Respiratory & PED'S Disorders

• Functions of the Pulmonary System

  • Ventilate the alveoli
  • Diffuse gases into and out of the blood
  • Perfuse the lungs so the body receives oxygen
  • Ventilation
• Ventilation:

  • Mechanical movement of gas or air into and out of the lungs
  • Minute volume
  • Ventilation rate multiplied by the volume of air per breath
  • Alveolar ventilation (effectively)
• The major muscles of inspiration include the diaphragm and external intercostals
• The accessory muscles of inspiration include sternocleidomastoid muscle and scalene muscles
• The accessory muscles of expiration: There are no major muscles of expiration; normally passive
• Surfactant: aids with reducing alveolar surface tension and ventilation
• Elastic properties of the lung and chest wall

  • Elastic recoil: rebound of lungs after inhalation
  • Compliance: amount of lung expansion during inspiration
• Gas transport has 4 steps

  1. Ventilation of the lungs
  2. Diffusion of oxygen from the alveoli into the capillary blood
  3. Perfusion of systemic capillaries with oxygenated blood
  4. Diffusion of oxygen from systemic capillaries into the cells
• Variations in pediatric anatomy & physiology include

  • Nose, throat, trachea, lower respiratory structures, chest wall, metabolic rate and oxygen needs
• Child's respiratory tract grows until about age 12
• An infant's airway is shorter and narrow when compared to adults
• For infants, having a swollen/ edema in airway is more serious than adults due to narrower airway, nasal patency is critical

  
• Newborns, until approximately 4 weeks of age, are obligatory nose breathers
• There is an inverse relationship between airway diameter and airway resistance, when resistance increases the size of diameter in the airway is decreased

  
• Infants have a larger tongue when in proportion to the mouth
• Infants have a smaller pharynx and a narrow trachea that is less ridged
• Infants epiglottis is larger and floppier than adults
• For infants, they have a smaller lung capacity and underdeveloped intercostal muscles give children less pulmonary reserve
• Infants have higher respiratory rates and demand for O2 in a young child makes hypoxia easy to occur
• Infant's lack of firm bony structure to rib/chest makes child more prone to retractions when in respiratory distress
• Infants lower airway, the alveoli change size and shape, and increase in number with age
• Infant's smooth muscles of bronchi and bronchioles develop during the first year of life. Until developed, less able to trap invaders
• In infants, the intercostal muscles are immature
• Infant's ribs are primarily cartilage and are very flexible- retractions seen, especially during respiratory distress
• Blood gas analysis is the major diagnostic tool for evaluating acid-base and today we will focus on pH, PaCO2, and Bicarbonate levels
• pH: determines the extent of acidity or alkalinity
• PaC02: reflects the adequacy of ventilation by the lungs
• Bicarbonate level: reflects the activity of the kidneys in retaining or excreting bicarbonate
• Respiratory Acidosis (indicate if it's increased, decreased or normal)

  • pH= decreased
  • PaCO2= increased
  • HCO2= Normal
• Respiratory Acidosis Signs and Symptoms

  • Headache, blurred vision, restlessness, sleepiness or fatigue, delirium, shortness of breath and coma
  • Confusion, lethargy, anxiety (same as alkalosis)
• Causes of respiratory Acidosis in PED'S

  • Acute respiratory failure where conditions such as
  • Croup, Epiglottitis, Bronchiolitis, Status asthmaticus
  • CAUSE: prolonged periods of apnea, deoxygenation or airway obstruction
• Causes of respiratory Acidosis in PED'S (additional)

  • Neuromuscular disease
  • CNS dysfunction causing impaired respiratory drive (blood gas imbalances)
• Respiratory Alkalosis (indicate if it's increased, decreased, or normal)

  • pH= Increased
  • PaCO2= Decreased
  • HCO3= Decreased (normal in come cases)
• Respiratory Alkalosis Signs and Symptoms

  • Hyperventilation
  • Nausea, vomiting
  • Confusion, Lethargy, Anxiety (same as acidosis)
• Potential causes of respiratory alkalosis in PED'S

  • Fever
  • Trauma and/or injury
  • Tumor
  • Panic attacks and anxiety with Hyperventilation
• Infant in respiratory distress Signs and Symptoms

  • Flaring of nostrils
  • "seesaw" abdomen distended while lower sternum retracts
  • Pooling of blood on back resulting in darkened, discolored areas (significant trauma)
  • Intercostal retractions
• Assessments for when children are in respiratory distress

  • Air entry, cough, adventitious sounds, respiratory effort
  • Vital signs, family history, behaviors change
  • Position of comfort, color (extremities & sputum)
• Nasal cannula & simple mask (O2 delivery) for adult: 1 - 6 L/min
• Simple mask (O2 delivery) children: 5 - 10 L/min
• Nasal cannula (O2 delivery) children: 1/2 to 2 - 3 L/min