Nutritional assessment and optimization US Medical PG Practice Questions and MCQs
Practice US Medical PG questions for Nutritional assessment and optimization. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Nutritional assessment and optimization US Medical PG Question 1: A 69-year-old man is brought to the emergency room by his daughter due to confusion. She reports that her father did not remember who she was yesterday, and his refrigerator was completely empty when she tried to make him lunch. She states that he was acting like himself when she visited him last week. She also notes that he has struggled with alcoholism for many years and has not seen a doctor in over two decades. She is unsure if he has any other chronic medical conditions. In the emergency room, the patient’s temperature is 101.2°F (38.4°C), pulse is 103/min, respirations are 22/min, and O2 saturation is 92% on room air. His BMI is 17.1 kg/m^2. Physical exam reveals an extremely thin and frail man who is not oriented to person, place, or time. As he is being examined, he becomes unresponsive and desaturates to 84%. He is intubated and admitted to the intensive care unit for what is found to be pneumonia, and the patient is started on total parental nutrition as he is sedated and has a history of aspiration from a prior hospitalization. Two days later, physical exam is notable for new peripheral edema. Laboratory tests at that time reveal the following:
Serum:
Na+: 133 mEq/L
Cl-: 101 mEq/L
K+: 2.4 mEq/L
HCO3-: 24 mEq/L
BUN: 22 mg/dL
Glucose: 124 mg/dL
Creatinine: 1.1 mg/dL
Phosphate: 1.1 mg/dL
Mg2+: 1.0 mg/dL
Which of the following could have prevented the complication seen in this patient?
- A. Initiation of furosemide
- B. Use of low-sugar TPN
- C. Use of enteral nutrition
- D. Initiation of intermittent dialysis
- E. Slow initiation of total parenteral nutrition (TPN) (Correct Answer)
Nutritional assessment and optimization Explanation: ***Slow initiation of total parenteral nutrition (TPN)***
- This patient likely developed **refeeding syndrome**, which is characterized by severe electrolyte shifts (especially **hypophosphatemia**, **hypokalemia**, and **hypomagnesemia**) and fluid retention (peripheral edema) upon rapid reintroduction of nutrition to severely malnourished individuals.
- A **slow and gradual introduction of TPN** would have allowed the body to adapt to the increased metabolic demands, preventing the sudden intracellular shift of electrolytes and subsequent depletion in the serum.
*Initiation of furosemide*
- Furosemide is a **loop diuretic** primarily used to treat fluid overload and edema by increasing renal excretion of water and electrolytes.
- While it could address the peripheral edema, it would not correct the underlying electrolyte imbalances of refeeding syndrome and could potentially worsen them (e.g., contributing to **hypokalemia**).
*Use of low-sugar TPN*
- Refeeding syndrome is triggered by the shift from fat metabolism to carbohydrate metabolism, leading to increased insulin secretion and subsequent intracellular movement of electrolytes.
- While a lower glucose load might slightly mitigate the insulin response, it does not address the core issue of rapid nutrient repletion in a severely malnourished state, and the absolute amount of carbohydrates would still be significant in TPN.
*Use of enteral nutrition*
- **Enteral nutrition** (feeding via the gastrointestinal tract) is generally preferred over TPN when feasible, as it helps maintain gut integrity and has a lower risk of certain complications.
- However, if initiated too rapidly in a severely malnourished patient, enteral nutrition can also precipitate refeeding syndrome, as the metabolic shifts are triggered by carbohydrate repletion regardless of the delivery route.
*Initiation of intermittent dialysis*
- **Intermittent dialysis** is a renal replacement therapy used for acute or chronic kidney failure to remove waste products and excess fluid.
- This patient's creatinine and BUN are only mildly elevated for someone with pneumonia and dehydration, indicating **no clear indication for dialysis**; phosphorus and magnesium could be corrected with supplementation.
