MCQs PEDIATRIC FROM MEDICAL COLLEGE OF GEORGIA

 

QUESTION  NO 1
A 7- year-old girl develops behavioral changes, and her performance in school begins to deteriorate. Several months later she develops a seizure disorder, ataxia, and focal neurologic symptoms. She is eventually quadriparetic, spastic, and unresponsive. Death occurs within a year. This patient may have had which of the following viral diseases at 1 year of age?

A. Chicken pox

B. German measles

C. Measles

D. Mumps

E. Parvovirus B19

The correct answer is C.

The child has subacute sclerosing panencephalitis (SSPE), which is fortunately a very rare, late complication of measles infection at an early age.

The existence of this complication is part of the rationale to immunize children to measles at an early age.

It is thought that very young children's immune and neurologic systems may permit the virus to become established in the brain.

The exact mechanism of injury is poorly understood, but the brain shows encephalitis involving both gray and white matter.

40% of cases die within 1 year, and it is thought that the disease is probably always eventually fatal.
None of the other diseases progresses to SSPE.                                      


QUESTION  NO 2

A 2-year-old child with leukemia develops nephrotic syndrome. Light microscopic studies are normal. Electron microscopic studies demonstrate fusion of epithelial foot processes. The current hypothesis for the pathogenesis of this change is that it is secondary to which of the following?
A. Consumption of complement factors

B. IgG directed against basement membrane

C. Immune complex deposition

D. Lymphokine production by T cells
E. Mesangial IgA deposition

The correct answer is D.

The child is suffering from minimal change or nil disease (lipoid nephrosis), which has a peak incidence at 2-3 years of age. Minimal change disease can be associated with food allergies, medications, or hematologic malignancies, or it can occur idiopathically.  

The pathology does not appear to involve complement, immunoglobulins, or immune complex deposition. Rather, an altered cell-mediated immunologic response with abnormal secretion of lymphokines by T cells is thought to reduce the production of anions in the glomerular basement membrane, thereby increasing the glomerular permeability to plasma albumin through a reduction of electrostatic repulsion. The loss of anionic charges is also thought to favor foot process fusion. Some authors have noted that other conditions associated with T-cell abnormalities, such as Hodgkin's disease and T-cell lymphoma, are sometimes associated with minimal change disease. 

Consumption of complement factors (choice A) is observed in many conditions in which complement activation occurs, for example, membranoproliferative glomerulonephritis.                                                     

IgG directed against renal and pulmonary basement membranes (choice B) is found in Goodpasture's syndrome, a cause of rapidly progressive glomerulonephritis and hemoptysis.

Immune complex deposition (choice C) is associated with type III hypersensitivity reactions, including postinfectious                                             

glomerulonephritis, lupus nephritis, Henoch-Schönlein purpura, cryoglobulinemia, and bacterial endocarditis. 

Mesangial IgA deposition (choice E) is associated with Berger's disease, or IgA nephropathy, a cause of glomerulonephritis.                                            

 

QUESTION  NO 3

Positron emission tomography (PET) scans used to detect cancer most commonly use a radioactive tracer tagged to a molecule that is an analogue of:
A) oxygen.

B) glucose.

C) hemoglobin.

D) nitrate.
E) phosphate

The correct Answer is B
The fluorine-18-labeled tracer fluorodeoxyglucose (FDG) is a glucose analogue taken up by metabolically active cells using glucose as a substrate for their metabolism. This enables the PET scanner to detect metabolically active tissues such as cancer metastases

QUESTION  NO 4

Your 6-year old patient is visiting his grandparents. You are rounding in the hospital when the grandfather, a 72-year-old male, is brought by ambulance to the emergency department with weakness and numbness of his left side that began earlier this morning. While in the emergency department he becomes comatose with infrequent, gasping breaths and is quickly intubated and placed on a ventilator. A full evaluation shows an acute ischemic right-sided stroke. His wife states that she wishes to have the ventilator stopped, as she believes this would be consistent with her husband's wishes in this circumstance. She understands that this would precipitate the patient's death. The wife presents a legally valid advance directive confirming her as the patient's health-care proxy.                                 

As you are known by the family, the emergency department physician seeks your advice. Which one of the following responses to the wife's request is most ethically appropriate?                                    

A) Withdraw the ventilator as requested.                                               
B) Contact the hospital ethics committee to initiate the legal requirements to process the wife's request.                                             

C) Inform the wife that all life-sustaining care should be given until the patient's condition has been determined to be irreversible.            

D) Inform the wife that intubation may have been avoided in the emergency department, but once life sustaining care has been initiated it should not be withdrawn.                                                       

E) Promptly contact hospital security or the local law enforcement agency to report the wife's request.                                                         
The Correct Answer is A

Competent adult patients have the right to refuse any medical intervention, even if forgoing this treatment may result in their death.                   

Legally and ethically it does not matter whether the patient requests that care be withheld before it is started, or that it be withdrawn once it is begun.  


All states currently allow competent patients to legally designate a health-care proxy to make these decisions for them if they become unable to communicate or incompetent to decide for themselves. The patient in this example has instituted such a legal advance directive and his proxy's desires should be respected as his own and the care withdrawn. 
If there were no advance directive the decision in this case would become more difficult, and might require a family conference or the involvement of an ethics committee. A patient's condition does not need to be terminal or irreversible in order to allow the removal of life-sustaining therapy.

