp is estimated by the measurement of the tricuspid regurgitant (TR) gradient. Continuous wave Doppler is used to measure the maximal tricuspid regurgitation velocity through the tricuspid valve, referred to as the tricuspid regurgitant peak velocity. An assumed RA pressure of 5 mmHg is typically used for the calculation. The RVSp is then calculated using the simplified Bernoulli equation22:
RVSp = 4 &#215; (tricuspid regurgitant peak velocity [m/s])2 + RA pressure
Occasionally an alternative, the Doppler-derived pressure gradient across a PDA, is used for the calculation of PA (pulmonary artery) pressures23. However, a TR jet is only present in approximately 50% of patients with chronic PH24,25,26. In these situations, measurements such as the end-systolic eccentricity index (sEI), which is a measure of LV circularity, may indicate the relative pressure between the ventricles. This measurement should be interpreted with caution in patients with systemic hypertension as the mild disease may go undetected due to elevated LV end-diastolic pressure. Figure 4 gives an example of an algorithm and comprehensive neonatal echocardiography assessment guidelines for pulmonary hypertension.
For the assessment of LV stroke volume, a pulse Doppler tracing in an apical five-chamber view at the level of the aortic valve is measured to obtain the time-velocity integral (TVI). This is combined with a measurement of aortic annulus diameter in the parasternal long-axis view. A calculation with the following formula is used to estimate LV output27:
LV output (mL/min/kg) = (TVI [cm] &#215; &#960; x [D/2]2 [cm2] &#215; heart rate)/weight.
However, in the presence of a PDA, the LV output measurement is not reflective of systemic blood flow secondary to the shunting at the PDA level3. The diastolic flow to peripheral organs by Doppler interrogation of the celiac artery, superior mesenteric artery, and middle cerebral artery can give an indication of a systemic steal by a PDA but may, alternately, reflect organ resistance, with low or absent diastolic flow seen in the setting of high resistance.
TnECHO can also be utilized to assist in detecting the presence of intracardiac thrombus, pericardial fluid, and its hemodynamic significance, guiding pericardiocentesis, as well as assisting in the placement of peripheral arterial lines, peripherally inserted central catheters, and umbilical venous catheters28.&#160;Here, to show the comprehensive approach to obtaining TnECHO and the hemodynamics information, we describe the imaging protocol and the elements of a TnECHO service (Figure 3).

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>DICOM VIEWER EP</td>
			<td>GEHealthcare</td>
			<td>H45581CC</td>
			<td>DICOM Viewer on MediaThis option provides the ability to export DICOM images including a DICOM viewer to storage media (USB, DVD), for easy access to patient images on offline computers.</td>
		</tr>
		<tr>
			<td>2D Strain</td>
			<td>GEHealthcare</td>
			<td>H45561WF</td>
			<td>Automated 2D EF Measurement tool based upon 2D-Speckle tracking algorithm.</td>
		</tr>
		<tr>
			<td>EchoPAC* Software Only v203</td>
			<td>GEHealthcare</td>
			<td>H8018PF</td>
			<td></td>
		</tr>
		<tr>
			<td>EchoPAC* Advanced Bundle Package</td>
			<td>GEHealthcare</td>
			<td>H8018PG</td>
			<td>Advanced QScan provides dedicated parametric imaging applications for quantitative display of regional wall deformation.</td>
		</tr>
		<tr>
			<td>Multi-Link 3-lead ECG Care cable neonatal DIN, AHA (3.6 m/12 feet)</td>
			<td>GEHealthcare</td>
			<td>H45571RD</td>
			<td>Multi-Link 3-lead ECG Care cable neonatal DIN, AHA (3.6 m/12 feet) Used together with neonatal leads H45571RJ</td>
		</tr>
		<tr>
			<td>Myocardial Work</td>
			<td></td>
			<td>H45591AG&#160;</td>
			<td>Myocardial Work adjusts the AFI (strain) results using the systolic and diastolic blood pressure measured immediately prior to the 
			echo exam. Using the Myocardial Work feature helps achieve a less load dependent strain/ pressure curve and work efficiency index</td>
		</tr>
		<tr>
			<td>12S-D Phased Array Probe</td>
			<td>GEHealthcare</td>
			<td>H45021RT</td>
			<td></td>
		</tr>
		<tr>
			<td>6S-D Phased Array Probe</td>
			<td>GEHealthcare</td>
			<td>H45021RR</td>
			<td></td>
		</tr>
		<tr>
			<td>Sterile ultrasound gel</td>
			<td>Parker labs</td>
			<td>PM-010-0002D</td>
			<td>sterile water solubel single packet ultrasound transmission gel</td>
		</tr>
		<tr>
			<td>Ultrasound gel warmer</td>
			<td>Parker Labs</td>
			<td>SKU 83-20</td>
			<td>ultrasound gel warmer for single gel package.</td>
		</tr>
		<tr>
			<td>Wireless USB adapter</td>
			<td></td>
			<td>H45591HS</td>
			<td>Wireless external G type USB adapter with extension cable and hardware for mounting on the rear panel.</td>
		</tr>
		<tr>
			<td>Vivid* E90 v203 Console Package</td>
			<td>GEHealthcare</td>
			<td>H8018EB</td>
			<td>Vivid E90 w/OLED monitor v203 Console</td>
		</tr>
	</tbody>
</table>

