Respiratory Assessment of the Newborn
http://edcenter.med.cornell.edu/CUMC_PathNotes/Pediatrics/Pediatric.html

http://www.vh.org/Providers/TeachingFiles/PAP/PAPHome.html

http://www-medlib.med.utah.edu/WebPath/PEDHTML/PEDIDX.html
 

http://www.neonatology.org/ref/dubowitz.html

http://www.neonatology.org/ref/survival.html

http://www.biotech.um.edu.mt/home_pages/chris/Respiration/oxygen5.html
 

  Michael R. Jackson RRT Peri/PediSpecialist
 Brigham & Women's NICU, Boston, MA
 With significant use of the on-line guide 
 by Theodore R. Thompson, M.D.

I. Respiratory Distress

A. Risk Factors (Partial list of Frequent Causes of Respiratory Distress in Newborn Infants)  (35 min)
Maternal:
        1. Diabetes
        2. hypertension, preeclampsia - prematurity
        3. uteroplacental insufficiency - SGA -IUGR
        4. CPD, bicornate uterus, maternal disease		  Delivery
  1. blood loss- maternal, placenta previa, abruptio 
  2. asphyxia - maternal hypoxia, insufficient placental flow,          blockage of umbilical flow, fetal disorders 
  3. meconium aspiration 
  4. postmaturity
Fetal
     1. premature - beta? 
     2. oligohydramnios or lung growth restriction in chest
    3. multiple gestation 		 Neonatal Conditions
  1. surfactant deficiency 
  2. TTN 
  3. apnea

 
 

     Brigham & Women's Hospital currenly sends most surgical cases to adjoining Children's Hospital.

 Medical 

Surgical
 Respiratory distress syndrome (RDS)  Pneumothorax
 Wet lung (transient tachypnea, RDS II)  Diaphragmatic hernia/eventration
 Aspiration syndromes (meconium, blood)  Lobar emphysema
 Persistent pulmonary hypertension of the newborn  Esophageal atresia with or without TE fistula
 Pneumonia/sepsis  Pleural effusion
 Polycythemia - hyperviscosity  Cystic lesions
 Pulmonary edema  Mass lesions
 Hypoplastic lungs  Airway disorders (upper, laryngeal, lower)
 Cardiac lesions  Phrenic nerve paralysis
 Hypoglycemia  
 Hypovolemia  
 Central nervous system  
B. Evaluation
  1. History, physical examination
  2. Downes' or RDS score - clinical
  3. Arterial blood gases Pulse oximetry - SaO2
  4. Chest x-ray
  5. Serum glucose and calcium; central hematocrit; WBC and differential; platelet count
  6. Maternal vaginal culture Group B strep
  7. Newborn surface (e.g., ear canal, gastric aspirate) smears, cultures (?); blood culture; urine culture (?); CSF culture (?)
C.
Signs (15 min)
  1. transition to extrauterine circulation 
  2. color  
  3. respiratory rate 
  4. oxygen saturation 
  5. quality of breath sounds
 Symptoms (30 min)
  1. changes in respiratory rate
  2. use of accessory muscles
  3. changes in oxygen saturation and color
  4. interpretation of newborn chest x-rays
 

 
  1. Tachypnea - above 60-80/minute
  2. Grunting - prevents alveolar collapse
  3. Retractions - compliant chest wall
  4. Flaring of alae nasi, open mouth - decreases resistance
  5. Cyanosis in room air; PaO2 below 60 mmHg (torr) in FIO2 >0.4
  6. Reduced air entry
  7. Apnea
  8. Stridor
D. Downes' or Silverman  RDS Score

 Downes Scoring system

 0
 1
 2
 Cyanosis
 None
 In room air
 In 40% FIO2
 Retractions
None
 Mild
 Severe
 Grunting
 None
 Audible with stethoscope
 Audible without stethoscope
 Air entry
Clear
 Decreased or delayed
 Barely audible
 Respiratory rate
 Under 60
 60-80
 Over 80 or apnea
 Score: 
> 4 = Clinical respiratory distress; monitor arterial blood gases
> 8 = Impending respiratory failure

E. Arterial Blood Gases

 Normal
 Respiratory Failure
 pH
 7.30-7.40
 <7.20
PaCO2
 30-35 mmHg
 >55-60 mmHg
PaO2
 Above 60 mmHg
 <60 mmHg in FIO2
FIO2
 Room air
 = 0.4-0.5*
Base deficit
 -5 to 0 mEq/L
  
