09- Pulmonary Disorders Flashcards
Delivery room interventions for preterm infants
-Adding trained personnel
-Increase temps to 77 - 79 F
-Used warm pads and pre-warmed radiant warmer
-Place the newborn in re-closable, food-grade polyethylene bag
-Use a transport incubater when moving newborn
-Provide O2
Care for preterm infants
-Use pulse oximetry
-Provide noninvasive CPAP (4-6 cmH2O)
-Initiating PPV (20-25 cmH2O)-increase cautiously
-Once intubated, provide PEEP (2-5 cmH2O)
give surfactant early
-Handle baby gently
-Avoid Trendelenburg placement
-Avoid rapid infusion of fluid
Initial respiratory support for preterm infants
-Provide CPAP to help increase FRC and stability to alveoli
-Positive Pressure Ventilation- If spontaneous respiration and CPAP can’t provide adequate oxygenation.
-PIP 20-25 cmH2O.
-If intubated- provide PEEP at 2-5 cm H2O
-Surfactant if baby is <30
Why avoid excessive oxygen delivery to premature infants?
-Increases risk of brain injury (due to germinal matrix bursting d/t vasodilation)
-Increases risk of retinal damage and ROP
-Can cause permanent structural damage to Type I cells in alveoli (from too much O2)
Different Oxygen-delivery devices
-Traditional nasal cannula
-Heated high-flow nasal cannula
-Mask
-Oxygen hood
-Incubator
NCPAP
-Nasal continuous positive airway pressure. Can be given through nasal prongs and masks.
-Used to treat RDS
Benefits of NCPAP
-Alveolar and airway stabilization
-Decreased airway resistance
-Improve V/Q matching
-Decreased WOB
-Increased lung expansion
-Preservation of the pt’s natural surfactant
-Increased lung compliance
-Stabilization of the pt’s respiratory pattern
Indications to use NCPAP
-Increased WOB
-Inability to maintain a PaO2>50 with FiO2 <60 PaCO2 > 50 and pH > 7.25
-Infiltrated lung fields or atelectasis on CXR
Extubation from mechanical ventilation
NIPPV
-Noninvasive Positive Pressure Ventilation
-Adds a second level of pressure delivery at regular intervals to pt in an effort to improve success of NCPAP (Pressure support and IPAP)
- Creates higher mean airway pressure than NCPAP
Goals of Mechanical Ventilation
-Facilitates alveolar ventilation and CO2 removal
- pH 7.25-7.35 with PaCO2 45-55 mmHg
-Provides adequate tissue oxygenation
-Reduce EOB
-Support all spontaneous respiratory efforts
-Avoid pulmonary tissue injury (over distention)
-Minimize interference of PPV with cardiac circulation
Hyaline Membrane disease (HMD)
-First characterized in the early 20th century
-Thought to be a rare form of pneumonia
-Later became known as RDS
Respiratory Distress Syndrome (RDS)
-Characterized by severe impairment of respiratory function, caused by immaturity of the lungs, primarily due to the lack of surfactant
-Formerly known as HMD
Surfactant
-Stabilized the air-liquid interface of the alveoli and bronchioles and lowers surface tension
-Lower ST improves lung compliance, which decreases WOB
- Made and excreted by alveolar type II cells
-Appear at wGA 17-26
Symptoms of RDS
Abnormal breathing patterns, such as tachypnea or apnea
-Subternal and/or intercostal retractions
-Nasal Flaring
-Grunting (pursed lips)
-See-saw breathing pattern
-Hypoxemia
-Cyanosis
-Hypercarbia
-Respiratory acidosis
-Atelectasis
Apnea of prematurity (AOP)
-A sudden cessation of breathing that lasts for at least 20s or is accompanied by bradycardia or O2 desaturation in an infant younger than 37 wGA
Causes of apnea in premature infants
-Incorrect neural signaling
-Airway obstruction
What causes apnea of prematurity?
