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NEONATOLOGY. Introduction. Newborn: A recently born infant in the first few hours of life Neonate: Refers to infants in the first 28 days of life. Physiological Adaptations at Birth. Three major physiological adaptations necessary for survival
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Introduction • Newborn: • A recently born infant in the first few hours of life • Neonate: • Refers to infants in the first 28 days of life
Physiological Adaptations at Birth • Three major physiological adaptations necessary for survival • Emptying fluids from their lungs and beginning ventilation • Changing their circulatory pattern • Maintaining body temperature
Chest • As the lungs are cleared of amniotic fluid and the fetus passes through the pelvis • The chest wall recoils and the newborn takes it’s first breath, stimulated by • Mild acidosis • Initiation of the stretch reflexes in the lungs • Hypoxia • Hypothermia
As the lungs expand, resistance in the pulmonary vessels decreases and blood flow to the capillary beds increases The pulmonary vessels which were collapsed intrauterine, now dilate The Ductus Arteriosus immediately closes Circulatory System
Circulatory System • The Foramen Ovale begins to close • The pressure changes in the lungs begins the diffusion of oxygen • When the cord is cut, the circulatory system must become an independently functioning unit
Apnea • Primary apnea • A self-limited condition (controlled by PCO2 levels) • Common immediately after birth • Secondary apnea • Respirations absent and do not begin again spontaneously
Causes of Hypoxia • Compression of the cord • Difficult labor and delivery • Maternal hemorrhage • Airway obstruction • Hypothermia • Newborn blood loss • Immature lungs (premature)
Airway and ventilation: Stimulation Ventilate with BVM Suction Intubation Management • Circulation • Heart rate • Circulatory access • Pharmacological • Narcan (~ 4 hours prior) • No narcotic antagonist, if mother drug abuser • Dextrose 10%
Preparation for Delivery • Effective triage • Preparation • Prior • Resuscitation • Postresuscitation
Risk Factors • The incidence of complications increases as birth weight decreases • Causes of low birth weight include: • Premature births • Undernourishment in the uterus • Maternal factors
Multiple gestation Inadequate prenatal care Mother’s age (<16 or >35) Hx of perinatal morbidity/mortality Post-term gestation Drugs/medications Toxemia, hypertension and/or diabetes Antepartum Risks
Premature labor Meconium-stained amniotic fluid Rupture of membranes >24 hours Use of narcotics ~4 hours Abnormal presentation Prolonged labor or precipitous delivery Prolapsed cord Bleeding Intrapartum Risks
Resuscitation Oriented History • Multiple pregnancy • Meconium • Prematurity • Maternal narcotic use
Assessment and Management • Initial steps should include : • Prevent heat loss • Clear the airway • Provide tactile stimulation • Evaluate the infant Figure 41-1
Prevention of Heat Loss • Immediately after delivery • Dry the infant's head and body • Remove any wet coverings from the infant • Cover with dry wrappings • Cover the newborn's head • Accounts for 20% of the newborn’s BSA
Hypothermia • Great risk of hypothermia in the newborn • Large body surface area • Decreased tissue insulation • Immature temperature regulatory mechanisms
Hypothermia • Neonate attempts to conserve body temp by vasoconstricting and increasing metabolism, which places them at risk for • Hypoxemia • Acidosis • Bradycardia • Hypoglycemia
Open Airway • Open airway by: • Correct positioning • Suction the mouth then nose • Avoid deep or vigorous suctioning that can stimulate a vagal response
Suction Equipment • Bulb suction • Suction catheters • Meconium aspirator
Suctioning • Monitor newborn’s heart rate during suctioning • Allow time for spontaneous ventilation during suctioning
Provision of Tactile Stimulation • If drying and suctioning do not induce respirations, provide additional tactile stimulation • Slapping or flicking the soles of the feet • Rubbing the infant's back
Assessment • Drying, positioning, suctioning and stimulation are necessary in every newborn • The next step depends on the newborns • Respiratory effort • Heart rate • Color