hemodynamic precision in the neonatal intensive care unit using targeted neonatal echocardiography

Targeted neonatal echocardiography (TnECHO) refers to the use of comprehensive echocardiographic evaluation and physiologic data to obtain accurate, reliable, and real-time information on developmental hemodynamics in sick newborns. The comprehensive assessment is based on a multiparametric approach that overcomes the reliability issues of individual measurements, allows for earlier recognition of cardiovascular compromise and promotes enhanced diagnostic precision and timely management. TnECHO-driven research has led to an enhanced understanding of the mechanisms of illness and the development of predictive models to identify at-risk populations. This information may then be used to formulate a diagnostic impression and provide individualized guidance for the selection of cardiovascular therapies. TnECHO is based on the expert consultative model in which a neonatologist, with advanced training in neonatal hemodynamics, performs comprehensive and standardized TnECHO assessments. The distinction from point of care ultrasonography (POCUS), which provides limited and brief one-time assessments, is important. Neonatal hemodynamics training is a 1-year structured program designed to optimize image acquisition, measurement analysis, and hemodynamic knowledge (physiology, pharmacotherapy) to support cardiovascular decision-making. Neonatologists with hemodynamic expertise are trained to recognize deviations from normal anatomy and appropriately refer cases of possible structural abnormalities. We provide an outline of neonatal hemodynamics training, the standardized TnECHO imaging protocol, and an example of representative echo findings in a hemodynamically significant patent ductus arteriosus.

The following representative results outline the evaluation of a hemodynamically significant patent ductus arteriosus (hsPDA) as an example of the use of TnECHO in clinical settings. As mentioned earlier, a comprehensive assessment with multiple measurements is performed to adjudicate hemodynamic significance. The Iowa PDA score (Table 3) is one of the scoring systems adopted into clinical use as it assists in quantifying the consequences of volume loading and systemic hypoperfusion associated with PDA s...

Watch this Scientific Journal Video about Hemodynamic Precision in the Neonatal Intensive Care Unit using Targeted Neonatal Echocardiography at JoVE.com

Hemodynamic Precision in the Neonatal Intensive Care Unit using Targeted Neonatal Echocardiography

Presented here is a protocol to perform comprehensive neonatal echocardiography by trained neonatologists in the neonatal intensive care unit. The trained individuals provide longitudinal assessments of heart function, systemic and pulmonary hemodynamics in a consultative role. The manuscript also describes the requirements to become a fully trained neonatal hemodynamics specialist.

Targeted neonatal echocardiography (TnECHO) refers to the use of comprehensive echocardiographic evaluation and physiologic data to obtain accurate, ...