 O2 saturation (SaO2)
 >90-92%
 <85%
*Pulmonary disorders

F. Chest X-Ray - Medical Versus Surgical Causes

 Medical  Surgical
 Respiratory distress syndrome - hyaline membrane disease  Pneumothorax
 Wet lung - transient tachypnea  Diaphragmatic hernia
 Pneumonia  Pleural effusion
 Aspiration - meconium, amniotic fluid  TE fistula
 Hemorrhage  Lobar emphysema
 Pulmonary insufficiency - immaturity  Cyst, masses, phrenic nerve paralysis
 Congestive heart failure - pulmonary edema  Airway disorders

G. Guidelines for Monitoring Oxygen Saturation Levels by Pulse Oximetry

 >95%
  Pulmonary hypertension (PPHN)
 85 (87) - 96%
  28-34 weeks
 85 (87) - 93 (96%)
  Below 28 weeks gestational age*
 90 - 100%
  First one to two days¦
 >92%
  Chronic lung disease
* Maintain <96% when possible
¦ Higher levels for more mature infant, PPHN; maintain <96% when possible if preterm infant

H. Suggested Management of Hypoxemia
1. Maintain PaO2
SaO2		  50-90 torr
85 (87) - 96%*		 BWH Oximeter
alarms 
87 low/97 high
 2. O2 administration  Warmed, humidified
Headbox, mask/funnel
5 liters/minute, 1/2 inch from nostrils
Make small changes in FIO2 (flip-flop)
Monitor FIO2, SaO2
 3. CPAP - PEEP
 4. Positive pressure ventilation
 5. ECMO  Oxygenation index [MAP x FIO2 x 100/PaO2] >40-45
*SaO2 = oxygen saturation level; maintain SaO2 <96% for preterm infants when possible, higher (>95%) in infants with pulmonary hypertension
A. Respiratory Distress

1. Downes' score >4-5, low  or  bSilverman grade high
2. PaO2 <60 mmHg in 40-50% oxygen
3. FIO2 >0.4 to relieve cyanosis
4. PaCO2 >55 mmHg with pH <7.30
5. pH <7.25-7.30
6. Apneic episodes
7. Limited capacity to:

  • Provide assisted ventilation
  • Monitor pH, PaCO2, PaO2, FIO2
  • Precise IV fluid support
B. Surgical Emergencies

C. Suspected Congenital Heart Disease

D. Birth Weight <1500 Grams and/or Gestational Age <31-32 Weeks

E. Severe Perinatal Distress (combined Apgar score <6)

F. Severe Infection

G. "Not Doing Well"

*Dependent on skills of personnel, availability of support service
VII. Prevent or Detect and Correct for Stabilization of the Ill Newborn Infant

A. Five Hs
1. Hypothermia
2. Hypotension
3. Hypoglycemia
4. Hypoxia
5. Hypercarbia

B. Plus Acidosis

 Cycle of Events Often Present in the Sick Newborn Infant
 
I. Suggested Indications for Positive Pressure Ventilation in the Newborn Infant

  1. Downes' or RDS score >8
  2. Severe apneic episodes, gasping respiratory efforts
  3. pH <7.25 AND PaCO2 >55-60 mmHg or rising >5-10 mmHg/hour
  4. Birth weight <1500 grams, gestational age <31 weeks (delivery room)
  5. Failure of nasal CPAP: PaO2 <60 mmHg, FIO2=0.6, CPAP=6 cm H2O
  6. pH <7.20 despite therapy (metabolic/respiratory acidosis)
  7. Shock (PEEP of 2-3 cm H2O)


 Differential Diagnosis

Modified from Klaus MH and Fanaroff AA. Care of the High-Risk Neonate, pg. 125

Question and Answer (10 min)

J.  Intubation of Newborn Infants
 
 

Birth Weight (grams) / Gestational Age (weeks) Internal Diameter 
(mm)*
End Tip of ET Tube to 
(number at lower lip or base of tape)
nasopharynx kg wt +4            oral tracheal kg wt +6              nasotracheal kg wt +7
Below 1000 2.5 4-5 cm 6-7 cm  7-8 cm
1000 / 27-28 2.5-3.0 5 cm 7 cm  8 cm
2000 / 32-34 3.0-3.5 6 cm
8 cm
  9 cm
3000 / 38-40 3.5-4.0 7 cm 9 cm 10 cm
4000 / abover 39 4.0 8 cm 10 cm 11 cm

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