Diseases (Pleura, Cancer, Vascular, ARDs, RF) Flashcards
The visceral + parietal pleura shares many things in common:
- rich network of lymphatics
- blood supply from the systemic circulation
What is the difference then?
Parietal pleura receives innervation from intercostal + phrenic n and their lymphatic networks contain stoma
Visceral pleura does NOT have any innervation and does NOT contain stoma.
Pleura consists of 4 layers:
Which layer contains the lymph and vasculature?
Which layer is most susceptible to developing cancers as a result of asbestos exposure?
1) mesothelium - frequent site of mesotheliomas as a result of asbestos exposure
2) loose connective tissue
3) elastic tissue
4) areolar tissue - lymph and vasculature
What is the purpose of stoma present in the lymphatic networks?
drains fluid, large molecules, particles, and cells from the pleural space
Physiologically, how does pleural effusions develop?
What are examples of altered states that cause this?
When the rate of fluid formation/filtration»_space; rate of fluid reabsorption (via lymphatics)
examples:
- increased systemic Pcap (ie RHF, increase fluid filtration from parietal layer)
- increased pulmonary Pcap (ie LHF, increase fluid filtration from visceral layer)
- increased capillary permeability
- decrease lymphatic outflow (tumor)
- decrease pleura pressure (atelectasis)
- decrease transdiaphragmatic transport (cirrosis)
How does RHF cause pleural effusions?
increased systemic Pcap (ie RHF, increase fluid filtration from parietal layer of pleura)
How does LHF cause pleural effusions?
increased pulmonary Pcap (ie LHF, increase fluid filtration from visceral layer)
Movement of fluid across the pleural space is governed by Starling’s Law, which is influenced by these 4 factors:
1) surface area
2) hydrostatic pressure
3) oncotic pressure
4) size of pore
Fluid in the pleural space is mostly derived from which layer of the pleura?
Parietal pleura - due to a net hydrostatic pressure from the systemic capillaries that moves fluid into the pleural space
Pleural effusions can be of two types:
transudate (low protein)
- due to change in systemic factors (hydrostatic pressure, oncotic pressure); likely due to CHF, cirrhosis, nephrotic syndrome, hypoalbuminea
exudate (high protein)
- due to change in the capillary permeability of the pleura; likely due to malignancy, infection, inflammation of the pleura
What is the Light Criteria? What is it used for?
if pleura/serum protein >0.5 and if pleura/serum LDH >0.6, then the fluid is EXUDATE.
What are some of the symptoms observed in a patient with pleural effusions?
dysnpea, pain, cough (due to atelectasis, vagal stimulation, and some underlying disease)
What is indicative of a friction rub?
inflammation, exudative pleural effusion
What are some of the physical findings observed in a patient with pleural effusions?
less chest wall expansion decreased tactile fremitus (palpable vibration) dullness decreased breath sounds friction rub
What type of defect is pleural effusions?
restrictive defect
What are some tests that can be performed to diagnose the etiology of pleural effusion?
cell count, cytology, culture
glucose, amylase, pH
CCC, GAP
What is a chylothorax?
How do you know if this has happened?
What are some common causes of this?
damage to the thoracic duct that results in a leakage of chyle (lymphatic fluid of intestinal origin) into the pleural space.
fluid has high TG or cholesterol content and/or a milky apperance
causes: malignancy (metastatic dz, lymphoma), trauma
What is the difference between a spontaneous and traumatic pneumothorax?
What are complications of either one of these?
spontaneous (2 types)
1˚ = healthy patients that have apical blebs
2˚ = Dz patients (COPD, CF)
traumatic (2 types)
surgical = thoractomy
non-surgical = rib fracture, blunt trauma, iatrogenic
Can lead to tension pneumothroax
What is tension pneumothorax?
What are the physiological consequences of this?
where the pressure in the pleural space is increased due to a one-way valve that prevents egress of air during expiration.
consequences:
- impaired venous return due to increased intrathoracic/pleural pressure
- severe hypoxia, since the collapsed lung functions as a massive SHUNT
What are some of the symptoms of a pneumothorax?
What are some of the physical exams findings?
Therapy?
symptoms: breathlessness, cough, chest pain, tachycardia, cyanosis, hypotension
physical exam:
hyper-resonance
decreased breath sounds
decreased tactile fremitus (palpable vibration)
asymmetry in chest wall size
tracheal shift away from side of pneumothroax
Therapy:
- air aspiration from pleural space
- oxygen to reverse hypoxemia
- pleurodiesis
- surgery
What are the two major types of lung cancer? subtypes?
I - small cell lung carcinoma (SCLC) II - non-small cell lung carcinoma (NSCLC) a) adenocarcinoma b) squamous cell carcinoma c) large cell carcinoma
What is small cell lung carcinoma?
In what population does it occur most often in?
How is SCLC classified? What is the purpose of treatment at these stages?
aggressive cancer that tends to grow and spread quickly and often metastasizes
occurs almost exclusively in smokers
classified as:
LIMITED - cancer is within one lung and/or mediastinal lymph nodes
trmt: chemo + radiation to cure the patient of cancer
EXTENSIVE - cancer has spread to the other side of the chest or to distant locations in the body
trmt: chemo to relieve the patient of symptoms, prolong life, and limit spread of cancer
What are the genetic mutations observed in SCLC and NSCLC?
both have decreased p53 and Rb, but increased myc.
Adnenocarcinoma has increased ras as well.
What are general clinical presentations of lung cancer?
What are paraneoplastic manifestations of SCLC? NSCLC?
general: cough, dyspnea, obstructive pneumonitis, SVC syndrome, hemoptysis, chest pain, fatigue, weight loss
paraneoplastic SCLC:
- ectopic ADH secretion
- SIADH
- Eaton lambert syndrome (muscle weakness due to autoimmune rxn aganist VG Ca channels)
- neuropathy
paraneoplastic NSCLC
- cachexia (dramatic weight loss and muscle atrophy)
- hypercalcemia (squamous cell carcinoma)
- skeletal, CT syndromes (adenocarcinoma)
- gynecomastia (large cell carcinoma)
How is prognosis of lung cancer determined?
1) performance status (ability to do daily activities)
2) stage of cancer
3) LDH levels
What are the 4 stages of NSCLC?
1 - tumor confined within lung parenchyma and has NOT spread to regional lymph nodes, <3 cm, surrounded by lung or visceral pleura, not invading into a main bronchus
2 - tumor confined within lung parenchyma and has spread to regional lymph (intrapulmonary/hilar) nodes
3 - tumor spread to mediastinal lymph nodes or to contralateral lung
4 - tumor spread outside of the lung
Explain the significance of the following lab values for lung cancer:
- anemia
- LDH
- CRP
- a1-acid glycoprotein
Anemia
LDH - tissue breakdown releases LDH, increased in cancer and inflammatory diseases
CRP - acute phase reactant protein that is elevated in inflammation
a1-acid glycoprotein - acute phase reactant protein that is elevated in inflammation
What is the ideal tumor therapy? (4)
targets tumor specific molecules that drive tumor growth
reversible
dispensable in normal cells
measurable
What are examples of non-small cell carcinoma?
What are examples of neuroendocrine tumors (tumors that secrete hormones directly into the blood)
non-small cell carcinomas (LAS)
- adenocarcinoma
- squamous cell carcinoma (SCC)
- large cell carcinoma
neuroendocrine tumors (CS)
- small cell carcinoma
- carcinoid tumor