1 When TnECHO is integrated with clinical findings, 2 it allows for formulation of a diagnostic impression, 3 individualized guidance 4 for selecting cardiovascular therapies, 5 and dynamic monitoring of response to treatments. 6 A standard targeted neonatal echocardiography<v>7 includes key measurements 8 that allow comprehensive assessments 9 of intricate cardiovascular physiology 10 during the neonatal period and beyond, 11 especially in preterm-born infants 12 predisposed to chronic pulmonary hypertension. 13 Applying a multi-parametric hemodynamic approach 14 using targeted neonatal echocardiography 15 allows for quantitative analysis, 16 thus increasing the refinement of clinical decision-making.17 Image acquisition skills<v>18 and a comprehensive understanding 19 of neonatal cardiovascular physiology are imperative. 20 We recommend formal neonatal hemodynamics training 21 per the ASE 2011 recommendations. 22 The visual demonstration of this method 23 gives the audience an understanding 24 of the echocardiographic views 25 and attributes of different disease processes.26 To begin, place the probe on the apex<v>27 with the position marker angling toward the left shoulder. 28 Click 2D to start the first image, 29 and then click the up/down button 30 on the interactive touchscreen 31 to orient the apex of the heart at the bottom of the screen. 32 Click Color on the console 33 and place the color box over the tricuspid valve 34 using the track ball.35 Adjust the velocity reset to a color scale 36 of 70 to 80 centimeters per second. 37 Then click on the cursor and use the track ball 38 to place the sample gate over the tricuspid valve. 39 Press the continuous wave Doppler button 40 to obtain the tricuspid regurgitant peak velocity 41 and click Freeze, followed by Image Store.42 Next, click 2D to reset the screen. 43 Click Color and then simultaneous buttons 44 to activate color Doppler. 45 Use the track ball to place the color box 46 over the pulmonary veins.47 Adjust the velocity and decrease the color Doppler 48 to 50 to 60 centimeters per second. 49 Click on the cursor 50 and place the sample gate over the pulmonary vein. 51 Click Pulsed Wave Doppler to obtain the pulsed wave.52 Save this by clicking Freeze, followed by Image Store. 53 Similarly, click on the cursor and place the sample gate 54 at the tips of the open mitral valves. 55 Click Pulsed Wave Doppler 56 to obtain the mitral valve E/A ratio.57 Click Freeze, followed by Image Store. 58 Rotate the probe clockwise to open 59 and visualize the left ventricular outflow tract. 60 Click cursor, place the sample gate at the mitral inflow 61 and outflow junction, and then click Pulsed Wave Doppler 62 to obtain the pulsed wave.63 Click Freeze, followed by Image Store to save the image. 64 Place the sample gate at the aortic valve 65 and follow the same procedure to capture the image. 66 To focus on the left ventricular outflow tract, 67 turn the width button to narrow the sector width, 68 place the sample gate over the aortic valve 69 at the level of the hinge points 70 and repeat the same steps shown earlier.71 Click the TVI button on the console 72 to activate tissue Doppler imaging. 73 Turn the width button to narrow the sector width 74 to interrogate the septum with a target frame rate 75 greater than 200 frames per second. 76 Place the sample gate below the mitral valve annulus 77 in the wall of the septum.78 Click Tilt to move the sector 79 to focus on the lateral wall of the left ventricle 80 and maintain the frame rate 81 at greater than 200 frames per second. 82 Place the sample gate 83 below the mitral valve annulus in the wall. 84 Move the sector to focus on the lateral wall 85 of the right ventricle.86 Then click Tilt and place the sample gate 87 in the lateral wall of the right ventricle. 88 Next, use the track ball to place the line of insonation 89 at the tricuspid valve annulus 90 perpendicular to the free wall hinge point 91 of the tricuspid valve. 92 Click the M Mode button on the console 93 for tricuspid annular plane systolic excursion.94 For transition to the apical two chamber view, 95 rotate the probe counterclockwise 96 and click Image Store for 2D images. 97 Click TVI, followed by Image Store to obtain TDI images. 98 For the apical three chamber LV view, 99 turn the probe counterclockwise and click Image Store.100 Turn the width button to narrow the sector 101 to the anterior wall and follow the steps shown earlier. 102 For the apical three chamber RV view, 103 turn the width button to completely visualize 104 the right ventricle lateral wall. 105 Use the track ball to place the color box 106 over the tricuspid valve.107 Place the sample gate over the tricuspid valve 108 where the blue jet is observed 109 and follow the steps shown earlier. 