Neonatal Resuscitation Truth and Consequences

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Neonatal ResuscitationTruth and Consequences

• Anjali Prasad Parish, MD
• Alaska Neonatology Associates, Inc.
• An affiliate of Pediatrix, Inc.

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Objectives

• Review evidence behind recommendations of NRP and
  need for revisions
• Specific issues not addressed by NRP
• Refresher of simple clues as to why an infant may
  not be responding to your treatment

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Opening Pressure

• Studies done in 1950s and 60s using isolated
  lung preparations from stillborn infants
• Demonstrated an opening pressure which has to
  be exceeded in order to expand the lung

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The collapsed lung of the newborn infant is a
solid structure . . .that when it expands it does
so not as in a balloon, but . . . like a ladys
fan. Dr. P. N. Coryllos Am. J Obst. And Gyn.,
1931
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Normal Onset of Respiration

• Reported in Acta Paediatrica in1962 study done
  in Stockholm, Sweden
• Made 79 attempts to record first breath taken by
  normal, vaginally delivered term infants 18
  successful and reported
• Placed a facemask and intraesophageal catheter on
  infants immediately after delivery and before the
  cord was clamped

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Normal Onset of Respiration

• Recorded negative inspiratory pressures as little
  as -5 to as much as -70 cm H2O
• Demonstrated establishment of residual volume
  in only 7 infants after first breath unable to
  demonstrate development of FRC with successive
  breaths

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Pressures of First Breath
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Opening Pressure for NRP

• Initial 1-2 breaths delivered should have Pip of
  30 cm H2O pressure then Pip should be readjusted
  to least amount necessary to see visible chest
  rise
• Same for term and preterm infants

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Expansion vs Rupture Pressure

• Published in 1965 in Lancet
• Lungs from newly born and stillborn infants were
  excised post mortem
• Suspended over a water bath and inflated with
  fixed increments of air volume until the lung
  ruptured
• Rupture was determined when extravasated air was
  seen under the pleura, bubbling seen from hilum,
  or slow fall in pressure

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Filling vs Rupture Pressure
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Inactivation of Surfactant?

• Observation that prophylactic surfactant therapay
  has not yielded better results than rescue
  therapy
• Even if immediately intubated, infants receiving
  prophylactic surfactant receive manual
  ventilation prior to its administration

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Researchers Hypothesize

• Does ventilation-induced lung damage occur within
  seconds?
• Had damage already been done before surfactant
  was given?
• Fetal lamb studies are shedding new light on
  these questions

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Just a Few Large Breaths

• Researchers in Sweden Pediatric Research, 1997
• Series of 5 two-lamb siblings were randomized
  within each pair either to receive or not receive
  6 large breaths at birth all lambs then received
  cautious ventilation surfactant was given at 30
  minutes of age
• 3 different lambs were given surfactant prior to
  first breath

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Results

• A few large breaths inhibited effect of
  surfactant on lung mechanics
• Lambs which received surfactant before the first
  breath received the most benefit from surfactant

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Surfactant After Breaths
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Surfactant Before Breaths
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Manual Ventilation

• Even with manometers, neonatal resuscitation bags
  provide varying pressures/volumes with every
  delivered breath
• These variations differ between types of
  providers as well

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Comparison Trial

• Dr. Neil Finer and colleagues Resuscitation, 49
  (3) (2001) p. 299-305
• Compared flow-inflating bag, self-inflating bag,
  and Neopuff Infant Resuscitator
• Used infant mannikin and compared accuracy of
  neonatal nurses, NNPs, neos, residents, and
  RTs using all 3 devices to deliver target PIP
  and PEEP

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Results

• Anesthesia Bags RTs performed the best only
  RTs could consistently deliver PEEP
• Using Neopuff, all groups could consistently
  delivery PIP and PEEP
• Significant difference between pressure at 1st
  and 5th second during prolonged 5-s inflations
  using anesthesia bags vs. Neopuff (median
  difference of 7.1 cmH20 using bags vs. 0.2 using
  Neopuff, plt0.001)

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Neopuff Infant Resuscitator

• Made by Fisher and Paykel Healthcare
• Pneumatically powered
• Fingertip breath-by-breath resuscitation using
  either ETT or mask
• Adjustable PIP and PEEP with max PIP protection
• Disposable, single-use T-piece for each pt

