UWorld I

Question 1

What is the pattern seen on ABG of patients with decreased respiratory drive (opioid/benzo overdose)?

Answer 1

Hypercapnia, Hypoxemia, Respiratory acidosis

pH 7.30, PO2 70 mmHg, PCO2 54 mmHg

Question 2

What is the pattern seen on ABG for patients with post-op atelectasis?

Answer 2

Hypoxemia (decreased lung airspace), hypocapnia (hyperventilation due to hypoxemia), respiratory alkalosis
pH: 7.49, PO2: 70 mmHg, PCO2: 27 mmHg

Question 3

What is the pattern seen on ABG for patients who are compensating for an acidotic environment?

Answer 3

High arterial oxygen, hypocapnia, metabolic acidosis

pH 7.30, PO2 110 mmHg, PCO2 22 mmHg

Question 4

Potential side effect of succinylcholine, esp in crush injury?

Answer 4

Hyperkalemia, enough to cause cardiac arrhythmias
SC is a depolarizing neuromuscular blocker that triggers the release of K+ from the cells. Add to hyperkalemia of couch injuries/rhabdomyolysis = severe hyperkalemia

Question 5

Side effect of nitrous oxide?

Answer 5

Inhibits vit B12, leading to inhibition of methionine synthase activity and neurotoxicity/peripheral neuropathy in patients with B12 deficencies

Question 6

Side effect of propofol?

Answer 6

Severe hypotension due to myocardial depression, especially in patients with ventricular systolic dysfunction

Question 7

Side effects of etomidate?

Answer 7

Inhibits 11B-hydroxylase, leading to adrenal insufficiency. Especially in elderly or septic patients

Question 8

Side effects of halothane?

Answer 8

Hepatotoxicity due to intermediary breakdown products

Question 9

Signs of myocardial contusion?

Answer 9

Tachycardia, new bundle branch block, or arrhythmias.

Question 10

Signs of ruptured bronchus?

Answer 10

Pneumothorax unresponsive to chest tube, pneumomediastinum, subcutaneous emphysema

Question 11

When is Gilbert syndrome commonly discovered?

Answer 11

Results in jaundice/scleral icterus during times of stress (surgery, infection, vigorous exercise)

Question 12

What is Leriche syndrome? What other symptom is almost always present?

Answer 12

Leriche syndrome is bilateral hip, buttock, and thigh pain resulting from arterial occlusion at the bifurcation of the aorta. Impotence is almost always present, and its absence is a strong sign that a case is not actually Leriche’s.

Question 13

What physical exam finding helps distinguish hemothorax from pneumothorax?

Answer 13

Dullness to percussion = hemothorax

Hyper resonance on percussion = pneumothorax

Question 14

What is CPAP used post-operatively?

Answer 14

Only after incentive spirometry has failed. It promotes lung expansion like IS does, but is more expensive and cumbersome.

Question 15

What are the risk factors for post-op pulmonary complications?

Answer 15

Smoking
Pre-existing pulmonary disease
Age >50
Abdominal or thoracic surgery
Surgery lasting >3 hours
Poor general health

Question 16

infection in what area can lead to subdural empyema?

Answer 16

Paranasal sinuses. Infection may spread through the bone, leading to fever, headache and AMS 2/2 mass effect

Question 17

What is Ludwig angina? Most common cause?

Answer 17

A rapidly progressive, bilateral cellulitis of the submandibular and sublingual spaces,
most commonly caused by an infected mandibular molar

Question 18

Infections in what areas may spread to the cavernous sinus?

Answer 18

Medial third of face, sinuses, or teeth via valveless facial venous system. Headache, fever, cranial nerve deficits (i.e. diplopia) and proptosis

Question 19

What antibiotics are concerning for possible AIN? What other signs may be present?

Answer 19

Beta-lactams are known to cause acute interstitial necrosis.

Leukocytes in UA and a rash are commonly seen in AIN.

Question 20

What complications result from using diuretics in hypovolemic patients?

Answer 20

Further volume depletion and acute tubular necrosis due to hypoperfusion

Question 21

What is an unintended consequence of initiating ventilatory support in a hypotensive patient?

Answer 21

Positive pressure ventilation increases intrathoracic pressure. In a severely volume depleted individual, this may cut of venous return to the heart = acute MI

Question 22

What causes vasovagal syncope?

Answer 22

Sudden increase in parasympathetic activity, resulting in bradycardia, systemic vasodilation, and decreased CO. Sudden cardiac death does not occur.

Question 23

When is reduced myocardial contractility seen and what does it lead to?

Answer 23

Occurs during myocardial infarction and can lead to cariogenic shock, possible sudden cardiac death. Distended neck veins should be visible

Question 24

How are exztraperitoneal and intraperitoneal bladder rupture differentiated?

Answer 24

Extravasation of urine into exztraperitoneal space causes localized pain in lower abdomen and pelvis.
Intraperitoneal rupture causes urine in the peritoneal space resulting in chemical peritonitis (diffuse abdominal tenderness, guarding, rebound).