The physiological immaturity of the neurological and chemical receptor systems of the body that regulate respiration and respond to hypoxemia and hypercapnia
Difference between apnea and periodic breathing
-Periodic breathing is benign, abnormal, with cycles of hyperventilation followed by apneic pauses os <3 s
-Apnea- stops breathing for > 20 s
Three forms of AOP
-Central apnea
-Obstructive apnea
-Mixed apnea
Central apnea
-All neurologic
-Caused by a dysfunction of the nerve centers in the brainstem to send signals to the muscles of respiration, and no attempt at inspiration can be observed
Obstructive apnea
-Characterized by some attempt to ventilate, resulting in chest wall movement but without gas entry, usually caused by an upper-airway obstruction
Mixed apnea
-Consist of obstructed respiratory effort, usually following central pauses
-MOST COMMON
Pathophysiology of AOP
-Dysfunction of the respiratory-control system is the primary cause of the central apnea component of AOP
-Control of ventilation occurs at brainstem
-Central and peripheral chemoreceptors both play a role
Management and treatment of AOP
Methylxanthines- Stimulant medications, generally stimulating the central nervous system and cardiac muscles. Caffeine citrate is most commonly used
What do Methylxanthines do?
-Stimulates respiratory drive
-Increases diaphragmatic activity
-Increases minute ventilation
-Enhances chemoreceptor sensitivity to CO2
-Reduces periodic breathing
-Reduces hypoxic respiratory depression
-Increases metabolic rate
Increases oxygen consumption
-Stimulates diuresis
Other ways to manage and treat AOP
-Blood transfusion- May alleviate anemia
-Nasal Cannula- Works as a mild pressure in upper airway to prevent obstructive, and tactile stimulation in nares to prevent central apnea
-Noninvasive ventilation- NCPPAP and NIPPV
-Body positioning-Prone position to prevent tongue from obstructing upper airway
-Stimulation-can be tactile or kinesthetic
Course and Prognosis of AOP
-Resolution of apnea is a major developmental milestone
-Discharge depends on observation of apnea-free time period (3-8 days)
-Some infants can be sent home with caffeine citrate and provided with a home cardiorespiratory monitor
-Family education is essential (on discharge and basic life-skills)
-Long term outcomes have been challenging
Bronchopulmonary Dysplasia (BPD)
-Chronic lung disease, currently defined as the need for supplemental O2 for at least 28 days after birth, assessed at discharge or when the baby is close to his or her estimated full-term
When to asses for BPD
-For infants born <32 wGA: At 36 weeks post-menstrual age or discharge (whiechever comes first)
-For infants born >32 wGA: At >28 days but <56 days post-natal age or discharge home
Severity of BPD
-Mild: No supplemental oxygen requirement at time of evaluation
-Moderate: Need for FiO2 <0.30 and/or PPV or NCPAPA at time of evaluation
-Severe: Need for FiO2 >0.30 and/or PPV or NCPAPA at time of evaluation
Risk factors for new BPD (13)
<28 wGA
-Birth weight < 1000g
-Hypothermia at admission
-Hypotension at admission
-RDS
-Need for prolonged MV
-Hypercarbia (>50mmHg)
-Need for exogenous surfactant therapy
-Higher fluid therapy (washes out surfactant)
-Nosocomial infection
-More than two blood transfusion
-Chorioamnionitis
-Preeclampsia
Risk factors for severe BPD
-Acidosis at admission
-Surfactant therapy
-Nosocomial infections
-PDA (Patent ductus arteriosus)
-Oligohydramnios
-Apgas score < 6 at 5 minutes
Management and treatment of BPD
-Guaranteed prevention: Prevent premature birth
-Minimal O2 use
-Exogenous surfactant
Open lung ventilation and gentle ventilation
-Corticosteroids
-Caffeine citrate
-Mast cell stabilizers
-Vitamin A
-Inositol
-Antioxidants
-Inhales nitric oxide: increases gas exchange
-Treatment of pulmonary edema
-Fluid restriction
-Diuretics
-Bronchodilators