Legal involvement is rarely required in situations where advance directives are already available and valid.                                               

 

QUESTION  NO 5

Which one of the following chemical occupational exposures is associated with leukemia?                                                                         
A) Arsenic                                                                                                 

B) Benzene                                                                                               

C) Cadmium                                                                                             

D) Organophosphates                                                                             

E) Perchloroethylene (tetrachloroethylene)                                          

The Correct Answer is B

Benzene is a human carcinogen and causes aplastic anemia, leukemia, and multiple myeloma. It is absorbed through the skin and respiratory tract. Arsenic is more toxic in its inorganic form and causes epidermal cancer. Cadmium is associated with kidney toxicity. Perchloroethylene (tetrachloroethylene) causes peripheral neuropathy, chemical hepatitis, liver damage, and kidney damage.       

 

QUESTION  NO 6

The parents of a 20-month-old female bring her to your office because she has lost consciousness twice recently. They describe two episodes where the child was crying vigorously then “turned purple and passed out.” The child is an otherwise healthy product of a term delivery. There is no history of head trauma and no family history of seizures or cardiac problems. The episodes are not associated with fever or other symptoms. Physical examination of the child is normal.
Which one of the following would be most appropriate at this point?
A. Reassurance                                                                                            

B. CT scan of the brain                                                                             
C. EKG and chest radiograph                                                                   

D. Measurement of serum glucose, electrolytes, and hematocrit          

E. Echocardiography.
                                                                               

The Correct Answer is A
The parents are describing classic breath-holding spells. These are a form of autonomic syncope frequently misdiagnosed as seizures. They occur in early childhood and infancy. They can be two forms: cyanotic, as described here, and pallid. The cyanotic form usually occurs after vigorous crying, while the pallid form commonly occurs after a sudden fright or minor injury. The history of a prodrome of injury, vigorous crying, or sudden fright is key to distinguishing a breath-holding spell from a seizure. Parents can be reassured that no brain damage occurs and, in the presence of a classic history, no further workup is necessary. An EKG and chest radiograph would be indicated if the history suggested orthostatic hypotension. A head CT scan would be indicated in the evaluation of new-onset seizures.    
 

 

QUESTION  NO 7

Which one of the following is contraindicated with circumcisions?                      
A.Local application of lidocaine 2.5%/prilocaine 2.5%cream (EMLA).                                                                                                      

B.A penile block using 1% mepivacaine (Carbocaine).                          

C.A penile block using 1% lidocaine (Xylocaine)/epinephrine.             

D.A penile block using .25% bupivacaine (Sensorcaine).                        

E.A penile block using 1% lidocaine (Xylocaine) and Neutracaine.
    

The Correct Answer is C
The only option listed that is contraindicated for circumcision is lidocaine with epinephrine. Epinephrine should NEVER be used in a local anesthetic for penile blocks because the penile artery is an end artery, and vasospasm can lead to necrosis of the penile tip. An old adage reminds physicians not to use Epinephrine in the following areas: “fingers,nose,penis,toes.                                                              
 

  

QUESTION  NO 8
Which one of the following NSAIDs is contraindicated in patients allergic to sulfonamides? 
                   
A-Ibuprofen (Advil)

B-Ketoprofen (Orudis)         
C-Diclofenac (Voltaren)         
D-Rofecoxib (Vioxx)      
E-Celecoxib        (Celebrex)                                                                       

The Correct Answer is E

Celecoxib has a reactive sulphur molecule and can cause allergic reactions in patients allergic to sulfonamide antibiotics.                              

 

QUESTION  NO 9

A 17-year-old wants to go to New Mexico to ski. In the past he has experienced moderate symptoms of acute mountain sickness (AMS), including headache, nausea, shortness of breath, and sleep disturbance. He has been otherwise healthy.
Which one of the following has been shown to be helpful in minimizing or preventing the symptoms of AMS?                                  

A-Fluid restriction 
                     
B-Furosemide (Lasix)
         
C-Erythromycin (EES)    
           
D-Acetazolamide (Diamox)

E-ß-Blockers (Propanolol)                                                                   
The Correct Answer is D

Acute mountain sickness (AMS) is a clinical syndrome which may affect up to 65% of persons ascending to altitudes greater than 8000 feet. While a standard definition of AMS does not exist, persons having three or more of the following symptoms may be considered to have AMS: headache, nausea, vomiting, sleep disturbance, anorexia, fatigue, or dyspnea.

Gradual ascent is recommended to allow acclimatization. Measures which may help minimize symptoms include avoidance of alcohol, increased fluid intake, and a high-carbohydrate diet.

Acetazolamide (Diamox) speeds the process of acclimatization. The drug is a carbonic anhydrase inhibitor which results in a renal bicarbonate diuresis and subsequent metabolic acidosis, thereby increasing ventilation and arterial oxygenation. The respiratory stimulation is particularly important during sleep, when it reduces the severe hypoxemia caused by periodic breathing. The drug also lowers cerebrospinal fluid volume and pressure, which may play an additional role in its therapeutic and prophylactic utility.
Fluid restriction and diuretics should be avoided because of the diuresis associated with acclimatization, which may by itself case dehydration. Antibiotics are of no benefit. -blockers would be harmful, by interfering with the physiologic responses of tachycardia and increased cardiac output at higher altitudes.
 

QUESTION  NO 10 

The presence of Philadelphia chromosome indicates which one of the following conditions?
A) Acute lymphocytic leukemia

B) Acute myelomonocytic leukemia

C) Chronic lymphocytic leukemia

D) Chronic myelogenous leukemia

E) Myelodysplasia

The Correct Answer is D
The Philadelphia chromosome is now easily detectable by Southern blot or polymerase chain reaction (PCR) technology. It is nearly always present in chronic myelogenous leukemia (CML), and is one of the best tests to differentiate this condition from other causes of WBC count elevation, especially myelodysplasia, leukemoid reactions, and other leukemias.

 

 
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