ENVELOP A 4 CREDITS 5 MARKS

Question 1

Q1:
Which of the following is the most common cause of acquired methemoglobinemia?
A) Carbon monoxide poisoning
B) Exposure to nitrites
C) Hemoglobin S disease
D) Lead poisoning
E) Hemolytic anemia

Answer 1

B) Exposure to nitrites

Question 2

Q2
Which of the following medications is most commonly associated with the development of methemoglobinemia?
A) Acetaminophen
B) Dapsone
C) Aspirin
D) Penicillin
E) Ibuprofen

Answer 2

B) Dapsone

Question 3

Q3
A 5-year-old child presents with cyanosis, a normal pulse oximetry reading of 85%, and chocolate-brown blood on examination. Which of the following is the most likely cause?
A) Acute asthma exacerbation
B) Methemoglobinemia
C) Hyperventilation syndrome
D) Cyanide poisoning
E) Carbon monoxide poisoning

Answer 3

Methemoglobinemia

Question 4

Q4
Which of the following findings is most characteristic of methemoglobinemia?
A) Increased PaO2
B) Normal pulse oximeter readings
C) Cyanosis with normal arterial oxygen tension (PaO2)
D) Hypercapnia
E) Severe metabolic acidosis

Answer 4

C) Cyanosis with normal arterial oxygen tension (PaO2)

Question 5

Q5:
In methemoglobinemia, the oxygen-carrying capacity of hemoglobin is impaired because:
A) Hemoglobin is unable to bind to oxygen
B) Hemoglobin binds oxygen but does not release it effectively
C) Methemoglobin does not carry any oxygen
D) Red blood cells are unable to release oxygen at tissues
E) Oxygen is carried by myoglobin instead of hemoglobin

Answer 5

B) Hemoglobin binds oxygen but does not release it effectively