A 13-year-old boy comes to the office for a sports participation physical examination. He has been playing in a summer basketball league and now wants to try out for the high school team. His last physical examination was 2 years ago and, according to him, he has been healthy except for a cold 2 weeks ago. Before you begin the physical examination, the nurse informs you that his routine urinalysis shows:
These laboratory results are most indicative of which of the following?
Correct Answer B:
The urinalysis in this scenario is significant for a tea-colored appearance, concentrated urine, proteinuria, hematuria, and red blood cell casts. The presence of red blood cell casts indicates that the origin of the bleeding is glomerular in nature, and thus is pathognomonic for acute glomerulonephritis. Postinfectious glomerulonephritis is the most common cause of acute glomerulonephritis in children, with group A beta-hemolytic streptococci being the most frequently associated bacterial etiology. Presenting clinical signs can include an asymptomatic individual with microscopic hematuria, or symptoms such as low-grade fever, malaise, lethargy, abdominal pain, and headache.
In an 11-year-old male with dark brown urine and hand and foot edema, which one of the following would be most suggestive of glomerulonephritis?
Acute glomerulonephritis (AGN) in children manifests as brown or cola-colored urine, which may be painless or associated with mild flank or abdominal pain. There are many etiologies of AGN but the most common in children are IgA nephropathy (which may directly follow an acute upper respiratory tract infection) and acute poststreptococcal glomerulonephritis following a streptococcal throat or skin infection (usually 7-21 days later).
In cases with more severe renal involvement, patients may develop hypertension, edema, and oliguria. RBC casts are the most classic finding on urinalysis in a patient with AGN. WBC casts are seen in acute pyelonephritis, often manifested by high fever, and costovertebral angle or flank pain and tenderness. Patients may also appear septic. Positive serum antinuclear antibodies are associated with lupus nephritis. Urine eosinophils are seen in the drug-induced tubulointerstitial nephritis. Serum complement levels are reduced, not elevated, in various forms of acute glomerulopathies, including poststreptococcal AGN.
An 8-month-old infant with trisomy 21 has a grade 2-3/6 systolic ejection murmur heard best at the left sternal border, but it can be heard all over the precordium. S2 is split normally and is loud. She has had two episodes of pneumonia in the past 2 months.
Which of the following is the most appropriate next step?
Correct Answer E:
Seek consultation with a cardiologist, as this patient with grade 2-3/6 systolic ejection murmur (heard best at the left sternal border and over the entire precordium) associated with two episodes of pneumonia, has a cardiac abnormality.
A PPD skin test is done in patients who are suspected of having tuberculosis. Initiating an immunologic evaluation should not be done in this patient because the patient is having recurrent pneumonia from heart disease, not because of immunocompromise. Likewise, a sweat chloride determination should not be done, because although the patient has had two pneumonias, these were most likely secondary to a heart defect, not cystic fibrosis.
A diabetic and obese 11-year-old boy is admitted to the hospital because of severe ketoacidosis and cardiovascular collapse. Initial management consists of cardiac monitoring and intravenous administration of fluids, electrolytes and insulin. The left femoral vein gets catheterized percutaneously because of the difficulty in obtaining satisfactory peripheral venous access. Six hours later, his mental status is improved, blood pressure is 120/70 mm Hg and serum glucose concentration is 13.9 mmol/L. At that time, physical examination discloses a cold left foot with diminished pulses compared with those of the right foot.
The most likely explanation for this finding is:
Correct Answer C:
During percutaneous placement of central venous lines, many complications are possible. Depending on the site of placement, the most serious complications vary. For all line placements however, injury to the accompanying artery poses a serious risk. In this case, the presence of a cold foot without pulses on the side ipsilateral to the line placement strongly suggests damage to the femoral artery.
A 10-year-old boy is brought to the emergency department by his father because the boy is slightly lethargic and has labored breathing. The father, who is a single parent, reports that the boy is "always thirsty" and "urinates a lot." The boy's pulse is 120/min, respirations are 32/min and blood pressure is 110/65 mm Hg. Laboratory studies show:
The boy is treated with intravenous insulin and isotonic saline solution. Several hours later, he is improved and his serum glucose concentration is 25 mmol/L.
This boy obviously has diabetes mellitus. Treatment with insulin has reduced his serum glucose concentration, and there will also have been a concomitant shift of K+ from the extracellular compartment into the cells. Unless replaced, this loss will have dire consequences. Therefore, the most appropriate next step is to add K+ to the intravenous fluid.
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