USMLE USMLE Certifications USMLE-STEP-2 Questions & Answers

• Question 191:

  A term infant is born at a small community hospital by cesarean section for failure to progress. The infant is noted to have the following abnormality at birth Which of the following is the most appropriate initial management?

  

  A. IV antibiotics alone

  B. emergency surgery for reduction

  C. monitor for spontaneous closure, with surgical intervention for persistent fascialdefect

  D. IV fluids, IV antibiotics, warm occlusive dressing, and transfer to a center with apediatric surgeon

  E. elective umbilical exploration

  Correct Answer: D

  This infant has an omphalocele. This is a result of failure of the abdominal muscles to close in the midline at the umbilical cord. The abdominal wall defect is therefore midline, with viscera enclosed in a sac composed of amniotic membranes. Children with omphalocele may have other associated anomalies. Infants with abdominal wall defects are at risk for fluid and temperature loss, and infection. Therefore, the initial management consists of measures to decompress the gastrointestinal tract, fluid resuscitation, IV antibiotics, and placing the viscera in a warm, moist occlusive dressing. An umbilical hernia results when the umbilical ring does not close, with viscera enclosed in a sac covered by peritoneum and skin. Many of these may spontaneously close on their own. Therefore, surgical intervention is restricted to those children with a persistent fascial defect. Omphalitis results from bacterial infection at the base of the cord and is well treated with antibiotics to cover skin organisms. Gastroschisis is a congenital evisceration, located to the right of the umbilical cord, and thought to be related to obliteration of one of the umbilical veins prior to birth. As with omphalocele, the child needs NG decompression, IV fluids and antibiotics, and a warm moist occlusive dressing. In gastroschisis, the bowel may be at risk of mechanical or vascular compromise, thus urgent surgical intervention is required

• Question 192:

  A term infant is born at a small community hospital by cesarean section for failure to progress. The infant is noted to have the following abnormality at birth Which of the following is the most likely diagnosis?

  

  A. umbilical hernia

  B. omphalitis

  C. omphalocele

  D. gastroschisis

  E. traumatic evisceration

  Correct Answer: C

  This infant has an omphalocele. This is a result of failure of the abdominal muscles to close in the midline at the umbilical cord. The abdominal wall defect is therefore midline, with viscera enclosed in a sac composed of amniotic membranes. Children with omphalocele may have other associated anomalies. Infants with abdominal wall defects are at risk for fluid and temperature loss, and infection. Therefore, the initial management consists of measures to decompress the gastrointestinal tract, fluid resuscitation, IV antibiotics, and placing the viscera in a warm, moist occlusive dressing. An umbilical hernia results when the umbilical ring does not close, with viscera enclosed in a sac covered by peritoneum and skin. Many of these may spontaneously close on their own. Therefore, surgical intervention is restricted to those children with a persistent fascial defect. Omphalitis results from bacterial infection at the base of the cord and is well treated with antibiotics to cover skin organisms. Gastroschisis is a congenital evisceration, located to the right of the umbilical cord, and thought to be related to obliteration of one of the umbilical veins prior to birth. As with omphalocele, the child needs NG decompression, IV fluids and antibiotics, and a warm moist occlusive dressing. In gastroschisis, the bowel may be at risk of mechanical or vascular compromise, thus urgent surgical intervention is required.

• Question 193:

  A 16-year-old girl with a history of ulcerative colitis managed with steroid therapy presents to the emergency department with a 36-hour history of nausea, crampy abdominal pain, and severe bloody diarrhea. On examination, the patient is febrile and pale, with a blood pressure of 90/60 mmHg and heart rate of 130 beats/min. Her abdomen is distended and diffusely tender. Acomplete blood count (CBC) demonstrates a leukocytosis with a left shift. The patient receives IV fluid resuscitation and nasogastric (NG) tube decompression. After 48 hours, there is no clinical improvement. Which of the following is the most appropriate next step in management?

