12 USMLE Step 1 Mixed Review Questions with Answers (Set 11)

These 12 quick USMLE review questions test high-yield facts that show up again and again on the exam: DKA severity, adoption studies, thyroid nodules, rheumatoid arthritis before surgery, relative risk, portal hypertension, vision in pregnancy, Crohn disease, emphysema, RhoGAM, muscle metabolism and pancreatitis. Each question includes the correct answer.

Written by Dr. Ray Makar, MD, author of the Repeated USMLE Questions eBook series.

Prefer video? Watch daily USMLE case questions on MedFocus by Dr. Ray on YouTube.

How to use this page: read the question, pick your answer, then tap Show Answer and Explanation.

Questions

Question 1. Which one of the following factors is the most accurate measure for the severity of diabetic ketoacidosis?

A- Blood ketones
B- Serum bicarbonate level
C- Serum glucose level
D- Urine ketones

B- Serum bicarbonate level- The patient is at risk of death if his serum carbonate level drops down. Blood ketones is a good measure but it can’t be all detected. Serum glucose can go to very high level without the presence of ketoacidosis.
The correct answer is B

 

Question 2. Which one of the following studies measures heritability and the influence of environmental factors?

A- Adoption study
B- Case-control study
C- Cohort study
D- Cross-sectional study

A- Adoption study- This study compares siblings raised by biological vs adoptive parents to measure heritability and influence of environmental factors.
The correct answer is A

 

Question 3. A 40-year-old woman complains of swelling in her neck. Examination reveals a small, non-tender nodule in her thyroid. Which of the following is the best next step of action?

A- Excisional biopsy
B- Fine needle aspiration
C- T4 and TSH levels
D- Ultrasound of the thyroid

C- T4 and TSH levels- It is the best next step to exclude malignancy. Malignant nodules are not functional.
The correct answer is C

 

Question 4. An old patient with a history of Rheumatoid arthritis is scheduled for a major operation. Which of the following is the most important test before surgery?

A- Anti-cyclic citrullinated peptide
B- Cervical spine x-ray
C- Erythrocyte sedimentation rate (SER)
D- Rheumatoid factor

B- Cervical spine x-ray- Prior to surgery and intubation, radiology is important to determine any fracture of cervical vertebra which is a complication of RA.
The correct answer is B

 

Question 5. A group of researchers investigates the effect of daily intake of baby aspirin on the development of coronary artery disease. They are observing two groups of people divided according to intake of aspirin or not and how many develop CHD on each group. The results are listed on a chart. Which of the following is the correct measure to make an assumption?

A- Odds ratio
B- Positive predictive value
C- Relative risk
D- Specificity

C- Relative risk- This research is prospective, observational study. Odds ratio is used in retrospective, case control study. Others are distractions.
The correct answer is C

 

Question 6. Which of the following is the most likely cause of sudden death in a case of portal hypertension?

A- Congestive heart failure
B- Rupture of esophageal varices
C- Hepatic encephalopathy
D- Ventricular fibrillation

B- Rupture of esophageal varices- this is the most dreaded complication of portal hypertension
The correct answer is B

 

Question 7. Which of the following is the most likely cause of decreased visual acuity in pregnancy?

A- Macular degeneration
B- Optic nerve degeneration
C- Retinal detachment
D- Thickening of the cornea

D- Thickening of the cornea- Most pregnant women retain fluids which may change thickness and shape of the cornea. It can lead to distorted vision which goes away after delivery.
The correct answer is D

 

Question 8. A young woman presents with chronic diarrhea found to have a rectovaginal fistula. Which of the following is most likely her diagnosis?

A- Celiac disease
B- Crohn’s disease
C- Ischemic colitis
D- Ulcerative colitis

B- Crohn’s disease
The correct answer is B

 

Question 9. Which of the following is the proper treatment for a case of chronic emphysema in a stable patient with a resting oxygen saturation of 86%?

A- Albuterol inhaler as needed
B- Continuous supplemental oxygen
C- Daily oral prednisone
D- Supplemental oxygen at night

B- Continuous supplemental oxygen
The correct answer is B

 

Question 10. A 26-year-old pregnant woman visits her primary care physician for a routine examination. Her examination is normal. Her blood group is O, Rh-negative. Administration of which of the following would prevent the development of related fetal complications?

A- Ferrous sulfate
B- Folic acid derivatives
C- Rh (D) immune globulin
D- Wide-spectrum antibiotics

C- Rh (D) immune globulin- It prevents the formation of antibodies to Rh D which in turn should prevent the development of erythroblastosis fetalis.
The correct answer is C

 

Question 11. A young man is involved in a car accident, which results in laceration to some great vessels, and is admitted for surgery. Which of the following organs is the LEAST affected by loss of blood for a an extended period of time?

A- Brain
B- Liver
C- Retina
D- Skeletal muscles
E- Small intestine

D- Skeletal muscles- Anaerobic glycolysis saves sometime for skeletal muscles to survive. Other organs need more oxygen to survive.
The correct answer is D

 

Question 12. Periumbilical discoloration is found in a patient diagnosed with acute pancreatitis. Which of the following signs is considered positive in this patient?

A- Cullen’s sign
B- Grey Turner sign
C- Murphy’s sign
D- Nikolsky’s sign

A- Cullen’s sign- It is positive if periumbilical discoloration is found in abdominal examination. Flank discoloration is also a common finding in acute pancreatitis. Murphy’s sign is positive in acute cholecystitis. Nikolsky’s sign is positive in pemphigus vulgaris.
The correct answer is A

 

High-yield points from this set

  • Serum bicarbonate best reflects DKA severity.
  • Thyroid nodule: check TSH first.
  • Get cervical spine films before intubating a patient with rheumatoid arthritis.
  • Esophageal variceal rupture is a common cause of sudden death in portal hypertension.

Keep practicing

Leave a Comment