A Modified Sonographic Algorithm for Image Acquisition in Life-Threatening Emergencies in the Critically Ill Newborn

This protocol is an adaptation of published literature on a sonographic assessment of a newborn with a life-threatening event in the neonatal intensive care unit or the delivery room. It's designed as a general competence that can be quickly learned and help the clinician to add sonographic assessment when life-threatening emergencies occur having an ultrasound device available. Demonstrating the procedure will be Eunice Valeria Serpa-Maldonado, Alejandra Sanchez-Cruz, Naomi Aguilar-Martinez, Rogelio Guillen-Torres, and Rosario Becerra-Becerra.

To begin, position the infant's head in a neutral position, clear the airway of secretions and nest the infant whenever possible. Administer oxygen as needed to maintain an oxygen saturation level of 90 to 95%or a fraction of inspired oxygen of 100%if the infant is in cardiac arrest. Place a pulse oximeter on the infant's right hand.

Attach cardiopulmonary leads and use a blood pressure monitor and a cuff of the correct size. Obtain the heart rate, respiratory rate, blood pressure, axillary temperature and blood gas analysis with glucose and calcium. Select the linear array probe HEUE eight to 18 megahertz HHD 7.5 to 10 megahertz, and press Small Parts on the console or the Menu on the electronic tablet.

Place the linear transducer with the notch facing to the right anteriorly on the neck at the level of the cricothyroid membrane and adjust the scanning depth to two to four centimeters. Locate the two thyroid lobes at the level of the cricoid. Identify the outline of the endotracheal tube or ETT.

Observe the ETT in situ, generating a posterior shadow and observe the esophagus on the left of the screen. Next, perform a longitudinal lung ultrasound to check for adequate bilateral pleural sliding. Assess the presence of parenchymal signs and confirm the absence of a lung pulse.

Select the phased array probe six to 12 megahertz. Press neonatal cardiac mode and click on the up down button. Using the liver as an acoustic window, ensure the right atrium is at the bottom of the screen.

Adjust the scanning depth to six centimeters in the sector width so that part of the liver and the complete heart are seen. With the notch pointing at five o'clock, obtain a subcostal long axis utilizing the liver as an acoustic window to the heart. Scan from posterior to anterior, recognizing the superior vena cava, the right and left atriums, the left ventricle and aortic valve and the crossing right ventricle and pulmonary valve.

On B mode imaging, identify the heart rate and qualitatively assess the contractility and the absence of PCECT. Abnormalities like pericardial effusion with cardiac tamponade, asystole with chest compressions, pulseless electrical activity and tacky arrhythmia can also be identified. Further to assess PCECT and pleural effusion, place the transducer under the xiphoid region with the notch facing three to five o'clock.

Then sweep from side to side to scan the diaphragm and the bottom of the lungs using the liver as an acoustic window. Compare the normal trans diaphragmatic view against right and left pleural effusion. To rule out pneumothorax, perform longitudinal lung ultrasound or LUS searching for parenchymal signs during ventilation.

If using a handheld device, obtain the parasternal lung axis view and LUS by selecting the linear array probe 7.5 to 10 megahertz. Press Small Parts on the menu on the electronic tablet and adjust the scanning depth to four to six centimeters. After resuming circulation with chest compressions obtain a para sternal long axis view of the heart using the linear handheld probe.

Point the notch to the left shoulder, then rotate clockwise until the right ventricle is visible on top and the descending aorta is at the bottom. Identify the right ventricle, the interventricular septum, the aortic valve, the left ventricle, the mitral valve the left atrium, the pericardium, and the descending aorta. Assess the HR contractility and the presence of PCECT.

Perform LUS, searching for parenchymal signs during ventilation to rule out pneumothorax. Adjust the scanning depth to six centimeters in the sector width so that part of the liver and the complete heart are visible. Press the Color on the console and adjust the velocity to a scale of 70 to 80 centimeters per second.