Respiratory Effort • Observe and evaluate the newborn’s respirations: • Normal crying • Inadequate or gasping is present • Slow or shallow rate • No response after 5 - 10 secs of stimulation
Ventilation • If remains apneic after a brief period (5 to 10 seconds) of stimulation: • Immediately initiate positive-pressure ventilation with a pediatric BVM device and supplemental oxygen (40 to 60 ventilations/min)
Heart Rate • Evaluate with a stethoscope or by palpating the umbilical cord or brachial artery: • Above 100 bpm, continue eval • Less than 100 bpm, BVM for 30 sec, re-eval • Less than 60 to 80 bpm, despite BVM, chest compressions • Does not respond to ventilation and compressions, Epi
Color • Assess the newborn’s color from central to the extremities: • Pink throughout • Peripheral cyanosis (acrocyanosis) • Central cyanosis
Supplemental Oxygen • Free-flow oxygen can be given through: • A face mask and flow-inflating bag • An oxygen mask • Blow-by free flow at 5 L/min • Maximum oxygen conc can be achieved when tube is held half inch from the nose
Routes of Drug Administration • Drugs rarely indicated • heart rate remains < 60 bpm despite adequate ventilation with 100% oxygen and chest compressions • Routes • tracheal route generally most rapidly accessible route • umbilical vein most rapidly accessible venous route • peripheral sites (scalp or peripheral vein) may be adequate but more difficult to cannulate • intraosseous (IO) route
Umbilical Vein Cannulation • Identify umbilical vein after trimming cord • Insert umbilical catheter or angiocath into vein • Secure base of cord to hold catheter in place and stabilize catheter with tape Figure 41-5
Drugs Used in Neonatal Resuscitation • Medications most frequently used during neonatal resuscitation • Epinephrine • Volume expanders • Naloxone
Premature Infant • Refers to a baby born before 37 weeks • Premature infants have an increased risk for: • Respiratory depression • Hypothermia • Head and brain injury
Premature Infant • Premature infant characteristics: • Large trunk • Short extremities • Translucent skin • Birth weight between 0.6 to 2.2 kg • Resuscitation should be attempted with any signs of life
Meconium Staining • Presence of fetal stool in amniotic fluid • Associated with • Increased perinatal mortality • Hypoxemia • Aspiration pneumonia • Pneumothorax • Pulmonary hypertension
Meconium Staining • Staining can range from: • Slight yellow or light green, to • Thick “pea-soup” appearance
Meconium Staining • Thick meconium leads to aspiration of particulate matter, leading to: • Atelectasis • Development of pneumothorax • Death
Meconium Staining • After meconium is observed in amniotic fluid, intervention is aimed at preventing or minimizing the risk of aspiration • Emergency care begins with preparation of necessary equipment
Intubation equipment Meconium aspirator Bulb syringe or DeLee suction 10 French or larger suction catheter Portable suction and irrigation solution Gauze pads BVM device Equipment
Meconium Staining • After delivery is complete, clear the infants airway • Suction the mouth, pharynx and nares • Routine suctioning is no longer recommended on the perineum
Meconium Staining • If the neonate is depressed perform direct endotracheal suctioning using the ET tube as a suction catheter • Provide blow-by oxygen and monitor fetal heart rate for bradycardia
Meconium Staining • Repeat the intubation-suctioning-extubation cycle • until no further meconium is obtained or bradycardia develops • Do not ventilate between intubations • After tracheal suctioning, continue resuscitation measures as needed
Blood glucose < 40 mg/dL May be due to: Inadequate glucose stores Increased utilization of glucose Persistent low blood glucose levels may have catastrophic effects on the brain Hypoglycemia
Risk Factors • Asphyxia • Toxemia • Smaller twin • CNS hemorrhage • Sepsis
Twitching or seizure Limpness Lethargy Eye-rolling High pitched crying Apnea Irregular respirations Possible cyanosis Assessment Findings
Management • ABC’s • Maintain body heat • Rapid transport • IV/IO D10 and repeat glucose checks