  A. colonoscopic decompression

  B. cyclosporine

  C. abdominal colectomy and ileostomy and Hartmann's procedure

  D. proctocolectomy with ileal pouch-anal anastomosis

  E. abdominal colectomy with ileorectal anastomosis

  Correct Answer: C

  This patient presents with an acute exacerbation of ulcerative colitis with systemic toxicity. Toxic megacolon is potentially life threatening and requires aggressive fluid resuscitation, bowel rest, and systemic antibiotics. High-dose steroids are initiated to treat the colonic inflammation. If there is no clinical improvement after 48 hours of medical therapy, urgent surgery is indicated. Azathioprine and 6mercaptopurine are immunosuppressive agents that may be beneficial in the treatment of steroid refractory colitis, but they are not indicated in the management of an acute toxic exacerbation. Opioid antidiarrheals are contraindicated, because they may increase colonic distention and increase the risk of perforation. Colonoscopy may also cause increased colonic distention with perforation. Urgent surgery in a patient with toxic megacolon should consist of abdominal colectomy, Hartmann's procedure (closure of the rectal stump), and ileostomy. Ileal pouchanal anastomosis is a lengthy procedure, and is considered only for elective reconstruction. When performed in a systemically ill patient undergoing emergency colectomy of an unprepped colon, there are increased risks of anastomotic complications. Ileorectal anastomosis is no longer appropriate for the management of ulcerative colitis because of the retained diseased rectal mucosa, with concomitant risk of malignancy.

• Question 194:

  A 16-year-old girl with a history of ulcerative colitis managed with steroid therapy presents to the emergency department with a 36-hour history of nausea, crampy abdominal pain, and severe bloody diarrhea. On examination, the patient is febrile and pale, with a blood pressure of 90/60 mmHg and heart rate of 130 beats/min. Her abdomen is distended and diffusely tender. Acomplete blood count (CBC) demonstrates a leukocytosis with a left shift. The patient receives IV fluid resuscitation and nasogastric (NG) tube decompression.

  Further therapeutic interventions should include which one of the following?

  A. 6-mercaptopurine

  B. azathioprine

  C. opioid antidiarrheals

  D. colonoscopic decompression

  E. high-dose IV steroids and broad-spectrum antibiotics

  Correct Answer: E

  This patient presents with an acute exacerbation of ulcerative colitis with systemic toxicity. Toxic megacolon is potentially life threatening and requires aggressive fluid resuscitation, bowel rest, and systemic antibiotics. High-dose steroids are initiated to treat the colonic inflammation. If there is no clinical improvement after 48 hours of medical therapy, urgent surgery is indicated. Azathioprine and 6mercaptopurine are immunosuppressive agents that may be beneficial in the treatment of steroid refractory colitis, but they are not indicated in the management of an acute toxic exacerbation. Opioid antidiarrheals are contraindicated, because they may increase colonic distention and increase the risk of perforation. Colonoscopy may also cause increased colonic distention with perforation. Urgent surgery in a patient with toxic megacolon should consist of abdominal colectomy, Hartmann's procedure (closure of the rectal stump), and ileostomy. Ileal pouchanal anastomosis is a lengthy procedure, and is considered only for elective reconstruction. When performed in a systemically ill patient undergoing emergency colectomy of an unprepped colon, there are increased risks of anastomotic complications. Ileorectal anastomosis is no longer appropriate for the management of ulcerative colitis because of the retained diseased rectal mucosa, with concomitant risk of malignancy.

• Question 195:

  A 32-year-old, previously healthy man is a victim of a drive-by shooting, sustaining a gunshot wound to the left lower extremity. The entrance wound is located over the medial aspect of the calf, with an exit wound over the anterior pretibial region. Neurovascular examination of the extremity is normal. There is associated soft-tissue injury from the blast effect and a severely comminuted tibial fracture demonstrated on radiographs. Appropriate management of this injury includes which of the following?

