The Newborn Infant

Chap 16. The Newborn Infant



99. 5. 10.

1st year resident, Lee Sun Joo




I. Adaptation of the Newborn to Air Breathing


1. The 1st breath of air
  • the fluid-filled alveoli of the lungs must fill with air.
  • the air must be exchanged by appropriate respiratory motion.
  • a vigorous microcirculation must be established.



2. Initiation of air breathing
  • very soon after birth -> shift to regular deeper inhalations.
  • aeration of the newborn lung is the rapid replacement of bronchial & alveolar fluid by air.
  • delay in the removal of fluid -> contributes to syndrome of transient tachypnea of the newborn.
  • as fluid is replaced by air, there is considerable reduction in pulmonary vascular compression.
  • from the 1st breath after birth, progressively lower pulmonary opening pressure is required.


3. Alveolar surface tension & Lung surfactant
  • prevents the collapse of the lung with each expiration.




4. The stimuli to breath air

1) physical stimulation - such as handling the infant during delivery

2) compression of the thorax during the 2nd stage -> forces some fluid from the respiratory tract

3) deprivation of O2 & accumulation of CO2 may stimulate respiration.



5. Management of delivery

1) immediate care

  • the face is immediately wiped & the mouth and nares are suctioned.
  • before clamping & severing the cord -> aspirate the mouth & pharynx again.
  • the infant is placed supine with the head lowered & turned to the side.
  • to minimize heat loss, the baby is wiped dry.

2) evaluation of the infant

  • health status of the mother.
  • prenatal complications.
  • labor complications.
  • gestational age.
  • duration of labor.
  • duration of ruptured membranes.
  • kinds, amounts, times, and routes of administration of medications.
  • kind & duration of anesthesia.
  • any difficulty with delivery.

3) Lack of effective respirations.

  • fetal hypoxemia or acidosis from any cause.
  • drug administered to the mother.
  • gross fetal immaturity.
  • upper airway obstruction.
  • pneumothorax.
  • other lung abnormalities.
  • aspiration of Amnionic Fluid grossly contaminated with mecomium.
  • CNS developmental abnormality.
  • septicemia.





II. Methods used to evaluate newborn condition


1. Apgar Score


table 16-1. Apgar Scoring System










Sign 0 1 2
Heart rate Absent Below 100 Over 100
Respiratory effort Absent Slow, irregular Good, crying
Muscle tone Flaccid Some flexion of extremities Active motion
Reflex irritability No response Grimace Vigorous cry
Color Blue, pale Body pink, extremities blue Completely pink



  • the 1-minute Apgar Score determines the need for immediate resuscitation.

    Apgar Scores : 7 ~ 10 -> require no aid

                                4 ~ 6 -> good.

                                0 ~ 3 -> will usually have slow to inaudible heart rates & reflex responses depressed

                                              or absent resuscitation should be start immediately.



  • Use and misuse of the Apgar Score

    1) Factors that may affect Apgar Scores

    • Tone, color, reflex irritability -> dependent on the physiologic maturity of the infant.

    • Maternal sedation or analgesia may decrease tone & responsiveness.

    • Neurologic conditions may decrease tone & interfere with respiration.

    • Cardiorespiratory conditions may interfere with heart rate, respiration, & tone.

    2) Apgar Score & subsequent disability

    • the 1-minute Apgar Score may be used to indicate the infant who requires special attention(does not correlate with future outcome).
    • the 5-minute Apgar Score is a useful index of the effectiveness of resuscitation efforts.
    • an Apgar Score of 0 to 3 of 5 minutes is associated with an increased risk of cerebral palsy(0.3% -> 1%).
      -> a low 5 minutes Apgar Score alone does not prove that later CP was caused by perinatal asphyxia.

    3) Later Scores.

    • Criteria for cerebral hypoxia leading to CP.

      ① profound metabolic or mixed acidemia (pH < 7.0) on an umbilical cord arterial sample.

      ② Apgar Score of 0 to 3 for longer than 5 minutes

      ③ Neonatal neurologic manifestations.

      ④ multisystem organ dysfunction.

