A 70-year-old Asian male presents with hematochezia. He has stable vital signs. Lower endoscopy is performed but is unsuccessful due to active bleeding.
Which of the following would be the next appropriate investigation?
Correct Answer E: In most patients with heavy gastrointestinal bleeding, localizing the bleeding site, rather than diagnosing the cause of the bleeding, is the most important task. Angiography (choice E) is performed when active bleeding that precludes colonoscopy occurs and after colonoscopy has failed to identify a bleeding site. Selective mesenteric angiography can detect bleeding at a rate of more than 0.5 mL/min.
→ A small-bowel radiograph (choice A) may be helpful after the active bleeding has stopped, but not during the acute phase of the bleeding.
→ A lower GI series (choice B) is usually nondiagnostic during heavy, active bleeding.
→ A major disadvantage of radionuclide imaging (choice C) is that it requires active bleeding to detect a source and can only localize bleeding to a general area of the abdomen. The role of radionuclide scanning, or nuclear scintigraphic imaging, in the diagnosis and treatment of patients who present with lower GI bleeding remains controversial.
→ Exploratory laparotomy (choice D) may be indicated if a blood pool scan or an arteriogram is nondiagnostic and the patient continues to bleed heavily.
A moderately obese 50-year-old female presents with a constant and dull right upper quadrant pain that radiates to her right shoulder.
Which one of the following is considered the best study to confirm the likely cause of the patient’s symptoms?
Correct Answer C: The symptom complex presented is typical of cholelithiasis. Abdominal ultrasonography is considered the best study to confirm this diagnosis because of its high sensitivity and its accuracy in detecting gallstones.
→ Plain radiography (choice A) of the abdomen may reveal radiopaque gallstones, but will not reveal radiolucent tones or biliary dilation.
→ Although rarely used, oral cholecystography (choice B) is 98% accurate, but only when compliance is assured, the contrast agent is absorbed, and liver function is normal.
→ A barium swallow (choice D) will identify some functional and structural esophageal abnormalities, but will not focus on the suspected organ in this case. The same is true of esophagogastroscopy (choice E).
An elderly patient presents for treatment of head trauma. He develops changes in behavior with frequent vomiting and headache.
All of the following are indicated initially, except:
Correct Answer D: CT scanning of the head is done before lumbar puncture because the most worrisome contraindication to lumbar puncture is the suspicion of increased ICP due to a cerebral mass lesion. Performing a lumbar puncture in these patients may lead to either trans-tentorial or uncal herniation and acute neurological deterioration.
A young man sustains a severe blow to the head. Skull x-rays show air in the cranial vault.
This finding represents which one of the following?
Correct Answer C: Pneumocephalus is the presence of air or gas within the cranial cavity. Pneumocephalus (ie, subdural air causing mass effect on the brain) is caused by conditions that lead to increased air pressure within the subdural space. For example in a subdural hematoma.
Causes of pneumocephalus include skull base fracture, transsphenoidal surgery, tumors involving the skull base and congenital skull base defects.
Following induction of anesthesia for a vaginal hysterectomy a patient is placed in the lithotomy position. Postoperatively, the patient complains of right foot drop.
Which nerve is most likely to have been injured during the procedure?
Correct Answer A: Peroneal nerve palsy is the term used when the nerve at the top of the calf behind the knee is compressed. If the peroneal nerve is injured, it cannot support the tibialis anterior, the muscle which lifts the foot. To diagnose foot drop, a physician will take a complete medical history and may order tests such as magnetic resonance imaging (MRI) or an electromyogram (EMG).
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