Thoracic Flashcards
What is a good way to remember the lymph node stations?
single digits are mediastinal and double digits are hilar
Describe the course of the thoracic duct.
- from the cistern chyli at L2
- closing T5 from right to left
- emptying into the junction of the L internal jugular and subclavian veins
- you fund the “duck” between the two “goose” (azygoose and esophagoose)
What is the final destination of the azygos vein?
the SVC
Where do the phrenic and vagus nerves run in relation to the hilum of the lung?
- the phrenic anteriorly
- the vagus posteriorly
What are the anatomic boundaries of the mediastinum?
- sternum anteriorly
- vertebrae posteriorly
- pleurae laterally
- thoracic inlet superiorly
- diaphragm inferiorly
What are the functions of type I and type II pneumocytes?
- type I are for gas exchange
- type II make surfactant
What are the pores of Kahn?
pores in the alveoli that enable direct air exchange
What are light’s criteria?
exudative if one or more of the following is true
- pleural to serum protein ratio > 0.5
- pleural to serum LDH ratio > 0.6
- pleural LDH > ⅔ normal limit of serum
What is the best predictor of post-op complications for patients undergoing lobectomy? What else is predictive?
- FEV1 < 80% is the best predictor
- DLCO < 10mL/min/mm (40%) predicted
How are PFTs used peri-operatively for patients undergoing lobectomy?
- the best predictor of post-op complications is an FEV1 < 80% predicted
- if borderline, can use a V/Q scan to show contribution of the diseased lung
- DLCO < 40% predicted is predictive of peri-operative risk
If a patient is planned to undergo lobectomy but has an FEV1 close to 80%, what can be used to better assess the risk for post-op complication?
a V/Q scan can show the contribution to pulmonary function that the diseased lobe makes
What size must a pleural effusion be to be visible on CXR?
at least 300cc
How is retained hemothorax managed?
with a chest tube followed by VATS/thoracotomy for washout
What is the treatment for empyema?
decortication
How is a chylothorax diagnosed?
- appears white and milky
- has a triglyceride level > 110 with lymphocyte predominance
- sudan red stains fat and will therefore be positive
What are the most common etiologies for chylothorax?
- half are due to malignancy, particularly lymphoma
- the other half are traumatic or iatrogenic with symptoms beginning after oral intake begins
How is chylothorax treated?
- first line is conservative management with a low-fat, medium-chain fatty acid diet (avoidance of long chains) or bowel rest with TPN, can also add octreotide
- If this fails or the etiology is traumatic, then the next step is ligation of the thoracic duct in the lower right mediastinum versus talc pleurodesis
What is the difference between a primary and secondary pneumothorax?
secondary are due to an underlying medical condition
What are the features of tension pneumothorax?
- absent breath sounds
- hypotension and tachycardia
- labored breathing and tachypnea
- chest pain and dyspnea
- prominent neck veins
What are the indications for operative intervention for pneumothorax?
- persistent air leak (>4 days) is an indication for VATS pleurodesis
- second recurrence of primary pneumothorax is an indication for blebectomy
- first occurrence of primary pneumothorax in a high risk professional (scuba diver, pilot)
If a patient has recurrent spontaneous pneumothorax and they go to the OR for blebectomy but blebs aren’t seen, what should you do?
an apical wedge resection
For stable patients with primary or secondary pneumothorax, what size pneumothorax is an indication for a tube?
- primary greater than 3 cm at the apex or 2 cm at the hilum
- secondary in all cases, regardless of size
How do you diagnose and manage acute mediastinal infection?
- diagnose with CT chest
- manage with source control and antibiotics
- sternal debridement if etiology is posted sternotomy
- cervical drain if it is a descending cervical infection
- VATS to drain mediastinum into pleural space if secondary to lower mediastinal infection
What is the most common cause of mediastinal adenopathy?
lymphoma
What is the most common type of mediastinal tumor in adults and children?
neurogenic, found in the posterior mediastinum
What is the most common site for a mediastinal tumor?
anterior
What is the differential for an anterior mediastinal mass?
- think “terrible T’s”
- thymoma, teratoma, (ectopic) thyroid, terrible lymphoma
What is the relationship/associations between thymomas and myasthenia gravis?