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Neopuff
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Use of Oxygen

• NRP recommends use of 100 oxygen
• Accepted standard of care no evidence based on
  trials
• Due to concerns for oxygen toxicity, attention
  has turned to room air resuscitation

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The Resair 2 Study

• Trial conducted in developing countries
• Consent obtained after resuscitation based on
  principles from FDAs clinical research on
  emergency care without the consent of subjects
• Abstract published in Pediatrics, 1998

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The Resair 2 Study

• Unblinded study asphyxiated infants with BWgt999
  grams randomized based on birthdate even date
  resuscitated with room air, odd with 100 O2
• 609 infants from 10 centers (288 received RA, 321
  received O2)

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Results

• No differences in heart rate in first 90 seconds
  of life however, 25.7 resuscitation failures
  in RA group switched to 100 O2 after 90 seconds
  but also 29.8 failures in O2 group (failure
  defined as bradycardia and/or central cyanosis
  after 90 seconds)
• Time to first cry or first breath was
  significantly shorter in room air group (by 24
  seconds)

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Conclusions of Resair 2 Trial

• Asphyxiated newborns can be effectively
  resuscitated with room air
• Does resuscitation with 100 O2 depress
  ventilatory drive?
• More studies needed

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Apgar Scoring

• Not included in the NRP program
• Created by Virginia Apgar
• Based on term infants only
• Original intent was as a practical method of
  evaluation of the condition of the newborn
  infant at one minute of life
• Original paper focused on how different types of
  delivery and anesthesia affected the infant at
  one minute

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Method of Apgar Scoring
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Factors Which May Affect Apgar Scores

• Gestational Age
• Maternal Medications
• Prenatal Insults
• Resuscitation
• Type of Delivery

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Effect of Gestational Age
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Who Should Assign an Apgar Score?

• Anyone not performing the resuscitation
• Scores should be assigned at selected intervals
• Retrospectively assigning scores defeats the
  purpose

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Using Apgar Scores to Predict Development of CP

• National Institute of Neurological and
  Communicative Disorders and Stroke
• 49,000 infants born between 1959-1966 were
  examined at birth 31,000 followed to 7 years of
  age
• Apgar score of lt or equal to 3 at 1 minute may be
  a risk factor for cerebral palsy
• Very low late Apgar score was correlated with
  increase incidence of cerebral palsy

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Apgar Scores and CP
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Percent CP vs Late Apgar Score
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Apgar Scores and CP

• 80 of children with Apgar scores of 0-3 at 10
  minutes were free of major handicap at early
  school age
• 55 of children with CP had Apgar scores of 7-10
  at 1 minute of age
• 73 of children with CP had Apgar scores of 7-10
  at 5 minutes of age

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Endotracheal Intubation

• Initial placement should be to centimeter mark of
  6 weight in kilograms
• Want the tip of tube to be 0.5-1.0 cm above the
  carina
• Head position can affect position of the tip
• Breath sounds easily transmitted throughout the
  chest, so CXRay best confirmation

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Signs of Misplaced ETT

• Stomach getting larger with ventilation
• Louder breath sounds in stomach--sounds can
  transmit from the stomach to the lungs
• Large airleak when initial tube size selected
  appropriately
• Decreased breath sounds on left side
• Pts heart rate and color not improving

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Case Number 1

• Pt transferred from an outside NICU for
  respiratory decompensation and possible need for
  ECMO
• Had been tried on multiple ventilators, including
  HFOV
• Could not reduce PCO2 to less than 60
• On arrival to was noted to have a large airleak
  around the ETT

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CXRay
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Case 2

• Infant intubated for grunting and retracting
• Breath sounds heard equally throughout chest and
  over stomach
• Equal chest rise
• Large stomach despite previous decompression with
  OG tube
• Infants heart rate 100 bpm and baby dusky pink
  color

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CXRay
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In Summary

• Neonatal resuscitation is clearly evolving
• Current recommendations are for term infants and
  original data did not include preterm infants
• Trials are needed but somewhat difficult since no
  gold standard exists for premature infants
• Apgar Scoring not included in NRP because it was
  created to compare infants, not govern their
  resuscitation