Nutritional assessment and optimization US Medical PG Question 2: Four days after admission to the hospital for anorexia nervosa, a 20-year-old woman has new-onset palpitations and paresthesias in all four limbs. Prior to admission, she was found unconscious by her parents on the floor of a residential treatment center. The patient was started on a trial of nutritional rehabilitation upon arrival to the hospital. Her temperature is 36°C (96.8°F), pulse is 47/min, and blood pressure is 90/60 mmHg. She is 160 cm tall and weighs 35 kg; BMI is 14 kg/m2. The patient appears emaciated. Examination shows lower leg edema. A 2/6 holosystolic murmur is heard over the 5th intercostal space at the midclavicular line. An ECG shows intermittent supraventricular tachycardia and QTc prolongation. Serum studies show:
Day 2 Day 4
Potassium (mEq/L) 3.5 2.7
Calcium (mg/dL) 8.5 7.8
Magnesium (mEq/L) 1.2 0.5
Phosphorus (mg/dL) 3.6 1.5
Which of the following is the most likely underlying cause of this patient's condition?
- A. Uncompensated metabolic alkalosis
- B. Thiamine deficiency
- C. Euthyroid sick syndrome
- D. Rapid gastric emptying
- E. Increased insulin release (Correct Answer)
Nutritional assessment and optimization Explanation: ***Increased insulin release***
- **Refeeding syndrome** is triggered by a sudden increase in carbohydrate intake after a period of starvation, leading to an abrupt rise in **insulin secretion**.
- Insulin shifts **potassium, phosphate, and magnesium** into cells, causing rapid and severe **hypokalemia, hypophosphatemia, and hypomagnesemia**, which manifest as cardiac arrhythmias, neurological symptoms (paresthesias), and muscle weakness.
*Uncompensated metabolic alkalosis*
- While metabolic alkalosis can occur in anorexia nervosa due to **vomiting**, it typically causes hypokalemia, not the widespread electrolyte derangements seen here.
- It does not directly explain the acute drop in **phosphate and magnesium** or the onset of refeeding syndrome symptoms.
*Thiamine deficiency*
- **Thiamine deficiency** can occur in malnourished patients and lead to Wernicke encephalopathy or Korsakoff syndrome, but it typically presents with ocular abnormalities, ataxia, and confusion, not primarily with the acute cardiac and electrolyte disturbances observed.
- While important for metabolism, it is not the **primary driver** of the acute electrolyte shifts characteristic of refeeding syndrome.
*Euthyroid sick syndrome*
- Characterized by **abnormal thyroid function tests** in a severely ill patient without primary thyroid disease, reflecting altered peripheral thyroid hormone metabolism.
- It does not directly cause the acute and severe **electrolyte abnormalities** (hypokalemia, hypophosphatemia, hypomagnesemia) or the specific clinical presentation of refeeding syndrome.
*Rapid gastric emptying*
- While rapid gastric emptying can be a feature in some eating disorders, it directly leads to symptoms like **dumping syndrome** (abdominal pain, diarrhea).
- It does not explain the profound **intracellular shift of electrolytes** and the resulting cardiac and neurological symptoms seen in this case.
Nutritional assessment and optimization US Medical PG Question 3: A 65-year-old man presents to the diabetes clinic for a check-up. He has been successfully managing his diabetes through diet alone, and has not experienced any complications related to retinopathy, neuropathy, or nephropathy. He recently started a new exercise regimen and is eager to see whether his weight has declined since his last visit. The nurse measures his height to be 170 cm and his weight to be 165 lb (75 kg). What range does this patient’s body mass index currently fall into?
- A. < 18.5
- B. > 30.0
- C. 25.0 - 29.9 (Correct Answer)
- D. 18.5 - 24.9
- E. > 40.0
Nutritional assessment and optimization Explanation: ***25.0 - 29.9***
- To calculate BMI, divide weight in kilograms by the square of height in meters: Weight = 75 kg, Height = 1.70 m.
- BMI = 75 / (1.70 * 1.70) = 75 / 2.89 ≈ **25.95 kg/m²**, which falls within the **overweight** range of 25.0 to 29.9.
