Apnea of Prematurity and BPD Flashcards
Premature infants and Periodic Respirations
Premature infants will have periodic respiration which comprise of sequential short apneic episode of 5-10 seconds followed by 10-15 seconds of rapid respirations
Apneic spells are abnormal when they last longer than 15 seconds or are associated with cyanosis, pallor, hypotonia, or bradycardia
Central Apnea
If no effort to breathe occurs during a apnea spell then it is known as a central apnea
Obstructive Apnea
If there is breathing effort but an obstruction is preventing the airflow than it is known as an obstructive apnea
Mixed Apnea
Mixed apnea is a combination of the central and obstructive types that start as obstructive and then will develop into being central
Primary Apnea
Apnea and bradycardia where the baby recovers with tactile stimulation
Secondary Apnea
Apnea and Bradycardia, does not recover with tactile stimulation, requires PPV to recover
What is babies respond to CO2 in babies
When there is an increase in CO2 babies will slow down their breathing and take bigger breaths to try and compensate
Premature Infants and Control of Respiration
Premature infants have immature control of respiratory drive in response to O2 and carbon dioxide (CO2).
In mature animals, an increase in alveolar PaCO2 elicits an increase in VT and respiratory rate. A decrease in FiO2 below room air also triggers an increase in VT.
In premature animals, an increase in PaCO2 temporarily increases VT but does not increase respiratory rate. A decrease in FiO2 below room air decreases VT and respiratory rate. This effect can lead to apnea in a premature infant.
External causes of apnea
Temperature, suction, vagal stimulation
Apneas can Lead to
Apneas can lead to bradycardia, arrythmias, and respiratory arrest
Frequent Apneas can lead to
Frequent apneas can lead to cerebral hypoxia and ischemic brain injury
Clinical Manifestation of Apnea
Snoring, choking, gasping
Cyanosis
Bradycardia
Hypoxia
Apnea that is secondary to prematurity should be treated with
methylxanthines, especially theophylline and caffeine.
These agents stimulate the central nervous system and increase the infant’s responsiveness to CO2.
CPAP for Apnea
CPAP also can be used to manage infant apnea.
CPAP probably increases FRC and improves arterial partial pressure of oxygen (PaO2) and PaCO2. CPAP may stimulate vagal receptors in the lung, increasing the output of the brainstem respiratory centers. Severe or recurrent apnea that is unresponsive to these interventions may necessitate mechanical ventilatory support.
Resolution of Apnea of prematurity
Apneic spells begin to disappear by weeks 37 to 44 of postmenstrual age with no apparent long-term effects. Infants who have apnea of prematurity are not at higher risk for sudden infant death syndrome (SIDS) than other infants.
bronchopulmonary dysplasia (BPD).
Infants, especially preterm infants, with severe respiratory failure in the first few weeks of life may develop a chronic pulmonary condition called bronchopulmonary dysplasia (BPD).
4 factors in BPD Pathogenesis
Lung immaturity
Respiratory failure
Oxygen supplementation
Mechanical ventilation
bpd vs rds
BPD IS an obstructive disease and RDS is a restrictive disease
The New BPD Diagnosis Criteria
The Diagnosis of bPD is based on how long the baby need oxygen and how much oxygen is needed
initiatin Fators in bPD
• The initiating factors are related to atelectrauma (lung collapse) and volutrauma (large tidal volume [VT]). Factors such as hyperoxia and hypoxia, mechanical forces, vascular maldevelopment, inflammation, nutrition, and genetics contribute to the abnormal development of the lung and lead to BPD.
Atelectrauma
Atelectrauma is a term coined to describe loss of alveolar volume that is both a result and a cause of lung injury. Atelectrauma leads to derecuitment (e.g., areas of alveolar collapse) of the lung.
Volutrauma
o Volutrauma is the term used to describe local overinflation (and stretch) of airways and alveoli. Volutrauma leads to damage to airways, pulmonary capillary endothelium, alveolar and airway epithelium, and basement membranes.
what is the result of atelectrauma and volutrauma
Both atelectrauma and volutrauma cause a need for increased supplemental O2 concentrations. whichleads to overproduction of superoxide, hydrogen peroxide, and perhydroxyl radicals. Preterm infants are particularly susceptible to O2 radicals because the antioxidant systems develop in the last trimester of pregnancy. Prolonged hyperoxia begins a sequence of lung injury that leads to inflammation, diffuse alveolar damage, pulmonary dysfunction, and death.
The response of the lungs to the combination of trauma and O2 toxicity
The response of the lungs to the combination of trauma and O2 toxicity is the production and release of soluble mediators. These mediators probably are released from granulocytes residing in the lung. The release of these mediators can injure the alveolar-capillary barrier and cause an inflammatory response.