Pleural disorders Flashcards
Describe the parietal pleura
- it lines the thoracic cavity, including the thoracic cage, mediastinum and diaphragm
- contains sensory nerve ending that can detect pain: pleuritis can be painful!!
Describe the visceral pleura
- lines the entire surface of the lung
- contains no sensory nerve endings that detect pain
What is the pleural space?
- potential space between the parietal pleura and visceral pleura filled with pleural fluid
What is pleural fluid?
- serous fluid that allows for parietal pleura (outer lining) and visceral pleura (inner lining) to glide over each other without separation
- provides lubrication and surface tension
- pleural fluid is prod by the parietal pleura and is absorbed by the visceral pleura as a continuous process
What are the mechanics of pulmonary ventilation? (relationship between the lungs and thoracic wall)
- lungs are surrounded by pleural fluid that lubricates movement of lungs within the cavity
- continual sunction of excess fluid into lymphatic channels acts like a glue to hold the lungs to the thoracic wall (allows for smooth movement)
- pleural pressure is a negative pressure that holds the lungs open (more negative pressure with inspiration)
What is intrapulmonary pressure?
- pressure within the alveoli
- as the chest expands on inspiration the intrapulmonary pressure becomes more negative, which causes air to be sucked into the lungs
What is intrapleural pressure?
- negative pressure is created in the pleural space as the thoracic cage enlarges and the lungs recoil during normal inspiration
- negative pressures may be lost if fluid collects in the pleural space, making the lung unable to expand fully
What is Pleuritis?
- it is a localized inflammation of pleural surfaces that produces sharp localized pain
- also known as pleurisy
- pleuritic pain is sharp, stabbing pain with splinting on inspiration
What is the clinical picture of pleuritis?
- localized, pleuritic chest pain increased with deep inspiration and coughing and may be associated with pleural rub
- pleural rub is a fine crackles best heard during inspiration and expiration at the site of chest pain
- ipsilateral shoulder pain
What are the causes of Pleuritis?
- viral infection (coxsackie B virus)
- thoracic trauma
- secondaray to pulm disorders: bronchiectasis, pneumonia, TB, pulmonary infarction, and lung cancer
- secondary to systemic diseases: RA, SLE, and metastatic cancer
How do you dx Pleuritis?
- CXR: normal unless primary lung disease
so dx is typically clinical, may do a work up to determine cause
What is the treatment of pleuritis?
- tx of primary cause
- sx tx of chest pain: moderate analgesics: NSAIDs, some pts may need course of narcotics or both
What is a pleural effusion?
results when fluid collects b/t the parietal and visceral pleural layers
- occurs when the normal flow of fluid is disrupted: too much fluid is produced and not enough fluid is removed
Clinical features of Pleural effusion?
- SOB
- cough
- pleuritic chest pain
- other signs and sxs depends on etiology
What are the 3 main causes of pleural effusion?
- CHF
- pneumonia
- malignancy
Dx of pleural effusion?
- careful hx
- thorough exam
- CXR
- chest CT
- pleural fluid analysis
What will you see on CXR that is a pleural effusion?
- order a PA and lateral decub
- if you see blunting of either costophrenic angle - indicates accumulation of between 250-500 ml of fluid
- lateral decubitus films will should fluid shift to dependent portion of thoracic cavity
- sub-pulmonic effusion: is accum of fluid between lung and diaphragm which gives false impression of elevated semi-diaphragm
Why is a thoracentesis helpful in pleural effusion eval?
- simple bedside procedure that permits fluid to be rapidly sampled visualized, and examined microscopically and quantified
- a systemic approach to analysis of fluid in conjunction with clinical presentation should allow the clinician to dx the cause of effusion in about 75% of pts
- this can be therapeutic as well as dx
How do you determine if pleural fluid is transudate vs exudate?
- gross appearance
- pH
- Gram stain, C & S
- cytology
- LDH
- protein
- glucose
- cholesterol
- amylase
What is Light’s criteria?
if at least one of following 3 criteria present, the fluid is defined as exudate:
- pleural fluid protein/serum protein ratio greater than 0.5
- pleural fluid LDH/serum LDH ratio greater than 0.6
- pleural fluid LDH greater than 2/3 the upper limits of lab’s normal serum LDH
What are exudative causes of pleural effusions?