  A. local wound irrigation, closure of the soft-tissue defect, closed reduction, and immobilization in a long-leg cast

  B. local wound irrigation with antibiotic solution, closed reduction, and immobilization in a long-leg cast, with continued local wound care through an anterior cast window

  C. tetanus prophylaxis, intravenous (IV) antibiotics, and operative wound irrigation and debridement, with application of an external fixation device

  D. tetanus prophylaxis, IV antibiotics, operative wound irrigation with closure of the soft-tissue defect, closed reduction, and immobilization in a long-leg cast

  E. tetanus prophylaxis, IV antibiotics, longleg splint for immobilization, and operative intervention during elective surgical schedule

  Correct Answer: C

  This is an open fracture, and management constitutes an orthopedic emergency. Tetanus prophylaxis is indicated because the softtissue injury is a tetanus-prone wound. An open fracture is associated with a high risk of osteomyelitis. Systemic antibiotics should be started in the emergency department and continued postoperatively. Optimal local wound irrigation and debridement is achieved under general anesthesia. This fracture is severely comminuted and most likely unstable. Fracture stabilization can be accomplished with internal fixation or application of an external fixation device. The soft-tissue defect associated with an open fracture should not be closed primarily. It may require further debridement. With aggressive local wound care, delayed closure may be possible if the wound remains clean. Local wound irrigation and debridement may be limited by patient discomfort. The addition of antibiotics to the irrigation solution is of no additional benefit. Closed reduction would not be possible in this patient because the fracture is severely comminuted. Furthermore, a longleg cast will not provide adequate immobilization of the unstable fracture fragments.

• Question 196:

  A 77-year-old male presents, accompanied by his wife to your clinic. She reports that the patient has been having visual hallucinations of little people in his room on and off for the past 3 months. Six months ago he developed a tremor and gait disturbance. Over this past year he has become more forgetful, and has had episodes of confusion. The most likely diagnosis is:

  A. Alzheimer dementia

  B. vascular dementia

  C. Parkinsion's disease with dementia

  D. Lewy body dementia

  E. Frontotemporal dementia

  Correct Answer: D

  Though Alzheimer's dementia is the most common form, it is characterized by a gradual and progressive course typically starting with a loss of short-term memory. Vascular dementia is known for its stepwise progression. Frontotemporal dementia (Pick's) usually presents insidiously with behavior and personality changes. Lewy body dementia shares features with Alzheimer's dementia and dementia associated with Parkinson's disease, but is more progressive than the dementia associated with Parkinson's disease, and tends to exhibit cognitive decline soon after the Parkinson's symptoms present. Visual hallucinations and fluctuating cognition are also common with this type of dementia

• Question 197:

  Match the below medication with the potential blood dyscrasia side effect it can be associated with. Carbamazepine

  A. leukocytosis

  B. thrombocytopenia

  C. agranulocytosis

  D. megaloblastic anemia

  E. lymphocytosis

  Correct Answer: C

  Valproate can be associated with thrombocytopenia and platelet dysfunction especially at high doses. Leukocytosis is a common benign effect of lithium. Clozaril can cause agranulocytosis in 12% of patients. Agranulocytosis can be an idiosyncratic adverse event with carbamazepine

• Question 198:

  Match the below medication with the potential blood dyscrasia side effect it can be associated with.

  Clozaril

  A. leukocytosis

  B. thrombocytopenia

  C. agranulocytosis

  D. megaloblastic anemia

  E. lymphocytosis

  Correct Answer: C

  Valproate can be associated with thrombocytopenia and platelet dysfunction especially at high doses. Leukocytosis is a common benign effect of lithium. Clozaril can cause agranulocytosis in 12% of patients. Agranulocytosis can be an idiosyncratic adverse event with carbamazepine

• Question 199:

  Match the below medication with the potential blood dyscrasia side effect it can be associated with. Lithium

  A. leukocytosis

  B. thrombocytopenia

  C. agranulocytosis

  D. megaloblastic anemia

  E. lymphocytosis

  Correct Answer: A

  Valproate can be associated with thrombocytopenia and platelet dysfunction especially at high doses.

  Leukocytosis is a common benign effect of lithium. Clozaril can cause agranulocytosis in 12% of patients. Agranulocytosis can be an idiosyncratic adverse event with carbamazepine

• Question 200:

  Match the below medication with the potential blood dyscrasia side effect it can be associated with. Valproate.

  A. leukocytosis

  B. thrombocytopenia

  C. agranulocytosis

  D. megaloblastic anemia

  E. lymphocytosis

  Correct Answer: B

  Valproate can be associated with thrombocytopenia and platelet dysfunction especially at high doses. Leukocytosis is a common benign effect of lithium. Clozaril can cause agranulocytosis in 12% of patients. Agranulocytosis can be an idiosyncratic adverse event with carbamazepine.