*< 18.5*
- A BMI less than 18.5 indicates **underweight**.
- The calculated BMI of approximately 25.95 is significantly higher than this range.
*> 30.0*
- A BMI greater than 30.0 indicates **obesity**.
- The calculated BMI of approximately 25.95 is below this threshold, indicating the patient is not obese.
*18.5 - 24.9*
- A BMI between 18.5 and 24.9 is considered the **normal or healthy weight** range.
- The patient's BMI of approximately 25.95 is slightly above this range, placing him in the overweight category.
*> 40.0*
- A BMI greater than 40.0 indicates **morbid obesity** or **Class III obesity**.
- The patient's calculated BMI of 25.95 is substantially lower than this severe obesity classification.
Nutritional assessment and optimization US Medical PG Question 4: An epidemiologist is evaluating the efficacy of Noxbinle in preventing HCC deaths at the population level. A clinical trial shows that over 5 years, the mortality rate from HCC was 25% in the control group and 15% in patients treated with Noxbinle 100 mg daily. Based on this data, how many patients need to be treated with Noxbinle 100 mg to prevent, on average, one death from HCC?
- A. 20
- B. 73
- C. 10 (Correct Answer)
- D. 50
- E. 100
Nutritional assessment and optimization Explanation: ***10***
- The **number needed to treat (NNT)** is calculated by first finding the **absolute risk reduction (ARR)**.
- **ARR** = Risk in control group - Risk in treatment group = 25% - 15% = **10%** (or 0.10).
- **NNT = 1 / ARR** = 1 / 0.10 = **10 patients**.
- This means that **10 patients must be treated with Noxbinle to prevent one death from HCC** over 5 years.
*20*
- This would result from an ARR of 5% (1/0.05 = 20), which is not supported by the data.
- May arise from miscalculating the risk difference or incorrectly halving the actual ARR.
*73*
- This value does not correspond to any standard calculation of NNT from the given mortality rates.
- May result from confusion with other epidemiological measures or calculation error.
*50*
- This would correspond to an ARR of 2% (1/0.02 = 50), which significantly underestimates the actual risk reduction.
- Could result from incorrectly calculating the difference as a proportion rather than absolute percentage points.
*100*
- This would correspond to an ARR of 1% (1/0.01 = 100), grossly underestimating the treatment benefit.
- May result from confusing ARR with relative risk reduction or other calculation errors.
Nutritional assessment and optimization US Medical PG Question 5: A 17-year-old girl is brought in by her mother due to rapid weight loss over the past month. The patient says she has been having episodes of diarrhea, which she attributes to laxatives she takes regularly to keep her weight down. She also says she has not had her period yet. The patient’s mother adds that the patient has been underperforming at school and acting very strangely at home. Her current BMI is 16.8 kg/m2. On physical examination, the skin on her limbs and around her neck is inflamed and erythematous. Her tongue is bright red and smooth. She states that over the last 2 weeks, she has been eating nothing but small portions of fruit. She is diagnosed with a vitamin deficiency. Which of the following statements is true about the vitamin most likely deficient in this patient?
- A. It increases the GI absorption of iron
- B. It is derived from tyrosine
- C. Synthesis requires vitamin B2 and B6 (Correct Answer)
- D. Synthesis requires vitamin B1 and B6
- E. It is used to treat hypertension
Nutritional assessment and optimization Explanation: ***Synthesis requires vitamin B2 and B6***
- The patient's symptoms (diarrhea, dermatitis, dementia-like behavior, glossitis, and weight loss) are classic for **pellagra**, which is caused by a deficiency in **niacin (vitamin B3)**.
- The synthesis of **niacin** from **tryptophan** requires **pyridoxine (vitamin B6)** and **riboflavin (vitamin B2)** as cofactors.
*It increases the GI absorption of iron*
- **Vitamin C** (ascorbic acid) enhances the **gastrointestinal absorption of non-heme iron** by reducing ferric iron to its ferrous form.
- Niacin does not play a direct role in the absorption of iron.
