Rei Sample Quiz

Explanation
ITP is an autoimmune phenomenon with increased platelet destruction due to the presence of anti-platelet antibodies. Patients with ITP are found to have high levels of either platelet-associated immune globulin, complement, or both. In addition to the presence of these antibodies, the diagnosis of ITP relies on meeting the following criteria:

normal blood count except for decreased platelets
normal bone marrow biopsy with normal or increased megalokaryocytes
increased percentage of large platelets on a peripheral smear
normal coagulation studies
no other obvious cause of thrombocytopenia
These criteria are easy to remember if one keeps in mind that ITP is a disease of platelet destruction, not of platelet production.

Explanation
RhoGAM (immunoglobulin G towards Rh-D antigen) is very effective in preventing isoimmunization to Rh-D. Its exact mechanism of action is unknown but its use is based on the principle of passive immunity preventing an immune response. A standard dose is 300 ug/vial which provides protection against maternal exposure to up to 30cc of fetal Rh(+) blood, this is equivalent to 15cc of fetal RBC’s.

A Kleihauer-Betke test allows identification of the number of fetal cells present in a given volume of maternal blood. Calculation of the total amount of fetal cells present in the maternal system can then be performed. Following this calculation RhoGAM is administered by giving a standard vial for each 15cc of fetal RBC (30cc blood) plus one additional vial to ensure complete coverage in case of any misjudgment in calculation.

Explanation
D Serial ultrasound evaluation

This scenario is consistent with acute maternal infection with parvovirus B19 (Fifth disease). In this setting approximately 30% of fetuses will develop viremia. This viremia can subsequently lead to erythropoietic derangement and ultimately fetal hydrops secondary to severe anemia. Fetal loss rates vary from 2-10% with maternal infection so not all infected fetuses manifest severe anemia. Routine termination with documented infection is therefore unwarranted. Since this patient is already infected and has mounted a primary immune response, vaccination would not be of benefit (currently no vaccine is available for parvovirus B19). Immunoglobin therapy is not readily available and if it were it would be given parenterally to avoid GI breakdown.

Adverse fetal effects typically occur within 3-6 weeks of maternal infection. Serial ultrasound over this period to look for early signs of anemia (skin edema, organomegaly, effusions, ascites) is the recommended evaluation. If evidence of severe anemia is found, fetal survival can be markedly improved by intrauterine transfusion. Fetal survival of 60-80% is seen with transfusion while only 15-30% survive without treatment.

Explanation
B Combined Fe/folate deficiency is never normocytic, normochromic anemia

The maternal blood volume rises by about one-third to provide for the increase in uteroplacental vasculature and pregnancy related venous dilatation. The plasma volume rises about 45%, but the red cell volume only rises by about 25%. This causes hemodilution producing the physiological anemia of pregnancy. Hemoglobin level may fall, but mean corpuscular volume [MCV] and mean corpuscular hemoglobin [MCH] both remain unchanged.

The result of combined iron and folic acid deficiency may be a normocytic, normochromic anemia. Anemia in pregnancy can increase the chances of fetal hypoxia, intra uterine growth restriction, premature labor, and puerperal sepsis. Folic acid deficiency is associated with a higher incidence of abruption. Post partum hemorrhage is not more common, but if moderate hemorrhage occurs, it may have profound results. When anemia is found late in pregnancy the patient may have iron deficiency, folic acid deficiency, hemoglobinopathy, exaggerated physiological anemia, occult blood loss, and/or primary hypoplasia of the bone marrow, and further evaluation should be entertained.

Explanation
B Maternal administration of V-ZIG reduces the occurrence of congenital
varicella syndrome

Maternal treatment with acyclovir has not been demonstrated to reduce or prevent fetal effects of congenital varicella syndrome. IV administration of this drug is recommended for neonates who develop varicella within the first 2 weeks postpartum. Oral acyclovir given within 24 hours of the rash will reduce new lesion formation and improve constitutional symptoms in children, adolescents, and adults. Oral acyclovir appears safe for pregnant women; however, varicella pneumonia is treated with IV acyclovir to reduce maternal mortality.

V-ZIG is expensive and sometimes hard to come by in a hurry in the quantity needed to administer to an adult. Consider doing some lab work to evaluate mom’s immune status. Many people are seemingly immune even though they were never vaccinated and do not remember having the disease. Many commercial labs can turn a stat specimen around in 24-36 hours.

Explanation
D IIIB

Cervical cancer is one of the most common malignancies in women in the developing world. For this reason the FIGO staging for cervical cancer performed clinically, not surgically. The only adjunctive tests, which can be used to stage cervical cancer, are intravenous pyelogram, chest x-ray, barium enema, and cytoscopy and proctoscopy.

The following is the staging for cervical cancer:

Stage 1 - Cancer in the cervix only

IA - Invasion of the cervical tissues can only be seen with a microscope. (Further classified into 1A1 and 1A2, depending upon depth)
IB - Lesions wider than 7 mm or deeper than 5 mm, or that can be seen without a microscope (Further classified for tumors larger or smaller than 4 cm)
Stage 2 - Cancer extends beyond the cervix, but not as far as the pelvic wall

2A - Extends to upper part of the vagina, but not to parametria
2B - Extends to the parametrial tissues (but not to the pelvic wall).
Stage 3 - The cancer has extended beyond Stage 2, but not beyond the pelvic area. Note: although this system does not include lymph node sampling, in other systems a positive lymph node would put the cancer in Stage 3.

3A - The cancer has spread to the lower third of the vagina, but nowhere else.
3B - The cancer has spread to the pelvic wall, or has blocked a ureter
Stage 4 - Cancer has spread to the bladder, rectum, or outside the pelvis.

4A - Spread to the rectum or bladder.
4B - Spread (metastasis) to distant organs such as the lungs or liver.
The presence of hydronephrosis or pelvic sidewall involvement classifies this patient as a FIGO Stage IIIB cervical carcinoma.