Miscellaneous lung disease: Pulmonary Emboli, pulmonary HTN, ARDS, and obstructive sleep apnea

Question 1

What is the presentation of someone with pulmonary embolus

Answer 1

They will have sudden onset of shortness of breath but with clear lungs on auscultation and a normal chest X-ray

Other hints: Pleuritic chest pain, tachypnea, tachycardia, hemoptysis

Question 2

What is the diagnostic tests for PE and their associated abnormalitity (this is a long answer)

Answer 2

Many tests that may or may not give answers

Best initial test: Chest X-ray, EKG, and ABG

1. ) Chest X-ray: Usually normal, but most common abnormality is atelectasis. Less common are wedge shaped infarctions (and more pg 160)
2. ) EKG: Sinus tachycardia will be present, most common is nonspecific ST-T wave changes. Less common is right axis deviation, right ventricular hypertrophy, or RBBB
3. ) ABG: Hypoxia and respiratory alkalosis (high pH and low pCO2)
4. ) Do spiral CT (CT angiogram) after the first three tests
5. ) V/Q scan: If normal, a clot is excluded - a positive test would be ventilation is there but no perfusion

Most accurate test: Angiography although dangerous

Question 3

What is the role of the D-dimer test in PE

Answer 3

D-dimer test: Negative test excludes clot, but positive test doesn’t mean anything - this is the correct answer when pretest probability of PE is low and you just want a simple noninvasive test

Question 4

What are all the treatments for PE, which is the best treatment, and when are the other treatments the correct answer

Answer 4

Best test: Heparin + warfarin and get INR to 2-3

Other treatments

1. ) IVC - only when anticoagulants are contraindicated such as melena and CNS bleeding, if recurrent emboli on heparin, or RV ventricular dysfunction
2. ) Thrombolytics: Hemodynamically unstable patients with hypotension and tachycardia, or acute RV dysfunction
3. ) Direct acting thombin inhibitors (argatroban, lepirudin): Heparin-induced thrombocytopenia
4. ) Never aspirin

Question 5

What is pulmonary hypertension and why is it caused

Answer 5

Any chronic lung disease causing back pressure into pulmonary artery

1. ) Most forms idiopathic
2. ) Chronic diseases such as COPD or fibrosis elevates pulmonary artery pressure
3. ) Hypoxemia reflexively vasoconstricts pulmonary circulation but causes pulmonary hypertension

Question 6

What is the presentation of someone with pulmonary hypertension

Answer 6

Very non specific, dyspnea, fatigue, chest pain, pulmonary/tricuspid insufficiency - hard to tell on physical examination

Question 7

What are the diagnostic tests you can use to determine if someone has pulmonary hypertension

Answer 7

1. ) Best initial test: Chest X-ray/CT - shows dilation of proximal pulmonary arteries with narrowing of distal vessels
2. ) Right heart/swan ganz catheter - most accurate test because can directly measure pressures

Other hints: EKG or echo showing RA/RV hypertrophy
V/Q scan will determine if cause is PE, and CBC showing polycythemia will confirm cause is hypoxia

Question 8

What is the treatment for pulmonary hypertension

Answer 8

1.) If underlying cause, treat that - first priority

2. ) If idiopathic, your choices are
   a. ) Prostacyclin analogues (PA vasodilators): Epoprostenol (any __prost)
   b. ) Endothelin antagonists: Bosentan
   c. ) Sildenafil

Also use oxygen which slows down disease progression

Only cure is lung transplantation

Question 9

How would a patient with obstructive sleep apnea present

Answer 9

Daytime solomnesce and history of loud snoring. Possible headache, depression, HTN, erectile dysfunction

Question 10

What is the most accurate and done test for obstructive sleep apnea

Answer 10

Polysomnography (sleep study)

Question 11

What is the treatment for obstructive sleep apnea in order

Answer 11

1. ) Weight loss and avoid alcohol
2. ) Nasal CPAP
3. ) Surgical widening of airway if this fails
4. ) Avoid sedatives (i.e. alcohol, benzos)

Remember, there is no pharmacology in this

Question 12

What is acute respiratory distress syndrome

Answer 12

Respiratory failure from overwhelming lung injury or systemic disease causing severe hypoxia, with decreased surfactant and lung cells leaky so alveoli fill with fluid

Question 13

What are causes of the overwhelming lung injury that causes ARDS

Answer 13

Mostly idiopathic, but injuries and illnesses can damage alveolar cells and capillary endothelial cells

These include: Sepsis, lung contusion, near drowning, burns or pancreatitis

Question 14

What is the diagnostic tests for ARDS

Answer 14

Chest X-ray/CT showing bilateral infiltrates that confluense so the entire CT on one side looks whited out. But you will see little columns of blackness (air bronchograms) that represent only spaces left where air is

Also, PO2/FIO2 ratio is below 200 as definition of ARDS (FIO2 is always 0.21). Also, by definition, right heart catherization is normal, that is, wedge pressure is normal

Question 15

What is the treatment for ARDS

Answer 15

No actual treatment, can only give support via 6ml/kg of tidal volume mechnical ventilation

Steroid effect unclear. Can use PEEP too to decrease FIO2 because above 50% is toxic to lungs, make sure plateau pressure is less than 30 cm of water measured on the ventilator.