EM COMAT TEST 2024/2025 WITH 200 REAL
EXAM QUESTIONS AND CORRECT
ANSWERS WITH DETAILED RATIONALES/
EMERGENCY MEDICINE (EM) COMAT
EXAM 2024 (BRAND NEW)
A 60-year-old male presents to the emergency department with darkened stools.
History reveals microcytic anemia that has been treated with iron supplementation.
Physical examination reveals a comfortable patient in no acute distress with a
cardiopulmonary and vascular physical exam. A complete blood count is obtained
revealing a hemoglobin and hematocrit of 12.8 g/dL and 34 %, respectfully and a
MCV of 70 fL. A digital rectal examination is performed and reveals normal
sphincter tone, no internal hemorrhoids, no stool in the vault, a normal prostate,
and no blood on the gloved figure. You note a tender nodule on the right mid-
thigh, just anterior to the iliotibial band. A fecal occult blood test is obtained and is
read as positive. Which of the following can cause a false positive result?
A. amoxicillin
B. beets
C. ferrous sulfate
D.poppy seeds
E. systemic lupus erythematosus - ANSWER-The correct answer is: B
RATIONALE: Fecal blood is tested in the setting of a complaint or physical exam
finding concerning for blood loss through the gastrointestinal tract. It is also a
useful tool for screening for colon cancer. The common point of care testing is the
guaiac test (gFOBT) which tests for the presence of heme, whether as a free
protein or as still attached to hemoglobin. Heme has active pseudoperoxidase
activity. In the presence of the developer which is hydrogen peroxide, guaiac acid
is oxidized providing a blue indicating hue. False positives are possible with this
test if there is an elevated concentration of heme from a recent diet of red meat, or
if there is an elevated peroxidase which can be found in some fruits and vegetables,
pg. 1
,including beets. This question also provides you with a tender thigh nodule which
may represent a chapman reflex point from the ascending colon. Although there
can be false positives based on diet, do not ignore other signs of potential colon
cancer.
Answer A: It has been a common in the lay literature that the antibiotic amoxicillin
can be the cause of a false positive on urine drug screens for cocaine. However,
this has been proven false by a obtaining urine drug tests from thirty three patients
receiving amoxicillin treatment. There have been no documented cases of
amoxicillin and false positive rates of gFOBT.
Answer C: This patient presents with a microcytic anemia treated with iron
supplementation. Although diet can produce false positives on gFOBT, iron
supplementation does not as the gFOBT is a test of heme and peroxidase activity
and is not effected by iron. The presence of iron, however, can darken the stool
leading to a melena-appearing stool that tests negative on gFOBT.
Answer D: Poppy seed is derived from an opium plant. During processing of the
seed for consump
A 25-day-old female is brought into the emergency department by her parents who
report the neonate has been fussy and had a fever at home of 101.5°F (38.6°C). Her
parents state that she has been having increased difficulty breathing but report that
she has been feeding well. Vital signs reveal a temperature of 39.4ºC (103ºF), heart
rate of 145/min, blood pressure of 75/35 mmHg, respirations of 38/min, and
oxygen saturation of 94%. Physical exam reveals a well appearing child with an
increased work of breathing, nasal flaring, and grunting. A plain film chest
radiograph, complete blood count, and blood cultures have been obtained with
results pending. What is the next best step in management?
A. CT scan of the chest
pg. 2
,B. IM lorazepam
C. IV ceftriaxone
D. lumbar puncture
E. stool ova and parasites - ANSWER-The correct answer is: D
RATIONALE: A lumbar puncture, to obtain CSF for culture and cell count is
indicated to determine the culprit for the neonates fever. Any child less than 30
days old presenting to the emergency department with a fever must have the full
septic workup performed. A full septic workup includes a chest radiograph, blood
cultures, complete blood count, lumbar puncture and urinalysis. The child's
presenting symptoms would suggest pneumonia as the cause for the fever and
difficulty breathing. As bacteremia and UTI may also be present a full workup still
must be performed, even if the child is well appearing. Once older than 30 days a
lumbar puncture is no longer indicated in well-appearing infants with a fever of
unknown source as the risk for meningitis drops to ~1%. If the child has a
clinically diagnosed bacterial infection (otitis media, pneumonia, cellulitis) this is
considered a legitimate "source" for fever. However the very young (< 30 days old)
may still have concomitant bacteremia or UTI and as such need a full septic work
up. If the child were to have meningitis, CSF results may point to the etiology
before culture results return. Bacterial meningitis will have low glucose, high
protein and high WBC's. Viral meningitis may have mostly normal results but still
with high WBC's. It is important to distinguish between real results and elevated
WBC's because of a traumatic tap. A ratio of 500-1000:1 RBC's:WBC's is
generally considered a traumatic tap. If the WBC count is higher that this ratio, an
infectious source must be considered. Urinary tract infection (UTI) should always
be in the emergency physician's differential as a source for a fever in a child and
considered in the septic algorithm. In neonates (< 30 days old) the risk of UTI is
~10-15% regardless of gender or circumcision status. Once over th
A 2-year-old male presents in November with a two-day history of upper
respiratory infection, a rectal temperature of 39.1°C (102.4°F), and the sudden
onset of inspiratory stridor, bark cough, and mild retractions.
Question 1 of 2 in this set
The most likely diagnosis is
pg. 3
, A. acute asthma exacerbation
B. cystic fibrosis
C. laryngomalacia
D.spasmodic croup
E. viral laryngotracheal bronchitis - ANSWER-The correct answer is: E
Viral laryngotracheal bronchitis, also known as croup, is a very common upper
airway disease affecting children 6 months to 6 years old. As the name implies, the
etiology is often viral with most cases being caused by parainfluenza virus,
although Staphylococcus aureus and Streptococcus pneumonia have been known to
cause bacterial croup as well. Children will classically present in late autumn to
early winter with inspiratory stridor, fever, retractions, and decreased pulse oxygen
saturation. Diagnosis is made clinically, although plain chest films will show the
classic "steeple sign" due to narrowing of the trachea.
Answer A: Asthma is an obstructive pulmonary process common in the pediatric
population with a multi-faceted etiology including environmental and genetic
factors. Acute exacerbation can be caused by allergen exposure and leads to
bronchospasm with associated wheezing and shortness of breath. Asthma
exacerbations can certainly have retractions and coughing, inspiratory stridor and
fever are not consistent with this diagnosis. Additionally, the child would likely
have had a history of pulmonary problems.
Answer B: Cystic fibrosis is an autosomal recessive disorder that is caused by a
mutation in the CTFR gene which is involved in sweat and mucus production. This
disease affects multiple organs, but specifically the lungs via excess mucus
production and decreased bronchial cilia action leading to mucus plugging and
bronchiectasis. These chronic mucus plugs can also lead to bacterial pneumonia. In
this scenario, fever and cough can both occur with pneumonia, but stridor is
specific to the upper airways/laryngotracheal area which neither cystic fibrosis nor
pneumonia sequelae particularly affect. Additional, this child was previously
healthy which would not be the case in cystic fib
pg. 4