    • low Apgar Score, the presence of umbilical cord acidemia in the absence of maternal acidemia, large base deficit, and nucleated erythrocytes in the peripheral blood. -> provide supporting evidence of asphyxia.



2. Umbilical cord blood Acid-Base Studies.

  : are useful in examining the metabolic status of the fetus in the minutes & hours prior to birth.

  • the lower limits of normal pH in the newborn 7.04 to 7.10.



    1) Effects of Gestational Age on Apgar Score & pH

  • a most important factor influencing the Apgar Score is gestational age.
  • Apgar Score of 7 in a preterm neonate may represent the upper normal value.
  • umbilical cord gas indices may be of more value than Apgar Scores in preterm infants.
  • a large base deficit and a low HCO3 ( < 12 mEq/L ) associated with mixed respiratory-metabolic acidemia is more after associated with a depressed neonate.


3. Clinical Dx of Asphyxia.

  • severe metabolic acidosis is poorly predictive of subsequent neurological impairment in the term infant.
  • in very low-birthweight infants(<1000g) newborn acid-base status may be more closely linked to long-term neurological outcome.
  • transient umbilical cord compression is the most common antecident factor in the development of fetal respiratory acidosis.
  • to cause hypoxic ischemic encephalopathy.

    ① umbilical artery metabolic or mixed respiratory, metabolic acidemia with pH < 7.00.

    ② a persistent Apgar Score of 0 to 3 for more than 5-minutes.

    ③ neonatal neurologic sequelae.

    ④ multiorgan system dysfunction.


4. Recommendations for blood gas determinations.
  • cord blood gas & pH analyses should be used in select neonates with low Apgar Scores to distinguish metabolic acidemia from hypoxia or other causes that might result in a low Apgar Score.

    III. Active Resuscitation.


    fig. 16-2






    • initial O2 deprivation -> transient period of rapid breathing -> primary apnea(a fall in heart rate & loss of neuromuscular tone) -> deep gasping respirations -> secondary apnea -> unless ventilation is assisted, death will occur.
    • unnecessary or overvigorous suctioning of mouth, nares, & trachea can result in significant vagal stimulation & reflex slowing of the heart rate.



    1. resuscitation protocol
    • prevent heart loss - warmer, dry off.
    • open the airway - suctioning.
    • evaluation the infant -observe for respirations, heart rate, & color.
    • respiratory effort
      • if absent, positive pressure ventilation is carrid out.
      • if present, heart rate is evaluated.

    • heart rate
      • < 100 beats/min -> PPV is instituted.
      • > 100 beats/min -> infant color is evaluated next.


    • color
      • if the infant exhibits central cyanosis, free flowing O2 is provided at concentrations of 80 to 100 %.


    • heart rate : evaluated after 15 to 30 sec of PPV.
      • > 100 -> evaluate color.
      • 60 < <100 & increasing -> ventilation is continued.
      • < 60, or below 80 & not increasing -> ventilation is continued & compressions are begun.

    • chest compressions
      • at a rate of 2-sec with a 1/2-sec pause every 3rd compression for ventilation.
      • compression is stopped every 30 sec for 6 sec while the heart rate is checked.


    • chemical resuscitation - epinephrine, volume expansion, naloxone
      • epinephrine 1:10000 -> IV or via the tracheal tube.
      • volume expansion -> 10ml/kg whole blood, 5% albumin, normal saline, Ringer lactate.
      • sodium bicarbonate 4.2% solution.


    • tracheal intubation
      • when prolonged PPV is required.
      • when bag & mask ventilation is ineffective.
      • when tracheal suctioning is required.
      • when diaphragmatic hernia is suspected.




    2. Technique of intubation
    • should delivery puffs of O2-rich air into the tube at 1- to 2-sec intervals with a force adequate to lift the chest wall gently.
    • pressures of 25 to 35 cmH2O are desired to expand the alveoli.



    3. Common Errors in resuscitation of the Newborn

    • failure to check resuscitation equipment before-hand.
    • use of a cold resuscitation table.
    • unsuccessful intubation.
    • inadequate ventilation.
    • failure to detect & determine cause of poor chest movement or persistent bradycardia.
    • failure to detect & treat hypovolemia.
    • failure to perform cardiac massage.




