**3. Central catheters**

Central vascular catheters such as umbilical arterial catheters (UAC), umbilical venous catheters (UVC), and peripherally inserted central catheters (PICC) are the most common central catheters placed in the sick neonate. Any neonate born at less than 32 weeks gestation will have at least a UVC and/or a PICC during their admission for nutrition and/or medications. In most units all of these lines are placed blind and confirmed with a single radiograph. UVC tip localization by standard radiography is imprecise. In one study approximately 30% of the radiographs were read as normal but actually had the UVC tip in the right atrium when checked with US [2]. Radiographic localization of UVC on anterior–posterior (AP) is difficult to place in ideal position because of the doming of the diaphragm. The lateral chest radiograph is better than the AP view of the chest but this view is not as convenient with the infant typically secured down for the procedure.

advances have pushed ultrasound (US) to have improved image quality and mobility while reducing cost and size of devices increasing the availability of ultrasound as a point-of-care bedside tool in several areas such as emergency medicine, obstetrics, and intensive care. Despite the early adoption in obstetrics and maternal-fetal medicine, the actual bedside implementation in neonatology has unfortunately been much slower. Examples in neonatology where POCUS may continue to expand include central line placement, endotracheal tube localization, diagnosis of pneumothoraces, cardiac function assessment, and bowel viability assessment just to name a few. What follows is a practical synopsis of the most active uses and

The newborn brain is readily accessible for sonographic imaging by the open soft tissue windows of the anterior fontanelle and the open sutures found between the unfused cranial bones. Neonatologists are quite familiar with viewing and interpreting cranial ultrasound images as these are routinely reviewed daily on clinical rounds. The primary views are coronal (front to back), sagittal (left to right) and axial views for posterior fossa [1]. POCUS can provide excellent views of the general architecture of the brain especially the two ventricles, evaluation of hemorrhage or calcifications and early evidence of ischemic changes. The use of POCUS for brain imaging is particularly useful when suspect hemorrhage may be responsible for deterioration or hemodynamic instability, at times when sonographic support is not readily available. The detection of increased pressure, cerebral edema or stroke is not sensitive with HUS and other imaging modalities such as CT or MRI are recommended. It is important to remember that these evaluations are limited in evaluating this triangulated view of the brain and can miss events or lesions outside of this window in the parietal regions. Head ultrasound is one of the easier techniques to learn for neonatologists since the views are already very familiar to them. The imaging techniques hinge upon establishing stable upright views of the two hemispheres and axial views of the posterior fossa structures. Neonatal providers have ample experience in reviewing and interpreting head ultrasounds for common pathology such as periventricular leukomalacia, intraventricular and intracranial hemorrhages and

Central vascular catheters such as umbilical arterial catheters (UAC), umbilical venous catheters (UVC), and peripherally inserted central catheters (PICC) are the most common central catheters placed in the sick neonate. Any neonate born at less than 32 weeks gestation will have at least a UVC and/or a PICC during their admission for nutrition and/or medications. In most units all of these lines are placed blind and confirmed with a single radiograph. UVC tip localization by standard radiography is imprecise. In one study approximately 30% of the radiographs were read as normal but actually had the UVC tip in the right atrium when checked with US [2]. Radiographic localization of UVC on anterior–posterior (AP) is difficult

opportunities for POCUS in neonatology.

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so most of the skills are focused on imaging.

**3. Central catheters**

**2. Head**

Ultrasound more accurately confirms the position of the catheter tip than radiographs and reduces the exposure of ionizing radiation. Ultrasound guidance results in faster placement and fewer manipulations and radiographs for both umbilical catheters and PICC as compared with conventional placement [3, 4]. POCUS can be very useful in localizing the tip of central catheters either during placement or after a catheter has been placed to follow any migration. Umbilical catheters can frequently migrate after placement in the first few days after insertion. This may be due to drying and shrinkage of a longer umbilical cord. POCUS allows for the direct visualization of the umbilical and PICC catheters and their tips and indirect visualization of the UVC in the hepatic portion of the catheter pathway where it is localized by the shadow cast by the catheter [4]. Ultrasound may be able to help guide the catheter and thereby reduce complications during UVC, UAC, or PICC insertion. Doppler ultrasound is also useful to examine the aorta and renal vessels when placing or evaluating a UAC **(Figure 1)**.

