Introducing Neonatologist Performed
Ultrasound To The NICU
Jae H. Kim MD PhD
Department of Pediatrics
UC San Diego Medical Center, San Diego, CA, United States.
Disclosure
• Research Grant
– GE Healthcare
• Consultant
– GE Healthcare
The Future
Steps to Routine US in the NICU
• Validation of normative and pathologic data
• Training of neonatologists = EDUCATION!!
• Greater availability of equipment: size and cost
ARS Question
1. Do you have ready access to bedside ultrasound
devices in your Unit?
• A. YES
• B. NO
ARS Question
2. Do you personally use bedside ultrasound in your
unit?
• A. YES
• B. NO
Objectives
• Describe the unique aspects of the newborn that favor
bedside ultrasound
• Interpret the technological advances in ultrasound in
interpreting clinical conditions
• Develop a framework to integrate new aspects of bedside
ultrasound into practice
Neonatal Applications of Ultrasound
By Non-Neonatology
–
–
–
–
Head
Cardiac
Chest/Diaphragm
Abdomen (kidneys, pylorus,
ovaries, uterus,
masses/tumors, testes,
bladder)
– Vascular access including
interventional
– Eyes
– (Fetal)
By Neonatology
• Existing
–
–
–
–
Head
Cardiac
Vascular access
Bladder
• Emerging
– Bowel
– Endotracheal tube
– Lung
• Potential
– Other catheters, ie. NG tube
– Body composition
Ultrasound Advances
The Physics of Ultrasound
Density 1
Where:
VL1 is the longitudinal wave velocity
in material 1.
Density 2
VL2 is the longitudinal wave velocity
in material 2.
http://www.ndt-ed.org/EducationResources/CommunityCollege/Ultrasonics/Physics/refractionsnells.htm
Doppler Principles
http://www.centrus.com.br/DiplomaFMF/SeriesFMF/doppler/capitulos-html/chapter_01.htm
Strengths and weaknesses of US imaging
Strengths
• Detection of fluid (effusion, ascites, pus, blood,
meconium)
• Detection of calcifications
• Characterization of tissue texture
• Ultrasound is safe non-ionizing form of radiation
• Easy repeatable bedside application
• Minimal stress to infant
• We are comfortable with it
– Frequently used tool in the nursery for the clinical management of
sick neonates
Weaknesses
• Not as resolved as MRI or CT
• Air interferes with image
Strengths of doing US in neonates
• Small size means more seen per view
– Reduced imaging time
• Minimal abdominal fat
• Much of the bowel is visible in most infants
• Open fontanelle and sutures allow for excellent cranial
imaging
• NICU’s generally have ready access to machines
Limitations of Radiographs
• Poor sensitivity (40%)
• 30-50% frank
perforation may not
have a positive
radiograph
• Abdomen shows
pneumoperitonium
(football sign)
Bowel Wall Grayscale
•
•
•
•
Appearance : texture, echogenicity, layers, pneumatosis
Caliber : diameter
Thickness : 1mm < normal < 2.7mm
Peristalsis : inactive, low, normal, hyperactive
Bowel ultrasound to assess bowel
motility in the neonate
Delene A. Richburg, MD
UCSD Neonatology Fellow
INTRODUCTION
• Bowel ultrasound (BUS) is utilized as a noninvasive tool to
assess suspected intestinal pathology such as
intussusception or inflammatory bowel disease.
• Grayscale and Doppler ultrasound has been studied and
utilized as a diagnostic tool in identification of specific
intestinal pathology such as necrotizing enterocolitis (NEC)
•
The portability and ease of use of BUS makes this
modality a potentially useful bedside diagnostic tool for the
neonatologist in the routine care of newborns.