*It is derived from tyrosine*
- **Tyrosine** is a precursor to several important compounds, including **catecholamines** (dopamine, norepinephrine, epinephrine) and **thyroid hormones**.
- **Niacin** is predominantly synthesized from the essential amino acid **tryptophan**.
*Synthesis requires vitamin B1 and B6*
- While **vitamin B6** is essential for niacin synthesis from tryptophan, **vitamin B1 (thiamine)** is not directly involved in this pathway.
- Thiamine's primary role is in carbohydrate metabolism.
*It is used to treat hypertension*
- While **niacin** can affect lipid profiles, it is **not commonly used as a primary treatment for hypertension**.
- **Niacin** is used, primarily in pharmacologic doses, to **lower LDL cholesterol** and **triglycerides** and **raise HDL cholesterol**, often in conjunction with other lipid-lowering agents.
Nutritional assessment and optimization US Medical PG Question 6: A 46-year-old woman presents to her primary care physician for her annual examination. At her prior exam one year earlier, she had a Pap smear which was within normal limits. Which of the following health screenings is recommended for this patient?
- A. Colorectal screening (Correct Answer)
- B. Blood glucose and/or HbA1c screening
- C. Blood pressure at least once every 3 years
- D. Yearly Pap smear
- E. Bone mineral density screening
Nutritional assessment and optimization Explanation: ***Colorectal screening***
- **Colorectal cancer screening** is generally recommended to start at age **45 years** for individuals at average risk.
- This patient is 46 years old, making immediate colorectal screening appropriate based on current guidelines.
*Blood glucose and/or HbA1c screening*
- **Blood glucose or HbA1c screening** for diabetes is recommended starting at age **35 for all adults** or earlier if there are risk factors such as obesity or a family history of diabetes.
- While this patient is 46, this screening should have already been initiated, and it is not the *most* uniquely recommended screening for this specific age that might have been overlooked.
*Blood pressure at least once every 3 years*
- **Blood pressure screening** should be performed **at least annually** for adults aged 40 and older, or more frequently if there are risk factors.
- Screening only every 3 years is insufficient for a 46-year-old patient.
*Yearly Pap smear*
- **Pap smear frequency** has changed; for women aged 30-65 with normal results, screening is recommended every **3 years** with cytology alone, or every 5 years with high-risk HPV testing alone or co-testing.
- A yearly Pap smear is no longer typical practice for a woman with normal prior results and no specific risk factors.
*Bone mineral density screening*
- **Bone mineral density (BMD) screening** for osteoporosis is typically recommended for women starting at age **65 years** or earlier if they have significant risk factors.
- This patient is 46 years old and has no mentioned risk factors, so BMD screening is not routinely indicated at this age.
Nutritional assessment and optimization US Medical PG Question 7: A 50-year-old man presents to the office for a routine health check-up. Managing his weight has been his focus to improve his overall health. The doctor discusses his weight loss goals and overall health benefits from weight loss, including better blood pressure management and decreased insulin resistance. The national average weight for males aged 50-59 years old is 90 kg (200 lb) with a standard deviation of 27 kg (60 lb). What would be the most likely expected value if his weight was 2 standard deviations above the mean?
- A. 36 kg (80 lb)
- B. 63 kg (140 lb)
- C. 172 kg (380 lb)
- D. 144 kg (320 lb) (Correct Answer)
- E. 118 kg (260 lb)
Nutritional assessment and optimization Explanation: ***144 kg (320 lb)***
- To find a weight 2 standard deviations above the mean, you use the formula: **mean + (2 × standard deviation)**.
- Given a mean of 90 kg and a standard deviation of 27 kg, the calculation is 90 + (2 × 27) = 90 + 54 = **144 kg**. In pounds: 200 lb + (2 × 60 lb) = 200 + 120 = **320 lb**.
*36 kg (80 lb)*
- This value is significantly below the mean and represents a weight **2 standard deviations below the mean**, not above it.
- Calculation: 90 - (2 × 27) = 90 - 54 = 36 kg.