    IV. Routine Newborn Care



    1. Estimation of Gestational Age

      1) sole creases

      2) breast nodules

      3) scalp hair

      4) ear lobes

      5) for males, testes & scrotum


    • A more definitive estimate can be made in a few days with the help of neurological examination.



    2. Care of the eyes


    1) Gonococcal Ophthalmia Neonatorum

    • 1% silver nitrate solution.
    • penicillin ointment in the strength of 100000 U/g
    • tetracycline ophthalmic ointment(1%)
    • EM ointment(0.5%)
    • povidone-iodine solution(2.5%)
    • PPNG: cefotaxime 100mg/kg as a single IM injection.

                    ceftriaxone 125mg/kg as a single IM injection.

    2) Chlamydial Conjunctivitis / Ophthalmia Neonatorum

    • TC & EM ophthalmic ointments.
    • 2.5% povidone-iodine solution.
    • Azthromycin : effective in treating genital & ocular chlamydia trachomatis in adults using a aingle 1-g oral dose.
    • Prophylactic treatment of the pregnant woman prior to delivery and/or the prophylactic treatment of her infant.

    3) Other causes of Neonatal Conjunctivitises.

    • S. aureus, S. pneumoniae, Neisseria meningitidis, P. aeruginosa, H. influenzae,

      E. coli and other coliform herpesviruses.


    3. Permanent Infant Identification
    • mother & infant should not be separated until identification is complete.
    • most hospitals today use footprints.



    4. Subsequent Care

    1) Temperature

    • drops rapidly immediately after birth.
    • must be cared for in a warm crib.


    2) Vitamin K : routine ad.

    3) Hepatitis B immunization

    • routine immunization of all newborns should be initiated prior to hospital discharge.
    • if the mother is HBsAg positive, the neonate should be passively immunized.

    4) Umbilical cord

    • within 24 hours it loses its characteristic bluish white, moist appearance & soon becomes dry & black.
    • separation : within the 1st 2-weeks.
    • strict aseptic precautions.
    • most apply triple dye or bacitracin ointment.
    • povidone-iodine applied daily was effective & acceptable.

    5) Skin care

    • should be promptly dried.
    • excess vernix, blood & meconium is gently wiped off.

    6) Stools and urine

    • meconium : for the 1st 2 or 3 days after birth.

                          90 % - within 24 hours.

                          the rest - within 36 hours.

    • voiding : usually occuring shortly after birth.
    • after the 3rd or 4th day, meconium is replaced by light yellow homogeneous feces with a characteristic odor.

    7) Icterus Neonatorum

    • 2nd & 5th day of life -> physiological jaundice of the newborn.
    • 3rd & 4th day : bilirubin -> more than 5mg/dl.

                                                  free or unconjugated bilirubin.
    • immaturity of the hepatic cells.
    • reabsorption of free bilirubin as the consequence of the enzymatic splitting of bilirubin glucuronide by intestinal conjugase activity in the newborn intestine.
    • in preterm infants, jaundice is more common & usually more severe & prolonged.


    8) Initial weight loss

    • for the 1st 3 or 4 days of life, infants lose weight.
    • preterm infants -> lose more weight

                                      regain more slowly
    • if, nourished properly, birth weight is regained by the end of the 10th day.
    • increases about 25g/day for the 1st few months.

    9) Feeding

    • regular nursing within the 1st 12 hours postpartum.
    • most term infants -> fed at intervals of about 4 hours.
    • preterm or growth retarded infants -> shorter intervals.
    • to remain at the breast for 10 minutes at first.

    10) Circumcision

    • routine circumcision of newborn males not be performed.

    11) Rooming-in

    • by the end of 24 hours, the mother is generally fully ambulatory : thereafter, with rooming-in.

    12) Hospital Discharge

    • newborn infant is discharged with its mother, maternal stay has determined that of the child.
    • potential social, psychological, & economic benefits of early discharge must be weighed against potential hazards.
Chap 16. The Newborn Infant



99. 5. 10.

