UWorld I Flashcards
What is the pattern seen on ABG of patients with decreased respiratory drive (opioid/benzo overdose)?
Hypercapnia, Hypoxemia, Respiratory acidosis
pH 7.30, PO2 70 mmHg, PCO2 54 mmHg
What is the pattern seen on ABG for patients with post-op atelectasis?
Hypoxemia (decreased lung airspace), hypocapnia (hyperventilation due to hypoxemia), respiratory alkalosis
pH: 7.49, PO2: 70 mmHg, PCO2: 27 mmHg
What is the pattern seen on ABG for patients who are compensating for an acidotic environment?
High arterial oxygen, hypocapnia, metabolic acidosis
pH 7.30, PO2 110 mmHg, PCO2 22 mmHg
Potential side effect of succinylcholine, esp in crush injury?
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
Side effect of nitrous oxide?
Inhibits vit B12, leading to inhibition of methionine synthase activity and neurotoxicity/peripheral neuropathy in patients with B12 deficencies
Side effect of propofol?
Severe hypotension due to myocardial depression, especially in patients with ventricular systolic dysfunction
Side effects of etomidate?
Inhibits 11B-hydroxylase, leading to adrenal insufficiency. Especially in elderly or septic patients
Side effects of halothane?
Hepatotoxicity due to intermediary breakdown products
Signs of myocardial contusion?
Tachycardia, new bundle branch block, or arrhythmias.
Signs of ruptured bronchus?
Pneumothorax unresponsive to chest tube, pneumomediastinum, subcutaneous emphysema
When is Gilbert syndrome commonly discovered?
Results in jaundice/scleral icterus during times of stress (surgery, infection, vigorous exercise)
What is Leriche syndrome? What other symptom is almost always present?
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.
What physical exam finding helps distinguish hemothorax from pneumothorax?
Dullness to percussion = hemothorax
Hyper resonance on percussion = pneumothorax
What is CPAP used post-operatively?
Only after incentive spirometry has failed. It promotes lung expansion like IS does, but is more expensive and cumbersome.
What are the risk factors for post-op pulmonary complications?
Smoking Pre-existing pulmonary disease Age >50 Abdominal or thoracic surgery Surgery lasting >3 hours Poor general health
infection in what area can lead to subdural empyema?
Paranasal sinuses. Infection may spread through the bone, leading to fever, headache and AMS 2/2 mass effect
What is Ludwig angina? Most common cause?
A rapidly progressive, bilateral cellulitis of the submandibular and sublingual spaces,
most commonly caused by an infected mandibular molar
Infections in what areas may spread to the cavernous sinus?
Medial third of face, sinuses, or teeth via valveless facial venous system. Headache, fever, cranial nerve deficits (i.e. diplopia) and proptosis
What antibiotics are concerning for possible AIN? What other signs may be present?
Beta-lactams are known to cause acute interstitial necrosis.
Leukocytes in UA and a rash are commonly seen in AIN.
What complications result from using diuretics in hypovolemic patients?
Further volume depletion and acute tubular necrosis due to hypoperfusion
What is an unintended consequence of initiating ventilatory support in a hypotensive patient?
Positive pressure ventilation increases intrathoracic pressure. In a severely volume depleted individual, this may cut of venous return to the heart = acute MI
What causes vasovagal syncope?
Sudden increase in parasympathetic activity, resulting in bradycardia, systemic vasodilation, and decreased CO. Sudden cardiac death does not occur.
When is reduced myocardial contractility seen and what does it lead to?
Occurs during myocardial infarction and can lead to cariogenic shock, possible sudden cardiac death. Distended neck veins should be visible
How are exztraperitoneal and intraperitoneal bladder rupture differentiated?
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).
