Thoracic Surgery Flashcards
Leading cause of cancer deaths in the US
Bronchogenic tumors
Is it better for prognosis to resect or radiate/chemo bronchogenic tumors?
resect
Advantages of VATS vs. open surgery
Decrease in post-op complications:
- Dysrhythmias
- MI
- PE
- Pneumonia
- Empyema
COPD patients are how many times more at risk of getting lung cancer
4x
Risk factors for bronchogenic tumors
Smoking, air pollution, industrial chemicals
If lung cancer patient also needs coronary bypass, which procedure should be done first?
- Coronary bypass
- 6 week delay if this is needed
What electrolyte abnormality occurs in up to 25% of lung cancer patients? What are the signs and symptoms?
Hypercalcemia
S/S: polyuria, polydipsia, confusion, vomiting, abdominal cramping, bradycardia
Smokers should be evaluated for what conditions prior to thoracic surgery?
HTN or ischemic heart disease
Patients with history of COPD need what type of testing prior to thoracic surgery?
Stress testing
Why do patients requiring thoracic surgery for lung cancer require endocrine evaluation?
To rule out para-neoplastic syndromes caused by some lung tumors
- Can cause carcinoid syndrome
Airway evaluation required for mediastinal masses
Radiographic
To determine if there is airway infringement
Symptoms of COPD
- Paradoxical breathing
- Tympanic chest percussion
- Rhonchi
- Wheezing
Symptoms of Cor pulmonale
- JVD
- Peripheral edema
- Split S2
- Rales
What are we looking for on chest x-ray of patient with lung cancer?
Evaluating for:
- airway infringement
- CHF
- pneumothorax
- tracheal shift
- PA enlargement
What does PA enlargement indicate on CXR?
Sign of increased pulmonary vascular resistance
EKG abnormality seen in RVH
Tall R in V1
EKG abnormality seen in R atrial hypertrophy
Biphasic P in V1
EKG abnormality combo indicative of increased risk of ischemia/infarction
Pathologic Q waves + LVH
Other EKG abnormalities we are looking for pre-op
S-T depression, BBB, T wave inversion
Best initial tool to evaluate pulmonary HTN?
Caveat?
Echo is best initial tool
BUT, higher level studies may need to follow
What room air ABG value indicates poor function in a COPD pt?
CO2 >45
Lab values indicative of increased risk of post-op complications
- SpO2 <90
- Albumin <3.6 g/dL–> increases risk 2.5 times
- BUN >22 mg/dL
- Renal function labs elevated esp. in chemo
- Electrolytes (Na, K, Ca especially)
Why does low albumin place patient at higher postop risk of complications?
Makes them prone to third-spacing and pulmonary edema
Which test is best predictor of pulmonary function?
No one test is good predictor
- Multi-modal testing is best
One pulmonary function test evaluates responsiveness to bronchodilators. How much of an improvement should be seen?
12% increase
What are general cut-offs in pulmonary function for increased risk?
- Predicted Post-op FEV1 and DLCO <40%
- PPO VO2 max <15 ml/kg/min
VO2 max of pt with inability to climb 1 flight of stairs
< 10
VO2 max of >20
Ability to climb 5 flights of stairs
Risk of complications in non-cardiac surgery for smokers?
Previous smokers?
Non-smokers?
- Smokers= 22%
- Past smokers = 13%
- Non-smokers - 5%
What percent of lung cancer patients are smokers?
87%
Mortality for smokers vs non-smokers in lung cancer
- 5% in smokers
0. 4% in non-smokers
Calculate pack year index for patient who smoked
0.5 pack/day for 14 years
7 pack year
What pack year has increased incidence of complications over “moderate smokers”?
> 20 pack year
How long before surgery must patient quit smoking to see risk reduction?
Best time to quit smoking before surgery?
- > 4 weeks
- At least 8 weeks before has more improvement
why might smoking cessation 4 days before surgery actually increase risk?
Increased mucus production
How does smoking cessation 1-2 weeks before surgery affect lung function?
Does this improve outcomes?
- Carboxyhemoglobin drops and mucociliary clearance improves
- no difference in outcomes
Best 2 leads to monitor during surgery
- Lead II for dysrhythmias
- V5 for ischemia
Which arm should art line be placed in for thoracotomy?
Dependent arm
Does PA catheter improve outcomes in thoracic surgery?
No
Frequent inaccurate measurements
Caution in vessels that could be clamped or ligated
Problem with EJs in thoracic surgery
Easily kinked in the lateral position
You are going to place a subclavian CVL to monitor CVP on your patient with lung cancer in the OR prior to excision of the mass. Which side should you place the CVL?
On the operative side so that if you do cause a pneumo its not in your one decent lung, its in the one they are about to operate on anyways
Tell me about the trachea
- Where does it begin?
- How long is it?
- Where does it bifurcate?
- Begins at C6
- 11-12 cm long
- Bifurcates at T5 (sternomanubrial joint)
Tell me about the Right Mainstem Bronchus
- Is it narrower or wider than the left?
- Degree of angle from the trachea
- What does it divide into?
- Where is the orifice from the carina?
- Wider than left
- angles away from trachea at 20 degrees
- Divides into 3 lobar branches
- Orifice of right upper lobe 1-2 cm from carina
Tell me about the Left Mainstem Bronchus
- Is it narrower or wider than the right?
- Degree of angle from the trachea
- What does it divide into?
- Where is the orifice from the carina?
- Narrower than right
- Angles away fro trachea at 45 degree
- Divides into 2 lobar branches (upper, and lower)
- Orifice of left upper lobe 5 cm from carina
Pressures in lung zone 1
PA > Pa > Pv
Pressures in lung zone 2
Pa > PA > Pv
Pressures in lung zone 3
Pa > Pv > PA
If a patient is laying supine, where is each lung zone?
Zone 1 is anterior
Zone 2 is the axilla
Zone 3 is posterior
In awake, spontaneous ventilation where is perfusion and ventilation best?
bases of lungs
Why is ventilation better in the bases?
- More negative pressure in the apices keep alveoli distended
- Alveoli in bases are less distended and more compliant, so most tidal breathing distributed to bases
Effects of awake patient laying lateral on V/Q
- Better ventilation of dependent lung
- Perfusion higher in dependent lung (gravity)
- No significant change in V/Q
Effect of laying lateral on diaphragm
Cephalad diaphragm displacement and reduced FRC
Effect of anesthetized patient with spontaneous ventilation laying lateral with chest closed on V/Q
- Nondependent lung is more compliant- so increased ventilation
- Dependent lung is more perfused because of gravity
- Result is V/Q mismatch
V/Q in mechanically ventilated paralyzed patient lying lateral with chest closed
What intervention can change this?
- diaphragm no longer helping maintain FRC
- Further decrease in ventilation in Dependent lung
- Increased ventilation in non-dependent lung
- More V/Q mismatch
Add PEEP to improve FRC and lessen V/Q mismatch