1st year resident, Lee Sun Joo




I. Adaptation of the Newborn to Air Breathing


1. The 1st breath of air
  • the fluid-filled alveoli of the lungs must fill with air.
  • the air must be exchanged by appropriate respiratory motion.
  • a vigorous microcirculation must be established.



2. Initiation of air breathing
  • very soon after birth -> shift to regular deeper inhalations.
  • aeration of the newborn lung is the rapid replacement of bronchial & alveolar fluid by air.
  • delay in the removal of fluid -> contributes to syndrome of transient tachypnea of the newborn.
  • as fluid is replaced by air, there is considerable reduction in pulmonary vascular compression.
  • from the 1st breath after birth, progressively lower pulmonary opening pressure is required.


3. Alveolar surface tension & Lung surfactant
  • prevents the collapse of the lung with each expiration.




4. The stimuli to breath air

1) physical stimulation - such as handling the infant during delivery

2) compression of the thorax during the 2nd stage -> forces some fluid from the respiratory tract

3) deprivation of O2 & accumulation of CO2 may stimulate respiration.



5. Management of delivery

1) immediate care

  • the face is immediately wiped & the mouth and nares are suctioned.
  • before clamping & severing the cord -> aspirate the mouth & pharynx again.
  • the infant is placed supine with the head lowered & turned to the side.
  • to minimize heat loss, the baby is wiped dry.

2) evaluation of the infant

  • health status of the mother.
  • prenatal complications.
  • labor complications.
  • gestational age.
  • duration of labor.
  • duration of ruptured membranes.
  • kinds, amounts, times, and routes of administration of medications.
  • kind & duration of anesthesia.
  • any difficulty with delivery.

3) Lack of effective respirations.

  • fetal hypoxemia or acidosis from any cause.
  • drug administered to the mother.
  • gross fetal immaturity.
  • upper airway obstruction.
  • pneumothorax.
  • other lung abnormalities.
  • aspiration of Amnionic Fluid grossly contaminated with mecomium.
  • CNS developmental abnormality.
  • septicemia.





II. Methods used to evaluate newborn condition


1. Apgar Score


table 16-1. Apgar Scoring System










Sign 0 1 2
Heart rate Absent Below 100 Over 100
Respiratory effort Absent Slow, irregular Good, crying
Muscle tone Flaccid Some flexion of extremities Active motion
Reflex irritability No response Grimace Vigorous cry
Color Blue, pale Body pink, extremities blue Completely pink



  • the 1-minute Apgar Score determines the need for immediate resuscitation.

    Apgar Scores : 7 ~ 10 -> require no aid

                                4 ~ 6 -> good.

                                0 ~ 3 -> will usually have slow to inaudible heart rates & reflex responses depressed

                                              or absent resuscitation should be start immediately.



  • Use and misuse of the Apgar Score

    1) Factors that may affect Apgar Scores

    • Tone, color, reflex irritability -> dependent on the physiologic maturity of the infant.

    • Maternal sedation or analgesia may decrease tone & responsiveness.

    • Neurologic conditions may decrease tone & interfere with respiration.

    • Cardiorespiratory conditions may interfere with heart rate, respiration, & tone.

    2) Apgar Score & subsequent disability

    • the 1-minute Apgar Score may be used to indicate the infant who requires special attention(does not correlate with future outcome).
    • the 5-minute Apgar Score is a useful index of the effectiveness of resuscitation efforts.
    • an Apgar Score of 0 to 3 of 5 minutes is associated with an increased risk of cerebral palsy(0.3% -> 1%).
      -> a low 5 minutes Apgar Score alone does not prove that later CP was caused by perinatal asphyxia.

    3) Later Scores.

    • Criteria for cerebral hypoxia leading to CP.

      ① profound metabolic or mixed acidemia (pH < 7.0) on an umbilical cord arterial sample.

      ② Apgar Score of 0 to 3 for longer than 5 minutes

      ③ Neonatal neurologic manifestations.

      ④ multisystem organ dysfunction.

