Acute Care Flashcards
What is acute respiratory failure?
when the pulmonary system is unable to maintain adequate gas exchange to meet metabolic demands
What is hypoxemic respiratory failure?
- PaO2 < 60mmHg in previously healthy children without intracardiac shunt
- caused by V/Q mismatch (perfusion of lung that is not adequately ventilated) and shunting (deO2 blood bypasses ventilated alveoli)
What is hypercarbic respiratory failure?
- PaCO2 >50mmHg in previously healthy children
- results from inadequate alveolar ventilation secondary to decreased minute ventilation (Vt x RR) or increased dead space ventilation (ventilation of areas receiving no perfusion)
Define pediatric ARDS
- Onset within 7 days of known clinical insult
- Respiratory failure not fully explained by cardiac failure or fluid overload
- Chest imaging findings of new infiltrate(s) consistent with acute pulmonary parenchymal disease
- Impairment in oxygenation (defines severity)
Causes of ARDS
- sepsis
- pneumonia
- shock
- burns
- traumatic injury
insult results in inflammation and increased vascular permeability leading to pulmonary edema
What are the causes of acute respiratory failure?
- most common: bronchiolitis (RSV), asthma
- pneumonia
- upper airway obstruction
- systemic inflammation resulting in ARDS
What are the causes of chronic respiratory failure (with acute exacerbations)?
- chronic lung disease (BPD, CF)
- neurologic or neuromuscular abnormalities
- congenital anomalies
What are the clinical manifestations of hypoxic respiratory failure?
- early: tachypnea, tachycardia (compensatory mechanisms to improve minute ventilation and cardiac output to maintain O2 delivery to tissues)
- dyspnea, nasal flaring, grunting, accessory muscle use, diaphoresis
- late: cyanosis, altered mental status (initially agitation, confusion)
What are clinical manifestations of hypercarbic respiratory failure?
- signs of increased minute ventilation (tachypnea, increased depth of breathing)
- altered mental status (somnolence)
- often also have hypoxia
What are CXR findings of ARDS?
diffuse infiltrates or pulmonary edema
What are the causes of hypoxic respiratory failure?
Results from impairment of alveolar-capillary function
- ARDS
- cardiogenic pulmonary edema
- interstitial lung disease
- aspiration pneumonia
- bronchiolitis
- bacterial/fungal/viral pneumonia
- sepsis
- intracardiac/intrapulmonary shunting seen with atelectasis and pulmonary embolism
What are causes of hypercarbic respiratory failure?
Failure of respiratory centre
- drugs (opioids, barbiturates, anesthestic agents)
Neurologic/neuromuscular abnormalities (inadequate chest wall movement causing atelectasis and respiratory failure)
- C-spine trauma
- demyelinating disease
- anterior horn cell disease
- bolutism
- muscular dystrophy
- myasthenia gravis
Diseases that cause increased resistance to airflow
- croup
- vocal cord paralysis
- post-extubation edema
Scoliosis (rarely can cause restrictive pulmonary function)
Abdominal distension causing impaired ventilation
- ascites
- post-operative
- obstruction
- mass
Chest wall injury/thoracic trauma (flail chest)
Treatment of respiratory failure: how to improve oxygenation
- change fiO2
- change mean airway pressure (PEEP, PIP, inspiratory time, gas flow)
Treatment of respiratory failure: how to eliminate CO2
- manipulate minute volume (Vt x RR)
What is the major complication of hypoxic respiratory failure?
Organ dysfunction
