TTN vs. TTT (Time to Transport):
Assessment of Neonatal Respiratory
Distress
Children’s/March of Dimes Neonatal
Conference
May 17, 2010
Mark Bergeron, MD, MPH
Associates in Newborn Medicine, PA, St. Paul
Assistant Professor, Pediatrics, University of Minnesota Medical
School
Disclosures
• I will not be discussing any experimental or
off-label uses for any therapies during this
presentation.
• I have no relevant financial relationships to
declare.
Objectives
1. Formulate a differential diagnosis for the infant in
respiratory distress.
2. Describe initial stabilization measures for the
infant in respiratory distress.
3. Describe situations where ongoing respiratory
distress requires transfer to a NICU for further
management.
Introduction
• Respiratory distress is a frequent problem in
the newborn period.
– Most common indication for evaluation or reevaluation of the newborn infant
– Affects as many as 7% of newborns
– Potentially life-threatening
– Must be promptly assessed and managed by an
on-site provider in the delivery room or
newborn nursery
Clinical Presentation
•
•
•
•
•
apnea
cyanosis
grunting
stridor
nasal flaring
• retractions
– subcostal
– intercostal
– suprasternal
• tachypnea
– (> 60/min)
• gasping
• choking
Image: Aly H. Pediatrics in Review (2004)
Narrowing the Differential
• Pulmonary
– Transient Tachypnea of the Newborn (TTN)
– Respiratory Distress Syndrome (RDS)
– Meconium aspiration syndrome
– Pneumonia/sepsis
– Pneumothorax
– Persistent pulmonary hypertension (PPHN)
• Non-pulmonary
– Congenital cyanotic heart disease
– Congenital airway anomalies
– Other (neurologic, hematologic, metabolic, endocrine,
maternal, etc.)
Case Studies
Case #1
• 3.6-kg term newborn female (20 minutes old) has
tachypnea and acrocyanosis. She is 40 weeks EGA
delivered by scheduled repeat c-section and Apgar scores
were 7 and 8 at 1 and 5 minutes, respectively.
• Vitals are normal with the exception of a respiratory rate of
84 and exam is notable for slight subcostal retractions but
otherwise normal. Over the next several hours, her
respiratory rate steadily improves to the 40s and her
acrocyanosis resolves.
Transient Tachypnea of the Newborn
(TTN)
• Most common etiology of newborn respiratory
distress.
– 11/1000 live births
– Represents 40% of cases of newborn respiratory distress.
• Caused by delayed clearance of fetal lung fluid in
both term and preterm infants
TTN Risk Factors
• At birth:
– Air spaces rapidly
clear fluid from
lung expansion
with air
• Promoted by:
– Labor
– Maternal
epinephrine
surge
Guglani et al. Pediatrics in Review 2008
TTN: Clinical Findings
• History:
– C/S > NSVD
• Exam:
– Tachypnea +/• Grunting
• Nasal flaring
• Retractions
• Transient oxygen
need
• Lab:
– Mild respiratory
acidosis or normal
blood gas
TTN: Radiographic Findings
• Chest X-ray:
– Increased
interstitial
markings (“wet
lung”)
– Increased fluid in
interlobar
fissures
Image: Aly H. Pediatrics in Review (2004)
TTN: Typical Course
• Usually benign,
self-limited
• Occasionally
requires therapy:
– Oxygen
– nCPAP
– Mechanical
ventilation
• Diuretics not
effective
– i.e. Lasix
• Typically resolves
by 2 days of age
• No lasting sequalae
Case #2
• 1.2-kg male infant born vaginally at 32
weeks EGA
• Apgars 6, 8
• Required bulb suctioning, brief PPV.
• Grunting, retractions, nasal flaring,
acrocyanosis immediately after birth.
• VS: HR 178, RR 79, Mean BP 39 mmHg.
O2 sat 74-78% in room air.
Case # 2 Continued
• Lab:
– CBC
unremarkable
– ABG:
• 7.26/67/58/19
• CXR: “Prominent
reticulogranular pattern uniformly
distributed with hypoaeration of
lungs. Increased air bronchograms
are observed.”
emedicine.com
Respiratory Distress Syndrome (RDS)
• Also called hyaline membrane
disease.
• Most common cause of
respiratory distress in preterm
infants.
• Due to structural and functional
immaturity of lungs.
