17. Pulmonary and Critical Care

Question 1

Complications of positive pressure ventilation (PEEP)?

Answer 1

1. alveolar damage
2. pneumothorax (SOB, tachy, tracheal deviation, unilat absence of breath sounds). Central venous pressure rises bc ventral veins can stretch from air in the chest cavity
3. Hypotension
   Note: cardiac tamponade can also lead to hypotension and elevated central venous pressure like in a pneumothorax, but has no unilateral absence of breath sounds

Question 2

What has been proven to prolong survival in patients with COPD and significant chronic hypoxemia?

Answer 2

Long-term supplemental o2 therapy

Note: SaO2 <=88%, PaO2 <=59 should be started on this

Question 3

How can a PE present as hemoptysis?

Answer 3

Occlusion of a peripheral pulm artery by thrombus can cause pulmonary INFARCTION with pleuritic pain and hemoptysis. Occurs in 1-% of PE patients.

Question 4

When is noninvasive positive-pressure ventilation (NPPV) indicated?

Answer 4

Acute exacerbation of COPD - dec mortality, rate of intubation, hospital length of stay, and risk of nosocomial infx.
Intubation with mechanical ventilation is recommended for patients who fail NPPV

Question 5

Mechanical ventilation improves oxygenation by providing an inc fraction of inspired oxygen (FiO2) and Positive end expiratory pressure (PEEP). FiO2 should be reduced as soon as possible below what level because it predisposes to oxygen toxicity.

Answer 5

<60%.

Note: PEEP may need to be increased to maintain adequate oxygenation

Question 6

Which side are diaphragmatic ruptures most common on?

Answer 6

Left because right is protected by the liver

Question 7

Patient with chronic cough that is worse overnight and not improved with antihistamine therapy should be suspected of having what? How do you dx?

Answer 7

Asthma - can present with chronic cough that’s predominantly nocturnal.
PFTs
Note: other causes of chronic cough are post nasal drip, GERD, ACE inhibitors

Question 8

What is the initial treatment of choice in asymptomatic or mildly symptomatic patients with hyponatremia due to SIADH (eg complication of small cell lung cancer)

Answer 8

Fluid restriction

Question 9

After CXR, what is done to evaluate a solitary pulmonary nodule?

Answer 9

Chest CT. From this you decide to observe, bx or resect the nodule.

Question 10

What should be done first in a patient with hemoptysis and high clinical suspicion for pulmonary Tb?

Answer 10

Place patient in respiratory isolation to prevent spread of infection before further diagnostic eval and treatment

Question 11

In a patient with hemoptysis, what is the procedure of choice to ID the site?

Answer 11

Bronchoscopy

Patient should also be placed with the bleeding lung in the dependent position (lateral)

Question 12

Idiopathic pulmonary fibrosis is a restrictive lung disease due to excess collagen deposition in peri-alveolar tissues. What does this due to the A-a gradient

Answer 12

Increases the A-a gradiant bc the excess collagen causes scaring, impairs gas exchange, causing an increased ventilation perfusion mismatch.

Question 13

What is the prime objective in management of rib fracture?

Answer 13

Adequate pain control to prevent hypoventilation and the associated complications of atelectasis and pneumonia

Question 14

Of the main cell types of lung cancer, what is the most common in both smokers and non smokers? Location?

Answer 14

Adenocarcinoma. Usually located peripherally and may present as a solitary nodule.

Question 15

management of pneumothorax

1. small pneumo in stable patient
2. large pneumo in stable patient
3. pneumo in hemodynamically unstable patient

Answer 15

1. Observation and supplemental o2 (enhances speed of resorption
2. decompression with a large-bore needle in 2nd or 3rd intercostal space in midclavicular line or at 5th intercostal space in mid or anterior axillary.
3. Emergent thoracostomy tube placement

Question 16

Atelectasis is a common postop complication. How does it develop?

Answer 16

Shallow breathing and weak cough due to pain. Most common on postop days 2 and 3 after abd or thoracoabdominal surgery.
Incentive spirometry decreases incidence

Question 17

ARDS is associated with hypoxemia and bilateral alveolar infiltrates not fully explained by volume overload. It impairs gas exchange, causes pulmonary HTN, and does what to lung compliance?

