Assessment of the Neonate

Fred Hill, MA, RRT

Reduction in Pulmonary Reserve

• Thorax is more flexible• Heart is larger in proportion

to thorax• Abdominal contents are

larger in proportion to thorax

Breathing and Coughing

• Newborns are “obligate nose breathers”

• Neonates lack a cough reflex• Smaller airways, but epithelial

cells are similar in size• Breathing rate = 30-50 vs 12-20;

premature = 40-60• Heart Rate = 100-140 vs 60-80

Upper Airway Anatomy

• Tongue is larger in proportion to oropharynx. More lymphoid tissues in pharynx.

• Larynx is more anterior and higher.• Epiglottis is larger and stiffer in proportion,

lies more horizontal, omega shaped• Cricoid cartilage is narrowest portion of

upper airway (~7 years changes to glottic area)

• Carina is only 4 cm below vocal cords• Tracheal diameter: 4 mm vs 16 mm

Other Considerations

• Ribs are more horizontal (not bucket handle). Rely primarily on diaphragmatic breathing.

• Breath sounds transmit well due to thin thoracic wall, but harder to localize sounds.

Newborn X Ray

Infant X Ray

Other Aspects of Newborn

• Higher metabolic rate: 100 cal/kg vs 40-50 cal/kg

• Reactions to medicines not predictable– High metabolic rate– Immature liver and kidneys

• High surface area to body weight ratio

Gestational Age Assessment

• Dubowitz Gestational Age Assessment– 11 physical signs– 10 neurologic signs– Useful in the first 5 days of life

• Ballard Gestational Age Assessment– 6 neurologic signs– 6 physical signs– Before 42 hours of life (ideal 30 to 42

hours)

Ballard Gestational Age Assessment

Physical Signs

• Skin• Lanugo• Plantar surface • Ear recoil• Breast tissue• Genitalia

Size for Gestational Age

• Two reasons for low-birth-weight infant– Prematurity– Growth retardation

• Size for gestational age– Appropriate for gestational age (AGA)– Large for gestational age (LGA)– Small for gestational age (SGA)

Weight vs Gestational Age: Boys

Weight vs Gestational Age: Girls

Signs of Respiratory Distress

• Synchrony of chest/abdomen movements

• Retractions– Lower chest (lateral ribs)– Xiphoid (substernal)

• Nasal flaring• Expiratory grunting• Cyanosis• Tachypnea

Respiratory Care Procedures

Fred Hill, MA, RRT

Endotracheal Tube Suctioning

• Two people– One to perform suctioning– One to monitor and provide support as

needed• Depth of catheter insertion

determined by length of ET tube; only to tip

• Size of suction catheter as per ETT size

• Suction pressure: -50 to -80 mm Hg

Suction Catheter Size

Endotracheal Tube Suction Catheter

2.5 5, 6

3.0 6-8

3.5 8-10

4.0 8-10

Suction Catheter Size

Nonintubated Suction Catheter

Preemie 5, 6

Term 6-8

Newborn to 6 months 8-10

Oxygen

• Hazards– Retinopathy of prematurity– Bronchopulmonary dysplasia

• Oxygen Hood (Oxyhood)– High flow device– Usually <0.6 FiO2– Flows >7 lpm– Appropriate temperature of gas

• Cannulas: always humidified with newborns, 1/8 to 1 lpm typical flows or 0.2 to 1 lpm

Oxyhood