– Underdeveloped parenchyma
– Surfactant deficiency
• Type II pneumatocytes
• Results in decreased lung
compliance, unstable alveoli
RDS Continued
• Risk factors
– Prematurity
• <28 weeks GA (≈100%)
• 28-34 weeks GA (33%)
• >34 weeks GA (5%)
– Perinatal depression
– Male predominance
– Maternal diabetes
– C-section
– Multiple birth
Respiratory Distress Syndrome: Clinical
Finings
•
•
Exam:
– Moderate to severe respiratory
distress
• Tachypnea
• Grunting
• Apnea
• Retractions
• Nasal flaring
• Cyanosis
Lab:
– Moderate hypoxia
– Respiratory acidosis
– Metabolic acidosis (delayed)
•
X-ray:
– Low lung volumes
– Diffuse atelectasis: “ground
glass opacities”
– Air bronchograms
– Difficult to distinguish from
pneumonia
emedicine.com
RDS: Typical Course
•
•
Prevention:
– Antenatal bethamethasone
– Arrest of preterm labor
Treatment
– Oxygen supplementation
– Assisted ventilation
• nCPAP
• mechanical ventilation
– FiO2 > .40
– Exogenous surfactant
replacement
– Fluid restriction
•
Outcome
– Peak severity 1-3 days
– Recovery coincides with
diuresis beginning at 72 hrs
– Severe cases evolve into
bronchopulmonary dysplasia
(chronic lung disease)
• Extreme prematurity
• Prolonged mechanical
ventilation
• Sepsis
Case #3
• 4.2-kg female infant is cyanotic and tachypneic at 30 minutes of age
following a vaginal delivery through meconium-stained amniotic fluid.
Apgar scores were 3 and 6. She had a spontaneous but weak cry at
birth and received some positive pressure ventilation followed by
suctioning.
• Vitals signs reveal a pulse of 169, respiratory rate of 115, and a mean
BP of 55. Sats are 76% despite 100% O2 by headbox. She is barrelchested, retracting, grunting, and has diminished coarse breath sounds
bilaterally.
• She is electively intubated, lines placed and labs sent.
Case # 3 Continued
• Lab:
– CBC: NL
– ABG: 7.19/72/36
• CXR:
•
Image: Aly H. Pediatrics in Review (2004)
Meconium Aspiration Syndrome (MAS)
• Meconium staining of amniotic fluid complicates nearly 15% of
all deliveries.
– Fetal distress
– Primarily term and post-term
• Meconium can be aspirated before, during or after delivery.
• Once aspirated, meconium causes
– Chemical pneumonitis
– Mechanical obstruction (“ball-valve”) with severe air-trapping
• Pneumothoraces (10-20%)
– Surfactant inactivation
– Severe hypoxemia and hypoventilation
• V/Q mismatch
Meconium Aspiration Syndrome: Clinical
Presentation
• Exam:
– Air trapping with barrel
chest
– Moderate to severe
respiratory distress
– Rales and/or rhonchi
– Hypoxia with cyanosis
– Hypoperfusion
• Lab:
– Acidosis
• Respiratory and
metabolic
• CXR:
– Hyperinflation/overdistensi
on
– Diffuse, patchy
intraparenchymal opacities
Meconium Aspiration Syndrome: Typical
Course
• Prevention?
– NRP
• Treatment:
– Oxygen
– Mechanical ventilation
• High-Frequency
– Jet
– Oscillator
– Surfactant replacement
• Complications
– Sepsis/pneumonia
– Airleaks
• Pneumothorax/pneum
opericardium
– Persistent pulmonary
hypertension (PPHN)
• Treated with inhaled
Nitric Oxide (iNO)
• ECMO
• Resolution
– Days to weeks
– Mortality 10-12%
Case #4
• 3.9-kg male infant develops
poor feeding, tachypnea and
mild oxygen need at 14 hrs of
life.
• Exam: equal and clear breath
sounds with tachypnea.
Otherwise unremarkable.
• Labs: WBC 4.3 x 103, ABG
NL, electrolytes and glucose
acceptable.
• CXR:
indyrad.iupi.edu
Congenital Pneumonia: Clinical
Presentation
• Most common neonatal infection
• Wide variety of presenting signs
– Varying degree of respiratory distress
– Lethargy, poor feeding
– Apnea
– Temperature instability
• High or low
• CXR: “Can look like anything!”
– Mild focal opacities
– Pleural effusion(s)
– Complete white-out
– Normal
Pneumonia: Epidemiology
• Hematogenous vs. aspiration acquisition
• Antenatal, perinatal, or postnatally acquired
• Common organisms:
– Antenatal: rubella, CMV, HSV, adenovirus,
Toxoplasma gondii, Treponema pallidum,
Mycobacterium tuberculosis, Listeria
monocytogenes, Varicella zoster and others
– Perinatal: GBS, E. coli, Klebsiella, Chlamydia
trachomatis
– Postnatal: adenovirus, RSV, Streptococcus,
Staphylococcus, gram negative enterics
Congenital Pneumonia: Typical Course
• Transient oxygen need
• Gradual resolution of tachypnea
• Antibiotic (ampicillin, gentamicin) therapy
5-7 days unless complicated by sepsis or for
specific organism requiring longer courses
of therapy
Other Pulmonary Causes of
Respiratory Distress
Other Pulmonary Causes of Respiratory
Distress
• Congenital
Diaphragmatic
Hernia
Other Pulmonary Causes of Respiratory
Distress
• Esophageal atresia
– Tracheoesophageal fistula
www.radiographics.rnsa.org
Other Pulmonary Causes of Respiratory
Distress
• Congenital
Cystic
Adenomatoid
Malformation
(CCAM)
• Pulmonary
sequestrations
www.medicine.cmu.ac.th
Other Pulmonary Causes of Respiratory
Distress
• Pneumothorax
Neopix (pedialink.org)
Non-Pulmonary Causes of Respiratory
Distress:
Congenital Heart Disease
Congenital Heart Disease
• Cyanotic
– Transposition of the great
arteries
– Total anomalous pulmonary
venous return
– Tricuspid atresia
– Tetralogy of Fallot
– Truncus arteriosus
– Pulmonary atresia
– Severe CHF
– Ebstein’s anomaly
– Double outlet right
ventricle
• Acyanotic
– Hypoplastic left heart syndrome
– Interrupted aortic arch
– Critical aortic stenosis
– Patent ductus arteriosus
– VSD/ASD
– AV canal defect
– Coarctation of the aorta*
– Valvular defects
* May present as cyanotic or acyanotic
Congenital Heart Disease
• Presenting features
– Murmur +/
– Tachypnea
– Cyanosis
– Active precordium
– Gallop rhythm
– Hypoperfusion
• Acidosis?