INTRODUCTION
• Intestinal motility as quantified by manometry is
known to increase with gestational and postnatal
age
• Clinical signs of intestinal dysmotility are
associated with poor tolerance of feeds in
premature infants
OBJECTIVE
To characterize normal intestinal motility in preterm
infants using bowel ultrasound in the first 5 days of
life
METHODS
Observational study of intestinal motility as visualized by bowel
ultrasound
Inclusion Criteria:
• Newborn infant cared for in the NICU at UCSD Medical
Center
Exclusion Criteria:
• Prenatal diagnosis of known intestinal abnormality
• Known or suspected genetic syndrome
• Postnatal suspected GI anomaly/pathology
METHODS
Ultrasound Examinations:
• Equipment : GE Vivid-i 13 MHz and 7 MHz
probe
• Timing:1st BUS at </= 36 hours of life 
daily BUS for the 1st five days of life
Images Reviewed for:
• Cumulative motility = Total number of
distinct peristaltic movements in 30 second
period
• SMA Doppler and resistive index
Analysis
• Review of images and comparison of
motility on DOL 1 to DOL 5
METHODS
•
•
•
•
•
Demographic details
Presence of bowel sounds
Type of feeds received and day started
Signs/Symptoms of feeding intolerance
Clinical team was not aware of ultrasound findings
Example of Images
Loops of
bowel
Lower Quadrant of Abdomen Visualized
by Ultrasound
Example of Images
Three 10 second clips such as this one were
obtained in each abdominal quadrant
RESULTS: Population Demographics
N = 20
Mean Gestational Age
31 wks (25 – 36 )
APGAR @ 1 minute
6
APGAR @ 5 minutes
8
Birth Weight
1618 grams ( 540 – 3380g)
Female
13 infants
Male
7 infants
Magnesium Exposure
13 infants
Antenatal Steroids
18
Fed on DOL #1
4
SGA
3
Motility Trends
DOL 1
Cumulative Motility *
27 (11 – 58)
DOL 5
41 (13 - 80)
Resistance Index
0.76
0.8
Enteral Feeds
4 infants
17 infants
* p= 0.013
Cumulative Motility Trends
90
80
70
Cumulative Motility
60
50
CM 1
40
CM5
30
20
10
0
1
2
3
4
5
6
7
8
9
10
11
Subject
12
13
14
15
16
17
18
19
20
Magnesium Exposure and Motility
p = 0.006
Feeding and Motility Trends
• Mean day of 1st feed : 3 ( 1 – 18)
• Mean day to reach full feeds: 16 ( 2 – 70)
• Cumulative motility on DOL 5 correlated with days to
reach full feeds and gestational age
– After adjustment for gestational age this correlation does not reach
statistical significance
CONCLUSIONS
• Intestinal peristalsis can be readily visualized utilizing
bowel ultrasound
• Cumulative motility quantified by bowel ultrasound
increases with post-natal and gestational age
• Magnesium exposure is associated with decrease
cumulative motility as quantified by bowel ultrasound
Strengths and Limitations
• First study to focus solely on peristalsis visualized by
bowel ultrasound in preterm infants
• Single examiner for each infant studied
• Clinical team blinded to the study results
• Small sample size
• Majority of infants had not reached full feeds by the
conclusion of ultrasound studies
Assessing the bowel by US
The Perfect Storm for NEC
PREMATURITY
ISCHEMIA
PATHOGENIC
BACTERIA
BREAKDOWN OF
MUCOSAL
BARRIER/DEFENSE
TRANSMURAL
BOWEL
INFLAMMATION
BOWEL
NECROSIS
ENTERAL
FEEDING
Imaging the Small Bowel by Grayscale and
Color
Epelman et al., 2007 Radiographics
Normal Peristalsis
Faingold et al., 2005 Radiol
Depicting Pneumatosis
Faingold et al., 2005 Radiol
NEC and sonography
Epelman et al., 2007 Radiographics
NEC and sonography
Epelman et al., 2007 Radiographics
NEC and sonography
Epelman et al., 2007 Radiographics
Measuring Superior Mesenteric Arterial
Flow
www.bmb.leeds.ac.uk
Interrogating Regional Blood Flow
Depicting Bowel Wall Blood Flow
Faingold et al., 2005 Radiol
Sono-Pathologic Correlation
Epelman et al., 2007 Radiographics
Sonographic Progression of NEC
Epelman et al., 2007 Radiographics
Echocardiography by the cardiologist and its
current limitations
 Assesses the structure
and function of the heart
 Depends on availability of
technicians and/or
pediatric cardiologists
 Restricted number of
studies for assessment
of cardiac disease or
dysfunction
 Inadequate for the
assessment of ongoing
changes in the newborn
“Functional Echocardiography (fECHO)”
 “Point of care Ultrasound”
 “Targeted neonatal echocardiography”
 Allows periodic reassessment





Myocardial function
Systemic and pulmonary blood flow
Extracardiac shunts
Organ blood flow
Tissue perfusion
Clinical use of fECHO
• Very preterm infant during the transitional period
• Assessment and monitoring of the ductus
arteriosus in the preterm infant
• The infant with suspected circulatory compromise
• Assessment and response to treatment of an
infant with high oxygen requirements
• Assessment of hypovolemia
Current use of fECHO
 40% of NICUs in Australia and New Zealand had one
neonatologist that performed functional echocardiography
 Widespread use in Europe
 Very few units in the U.S. are developing the capacity to
use fECHO routinely
 Neonatal guidelines have been written
(Martens et al., J Am Soc Echocardiogr. 2011 Oct;24(10):1057-78.)