*63 kg (140 lb)*
- This value is **below the mean** and represents a weight approximately **1 standard deviation below the mean**, not above.
- Calculation: 90 - 27 = 63 kg.
*172 kg (380 lb)*
- This value is **too high** for 2 standard deviations above the mean and would represent a weight closer to **3 standard deviations above the mean**.
- Calculation: 90 + (3 × 27) = 90 + 81 = 171 kg (approximately 172 kg).
*118 kg (260 lb)*
- This value represents a weight approximately **1 standard deviation above the mean**, not 2.
- Calculation: 90 + 27 = 117 kg (approximately 118 kg or 260 lb).
Nutritional assessment and optimization US Medical PG Question 8: A 28-year-old male presents to his primary care physician with complaints of intermittent abdominal pain and alternating bouts of constipation and diarrhea. His medical chart is not significant for any past medical problems or prior surgeries. He is not prescribed any current medications. Which of the following questions would be the most useful next question in eliciting further history from this patient?
- A. "Does the diarrhea typically precede the constipation, or vice-versa?"
- B. "Is the diarrhea foul-smelling?"
- C. "Please rate your abdominal pain on a scale of 1-10, with 10 being the worst pain of your life"
- D. "Are the symptoms worse in the morning or at night?"
- E. "Can you tell me more about the symptoms you have been experiencing?" (Correct Answer)
Nutritional assessment and optimization Explanation: ***Can you tell me more about the symptoms you have been experiencing?***
- This **open-ended question** encourages the patient to provide a **comprehensive narrative** of their symptoms, including details about onset, frequency, duration, alleviating/aggravating factors, and associated symptoms, which is crucial for diagnosis.
- In a patient presenting with vague, intermittent symptoms like alternating constipation and diarrhea, allowing them to elaborate freely can reveal important clues that might not be captured by more targeted questions.
*Does the diarrhea typically precede the constipation, or vice-versa?*
- While knowing the sequence of symptoms can be helpful in understanding the **pattern of bowel dysfunction**, it is a very specific question that might overlook other important aspects of the patient's experience.
- It prematurely narrows the focus without first obtaining a broad understanding of the patient's overall symptomatic picture.
*Is the diarrhea foul-smelling?*
- Foul-smelling diarrhea can indicate **malabsorption** or **bacterial overgrowth**, which are important to consider in some gastrointestinal conditions.
- However, this is a **specific symptom inquiry** that should follow a more general exploration of the patient's symptoms, as it may not be relevant if other crucial details are missed.
*Please rate your abdominal pain on a scale of 1-10, with 10 being the worst pain of your life*
- Quantifying pain intensity is useful for assessing the **severity of discomfort** and monitoring changes over time.
- However, for a patient with intermittent rather than acute, severe pain, understanding the **character, location, and triggers** of the pain is often more diagnostically valuable than just a numerical rating initially.
*Are the symptoms worse in the morning or at night?*
- Diurnal variation can be relevant in certain conditions, such as inflammatory bowel diseases where nocturnal symptoms might be more concerning, or functional disorders whose symptoms might be stress-related.
- This is another **specific question** that should come after gathering a more complete initial picture of the patient's symptoms to ensure no key information is overlooked.
Nutritional assessment and optimization US Medical PG Question 9: A 66-year-old man weighing 50 kg (110 lb) is admitted to the hospital because of sepsis complicated by acute respiratory distress syndrome. The physician decides to initiate total parenteral nutrition and prescribes short-term hypocaloric intake of 20 kcal/kg/day with 20% of the total energy requirement provided by proteins and 30% provided by fats. The physician calculates that a total volume of 1100 mL/day should be infused during the parenteral nutrition therapy to maintain fluid balance. A colloid containing 10 g/dL of albumin and an emulsion with a fat concentration of 33 g/dL are used to prepare parenteral nutrition modules. Which of the following is the most appropriate module to meet the carbohydrate requirement in this patient over the next 24 hours?
