Test 55

Question 1

Antipsychotics

Answer 1

Antipsychotic medication is first-line treatment for schizophrenia in acute and maintenance phases, and drug selection is based on adverse effect profiles. Because of the high risk for weight gain and metabolic adverse effects, olanzapine should be avoided in the initial management of first-episode psychosis for adolescents with weight concerns. Instead, aripiprazole is a more appropriate choice for this overweight adolescent because it is associated with comparatively less weight gain and fewer metabolic adverse effects.

Question 2

Neurogenic arthropathy

Answer 2

Subacute neuropathic (Charcot) arthropathy is characterized by the presence of foot inflammation (erythema, warmth, edema) and x-ray findings of osseous destruction (phalangeal osteolysis, partial disappearance of the metatarsal heads).

Question 3

Likelihood ratio

Answer 3

The likelihood ratio (LR) has direct clinical significance and does not change as the disease prevalence changes. LRs can also be used to grade the clinical significance of various results when >2 different test results are possible.

Question 4

Confounding, effect modification, bias, errors

Answer 4

Verification bias occurs when a study uses gold standard testing selectively in order to confirm a positive (or negative) result of preliminary testing. This can result in overestimates (or underestimates) of sensitivity (or specificity).

Question 5

Mastoiditis

Answer 5

Acute mastoiditis, a complication of acute otitis media (AOM), is caused by spread of the infection from the middle ear space to the mastoid air cells. In addition to the fever and otalgia often present in AOM, patients also have mastoid inflammation, resulting in tenderness of the mastoid process and displacement of the auricle.

Question 6

Gastrostomy tube

Answer 6

Enteral feeding is preferred to parenteral feedings for patients who have a functioning gastrointestinal system. The standard composition of 30 kcal/kg/day and 1 g/kg/day of protein is satisfactory for most patients with adequate baseline nutrition.

Question 7

Intestinal helminth parasites

Answer 7

Hookworm infections are encountered worldwide, particularly in tropical areas, and present with abdominal symptoms and failure to thrive. Common laboratory findings include microcytic anemia and eosinophilia. Examination of the stool for hookworm eggs is diagnostic.

Question 8

Pseudomonas

Answer 8

Ecthyma gangrenosum is most commonly seen in immunocompromised patients with Pseudomonas aeruginosa bacteremia. Manifestations typically include the rapid evolution of greater than or equal to 1 skin lesion from an erythematous macule to a pustule or bullae and then into a nonpainful gangrenous ulcer. Fever and systemic signs of illness are common.

Question 9

Pseudomonas

Answer 9

Patients with immunocompromise who develop ecthyma gangrenosum likely have Pseudomonas aeruginosa bacteremia. Urgent blood and wound cultures are required; patients should then receive empiric intravenous antibiotics with 2 medications active against Pseudomonas. Commonly, patients receive a beta-lactam (piperacillin-tazobactam) and an aminoglycoside (gentamicin).

Question 10

Hematuria

Answer 10

Gross hematuria warrants evaluation of both upper and lower urinary tracts. Computed tomography urogram is recommended for the upper tract; ultrasound is an alternate test, especially for patients with chronic kidney disease. Cystoscopy is recommended for evaluation of the lower tract, with urine cytology as an alternate test for low-risk patients.

Question 11

CF

Answer 11

Meconium ileus (“ground-glass” mass), characterized by intestinal obstruction of the distal ileum with meconium, is virtually pathognomonic for cystic fibrosis. A family history of recurrent sinus infections may be a clue for diagnosis.

Question 12

Lung nodule

Answer 12

A solitary pulmonary nodule (SPN) is defined as a round opacity less than or equal to 3 cm in diameter and surrounded by pulmonary parenchyma. Because a SPN can be malignant, it’s appearance should be compared to that on previous imaging. Patients with no previous imaging or a SPN that has grown or changed in appearance should undergo CT scan of the chest for further investigation.

Question 13

CKD

Answer 13

CKD is most often caused by poorly controlled diabetes mellitus and hypertension. In patients with severely increased albuminuria (>300 mg/day), blood pressure control (not intensive glycemic control) has been shown to reduce CKD progression.

Question 14

MI

Answer 14

Premature discontinuation of dual antiplatelet therapy (aspirin and P2Y12 receptor blocker) is the strongest predictor of stent thrombosis after coronary stent placement. Patients should be aggressively screened and counseled for medication compliance to reduce the risk of stent thrombosis.

Question 15

GBS

Answer 15

GBS is an immune-mediated polyneuropathy that causes symmetric motor weakness and reduced/absent deep tendon reflexes. Patients are at high risk of respiratory failure and require frequent monitoring of tidal volume and negative inspiratory force to assess respiratory status.

Question 16

GBS

Answer 16

GBS is treated with plasma exchange or IV Ig to speed recovery and reduce risk of respiratory failure. Patients who are nonambulatory should receive treatment if symptoms have been present <4 weeks.

Question 17

GBS

Answer 17

Patients with GBS tend to worsen over 2 weeks, plateau for 2-4 weeks, and then spontaneously recover over months. Time to recovery is shortened by the use of plasma exchange or IV Ig.

Question 18

Hep c

Answer 18

Patients with chronic hepatitis C infection may experience rapid hepatic decompensation and liver failure if they develop acute hepatitis A virus (HAV) or hepatitis B virus (HBV) infection. Consequently, in addition to alcohol avoidance, patients should be vaccinated against HAV and HBV if they do not have preexisting immunity.