 Not yet been shown to have effect on outcomes
Umbilical Lines
Umbilical catheter placement
• Routine neonatal emergency procedure that has large
variability in technical methods.
• Commonly used methods are not able to accurately
estimate the insertion lengths
• X-rays cannot always identify malpositioned catheters
• Placement of umbilical lines takes time away from nursing
during a critical transition period.
Fleming et al (2011) J Perinatol, 31(5), 344-349.
US placement of umbilical lines
Objective
• We sought to determine a more time efficient and accurate means of umbilical
catheter placement using bedside ultrasound.
Methods
• This is a prospective, randomized, pilot trial of infants of any age or weight
admitted to the NICU that required umbilical catheter placement.
• Infants were excluded if they had congenital heart disease, abdominal wall
defects, or had a single umbilical artery.
• Catheters were placed using either conventional method with blinded
evaluation of the catheters using ultrasound or placed with ultrasound
guidance with input as to catheter tip location.
• Number of X-rays needed to confirm proper positioning, completion time
points throughout the procedure, and manipulations of the lines were
recorded for both groups.
Fleming et al (2011) J Perinatol, 31(5), 344-349.
Placing the Umbilical Vein Catheter
TOO LOW
TOO HIGH
Fleming et al (2011) J Perinatol, 31(5), 344-349.
Timeline of umbilical catheter procedure
•
•
•
•
•
•
•
•
•
•
•
Start procedure
Unsuccessful attempts
Line(s) placed and secured
Call for X-ray
X-ray taken
X-ray read
Line may need adjustment and/or replacement
Line resecured
Repeat X-ray
X-ray reread
If successful, nurse notified to use line
Benefits of Ultrasound for Umbilical Catheter
Placement
• Decreased time of line placement (average
savings of 64 minutes)
• Decreased the number of manipulations needed
and X-rays taken to place the catheters.
• Average X-ray time from request to viewing per
X-ray was 40 minutes for all subjects.
Fleming et al (2011) J Perinatol, 31(5), 344-349.
Conclusions
• Ultrasound guided umbilical catheter placement can be a
faster method to place catheters requiring fewer
manipulations and X-rays when compared to conventional
catheter placement.
Fleming et al (2011) J Perinatol, 31(5), 344-349.
Ultrasound Guided Peripheral Inserted Central
Catheter Insertion in Neonates
Anup Katheria MD, Sarah E. Fleming MD, Jae H.
Kim MD PhD. Pediatrics, UC San Diego Medical
Center, San Diego, CA, United States.
Peripherally Inserted Central Catheters
• Upper PICC
• Lower PICC
Background:
• Peripheral inserted central catheter (PICC) placement is a
routine neonatal procedure
• Commonly used methods are not very accurate in
positioning PICCs
• Placement of PICC routinely incorporates tip confirmation
using conventional radiographs
• Ultrasound is a safe and commonly used tool in the
nursery for the clinical management of sick neonates
Katheria et al, unpublished
Objective/Methods:
• Objective
• We sought to determine a more time efficient and accurate means of
PICC placement using bedside ultrasound.
• Methods
• This is a prospective, randomized, pilot trial of 50 infants of any age or
weight admitted to the NICU that require PICC catheter placement.
• Infants were excluded if they had known vascular anomalies of their
vena cavae.
• Catheters were placed using either conventional method with blinded
evaluation of the catheters using ultrasound or placed with ultrasound
guidance with input as to catheter tip location.
• Number of X-rays needed to confirm proper positioning, completion
time points throughout the procedure, and manipulations of the lines
were recorded for both groups.