110 Use the track ball to move the color box 111 over the pulmonary artery. 112 Click cursor and place the sample gate 113 over the pulmonic valve.114 Then obtain the pulsed wave Doppler 115 and the continuous wave Doppler 116 of the right ventricular outflow. 117 Click on Freeze, followed by Image Store to save the image. 118 For obtaining a parasternal long axis view, 119 place the probe straight down on the third 120 or fourth intercostal space just to the left of the sternum 121 with the notch pointing toward the right shoulder.122 Click 2D and the up/down tab on the interactive control 123 to orient the right ventricle at the top of the screen 124 and click Image Store, followed by cursor. 125 Place the line of insonation 126 through the left ventricle 127 at the tips of the mitral valve leaflets, 128 ensuring that the line is perpendicular 129 to the intraventricular septum 130 and that the left ventricle is not foreshortened. 131 Click M Mode, Freeze, and Image Store.132 Turn the width button and focus on the aortic valve. 133 Turn the depth knob to adjust the depth 134 or turn the zoom button on the console 135 to view the aortic annulus. 136 Click cursor and place the line of insonation 137 through the aortic valve annulus and left atrium 138 or left atrium and aortic dimensions.139 Click M Mode, Freeze, and Image Store. 140 Move the probe in an angling motion from the aortic arch 141 toward the pulmonary artery 142 by angling the probe toward the right flank. 143 For the aortic arch view, 144 place the sample gate at the pre-ductal aortic arch 145 and then at the post-ductal arch below the level of ductus.146 For the high parasternal view, click the Freeze button twice 147 to obtain the ductal view with a color sweep 148 of patent ductus arteriosus, or PDA. 149 Click Freeze, Select All, and Image Store. 150 In the presence of a PDA, click cursor, 151 place the sample volume at the narrowest point of the PDA, 152 obtain the pulsed wave, and save the image.153 For the subcostal view, 154 the probe is positioned in a transverse fashion 155 with the probe mark pointing to the left of the infant. 156 For the sagittal subcostal view, 157 the probe is situated between the xiphoid process 158 and the umbilicus in the midline 159 with the probe mark pointing toward the head of the patient. 160 Angle the probe tilting toward the left of the patient 161 to visualize the inferior vena cava and the hepatic vein 162 and continue tilting toward the left 163 to visualize the abdominal aorta, celiac artery, 164 and superior mesenteric artery.165 Finally, place the sample gate at the vessels. 166 The echocardiographic results are rated 167 using a rating system such as the Iowa PDA score. 168 This scoring system assesses the surrogate consequences 169 of volume loading on the heart and systemic hypoperfusion 170 associated with patent ductus arteriosus shunt.171 The representative results of a case vignette 172 to illustrate the echocardiography 173 performed using this protocol 174 and the Iowa PDA score are shown here. 175 A premature male infant received the targeted 176 neonatal echocardiography evaluation at two days of life 177 to assess the hemodynamic significance of PDA. 178 The evaluation measurements 179 gave the Iowa PDA score of eight, 180 suggesting hemodynamically significant PDA.181 Precision in image acquisition<v>182 which includes appropriate alignment, angle of insonation, 183 and accuracy of the image plane 184 is important for this technique. 185 Misalignment or foreshortening of the images 186 can result in inaccurate measurements. 187 In the case of chronic pulmonary hypertension, 188 TnECHO offers non-invasive screening 189 and assesses the need for a definitive diagnostic evaluation 190 with cardiac catheterization.191 The ongoing advancements in TnECHO and neonatal hemodynamics 192 can yield significant clinical improvement 193 in the care of our most vulnerable patients in the future.

hemodynamic-precision-neonatal-intensive-care-unit-using-targeted

Research

JoVE Journal

Medicine

725 Görüntüleme.  University of Oklahoma Health Sciences Center. 1 TnECHO klinik bulgularla bütünleştirildiğinde, 2 tanısal bir izlenimin formülasyonuna, 3 kardiyovasküler tedavilerin seçilmesi için kişiselleştirilmiş rehberliğe4, 5 ve tedavilere yanıtın dinamik olarak izlenmesine izin verir. 6 Standart bir hedefli neonatal ekokardiyografi7, karmaşık kardiyovasküler fizyolojinin 9 kapsamlı değerlendirmelerine izin veren anahtar ölçümleri 8 içerir 10 yenidoğan döneminde ve sonrasında, 11 özell...