    • low Apgar Score, the presence of umbilical cord acidemia in the absence of maternal acidemia, large base deficit, and nucleated erythrocytes in the peripheral blood. -> provide supporting evidence of asphyxia.



2. Umbilical cord blood Acid-Base Studies.

  : are useful in examining the metabolic status of the fetus in the minutes & hours prior to birth.

  • the lower limits of normal pH in the newborn 7.04 to 7.10.



    1) Effects of Gestational Age on Apgar Score & pH

  • a most important factor influencing the Apgar Score is gestational age.
  • Apgar Score of 7 in a preterm neonate may represent the upper normal value.
  • umbilical cord gas indices may be of more value than Apgar Scores in preterm infants.
  • a large base deficit and a low HCO3 ( < 12 mEq/L ) associated with mixed respiratory-metabolic acidemia is more after associated with a depressed neonate.


3. Clinical Dx of Asphyxia.

  • severe metabolic acidosis is poorly predictive of subsequent neurological impairment in the term infant.
  • in very low-birthweight infants(<1000g) newborn acid-base status may be more closely linked to long-term neurological outcome.
  • transient umbilical cord compression is the most common antecident factor in the development of fetal respiratory acidosis.
  • to cause hypoxic ischemic encephalopathy.

    ① umbilical artery metabolic or mixed respiratory, metabolic acidemia with pH < 7.00.

    ② a persistent Apgar Score of 0 to 3 for more than 5-minutes.

    ③ neonatal neurologic sequelae.

    ④ multiorgan system dysfunction.


4. Recommendations for blood gas determinations.
  • cord blood gas & pH analyses should be used in select neonates with low Apgar Scores to distinguish metabolic acidemia from hypoxia or other causes that might result in a low Apgar Score.

    III. Active Resuscitation.


    fig. 16-2






    • initial O2 deprivation -> transient period of rapid breathing -> primary apnea(a fall in heart rate & loss of neuromuscular tone) -> deep gasping respirations -> secondary apnea -> unless ventilation is assisted, death will occur.
    • unnecessary or overvigorous suctioning of mouth, nares, & trachea can result in significant vagal stimulation & reflex slowing of the heart rate.



    1. resuscitation protocol
    • prevent heart loss - warmer, dry off.
    • open the airway - suctioning.
    • evaluation the infant -observe for respirations, heart rate, & color.
    • respiratory effort
      • if absent, positive pressure ventilation is carrid out.
      • if present, heart rate is evaluated.

    • heart rate
      • < 100 beats/min -> PPV is instituted.
      • > 100 beats/min -> infant color is evaluated next.


    • color
      • if the infant exhibits central cyanosis, free flowing O2 is provided at concentrations of 80 to 100 %.


    • heart rate : evaluated after 15 to 30 sec of PPV.
      • > 100 -> evaluate color.
      • 60 < <100 & increasing -> ventilation is continued.
      • < 60, or below 80 & not increasing -> ventilation is continued & compressions are begun.

    • chest compressions
      • at a rate of 2-sec with a 1/2-sec pause every 3rd compression for ventilation.
      • compression is stopped every 30 sec for 6 sec while the heart rate is checked.


    • chemical resuscitation - epinephrine, volume expansion, naloxone
      • epinephrine 1:10000 -> IV or via the tracheal tube.
      • volume expansion -> 10ml/kg whole blood, 5% albumin, normal saline, Ringer lactate.
      • sodium bicarbonate 4.2% solution.


    • tracheal intubation
      • when prolonged PPV is required.
      • when bag & mask ventilation is ineffective.
      • when tracheal suctioning is required.
      • when diaphragmatic hernia is suspected.




    2. Technique of intubation
    • should delivery puffs of O2-rich air into the tube at 1- to 2-sec intervals with a force adequate to lift the chest wall gently.
    • pressures of 25 to 35 cmH2O are desired to expand the alveoli.



    3. Common Errors in resuscitation of the Newborn

    • failure to check resuscitation equipment before-hand.
    • use of a cold resuscitation table.
    • unsuccessful intubation.
    • inadequate ventilation.
    • failure to detect & determine cause of poor chest movement or persistent bradycardia.
    • failure to detect & treat hypovolemia.
    • failure to perform cardiac massage.




