better guidelines better outcomes neonatal resuscitation Anne G. Wlodaver, MD neonatology OU medical center the birth experience a challenging transition birth requires major and sudden transitions some babies get in trouble making the transition we help them with neonatal resuscitation guidelines define best practices you should implement best practices because best practices create better outcomes we are here to help you the mysterious tree of the fetal life birth: a transition the fountains of life: placenta @birth a sudden and massive transition major lung changes major circulatory system changes temperature regulation changes 1
circulatory transition 3. closure of ductus arteriosus 2. closure of foramen ovale 1. cutting umbilical cord delayed cord clamping the transition ductus arteriosus intra-uterine life depends on placenta O 2 from from the mother s blood lungs are fluid-filled blood flow to lungs is low intracardiac and extracardiac shunts extra-uterine life depends on lungs O 2 from the air filling up the lungs lungs are air-filled blood flow to lungs increases dramatically shunts reverse direction and then close cardiac adaptation: closed ductus the lung transition air flow loss of fetal lung fluid establishment of functional residual capacity secretion of surfactant blood flow decrease of vascular resistance in lungs increased systemic blood pressure functional closure of shunts large increase in pulmonary blood flow 2
building FRC where there was fluid FLUID ventilation in utero after birth building FRC getting in trouble who needs resuscitation? some need help 90% 10% any newborn too depressed to initiate the first breath drying & warming neonatal resuscitation 3
some need more help anticipate need for resuscitation 90% 10% is the birth at term? is the amniotic fluid clear? is the baby breathing or crying? is there good muscle tone? 1-2 % extensive measures drying & warming neonatal resuscitation questions to ask gestational age what is the expected gestational age? is the amniotic fluid clear? how many babies are expected? are there any additional risk factors? has a big influence on lung physiology in premies low surfactant makes lungs stiffer and harder to inflate in postdates meconium aspiration can lead to airway obstruction the very low birth weight time to first breath 1.5% of live births in US require careful delivery room management 10 15 seconds 77% admitted to NICUs high mortality rate Saugstad OD: resuscitation of asphyxiated NB with RA vs oxygen: an international controlled trial. Pediatrics 102:1,1998 4
time to first cry apnea at birth 30s 72s room air 102s 100% O 2 Vento M: Pediatrics 107:642,2001 stimulation will be sufficient to make a baby breathe after primary apnea decreased HR, preserved BP ventilation will be needed if baby is in secondary apnea decreased HR, low BP since you don t have time and cannot tell the difference at time of birth, ventilation may have to be initiated right away (within 60 sec) ventilation adequately ventilated, the heart will be oxygenated enough to beat cardiac compression in an inadequately ventilated newborn is futile ventilation is the main goal of newborn resuscitation focus on ventilation 1v = a + b optimize oxygen 2 let s talk about oxygen where does the fetus get his O 2? what is the pressure of O 2 in mom s placental blood? where does the newborn get his O 2? what is the pressure of O 2 in room air? 5
placental blood oxyhemoglobin dissociation curve oxygen 21% po2=160 mm Hg argon 1% nitrogen 78% 593 mm Hg room air atmospheric pressure at sea level is 760 mmhg partial pressure of oxygen in the air we breathe is therefore 0.21 x 760 = 160 mm Hg oxygen cascade from the atmosphere to the mitochondria of cells at sea level: 760 mm Hg x 0.21 (FiO₂) 160 mm Hg Diluted by water vapor: (760 47) x 0.21 = 149 mm Hg in alveoli diluted with CO₂: 149 40/0.8 (RQ) = 100 mm Hg from alveoli to arteries, gradient of 5 to 10 mm Hg (diffusion gradient, physiologic shunt) in the veins: po₂ about 45 mm Hg mitochondria: 3 to 4 mm Hg where O₂ is used for the Krebs cycle to produce energy for the cell s life coronary & carotid arteries 3 leads ECG auscultation and palpation not as accurate the oximeter takes at least 2 minutes to get a pulse but will give a saturation 3 leads ECG obtains a HR within 1 minute but will not give the oxygen saturation 6
200 neonatal arterial po 2 over time (min after birth) 180 160 140 po 2 of room air at sea level 120 po 2 100 po2 80 60 40 50 63 73 80 Log. (po2) 20 27 umbilical vein 0 1 10 100 1000 10000 minutes post birth (logarithmic scale) mean normal arterial bl gas values oxygen saturations 10 min 1 hr 1 day 1 week ph 7.207 7.332 7.369 7.371 pco2 46.1 36.1 33.4 35.9 po2 49.6 63.3 72.7 80.3 Bicarb 16.7 19.2 20.2 21.8 In the fetus: max 60% After delivery one minute: 60% 3 minutes: 70% 5 minutes: 80% 10 minutes: 90% temperature control plastic wrap 3 7
functional residual capacity first breaths 4 transition from liquid to air-filled lungs release surfactant create lung volume with air (FRC) increase pulmonary blood flow establish respiration and effective gas exchange improve and maintain heart rate T-piece resuscitation 5 bag valve mask (bvm) valve between mask and bag can provide positive pressure ventilation (PPV) a pressure relief valve prevents overinflation of the lungs face masks flow-inflating bag needs a source of gas to inflate prolonged inflation can be provided can provide PEEP (but inconsistent) danger to give too high a volume 8
T-piece devices gas flows through a T-piece can give PPV and be adjusted to a set PIP and PEEP good device to give PEEP to a breathing infant Neo-Tee is disposable, easily transported Neopuff is bigger and more cumbersome MR SOPA 9