– Weak pulses
– Hepatomegaly
• CXR
– Heart size/shape
• Ebstein’s anomaly
• Tetralogy of Fallot
• CHF
– Abnormal lung
vascularity
• Increased
• Decreased
• Echocardiogram
• EKG
Differentiating CHD from Pulmonary
Disease
Aly H. Pediatrics in Review (2004)
Management of the Newborn
with Respiratory Distress
Initial Assessment: “ABCs”
• First:
– Airway
– Breathing
– Circulation
• Next:
– Stabilize
– Gather data
– Generate DDx
• Finally:
– Consult?
– Manage or
Transfer
Initial Assessment, continued
• Identify life-threatening
conditions that require
prompt support
– Inadequate or
obstructed airway
• Gasping
• Choking
• Stridor
– Inadequate
oxygenation
• Cyanosis
– Central vs. peripheral
– Inadequate ventilation
• Tachypnea
• Grunting
• Nasal flaring
• Retractions
– Inadequate perfusion
• Pallor
• Capillary refill
Clues from the History?
•
•
•
•
•
•
Prolonged maternal rupture of membranes?
Maternal GBS status?
Maternal fever?
Fetal distress?
Meconium?
Onset of respiratory distress?
– Immediate?
– Delayed?
Objective Data
• Physical exam findings:
– Breath sounds
– Stridor
– Severity
• Laboratory data:
– CBC w/ differential
– Glucose
– Blood gas
– Blood culture
– CXR
– Hyperoxia test?
Management
• Supplemental oxygen:
– Blow by
– Head box
– Nasal cannula
– Face mask
• Monitoring
– HR, RR
– Pulse ox
• How long?
– 2 hrs?
– 4 hrs?
– Longer?
• NPO
Hermansen CL, Lorah KN. American Family Physician. 2007.
Management
• Infants with TTN and no sepsis risk factors
likely just need support and observation.
• Infants with possible meconium aspiration,
RDS, sepsis or pneumonia require a sepsis
evaluation with blood culture, cbc and IV
antibiotics x 48hrs and repeat CXR(s).
• Unclear risk factors or presentation?
– Undertake sepsis evaluation
So when to transport?!
• It depends…
– Failure to resolve in 2-4 hrs
– Worsening condition
• Perfusion
• Oxygen needs
• Distress
– Staff ability/comfort/availability
• IV access
• Airway
– Any suspicion of cardiac disease
Take-Home Points
•
•
•
•
Respiratory distress is common!
Most do well with little intervention.
Short differential dx
When to transport is up to you!
– Every situation is unique
• Help is just a phone call away!
How to Arrange Transport?
•
•
Neonatologist on-call (In-house 24/7)
– St. Paul NICU:
• (800) 869-1350
• (651) 220-6210
– Minneapolis NICU:
• (800) 636-6283
• (612) 813-6295
Transport team
– Centralized Children’s Neonatal Transport Team in 2010
• Air
– Helicopter
– Fixed-wing plane
• Ground
References
•
•
•
Aly H. Respiratory disorders in the newborn: Identification and diagnosis.
Pediatrics in Review 2004;25:201-207.
Guglani L, Lakshminrusimha S, Ryan RM. Transient tachypnea of the
newborn. Pediatrics in Review 2008;29:e59-e65.
Hermansen CL, Lorah KN. Respiratory distress in the newborn. American
Family Physician 2007;76:98-994.
Additional suggested reading:
• Fidel-Rimon O, Shinwell ES. Respiratory distress in the term and near-term
infant. NeoReviews 2005;6:e289-e296.
Suggested resources:
• NRP Program, AAP/AHA
• S.T.A.B.L.E. Program
We’re online!
www.newbornmed.com
• Provider resources
• Family resources
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• Articles
• NICU profiles
Thank You!