- anything that causes inflammatory or infiltrative disease of the pleura (damaging capillary membranes):
neoplasm - disruption causes increased permeabiltity with lymphatic obstruction as well - lung cancer, breast cancer, lymphoma responsible for 75% of all malignant pleural effusions
infections: uncommonly assoc with acute bacterial pneumonias (small and transient), empyema (not just disruption of capillary membranes but the organisms have entered the pleural space), TB, viral pneumonitis, and mycoplasmal pneumonia
- autoimmune disease
- pulmonary infarction (PE)
- intra-abdominal pathology (development of sub diaphragmatic abscess, pancreatitis)
Transudative causes of pleural effusion? What it looks like?
- straw colored, clear, odorless fluid
- anything that causes increased hydrostatic pressure or decreased capillary colloid osmotic pressure such as:
CHF (most common), severe hypoalbuminemia (nephrotic and liver failure), and cirrhosis (assoc with ascites) - if transudate: no further lab analysis is indicated
If exudate you should consider what tests?
- WBC with diff
- bacterial culture
- cytological exam
- glucose level
- amylase
Tx focus of pleural effusions?
- transudative effusion: focus on systemic cause
- exudative: dependent on exact subtype
- consider chest thoracostomy: if gross pus/empyema, hemothorax, complicated parapneumonic processes, and malignant effusion
What is a parapneumonic effusion?
- pleural effusions that occur in the pleural space adjacent to a bacterial pneumonia
- typically are small and resolve with approp abx therapy
- however if bacteria invade the pleural space, a complicated parapneumonic effusion or empyema may result
What are the characteristics of a complicated parapneumonic effusion?
- persistent bacterial invasion of pleural space
- glucose less than 60 mg/dl
- pH less than 7.2
- positive culture
- pleural LDH greater than 3x the upper limit for serum
- pleural fluid is loculated (compartmentalized)
What cancers are the most common cause of malignant pleural effusions?
Lung cancer and breast cancer account for 50-65% of malignant pleural effusions
- others are: lymphoma and pleural mesothelioma
What type of effusion is a very likely indication of neoplasm?
- bloody pleural effusion occuring in a pt without a hx of trauma or pulmonary infarction is indicative of neoplasma in 90% of cases
Tx of malignant pleural effusions?
- serial thoracentesis (getting tapped regularly)
- chest tube with pleurodesis
- pleuroperitoneal shunt
- pleurectomy
What is a mechanical pleurodesis?
- ## electro-cautery scratch pad: the surgeon gently strokes the pleura, this roughens up the pleura so that when the abrasion heals the lung will adhere to the chest wall
What is a chemical pleurodesis?
- instill chemical irritant into pleural space which causes adhesion of the lung to the chest wall.
sclerosing agents used: Talc, bleomycin, or doxy - admin through a chest tube or by VATS to create inflammation and subsequent fusion of the parietal and visceral pleura
- goal is to cause an irritation b/t the 2 layers covering the lung
- the sclerosant irritates the pleurae which results in inflammation and causes the pleurae to stick together
- the procedure can be done at the bedside or in the operating room
What is a hemothorax, what is the cause?
- hemorrhagic pleural effusion
- results from blood accumulating in the pleural cavity
- usually due to trauma: a blunt or penetrating injury to the thorax, resulting in a rupture of the pleura, and this rupture allows blood to spill into the pleural space, equalizing the pressures between it and the lungs
What are causes of a spontaneous hemothorax?
- pulmonary: bullous emphysema, PE, infarction, TB, AVMs
- pleural: torn adhesions, endometriosis
- neoplastic: primary, metastatic
- blood dyscrasias: thrombocytopenia, hemophilia, and anticoagulation
- thoracic pathology: ruptured aorta, dissection
- abdominal pathology: pancreatic pseudocyst, hemoperitoneum
Goal of hemothorax tx? options for tx?
- to remove pleural blood and allow for complete lung re-expansion
- tx:
thoracentesis: bedside/US guided/ CT guided
thoracostomy drainage: the mainstay (chest tube)
thorascopic surgery
thoracotomy: massive hemothorax/instabiity/chronic hemothorax
What is atelectasis?
- incomplete expansion of lung which leads to the collapse of alveoli
- increased negative pressure can lead to collection of fluid in the porton of the lung which isn’t expanding
- this can cause an effusion by fluid leaking out of the lung into the chest cavity
- atelectasis typically leads to small pleural effusions not requiring intervention
What are the clinical manifestations of atelectasis?
- pain
- cough
- dyspnea
- dullness to percussion
- diminished or absent vocal resonance
- diminished or absent tactile vocal fremitus
- friction rub
What is a pneumothorax?
