Chapter 11 Respiratory Disorders
ANATOMY AND PHYSIOLOGY
Upper airway = nasopharynx and oropharynx connected to the ears by the eustachian tubes.
The nose, pharynx, and larynx are separated from the lower airway by the trachea.
The larynx is covered by the epiglottis.
Cilia and mucus in the nostrils warm, clean, and humidify the air.
Lower airway = trachea, bronchi, bronchioles, and alveoli.
Left lung = two lobes/ Right = three lobes.
At the capillaries = oxygen and carbon dioxide diffuse.
Surfactant is a phospholipid that preventing lungs from collapsing completely at the end of each expiration.
There are two pleural membranes, normally separated by only enough fluid to lubricate for painless movement:
Parietal pleura lines thoracic cavity.
Visceral pleura surrounds each lung
Normal breathing is involuntary; the CNS controls rate and volume of respiration.
DEVELOPMENTAL DIFFERENCES IN THE RESPIRATORY SYSTEM
A child’s upper airway is shorter and narrower than an adult’s.
Newborn airways are approximately 4 mm in diameter compared with 20 mm for the average adult’s
airway.
Inflammation 1 mm in circumference would decrease a child’s airway diameter 50%, but only 20% for
an adult.
Newborns breath through noses until 1 month of being born.
Until 4 months; sphenoid and frontal sinuses develop later in childhood and continue to mature to
adolescence.
The child’s larynx is more flexible than an adult’s and easily stimulated to spasm.
The child’s intercostal muscles are not fully developed; pronounced abdominal wall movement with
respiration is normal until 6 years old.
Periods of apnea (the absence of respiration) that last up to 15 seconds are normal in the newborn period.
A child’s metabolic rate is higher than that of an adult’s, creating a higher oxygen demand. Newborns use 4 to 8 L of oxygen a minute, and adults
use 3 to 4 L per minute. A child’s respiratory rate is thus faster, with an irregular pattern.
Newborns do not have the defense of bronchospasms or constriction to trap foreign irritants because smooth muscles are not fully
developed until about 5 months of age.
A child’s cartilage surrounding the trachea is more flexible and can compress the airway if the head is not positioned properly.
Eustachian tubes are shorter and more horizontal in children than in adults.
A child’s tonsils and lymphoid tissues are larger than an adult’s.
Anterior-to-posterior diameter of chest is equal at birth but decreases with age.
,RESPIRATORY DISORDERS
General History
Gestational age
Medical history including onset of current symptoms, pattern of recurrent sore throats, eczema, respiratory problems at birth
Detailed family history, including chronic respiratory conditions such as asthma
Exposure to environmental irritants, pets, and smokers in household
Feeding and sleeping patterns
Growth and reaching milestones
International travel or adoption
Physical Assessment
Chest diameter, anterior-to-posterior diameter
Work of breathing, respiratory effort
Flaring, tachypnea, retractions, paradoxical breathing
Optimal chest expansion when positioned supine with head of bed elevated at a 45-degree angle
Tripod, jaw thrust, or insistence on sitting upright are signs of air deficiency
Asymmetrical chest rise may indicate tension pneumothorax
Acrocyanosis normal up to 48 hours after birth
Nasal flaring—widening of nares with inspiration (As seen in picture)
Sign of air hunger
Clubbing of fingertips: loss of 160-degree angle of nail bed
o May be a sign of chronic hypoxia such as seen in cystic fibrosis (CF) and similar chronic
respiratory disorders
Hydration status
o Mouth breathing, tachypnea, fever, and anorexia all contribute to dehydration
Barrel Chest
A child’s anterior-to-posterior diameter is equal until about the age of 2 years. In older children,
this characteristic may signify a chronic obstructive lung condition known as “barrel chest,” typically
observed in CF or asthma.
Assessing Differences in Skin Color
In dark-skinned infants and children, determine the normal skin color and assess for differences.
Erythema will appear violet or dusky red, cyanosis will appear black, and jaundice will appear darker
than normal skin. In Asian and dark-skinned infants, jaundice is best assessed as a yellow imprint when pressure is applied to infant’s
forehead or tip of nose and then removed.
Auscultation
, Anterior and posterior chest, and bilateral mid-axillary for aeration
Respiratory rate varies based on child’s age
Heart rate depends on age; increases with fever, dehydration
Adventitious breath sounds
o Crackles (rales): fine cracking noises heard on inspiration
Air moves through fluid-filled alveoli as in pneumonia
May not change after coughing
Simulate sound by rolling hair between your fingers
o Snoring (rhonchi): low-pitched sounds heard throughout respiration
Air passes through thick secretions
May clear after coughing
o Stridor: high-pitched sound heard on inspiration in the upper airway in conditions such as croup
o Wheezes: high-pitched musical sounds heard throughout respiration
Air passing through constricted bronchioles or narrowed smaller airways as in asthma
Percussion
Lung should resonate when percussed
Flat or dull sounds in consolidated area
Tympany with pneumothorax
Hyperresonance may be heard with the presence of asthma.
Palpation
Lymph nodes in head and neck may be enlarged because of infection.
Assess sinuses in older children for tenderness.
Tactile fremitus, the vibrations made during speech or making sounds, will increase with pleural effusion and pneumonia.
Absent in atelectasis or pneumothorax or barrel chest
Pulses should be equal when comparing peripheral pulses with central pulses.
Severe respiratory distress and decreased perfusion result in weaker peripheral pulses.
Signs of respiratory failure: Muscles of ventilation are fatigued, and greater metabolic and oxygen requirements.
Diagnostic Tests
The following subsections describe diagnostic tests are used when a respiratory issue is suspected.
BOX 11–1 | Signs of Respiratory Distress
SIGNS OF RESPIRATORY DISTRESS
Tachypnea
Dyspnea
Hypernea
Nasal flaring
, Use of accessory muscles
Retractions: intercostal—mild distress, suprasternal, subcostal, and supraclavicular seen in moderate distress
Sitting with head of bed elevated
Coughing: intermittent
Adventitious breath sounds
Tachycardia
Dusky nail beds
Hypercapnia
Hypoxia: ability to speak full sentences
Crying: strong
SIGNS OF RESPIRATORY FAILURE
Mental status change, extreme irritability
Circumoral cyanosis or mottled skin color
Lethargy, change in mental status
Grunting
Head bobbing
Coughing continuously
Retractions: moderate along with the use of accessory muscles
“Quiet” breathing
Sitting forward with arms, knees for support, tripod
Normal or shallow respirations
Seesaw respirations
Hypopnea
Hypoxemia, lower than normal oxygen in the blood, that is persistent with supplemental oxygen administered
Weak or absent cry
Tachycardia: further elevated
Arterial Blood Gas
Pao2 is the amount of oxygen in lungs available to diffuse into blood.
o Decreased because of hypoventilation, ventilation-perfusion mismatch, or shunting
Paco2 is the amount of carbon dioxide in blood that can diffuse out of the blood.