    IV. Routine Newborn Care



    1. Estimation of Gestational Age

      1) sole creases

      2) breast nodules

      3) scalp hair

      4) ear lobes

      5) for males, testes & scrotum


    • A more definitive estimate can be made in a few days with the help of neurological examination.



    2. Care of the eyes


    1) Gonococcal Ophthalmia Neonatorum

    • 1% silver nitrate solution.
    • penicillin ointment in the strength of 100000 U/g
    • tetracycline ophthalmic ointment(1%)
    • EM ointment(0.5%)
    • povidone-iodine solution(2.5%)
    • PPNG: cefotaxime 100mg/kg as a single IM injection.

                    ceftriaxone 125mg/kg as a single IM injection.

    2) Chlamydial Conjunctivitis / Ophthalmia Neonatorum

    • TC & EM ophthalmic ointments.
    • 2.5% povidone-iodine solution.
    • Azthromycin : effective in treating genital & ocular chlamydia trachomatis in adults using a aingle 1-g oral dose.
    • Prophylactic treatment of the pregnant woman prior to delivery and/or the prophylactic treatment of her infant.

    3) Other causes of Neonatal Conjunctivitises.

    • S. aureus, S. pneumoniae, Neisseria meningitidis, P. aeruginosa, H. influenzae,

      E. coli and other coliform herpesviruses.


    3. Permanent Infant Identification
    • mother & infant should not be separated until identification is complete.
    • most hospitals today use footprints.



    4. Subsequent Care

    1) Temperature

    • drops rapidly immediately after birth.
    • must be cared for in a warm crib.


    2) Vitamin K : routine ad.

    3) Hepatitis B immunization

    • routine immunization of all newborns should be initiated prior to hospital discharge.
    • if the mother is HBsAg positive, the neonate should be passively immunized.

    4) Umbilical cord

    • within 24 hours it loses its characteristic bluish white, moist appearance & soon becomes dry & black.
    • separation : within the 1st 2-weeks.
    • strict aseptic precautions.
    • most apply triple dye or bacitracin ointment.
    • povidone-iodine applied daily was effective & acceptable.

    5) Skin care

    • should be promptly dried.
    • excess vernix, blood & meconium is gently wiped off.

    6) Stools and urine

    • meconium : for the 1st 2 or 3 days after birth.

                          90 % - within 24 hours.

                          the rest - within 36 hours.

    • voiding : usually occuring shortly after birth.
    • after the 3rd or 4th day, meconium is replaced by light yellow homogeneous feces with a characteristic odor.

    7) Icterus Neonatorum

    • 2nd & 5th day of life -> physiological jaundice of the newborn.
    • 3rd & 4th day : bilirubin -> more than 5mg/dl.

                                                  free or unconjugated bilirubin.
    • immaturity of the hepatic cells.
    • reabsorption of free bilirubin as the consequence of the enzymatic splitting of bilirubin glucuronide by intestinal conjugase activity in the newborn intestine.
    • in preterm infants, jaundice is more common & usually more severe & prolonged.


    8) Initial weight loss

    • for the 1st 3 or 4 days of life, infants lose weight.
    • preterm infants -> lose more weight

                                      regain more slowly
    • if, nourished properly, birth weight is regained by the end of the 10th day.
    • increases about 25g/day for the 1st few months.

    9) Feeding

    • regular nursing within the 1st 12 hours postpartum.
    • most term infants -> fed at intervals of about 4 hours.
    • preterm or growth retarded infants -> shorter intervals.
    • to remain at the breast for 10 minutes at first.

    10) Circumcision

    • routine circumcision of newborn males not be performed.

    11) Rooming-in

    • by the end of 24 hours, the mother is generally fully ambulatory : thereafter, with rooming-in.

    12) Hospital Discharge

    • newborn infant is discharged with its mother, maternal stay has determined that of the child.
    • potential social, psychological, & economic benefits of early discharge must be weighed against potential hazards.