- collection of air within the pleural space
- pleural pressure in the affected hemithorax exceeds atmospheric pressure, from the result of a check valve mechanism that facilitates the ingress of gas into the pleural space during inspiration, but blocks the egress of gas from the pleural space during expiration
- impairs respiratory function
- decreases venous return to the right side of the heart
- pt can become toxic very quickly
What is the general management for a pneumothorax?
- first: evacuate the air
- second: address the underlying cause
- third: promote pleural symphysis
What is the classification system of a pneumothorax?
- spontaneous pneumo: primary and secondary
- traumatic pneumothorax:
pulmonary source, tracheobronchial source and esophageal source
Who is most likely to get a primary spontaneous pneumothorax?
- disease in younger peeps (15-35)
- affects males more than females
- tall, slim, body habitus (marfans body type)
- cigarette smoking implicated
- usual cause: rupture of subpleural bleb - small air filled lesions just under pleural surface
tx for primary spontaneous pneumothorax?
- tx is hospitalization, tube thoracostomy to closed drainage, lung re-expansion against chest wall, and control of any persistent air leak (if sig. pneumo)
- sometimes you can just observe pt if not in distress
What is a secondary spontaneous pneumo due to? Tx?
underlying pulmonary disease
- COPD/lung malignancy/CF
- necrotizing infections like TB, pneumocystis jirovecii
- Tx: O2, tube thoracostomy, persistent: VATS for resection or if pleurodesis needed
Causes of traumatic Ptx?
- parenchymal injury vs. Tracheobronchial vs Esophageal
- blunt or penetrating
- iatrogenic: hospital caused:
central lines/thoracentesis/bx
ET tube placement
endoscopy/ dilational techniques
operative - barotrauma: ventilation/blast injury
- boerhave’s syndrome (esophageal rupture)
What is an open pneumothorax?
- sucking-chest wound
- when a traumatic chest wall defect persists, through which ambient air enters the pleurals space during inspiration creating complete lung collapse
- dressing
- thoracostomy away from traumatic wound
Tx options for a pneumothorax?
- observation: inpatient vs outpatient
- oxygen
- thoracostomy drainage: 3rd interpsace - 5th interspace
- VATS if surgery reqd
What causes asbestosis? Characteristics? Spectrum of disease?
- caused by inhalation of asbestos fibers
- characterized by slowly progressive, diffuse pulmonary fibrosis.
- The spectrum of pulmonary disorders associated with asbestos exposure includes:
asbestosis, pleural disease (focal and diffuse benign pleural plaques) - malignacies (non-small cell and small cell carcinoma of the lung as well as malignant mesothelioma)
Clinical findings of asbestosis?
- most pts are asymptomatic for at least 20-30 years after the initial exposure
- usually the first sx is the insidious onset of breathlessness with exertion
- progressive dyspnea and may develop bibasilar crackles
- cough, sputum production, and wheezing are unusual
- lab studies not useful
- radiography: wide spectrum but ***pleural involvement is a hallmark
Tx or preventative measures for Asbestosis?
- no specific tx
- focus should be on preventive measures:
smoking cessation
early detection of physiologic and radiographic abnormalities (CXR and PFTs recommended every 3 to 5 years) - prevention of further airborne asbestos exposure
- supp O2 when there is resting hypoxemia or exercise induced oxygen desaturation
- prompt tx of respiratory infections
- pneumococcal and influenza vaccination
What is mesothelioma?
- insidious neoplasm arising from the mesothelial surfaces of the pleural
- 70% of cases associated with documented asbestos exposure
- synergistically increased risk of cancer if combined with smoking
- long latency of around 30-40 years from exposure to development of malignancy
Presentation and common physical findings of Mesothelioma?
- typical pt presents in 5th-7th decades with dyspnea and nonpleuritic chest pain
- common physical findings: unilateral dullness to percussion at lung base, palpable chest wall masses (endstage), and scoliosis towards the side of malignancy
radiology: most will show unilateral pleural abnormality with a large, unilateral pleural effusion
What are the different collagen-vascular diseases that can affect the pleura?
- RA
- SLE
- sarcoidosis
- mixed CT disease
- Wegener’s Granilomatosis
- Sjogren’s syndrome
Causes of pleuritic chest pain?
- viral pleurisy
- pneumonia
- acute PE
- pneumothorax
- pericarditis
- collagen vascular disease
- drug induced lupus
- IBD
- familial mediterranean fever
- radiation pneumonitis
- pulmonary histoplasmosis, infection with lung fluke paragonimus
