Pediatric MCQ and Nots

behavior q.&ans

Correct Answer: C
The neonate in the vignette has gastroesophageal reflux (GER) caused by overfeeding.

A 2-week-old boy is brought to the clinic for persistent vomiting.

The neonate is exclusively fed a standard cow milk– based formula.

He takes 4 oz every 2 hours and vomits after every feeding, despite burping.

The emesis is not bloody, bilious, or projectile.

He has 4 yellow, seedy, soft stools per day without blood.

He is otherwise healthy.

The neonate was born at term via an
uncomplicated delivery and had an unremarkable newborn nursery course.

His weight today is
greater than his birth weight.

His vital signs and physical examination findings are unremarkable.

Of the following, the MOST likely cause of this neonate’s symptoms is

A. gastroesophageal reflux disease
B. milk protein allergy
C. overfeeding
D. pyloric stenosis

Heritable thrombophilia may be caused by:
1. Antithrombin deficiency:
Antithrombin is a glycoprotein, which inhibits a range of clotting factors including IXa, Xa, XIa, XIIa, thrombin and VIIa.
There are two types of antithrombin deficiency:
* Type I - characterised by a deficiency of antithrombin
* Type II - characterised by production of a functionally abnormal protein
Those patients with type I deficiency generally have an increased risk of thrombosis compared with those with a type II deficiency. The relative risk of venous thrombosis in these patients is +/- 25-50 fold (Rosendaal, 1999). Thrombosis often occurs in patients before 25 year of age.
2. Protein C deficiency:
Protein C is a vitamin K-dependent protein synthesised in the liver. It circulates in an inactive form, which becomes activated by thrombin/thrombomodulin complexes on the surface of endothelial cells. Activated protein C inhibits coagulation by degrading coagulation factors Va and VIIIa and resulting in decreased thrombin formation. It requires protein S as a cofactor.
Causes of protein C deficiency are:
- congenital - homozygous deficiency - those with severe deficiency - (protein C levels <1% of normal) present with severe neonatal purpura fulminans, cerebral thrombosis and DIC. Those with milder defects have protein C levels of 10-24 % of normal. They can present with massive venous thrombosis as older children.
- heterozygous deficiency (protein C levels 30 - 40% of normal) - most frequently presents after puberty with deep venous thrombosis of the lower limb. It can also present with recurrent superficial thrombophlebitis and DVT. Most thrombotic episodes occur spontaneously but known associated risk factors include surgery with immobilisation, pregnancy and the oral contraceptive.
Many people remain asymptomatic. A positive family history of thrombosis is associated with an increased risk of symptoms - +- 50% of individuals with heterozygous protein C deficiency and a family history of thrombosis, will experience a thrombotic event.
3. Protein S deficiency:
Protein S, as mentioned, is a cofactor for protein C. 65% of total plasma protein S exists in a complex with C4b-binding protein with 35% of protein S circulating free in the plasma.
There are three types of inherited protein S deficiency:
* Type I - reduced production of normal protein S
* Type II - production of a functionally abnormal protein S
* Type III - free protein S levels are reduced, with normal total protein S levels
A positive family history of thrombosis is associated with an increased risk of symptomatic protein S deficiency.
4. Factor V Leiden
Factor V Leiden refers to a point mutation in the gene for factor V that results in resistance of factor V to the actions of activated protein C, and consequently a thrombophillic state. Protein C levels are not decreased.
Other causes of heritable thrombophilia include:
5. Prothrombin G20210A mutation
6. Dysfibrinogenaemia
7. Mixed aetiology - elevated factor VIII; hyperhomocysteinaemia
Lupus anticoagulants are an acquired cause of increased thrombosis. They are commonly found in the elderly in whom they usually do not cause clinical pathology.In younger people, they are associated with SLE, HIV and certain drugs. Antiphospholipid antibodies cause an in vitro coagulation defect with an increased in vivo propensity to arterial and venous thrombosis. They may also be associated with recurrent foetal loss.