DISORDERS OF THE RESPIRATORY SYSTEM PART 2.2 (based on T) Flashcards
What are the two layers of the pleura?
Parietal pleura (lines the chest wall) and visceral pleura (lines the lung)
What is the function of pleural fluid?
Allows smooth movement of the lungs during normal ventilation
How is pleural fluid produced?
By filtration from systemic capillaries within the parietal interstitium, with production greatest at the lung apex
What maintains pleural fluid balance?
Pulmonary capillary hydrostatic and oncotic pressure, lymphatic drainage, and integrity of pleural and capillary membranes
What can cause excess pleural fluid formation?
Disturbance in hydrostatic/oncotic pressures, lymphatic drainage, or membrane integrity
What is pleural effusion?
Accumulation of fluid between the parietal and visceral pleura
What are the clinical manifestations of a small pleural effusion?
Usually asymptomatic
What are the clinical manifestations of a large pleural effusion?
Respiratory distress, dyspnea, dry cough, chest/shoulder pain worsened by inspiration
What are general causes of pleural effusion due to increased pleural fluid formation?
LV failure, pneumonia, pulmonary embolus, increased capillary permeability, lung atelectasis, ascites, peritoneal dialysis
What can cause decreased pleural fluid absorption?
Lymphatic obstruction, right ventricular failure, superior vena cava syndrome, aquaporin system disruption
What are the diagnostic tests for pleural effusion?
Pleural fluid analysis (protein, LDH, bacterial culture, gram stain, glucose, pH, WBC/RBC counts, amylase, cytology) and serum tests (CBC, LDH, total protein, glucose)
What are Light’s criteria for exudative pleural effusion?
Pleural fluid/serum LDH >0.6, Pleural fluid/serum protein >0.5, Pleural fluid LDH >2/3 upper limit of normal serum LDH, Pleural fluid cholesterol >55 mg/dL
What is the key difference between exudative and transudative pleural effusion?
Exudative effusions fulfill at least one Light’s criteria, while transudative effusions do not
What procedure is used to obtain pleural fluid for analysis?
Thoracentesis
What is the first-line management of pleural effusion?
Thoracentesis if the cause is unresolved
What is the preferred method for draining pleural effusion in chest trauma?
Tube thoracostomy
What are some pleural fluid appearances and their causes?
Grossly purulent: Empyema;
Thick tan brown: Staphylococcus aureus;
Putrid: Anaerobes;
Bloody: Hemothorax, Malignancy;
Milky: Chylothorax;
Yellow-green: Rheumatoid arthritis;
Black: Aspergillus nigricans
What is the key feature of transudative pleural effusion?
Results from imbalance of hydrostatic or oncotic pressures,
contains little protein and few cells (<500 cells/mm³), and
has serum-like glucose and hydrogen ion concentrations
What are common causes of transudative pleural effusion in children?
Atelectasis, LV failure, nephrotic syndrome, free peritoneal fluid, hypothyroidism
What distinguishes exudative pleural effusions from transudative?
Exudative effusions result from inflammation or lymphatic obstruction, causing fluid leakage with higher protein and cellular content
What are parapneumonic effusions?
Pleural effusions as a complication of bacterial pneumonia, especially in children under 2 years old
What are clinical signs of parapneumonic effusion?
Initially low WBC count, later high WBC count, elevated LDH, low glucose and pH, progressive fibrin deposition
What is the management of parapneumonic effusion?
IV antibiotics for infection, thoracotomy if massive effusion
What is pneumothorax?
Abnormal presence of air in the pleural space
What are causes of pneumothorax?
Traumatic, iatrogenic, spontaneous, post-infectious, inhalation toxins, congenital
What are clinical manifestations of pneumothorax?
Sudden chest pain, tachypnea, dyspnea, cyanosis, ipsilateral shoulder pain, hyperresonance on percussion
What is the diagnostic test for pneumothorax?
Chest radiograph (CXR), CT scan for bullae and blebs
What is the treatment for pneumothorax?
Evacuating air from the pleural space and sealing the leakage”
What causes disorders of ventilation in short limb dwarfism?
Reduced thoracic cage size, lateral narrowing, and sometimes shortening of the thoracic spine.
Do most patients with short limb dwarfism survive?
Most patients do not survive, but some with asphyxiating thoracic dystrophy improve their ventilation as they grow up.
What is Werdnig-Hoffman disease caused by?
A decrease in motor neurons, chromatolysis, proliferation of astrocytes and microglia, and diminution of spinal cord ventral roots due to the loss of myelinated fibers.
What is a common symptom of Werdnig-Hoffman disease?
