NRP 2006: The Canadian Context Therapeutic Use of Oxygen In Newborn Resuscitation

1
NRP 2006 The Canadian ContextTherapeutic Use
of Oxygen(In Newborn Resuscitation)

• D.D. McMillan,MD
• November 17, 2006

2

• Half of what we know today
• will be shown not to be true
• within 10 years

3

• But which half!

4
New Equipment- NRP 2006

• Blended oxygen
• Pulse oximeter
• Ventilation with PEEP
• Laryngeal mask airway
• CO2 detector
• Servocontrol probe
• Plastic baggies

5
Methods for Blended Oxygen

• Blender
• Air and O2 flowmeters
• Air (L/Min) O2(L/Min) O2 Concentration()
• 5 0 21
• 4 1 37
• 3 2 53
• 2 3 68
• 1 4 84
• 0 5 100
  

6
Body Utilization of Oxygen

• Cytochrome oxidase producing energy (gt90)
• Oxidoreductases (eg. Xanthine oxidase)
• Incorporation into substrate (eg.Oxygenases)
• Non enzymatic (lt1)

7
Mediators Of Oxygen Toxicity
Richmond, 2006
8
Frank, 1980
9
Organ Site Of Free Oxygen Radical Damage

• Lungs
• Eyes
• Brain
• Gastrointestinal Tract
• Kidneys
• Other

10
Lambs Breathing 100 O2Bressack 1979
11
Lambs Breathing 100 O2Bressack 1979
12
AAP NRP Guidelines 2006Babies Born At Term

• Use 100 oxygen when a baby is cyanotic or when
  positive-pressure ventilation is required
• Research suggests that resuscitation with less
  than 100 may be just as successful.
• If resuscitation is started with less than 100
  oxygen, administer supplemental oxygen up to 100
  if there is no improvement within 90 seconds
  following birth.
• If supplemental oxygen is unavailable, use room
  air for positive-pressure ventilation.

13
AAP NRP Guidelines 2006Preterm Babies (lt32 Weeks
Gestation)

• Use an oxygen blender and pulse oximeter during
  resuscitation.
• Begin PPV with oxygen concentration between room
  air and 100 oxygen. No studies justify starting
  at any particular concentration.
• Adjust oxygen concentration to achieve an
  oxyhemoglobin saturation that gradually increases
  toward 90. Decrease the oxygen concentration as
  saturations rise over 90.
• If heart rate does not respond to gt100 bpm,
  correct ventilation problems use 100 oxygen.

14

• What is the Evidence to Support
• Room Air over 100 Oxygen
• for Newborn Resuscitation?

15
Treatment Allocation Follow Up
Ramji, 1993
16
Neonates With Abnormal Neurologic Examination
During The First Week
Ramji, 1993
17
Saugstad, 1998
18
Kaplan-Meier plot showing the proportion that had
not taken the first breath in room air- and
oxygen-resuscitated newborn infants. Time to
first breath was significantly longer in the
oxygen-resuscitated group compared with the room
air-resuscitated group. In the oxygen group,
60/313 (19.2) required gt3 minutes to take the
first breath compared with 28/284 (9.9) in the
room air group (OR 0.47 95 CI 0.29-0.76).
Saugstad, 1998
19
Mortality with Oxygen or Air for Resuscitation-
Saugstad, 2005
20
Mortality with Oxygen or Air for Resuscitation-
Saugstad 2005
21
Room Air Versus 100 OxygenDeath At Latest
Follow Up
Tan, 2006
22
Room Air Versus 100 OxygenH.I.E. Grade 2 or 3
Tan, 2006
23
Tan 2006- Room Air Versus 100 OxygenFirst
Arterial Blood Gas Within 2hours After Birth
24
Tan 2006Room Air Versus 100 OxygenFirst
Arterial Blood Gas Within 2hours After Birth
25
Problems with studies

• Limited number of studies/babies
• Majority in developing countries
• High mortality rates
• Variable/imprecise criteria for resuscitation
• Failure to blind
• Design to show equivalence

26
Possible Mechanisms of Effects

• Oxygen free radical damage
• Upregulation of NO in PMNS (peroxynitrites)
• Activation of inflammatory mediators
• Oxidation of DNA phenylalanine
• Decreased cerebral blood flow
• Increased oxygen consumption
• Increase in intracellular calcium
• Upregulation of pro-aptoptotic pathways
• Increased apoptosis neural stem cells

27
Brain Injury and Oxygen Exposure First 8 Days
After Birth
Collins Ped Res, 2001
28
Is there Opposing Evidence?

• No human studies
• Newborn piglets resuscitated with air (Solas)
• - Increased CNS amino acids (eg.glutamate)
• - Increased oxygen delivery to brain
• (No change in glutamate)
• - Lower mean BP CNS microcirculation
• (No change in CNS amino acids)
• Others show no difference in animal studies

29
Rabi, 2006
30
Rabi, 2006
31
Oxygen Saturation After Birth
32

• Does it have to be all or none?
• Can we titrate oxygen to meet the needs of the
  newborn baby?

33
Smoothed Frequency Distribution of Actual
Oxygen-Saturation Values on Pulse Oximetry During
Oxygen Therapy After Randomization
Askie, 2003
34
(No Transcript)
35
Canadian Recommendations For Oxygen During
Resuscitation

• Positive-pressure ventilation should be initiated
  with air (21 oxygen).
• Supplemental oxygen should be used if the baby
  remains cyanotic or heart rate is less than 100
  bpm at 90 seconds.
• Blended gases should be available in the delivery
  room and during transport to the NICU.
• To avoid hyperoxemia, pulse oximetry should be
  available in rooms for delivery of babies lt33
  weeks gestation. Even without clear definition
  of hyperoxia for preterm infants, avoid
  saturations above 95 when supplemental oxygen is
  used.

36
Where are we Now?Survey of U.S. Deliveries
(Leone 2006)

• 52 Pulse oximeters
• 42 Blenders
• -77 Oxygen to start
• -68 Use pulse oximeters to adjust
• 76 PEEP for preterms
• (58 flow-inf, 19 self-inf, 16 T-piece)

37
Thankyou