Restrictive Lung Disease Flashcards
What is the basic physiology with restrictive lung disease?
- Decreased lung volumes and compliance- multiple causes
- skeletal structure
- weakened muscles of respiration
- abdominal wall or contents can affect mobility of diaphragm and thoracic cage
- obesity, pregnancy
- creates a V/Q mismatch
Describe the flow volume loop seen in restrictive lung disease
- Same shape as normal, but much smaller
- This is not a disease of flow b/c flow is adequate, it is a disease of compliance and volume
What will pulmonary function tests show in a pt with restrictive lung disease?
- Reduction in:
- total lung capacity- used to classify severity of the restrictive dx
- mild: 65-80%
- moderate: 50-65%
- severe: <50%
- FRC
- Reserve volume
- vital capacity
- FEV1 (forced expiratory volume in 1 second)
- FVC (forced vital capacity)
- total volume exhaled
- total lung capacity- used to classify severity of the restrictive dx
-
NO change in FEV1: FVC ratio
- b/c it is not a disease of flow, it is a disease of compliance
Reduced lung compliance leads to _______ and _______.
decreased FRC and arterial hypoxemia due to V/Q mismatch.
AND
increased WOB and dyspnea
What does the breathing pattern look like for a pt with restrictive lung disease?
- Rapid and shallow, which increases dead space ventilation
What are the different classifications of restrictive lung disease?
- Acute intrinsic
- pulmonary edema
- ards
- Chronic intrinsic
- diseased lung parenchyma- sarcoidosis (inflammatory disease)
- Chronic Extrinsic
- chest wall, intraabdominal, and neuromuscular diseases
- Disorders of the pleura and mediastinum
What is Pulmonary edema?
Classification?
Causes?
Diagnosis?
- Leakage of IVF from the pulmonary vasculature into the lung interstitium and into the alveoli
- Acute intrinsic restrictive lung disease
- Causes:
- increased capillary hydrostatic pressure (cardiogenic pulm edema)
- increased capillary permeability (inflammatory process)
- Diagnosed:
- bilateral symmetrical opacity on CXR
- If cardiogenic, will see accompanying dyspnea, tachypnea, SNS activation
What is aspiration pneumonitis?
Classification?
Symptoms?
- Aspirate is rapidly distributed throughout lungs and gastric fluid destroys the surfactant-producing cells and injurs the endothelium of the capillaries
- Causes capillary permeability with atelectasis and edema formation
- Acute intrinsic classification
- Symptoms:
- arterial hypoxemia
- tachypnea
- bronchospasm
- pulmonary vascular constriction can develop into pulmonary HTN
- CXR changes 6-12 hrs after event.
- usually right lower lobe
How is Aspiration pneumonitis treated?
- deliver increased FiO2
- Give PEEP
- Beta2 agonists for bronchospasm
- prophylactic anitbiotics and steroid use not supported
What is Negative Pressure Pulmonary edema?
Classification?
Causes?
- Occurs minutes to 3 hours after acute upper airway obstruction in a spontaneously breathing patient due to high negative intrapleural pressures against a closed glottis/upper airway
- Acute Intrinsic
- Causes:
- post-extubation laryngospasm
- OSA
- hiccups
- epiglottitis
- Tumors
In negative pressure pulmonary edema:
What do the highly negative intrapleural pressures cause?
What does this result in?
- Decreased interstitial hydrostatic pressure
- increased venous return
- increased afterload on left ventricle
- increased SNS outflow- HTN, central displacement of blood volume
- *Results in acute pulmonary edema
- **the high negative pressures can only be caused by a pt spontaneously breathing
How does a pt with Negative pressure pulmonary edema present?
How long does it last?
Treatment?
- Presents with:
- tachypnea
- cough
- failure to maintain SaO2 > 95%
- Most commonly seen in muscular men- b/c they can generate strong neg pressures
- Duration: usually self limited, lasting 12-24 hours
- Treatment:
- supplemental O2
- maintenance of patent upper airway
- occasionally mechanical ventilation is required for a brief period
What is Sarcoidosis?
Classification?
Where is it often found?
- Systemic granulomatous disorder that changes the intrinsic properties of the lung due to pulmonary fibrosis and results in pulm HTN and cor pulmonale–> results in more fibrosis and loss of pulmonary vasculature
- Chronic Intrinsic
- Often found in the thoracic lymph nodes and lungs
What is a potential problem with a laryngeal sarcoid?
a Myocardial sarcoid?
- Laryngeal sarcoid
- can interfere with the passage of an adult sized tube
- Myocardial sarcoid
- rare conduction defects ( heart block, dysrhythmias, restrictive cardiomyopathy
How do patients with Sarcoidosis present?
What kind of procedure are they probably getting
How should you consider?
- Patients present with:
- dyspnea/cough
- rapid, shallow breathing
- sometimes asymptomatic but diagnosed by abnormal CXR
- Procedure: mediastinoscopy for diagnosis via lymph node tissue
- Patients are often treated with corticosteroids, consider need for stress dose