Answer 17

DECREASES lung compliance (loss of surfactant and inc elastic recoil of edematous lungs).
Inc A-a gradient

Question 18

Presence of 1+ clinical indicators of thermal inhalation to the upper airway and/or smoke inhalation injury to the lungs warrants early intubation to prevent upper airway obstruction by edema. what are these indicators?

Answer 18

burns on the face, singing of the eyebrows, oropharyngeal inflammation/blistering, oropharyngeal carbon deposits, carbonaceous sputum, stridor, carboxyhemoglobin >10%, hx of confinement in a burning building

Question 19

What defines a high risk of malignancy for a solitary pulmonary nodule in terms of size, pt age, smoking status, smoking cessation, and nodule margin characteristics? Best next step?

Answer 19

1. size: >=2cm
2. pt age: >60
3. smoking status: current
4. smoking cessation: <5y
5. margin: corona radiata or spiculated
   Should surgically excise these nodules
   Note: following the nodule with serial Cts is approp for low prob for malignancy nodules.

Question 20

What are indications of impending respiratory failure in severe asthma exacerbation? Tx?

Answer 20

Elevated or normal PaCO2 (should be decreased if approp resp drive from hyperventilation). Dec breath sounds, absent wheezing, dec mental status, hypoxia with cyanosis are other signs.
Endotracheal intubation to maintain o2 and ventilation

Question 21

What should be done to further evaluate an individual with recurrent episodes of pneumonia in the same location?

Answer 21

CT scan of the chest since lung malignancy is a potential cause.
Note: barium swallow can be used to eval GERD or dysphagia which can also cause recurrent pneumonia

Question 22

When are abx indicated for tx of acute COPD exacerbation?

Answer 22

Moderate to severe exacerbation (>=2 cardinal sx) or if they need mechanical ventilation.
Not indicated in mild exacerbation
Cardinal sx: inc dyspnea, inc cough, sputum production

Question 23

Patient with hx of cancer, worsening shortness of breath over a couple of weeks that’s worse at night should raise concern for what? Physical exam findings?

Answer 23

Malignant pleural effuse d/t breast cancer recurrence.

PE: dec breath sounds, dec tactile fremitus, dull to percussion

Question 24

Pulm contusion is a common complication of blunt thoracic trauma. What is the hallmark of a pulmonary contusion on CT and xray? Management?

Answer 24

patchy, irregular (nonlobular) alveolar infiltrate

Manage: supportive, pain control, pulm hygiene

Question 25

Hypocapnia and resp alkalosis in a patient with hx of coronary artery disease, bibasilar crackles, dec breath sounds at the bases is due to what?

Answer 25

CHF exacerbation with possible pleural effusion. LV dysfunction allows fluid to pool in the lungs

Question 26

What does a flow-volume loop look like if there is a fixed upper-airway obstruction?
What is a common cause of an acute fixed upper-airway obstruction?

Answer 26

Flattens top and bottom of the loop due to limiting of inspiration and expiration
Laryngeal edema secondary to allergy - tx with epi, corticosteroids, antihistamines

Question 27

Cough with large-vol mucopurulent sputum production, hemoptysis, and dyspnea are common in what condition? What imaging is diagnostic?

Answer 27

Bronchiectasis

High-resolution CT (bronchial dilation, lack of airway tapering, and bronchial wall thickening)

Question 28

Asthma <=2 days per week, nighttime awakenings <=2x per month, normal FEV1 and FEV1/FVC ratio and no activity limitations is classified as intermittent or persistent asthma? management?

Answer 28

Intermittent

SABA - short acting beta agonist (eg albuterol) - don’t need daily controller meds (eg inhaled corticosteroid)

Question 29

What is the MC malignancy diagnosed in patients exposed to asbestos? When are bilateral vs unilateral pleural abnormalities seen?

Answer 29

Bronchogenic carcinoma is MC. Pleural mesothelioma is also possible but less common than bronchogenic carcinoma.
Unilateral pleural abnormalities = pleural mesothelioma
Bilateral pleural plaques = bronchogenic carcinoma

Question 30

What level of hypoxemia is necessary for long term oxygen therapy to decrease mortality in patients with COPD? What risk factor in general is assoc with a mortality benefit and reduced progression of disease in patients with COPD?

