Wiki: 2007 Pediatric In-service Exam Topic Review

1. Physical findings in excessive vitamin A intake

Carotenemia, the ingestion of excessive amounts of vitamin A precursors, can manifest by a yellow-orange coloring of the skin, especially in the palms of the hands and the soles of the feet. It differs from jaundice in that the sclerae remain white. High doses above the RDA are teratogenic (category X).

Physical findings of acute toxicity:
Muscle and bone tenderness, especially over the long bones of the upper and lower extremities.
Neurologic manifestations with signs of increased intracranial pressure (eg, children may have bulging fontanelles) 

Physical findings of chronic toxicity: 
Alopecia 
Skin erythema 
Skin desquamation
Brittle nails 
Exanthema 
Cheilitis 
Conjunctivitis 
Petechiae 
Liver cirrhosis 
Premature epiphysial closure in children 
Hepatosplenomegaly 
Peripheral neuritis 
Benign intracranial hypertension 
Ataxia 
Papilledema 
Diplopia 
Hyperostosis 
Edema 
Hepatic hydrothorax 

reference: Hathcock JN, Hattan DG, Jenkins MY, et al. Evaluation of vitamin A toxicity. Am J Clin Nutr. Aug 1990;52(2):183-202 2.

2. Fluid Management of acute burn injury

• Crystalloid solutions (e.g. Lactated Ringers) are recommeded in the 1st 24h.
• If hypotensive, then 20cc/kg bolus, repeat if remains hypotensive
• then use Parkland fluid recuscitation formula:
  crystalloid (LR) at 4ml/kg/day per % body surface area burned, PLUS maintenance rate
  -- give half over first 8 hours, then half over the next 16 hours.
• Monitor urine output.  Consider 20ml/kg bolus if output < 1 ml/kg/hour.  Decrease rate to 2/3 of the Parkland Formula if output > 3 ml/kg/hour.  

topic resource: Harriet Lane Handbook. 17th edition. pp. 119-120.

3. Management of complications of odontogenic infection

•  Infections of odontogenic
  origin with systemic manifestations (eg, elevated temperature,sepsis, facial cellulitis, difficulty in breathing
  or swallowing, fatigue, nausea) require antibiotic therapy.
• Severe but rare complications of odontogenic infections include cavernous sinus thrombosis and Ludwig’s angina (serious infection of the tissues in the floor of the mouth). Immediate hospitalization with intravenous antibiotics, incision and drainage, and consultation with an oral and maxillofacial surgeon are required.
• The antibiotics of choice for odontogenic infection are amoxicillin and clindamycin

resource: Guidline on Pediatric Oral Surgery

4. Management of hydrocarbon ingestion.

• Hydrocarbon examples: solvents, fuels, gasolines, lighter fluid
• in general, no charcoal, lavage, or induction of emesis.
• exception of above rule is if hydocarbon containsa  toxic substance (heavy metal, insecticide, etc.) or if massive amount is ingested.  In this case consider lavage after intubating to protect the airway.
• Monitor ABCs.
• If dysrhythmia occurs, epinephrine is contraindicated (increased risk of v. fib).
• Criteria for hospitalization: all symptomatic patients (look for respiratory symptoms from aspiration, seizures, lethargy, coma, nausea/vomiting, liver failure, dysrhythmias) and those with abnormal CXR should be admitted.  If assymptomatic, monitor for 6 hours in ER; keep in mind that symptoms can begin up to 24h after ingestion. 

resource: The Philadelphia Guide: Inpatient Pediatrics.. 2005 ed. pp. 409-410.

5. Pathophysiology of ventricular septal defect.

• Small defects are not usually hemodynamically significant.
• Large defects allow significant left-to-right shunting which may lead to pulmonary overcirculation, decreased cardiac output, and CHF,
• Large, unrepaired defects can lead lead to pulmonary vascular obstructive disease, and Eisenmenger's Syndrome (process in which a left-to-right shunt in the heart causes increased flow through the pulmonary vasculature, causing pulmonary hypertension, which in turn, causes increased pressures in the right side of the heart and reversal of the shunt into a right-to-left shunt.).
• Further complications include RV outflow obstruction, aortic regurgitation, and endocarditis.

resource: The Philadelphia Guide: Inpatient Pediatrics.. 2005 ed. p. 34.

6. Laboratory evaluation of microcytic anemia.

• Keep in mind the common causes: Fe deficiency (most common cause), thalassemia, chronic inflammation, lead poisoning, sideroblastic anemia.
• thalassemia trait: RBC count and RDW often normal
• Fe deficiency: low RBC count, increased RDW, low retic count, low ferritin, low serum iron and/or transferrin, increased TIBC.
• Mentzer index (MCV/RBC) can help screen between Fe def. and thalassemia.  (< 11.5 suggests thalassemia minor, > 13.5 suggest Fe deficiency).

resource: Harriet Lane Handbook. 17th edition. p. 335-344..
resource: The Philadelphia Guide: Inpatient Pediatrics.. 2005 ed. p. 126.

7. Knowledge of the regulation of serum osmolality.

• calculated serum osmolality = (2 x Na) + (glucose / 18) + (BUN / 2.8)
• Normal range: 285 - 295 mOsm/L
• If measured serum osmolality is greater than 10 above the calculated, then consider causes for the gap (ethanol, mannitol, ethylene glycol, etc.).
• Normally, human urine is hyperosmolal and urination depends on the excretion of osmotically active substances.
• Maintenance of osmolality is largely related to the regulation of water balance.
• Osmoreceptor cells in the anterior hypothalamus are very sensitive to changes in ECF osmolality, and activate electrical impulses that result in ADH release from the posterior pituitary.  Also, carotid baroreceptors can cause ADH release.
• ADH increases water reabsorption in the renal collecting tubules.
• The system is highly efficient...normally there is no more than a 1 to 2 % variability in plasma osmolality despite wide fluctuations in water and solute intake (e.g. eating a bag of pretzels without any fluid). 
  

resource: The Philadelphia Guide: Inpatient Pediatrics.. 2005 ed. p. 23., & UpToDate article "Physiologic regulation of effective volume and plasma osmolality." by Rose, Burton, MD.

8. Prevention of drowning in swimming pools.

• adult supervision
• 4 sided fence
• American Academy of Pediatrics does not recommend swimming classes as the primary means of drowning prevention for children younger than 4 years of age.

resource : AAP Policy Statement on Drowning