Use of POCUS for vascular access for PICCs has been limited due to the greater skillset required to accessing these small veins compared to older children. Setting up dedicated PICC teams can help develop this expertise to promote this aspect of central catheter POCUS.

With US, the UVC can be placed just beyond the IVC-RA junction. This permits good visualization and eliminates any risk of extravasation of the catheter in the liver. The UAC is readily placed just behind the heart which approximates the T7–8 position. The recognition of PICC movement in the large vessels makes it particularly challenging to manage the best position to place these catheters. Movement of the arm or leg to identify the deepest position of the PICC will ensure that the catheter does not inadvertently migrate deeper after placement and cause more risk of complications. For upper PICCs the arm position in a 45 degree flexed position at the shoulder and elbow usually represents the deepest point for a PICC while the knees bent close to the chest represent the deepest point for lower PICCs. The upper PICC can be placed at least 1 cm before the SVC-RA junction while the lower PICC is placed at 1–2 cm below the IVC-RA junction (**Figure 2**).

**Figure 1.** Umbilical catheter placement (a) UVC-umbilical venous catheter, (b) UAC-umbilical arterial catheter.

**Figure 2.** PICC localization (a) upper PICC, (b) lower PICC, PICC-peripherally, inserted central catheter, RA-right atrium, SVC-superior vena cava, IVC-inferior vena cava.

To start, cardiac POCUS can provide a rapid qualitative assessment of contractility: normal, hyperactive, reduced contractility (mild, moderate, or severe). Fractional shortening measurements are relatively easy to obtain and provide quantitative information. Cardiac filling as a measure of volume assessment can also be determined quickly. The PDA represents an important shunt to assess to facilitate clinical management to determine if the PDA is contributing to cardiorespiratory compromise or systemic hypoperfusion. The PDA can be determined to be open or closed (**Figure 3**). The presence of a patent ductus arteriosus can lead to an overestimate of cardiac output using usual left ventricular output measurements. An alternative measure of cardiac output using superior vena caval flow (SVC) measurements as a surrogate measure has been proposed [6–9]. Unfortunately, SVC flow has not become widely used as it has proven to be difficult to minimize inter-operator variability in this measurement. While several examples of benefit of neonatal cardiac POCUS have been published, there remains a paucity of neonatal clinical studies to validate each of the functional assessments and their ability to improve diagnostic or management of the sick neonate [10, 11]. As more neonatologists become comfortable with the skillset of cardiac echocardiography, there is a need for improved standardization and quality assurance [12, 13]. There have been some attempt to standardize the practice but many feel that the standards set are excessive and restrict early adoption [14, 15]. The anatomic assessment of the heart for the most part should be left to the cardiologist but it is equally important to recognize patterns of normal structure to know

Current Neonatal Applications of Point-of-Care Ultrasound

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**Figure 3.** PDA (a) large PDA, (b) no PDA, LPA-left pulmonary artery, DA-descending aorta.

Nevertheless, despite a number of hurdles, there remains tremendous promise that neonatal cardiac POCUS can provide a focused assessment to provide hemodynamic information to

The evaluation of lung by POCUS in neonates is increasingly practiced as the imaging technique is relatively simple and the lung is readily accessible for interrogation through the chest wall. Several recent articles have noted lung ultrasound to be as good if not better than X-ray as a diagnostic modality. Reduction in cost of image acquisition and exposure to ionizing

when there is suspicion of a congenital heart lesion.

the bedside clinician.

**5. Lung**

Other areas of benefit from POCUS in the NICU are arterial line placement where localization of the vessel and flow identification by Doppler ultrasound can be performed. A modified Allen test with Doppler ultrasound evaluation of collateral flow is useful prior to the procedure. Real-time ultrasound can result in fewer attempts and less chance of a hematoma as compared with palpation.