Severe skeletal muscle weakness with or without diaphragm involvement.
What does childhood interstitial lung disease (ILD) cause?
Rare respiratory disorders that are mostly chronic and associated with high morbidity and mortality.
What is the typical presentation of childhood ILD?
Insidious onset with symptoms like cough, dyspnea, exercise limitation, respiratory crackles, and wheezing.
What can be seen in the advanced stage of childhood ILD?
Finger clubbing and cyanosis during exercise or rest.
What diagnostic test is used for childhood ILD?
High-resolution CT, pulmonary function tests, bronchoalveolar lavage, and lung biopsy (gold standard).
What is the first-line management for childhood ILD?
Oxygen, nutrition, immunization, and avoidance of air pollution.
What are superior mediastinal tumors commonly associated with?
Thymus masses and cystic hygromas.
Where are cystic hygromas typically located?
In the superior and anterior mediastinum.
Which tumors are most commonly found in the middle mediastinum in children?
Lymphatic tumors, which are most common childhood malignancies.
What is the management for posterior mediastinum neurogenic tumors?
Surgery and radiation therapy, as they are often radiosensitive.
What are common primary benign pulmonary tumors?
Hamartomas, plasma cell granulomas, bronchial adenomas, papillomas, and hemangiomas.
What are the symptoms of obstructive sleep apnea (OSA)?
Loud snoring, difficulty breathing during sleep, and sleep-related breathing pauses.
How is obstructive sleep apnea (OSA) diagnosed?
Lateral neck radiograph and sleep study.
What is the treatment for obstructive sleep apnea (OSA)?
Tonsilloadenoidectomy, nasal continuous positive airway pressure (NCPAP), nasopharyngeal intubation, and craniofacial operations.
What are the symptoms of alveolar hypoventilation?
Sleep-related cyanosis, hypoventilation without snoring, and unexplained cor pulmonale.
How is congenital central hypoventilation syndrome treated?
With ventilatory support and, in some cases, diaphragmatic pacing.
What is a common complication of pneumonia in children?
Lung abscess, often involving mixed flora of aerobes and anaerobes.
What are the physical exam findings in lung abscess?
Decreased breath sounds (effusion and empyema), increased breath sounds (consolidation), scattered crackles, rhonchi, and finger clubbing in ⅓ of cases.
What is the treatment for a lung abscess?
Broad-spectrum antibiotics for 4-6 weeks, chest physiotherapy, postural drainage, and surgical drainage if no response to antibiotics.
What is pneumothorax?
Presence of gas in the pleural cavity.
Which type of pneumothorax occurs without underlying lung disease?
Primary spontaneous pneumothorax, commonly observed in tall males and smokers.
What is the treatment for pneumothorax?
Supplemental oxygen and chest tube thoracostomy (CTT) if the area is large.
What is atelectasis?
Partial or total collapse of a previously expanded alveolus or lung segment.
Which diagnostic sign is seen in atelectasis?
Ipsilateral mediastinal shift on chest x-ray (CXR).
What is bronchiectasis caused by?
Abnormal dilation, distortion, and destruction of the bronchial tree due to chronic infections or inflammation.
Which organisms are involved in bronchiectasis?
Necrotizing bacterial infections.
What are common symptoms of bronchiectasis?
Chronic cough, increased sputum production, progressive shortness of breath, easy fatigability, hypoxia, and hemoptysis.
What is the treatment for bronchiectasis?
Beta-2 agonists (salbutamol), broad-spectrum antibiotics, 2D echo, and annual vaccinations for influenza and pneumococcus.
What defines respiratory failure in children?
Inability to deliver oxygen and remove carbon dioxide from the pulmonary capillary bed, often indicated by PaCO2 >50 mmHg or PaO2 <60 mmHg on room air.
What are the types of respiratory failure?
Type I (Non-ventilatory): PaO2 is low; Type II (Ventilatory): PaCO2 is elevated.
What is the management for acute respiratory failure in children?
Oxygen, intubation, mechanical ventilation, and treatment of the underlying cause.
What is ARDS?
Acute non-cardiogenic pulmonary edema with bilateral infiltrates on CXR and a PaO2 to FiO2 ratio of <200.
How is ARDS in children different from adults?
Pediatric ARDS has a different pathophysiology and response to treatment.
What are the signs of respiratory failure?
Tachypnea, bradypnea, apnea, nasal flaring, chest retraction, head bobbing, and cyanosis.
What is the treatment for chronic respiratory failure in children?
Continuous oxygen supplementation at home or tracheostomy.
What is BiPAP used for in children?
Ventilatory support during sleep, especially for those with sleep apnea or intrinsic lung disease.