- 50% are malignant
- 50% are symptomatic
- 50% have myasthenia gravis
- 10% of MG patients have thymoma
- 80% of MG patients improve with thymectomy
Describe the diagnosis, etiology, and treatment of chylothorax.
- diagnosis is made based on finding white, milky fluid with a triglyceride level greater than 110 that stains with Sudan red (stains fat)
- half are due to malignancy, the other half to traumatic or iatrogenic injury of the thoracic duct
- treat with avoidance of long-chain fatty acids versus bowel rest and TPN, octreotide is second line
- operative intervention indicated for traumatic injury or failure of conservative management: ligation of thoracic duct in low right mediastinum versus talc pleurodesis
What is the most common cause of SVC syndrome?
malignancy is most common, particularly small cell
What is the treatment for SVC syndrome?
position patient to reduce edema, steroids, anticoagulation, emergent radiation if extreme
What is the only real indication for emergent radiation therapy?
very extreme SVC syndrome secondary to malignancy
What is the recommendation for lung cancer screening?
annual low dose CT for 3 years in those 55-80 with a greater than 30 pack year history who have quit in the last 15 years
What is the strongest prognostic indicator for patients with lung cancer?
nodal involvement
What is the most common site of lung cancer metastasis?
brain (also goes to supraclavicular nodes, contralateral lung, bone, liver, adrenal)
How should pulmonary nodules be followed or evaluated?
- should be followed for two years
- if low risk of cancer, serial CT at 3, 6, 12, 24 months
- if med risk of cancer, PET/CT and biopsy
- if high risk of cancer, VATS biopsy with frozen and resection if malignant
How long should solitary pulmonary nodules be watched if no growth is seen?
two years
What is the most common type of lung cancer?
non-small cell
Which lung cancers are more central?
- squamous and small cell
- adenocarcinoma is more peripheral
What are the common paraneoplastic syndromes associated with lung cancer?
- squamous with PTHrP causing hypercalcemia
- small cell with ACTH and ADH secretion
Describe TNM staging for lung cancer.
- T1 is < 3 cm
- T2 is 3-5 cm
- T3 is 5-7 cm or invading chest wall or pericardium
- T4 is >7 cm or invading mediastinum
- N1: ipsilateral peribronchial or hilar nodal involvement
- N2: ipsilateral mediastinal or subcarinal node involvement
- N3: contralateral nodal involvement
- M1: nodules in contralateral lung, malignant pleural effusion, malignant pericardial effusion, distant metastasis
How is lung cancer treated?
- stage I: resection or definitive radiation if not a surgical candidate
- stage II: resection or definitive radiation if not a surgical candidate
- locally advanced stage III: resection after neoadjuvant chemoRT
- stage III with T4 or N3: chemo radiation
- stage IV: palliative resection or radiation
When can you do VATS versus open resection of a lung cancer?
VATS okay for tumor < 5cm, peripheral disease, and no regional lymphadenopathy or local invasion
What surveillance is recommended for lung cancer?
- stage I/II: CT chest every 6 months for 3 years then annual noncon CT chest
- stage III/IV: CT chest every 3-6 months for 3 years, then every 6 months, then every year
What volume of blood from a chest tube following trauma indicates a need for thoracotomy?
> 1500cc initially or >200cc every hour for 3 hours
How is a tracheoinnominate fistula managed?
- temporize with overinflation of the cuff or anterior pressure with a finger through the tracheostomy opening
- definitive treatment with sternotomy and ligation of innominate artery
How can you prevent development of a tracheoinnominate fistula?
place it between the 2nd and 3rd tracheal ring
Where are bronchiogenic cysts found and how are they managed?
found posterior to the carina and require surgical resection
What is the most likely diagnosis for a popcorn lesion in the lung with calcifications?
a benign hamartoma, repeat CT chest in 6 months
What are the most common lung tumors, benign and malignant, in children?
- benign: hemangioma
- malignant: carcinoid
What type of lung cancer mimics pneumonia?
bronchoalveolar cancer, which grows along the alveolar walls and is usually multifocal