Observe the crossing of the great vessels in adequate outflow without aliasing and acceleration. Use the normal color subcostal long axis to compare with abnormal cases where great vessels don't cross and there's left or right ventricular outflow, tract obstruction. Then click on 2D and obtain a four chamber view with the notch on the transducer directed toward the left axilla at the two to three o'clock position as viewed from the apex.

Identify the right atrium, the tricuspid valve the right ventricle, the intraventricular septum, the left atrium, the mitral valve, and the left ventricle. Subjectively evaluate the contractility by examining the change in ventricular cavity size during systole. Click on the M mode button then use the track ball to place the cursor on the tricuspid and mitral annulus to measure their systolic excursions and compare these measurements to the mammograms based on gestational age.

To assess the cardiac filling and fluid status, differentiate a normal filled heart versus an underfilled one by evaluating the end diastolic area where obliteration of the cavity suggests hypovolemia. Whereas an overloaded heart often appears dilated with poor contractility. Rule out PCECT by looking for a large pericardial effusion with altered contractility which indicates PCECT.

Select the linear array probe 7.5 to 10 megahertz to obtain HHD with per sternal long axis view. Press Small Parts on the menu on the electronic tablet. Adjust the scanning depth to four to six centimeters.

Obtain a per sternal long axis view with the linear handheld probe. Point the notch to the left shoulder. Then rotate clockwise to three to four o'clock until the right ventricle is on top of the screen and the descending aorta is at the bottom.

Then identify the right ventricle, the interventricular septum, the aortic valve, the left ventricle, the mitral valve, the left atrium, the pericardium, and the descending aorta. Subjectively evaluate the contractility by examining the change in the ventricular cavity size during systole. Differentiate a normal filled heart versus an underfilled one by evaluating the end diastolic area.

Obliteration of the cavity suggests hypovolemia whereas an overloaded heart appears dilated with poor contractility. Rule out PCECT as indicated by fluid anterior to the descending aorta. Select the linear array probe HEUE eight to 18 megahertz, HHD 7.5 to 10 megahertz.

Press Small Parts on the console or the Menu on the electronic tablet. Turn off the harmonics. Adjust the scanning depth to four to six centimeters.

Divide the thorax into six regions using the anterior, posterior, axillary and parasternal lines. Identify the anterior region from the parasternal line to the anterior axillary line. Then use the inter mammary line to divide into the upper and lower anterior regions and identify the lateral region from the anterior to posterior axillary line.

Perform a longitudinal scan with the notch facing up, medial to lateral in the anterior regions and posterior to anterior in the lateral regions. Obtain clips of six to 10 seconds. Rotate the transducer 90 degrees to scan from top to bottom through the intercostal spaces.

Assess pleural sliding to search for a pneumothorax and identify the two in fro motion of the pleural line, synchronizing with the respiratory movement. The presence of parenchymal signs rules out pneumothorax. Perform M mode to search for the barcode sign.

Rotate the transducer 90 degrees and place the transducer between the second and third intercostal spaces to obtain the anterior superior transverse plane with the notch pointing to the right. The sternum and mediastinal structures are observed in a healthy newborn. Identify the presence of a pleural effusion characterized by fluid accumulation in the pleural cavity on longitudinal and lateral scans A total of 1045 hemodynamic consultations point-of-care ultrasound studies were carried out in our hospital, and 25 corresponded to the protocol.

The types of decompensations included 14 respiratory, eight hemodynamic, and three cardiac arrest related cases. Diagnoses comprised pneumothorax in 12 patients pleural effusion in four, PCECT in three, altered contractility in two, mobilization of the endotracheal tube and hypoglycemia in one each. Most patients survive the event and 68%survive to discharge with 19 procedures performed including chest tubes, chest tube corrections, pneumothorax and pleural effusion needle drainages, tamponade needle drainages, endotracheal tube adjustment and glucose bolus administered.

Remember that sonographic assessment gives you additional information and does not substitute traditional neonatal resuscitation and stabilization maneuvers. It adds safety to procedures that normally would be done blindly. It is important that after the emergencies resolve, further management should be guided by a comprehensive hemodynamic consultation and pediatric cardiology assessment.