Katheria et al, unpublished
Results
• US decreased the time of line placement by an average of 30
minutes (p=0.034)
• US decreased the median number of manipulations required (0
vs 1) and X-rays taken (1 vs 2) to place the catheters.
• Average X-ray time from request to viewing per X-ray was 40
min for all subjects.
• Early identification of the PICC by RTUS was possible in all
cases and would have saved an additional 38 minutes if
radiographs were not required.
Conclusion
• Ultrasound-guided central catheter placement is a faster
method to place catheters requiring fewer manipulations and Xrays when compared with conventional catheter placement.
Katheria et al, unpublished
Issue with visualizing the PICC
• Lower PICC
– Easy to visualize the IVC
– Abdominal gas may get in the way
– Ideal placement would be at the IVC/RA junction at the most
superior position the PICC can travel
• Upper PICC
–
–
–
–
–
Much more difficult to visualize
Thinner catheters than umbilical catheters
More variability and obliqueness in angle
Greater movement of catheter in the large vessels and right atrium
Increased training required for this
Katheria et al, unpublished
Neonatal intubation
Background:
• The placement of the endotracheal tube (ETT) in
neonates is a challenging procedure that currently
requires timely confirmation of tip placement by
radiographic imaging.
• The length of time from ordering to obtaining a
confirmatory chest radiograph varies considerably placing
the sick newborn at risk for ETT related complications.
Dennington et al, unpublished
ETT visualization by US
• Objective:
• We sought to determine if bedside ultrasound
(US) could demonstrate ETT tip location in
preterm and term newborns to offer a quicker
method of ETT positioning.
•
Dennington et al, unpublished
ETT visualization by US
•
•
•
•
Study design:
prospective pilot study with 30 newborns
UC San Diego Medical Center
had an existing and secured ETT with a chest radiograph
confirming placement.
• Within several hours of a radiograph each infant had a
single US exam with a 12 MHz linear transducer on a
portable US machine (Vivid i, General Electric).
• To assist localization, gentle longitudinal movements of
the ETT of less than 0.25 cm were done concurrent with
US visualization.
• Measurements of ETT tip to the carina were made on the
radiograph and mid-sagittal US images.
ETT visualization by US
Imaging the ETT by US
Results
• mean gestational age of 30.2 ± 4.9 (s.d.) weeks
• mean birth weight 1595.2 ± 862 grams
• US images were taken a mean 2.9 ± 2.2 hours after
radiographs
• the ETT was visualized by US in all newborns
examined
• No direct landmark for the carina was clearly visible
by US. The carina was defined by anatomy as the
tracheal position at the level of the superior aspect of
the right pulmonary artery
• Each study took less than 5 minutes to obtain and no
clinical deteriorations occurred during any studies
Dennington et al, unpublished
ETT to carina distance correlated between US and XR
Dennington et al, unpublished
Conclusions
• Bedside US can be used to visualize and record the
anatomic position of the ETT position in preterm and term
infants.
• Further work on training competency and detection of
malpositioned tubes are required before endorsement of
this method.
Detecting air leak with US
Lung US
Normal
Copetti et al (2008) Neonatology, 94(1), 52-59.
Diseased
Interstitial edema
Normal
Copetti et al (2008) Neonatology, 94(1), 52-59.
Interstitial Edema
Defining pneumothorax with US
Defining pneumothorax with US
Bladder US
Benefits of US
• Reduction in ionizing radiation
• Greater resolution of functional clinical data
• Multisystem assessment with one tool
What are our current needs?
•
•
•
•
Less x-rays
Less handling and manipulation of baby and catheters
More efficient vascular access
More frequent bedside information to guide management
Limitations of Real-time ultrasound
•
•
•
•
•
•
Cost of technology
Learning curve
Lack of training
Not in medical specialty domain
Fear factor
Lack of solid clinical data validating their application value
Steps to Routine US in the NICU
• Validation of normative and pathologic data
• Training of neonatologists = EDUCATION!!
• Greater availability of equipment: size and cost
ARS Question
3. Do you see bedside US by the neonatologist as the
future?
• A. YES
• B. NO
ARS Question
4. If offered to you what is the maximum amount
of training you would be willing to undergo?
•
•
•
•
A. 10h
B. 25h
C. 50h
D. 100h
The Future