Answer 30

Significant hypoxemia (eg SpO2 <=88%, SpO2 <=89% with RHF or erythrocytosis). Not beneficial in mild hypoxemia
Smoking cessation.

Question 31

Mycobacterium Tb is an aerobic organism that preferentially infects what part of the lung?

Answer 31

Apices d/t high O2 tensions and slower lymph elim. Reactivation TB occurs at the site of latent infx (apical lobes)
HIV pts have a higher risk of reactivation Tb

Question 32

Patients with intermittent fever, weight loss, chronic rhinosinusitis (upper resp tract), tracheal narrowing with uleration (lower resp tract) involvement, multiple lung nodules with cavitation, anemia of chronic disease, and renal involvement should be suspected of having what?

Answer 32

Granulomatosis with polyangiitis (Wegener’s).
Systemic vasculits characterized by upper and lower resp tract granulomatous inflam and glomerulonephritis that can be rapidly progressive

Question 33

What is the CURB-65 criteria? What is it used for?

Answer 33

Confusion, Urea >20, Resp >=30, BP (SBP<90, DBP <60), >=65yo
0=outpatient tx (macrolide or doxy or fluoroquinolone or beta-lactam + macrolide)
1-2 = inpt tx (beta lactam + macrolide; fluoroquinolone)
3-4 = inpt, ICU (beta lactam+ macrolide or fluoroquinolone)

Question 34

Pulm pathology may lead to SIADH which is characterized by HYPOtonic hyponatremia in a EUVOLEMIC patient.
T/F: normal saline may worsen hyponatremia in these patients?

Answer 34

True- results in net free water retention. Kidney works properly and gets rid of solute (Na) but water is retained

Question 35

Differentiate complicated vs uncomplicated parapneumonic (lung) effusions

Answer 35

Uncomplicated: sterile, pH >=7.2, glucose >=60, WBC <=50,000
Complicated: bacterial invasion of pleural space (located, empyema); pH<7.2, glucose <60, WBC >50,000, high protein (inc micro perm and cell destruction)

Question 36

If a patient has a witnessed aspiration event (eg vomit during intubation that requires suctioning) and has profound hypoxemia a few hours later, what should be suspected?

Answer 36

Aspiration pneumonitis - d/t inflam rxn to aspirated gastric acid
Tx: supportive (No abx) - differs from aspiration pneumonia bc presents in hours rather than days
note: aspiration pneumonia would require abx (clinda or beta lactam)

Question 37

Pleural protein/serum protein ratio >0.5
Pleural LDH/serum LDH >0.6
Pleural LDH >2/3 ULN for serum LDH
This pleural fluid analysis is characteristic for what type of pelural effusion?

Answer 37

Exudative.
Etiologies: empyema, chylothorax (lymph flow through thoracic duct is disrupted –> milky white fluid and inc triglycerides) , malignancy, or Tb
MOA: high level of pleural protein and LDH due to direct leakage of fluid
Tx - draining via thoracentesis or chest tube

Question 38

What are the two ways you can you improve oxygenation in mechanically ventilated patients? Why dont you want to inc FiO2 >60?

Answer 38

Increase FiO2 or PEEP
high FiO2 (>60%) inc risk of pulm o2 toxicity- inc PEEP to allow for reductions in Fio2
Note: PEEP prevents alveolar collapse

Question 39

Why does consolidative pneumonia result in V/Q mismatch?

Answer 39

alveoli are filled with inflam exudate –> impaired alveolar ventilation in that part of the lung –> lun perfused but not ventilated. Cant correct hypoxemia with inc FiO2.

Question 40

How can supplemental O2 in patients with advanced COPD cause worsening hypercapnia?

Answer 40

Inc dead space perfusion –> V/Q mismatch, dec affinity of oxyhemoglobin for CO2, and reduced alveolar ventilation.
Hypercapnia causes reflex cerebral vasoDILATION (CO2 is a dilator) –> seizures.