- A. 500 mL of 25% dextrose solution (Correct Answer)
- B. 750 mL of 25% dextrose solution
- C. 750 mL of 10% dextrose solution
- D. 500 mL of 10% dextrose solution
- E. 250 mL of 50% dextrose solution
Nutritional assessment and optimization Explanation: ***500 mL of 25% dextrose solution***
- The patient requires 1000 kcal/day total (50 kg * 20 kcal/kg/day). With 20% from protein (200 kcal) and 30% from fat (300 kcal), 500 kcal must come from carbohydrates. Given that **1 g of dextrose provides 3.4 kcal**, 500 kcal requires approximately 147 g of dextrose (500 kcal / 3.4 kcal/g). A **25% dextrose solution contains 250 g of dextrose per liter**, so 500 mL would provide 125 g of dextrose (0.5 L * 250 g/L), which translates to 425 kcal (125 g * 3.4 kcal/g). This is the closest and most appropriate option.
- While not exactly 500 kcal, this option delivers the closest amount of carbohydrate calories while fitting within fluid restrictions and is a common concentration used in TPN.
*750 mL of 25% dextrose solution*
- This option would provide approximately 187.5 g of dextrose (0.75 L * 250 g/L), resulting in 637.5 kcal. This is **too high a carbohydrate load** for the patient's calculated needs (500 kcal from carbs) and would exceed the desired energy distribution.
- Additionally, this volume might lead to **fluid overload** given the 1100 mL/day total fluid restriction.
*750 mL of 10% dextrose solution*
- This option provides approximately 75 g of dextrose (0.75 L * 100 g/L), resulting in 255 kcal. This is **insufficient to meet the required 500 kcal** from carbohydrates.
- While the volume is high, the caloric content from carbohydrate is low.
*500 mL of 10% dextrose solution*
- This option provides approximately 50 g of dextrose (0.5 L * 100 g/L), resulting in 170 kcal. This is **significantly below the target of 500 kcal** from carbohydrates and would lead to underfeeding.
- It would also leave a substantial amount of the 1100mL fluid volume unaccounted for if this were the only carbohydrate source.
*250 mL of 50% dextrose solution*
- This option provides approximately 125 g of dextrose (0.25 L * 500 g/L), resulting in 425 kcal. While the caloric content is similar to the correct answer, using **50% dextrose in a standard TPN formulation can be challenging** due to its high osmolality, and typically requires central line administration, which might not be practical for a "module" if other components dilute it.
- A 25% solution is generally preferred for its better compatibility within TPN admixtures and safer peripheral administration if necessary.
Nutritional assessment and optimization US Medical PG Question 10: Three days after being admitted to the hospital because of a fall from the roof of a two-story building, a 27-year-old man is being monitored in the intensive care unit. On arrival, the patient was somnolent and not oriented to person, place, or time. A CT scan of the head showed an epidural hemorrhage that was 45 cm3 in size and a midline shift of 7 mm. Emergency surgery was performed with craniotomy and hematoma evacuation on the day of admission. Perioperatively, a bleeding vessel was identified and ligated. Postoperatively, the patient was transferred to the intensive care unit and placed on a ventilator. His temperature is 37°C (98.6°F), pulse is 67/min, and blood pressure is 117/78 mm Hg. The ventilator is set at a FiO2 of 55%, tidal volume of 520 mL, and positive end-expiratory pressure of 5.0 cm H2O. In addition to intravenous administration of fluids, which of the following is the most appropriate next step in managing this patient's nutrition?
- A. Enteral feeding via nasogastric tube (Correct Answer)
- B. Oral feeding
- C. Keep patient NPO
- D. Total parenteral nutrition
- E. Enteral feeding using a percutaneous endoscopic gastrostomy (PEG) tube
Nutritional assessment and optimization Explanation: ***Enteral feeding via nasogastric tube***
- This patient has been **somnolent** and on a ventilator for 3 days after a significant head injury, indicating a prolonged period without oral intake and an inability to protect his airway for oral feeding. **Early enteral nutrition** via a nasogastric tube is preferred in critically ill patients, especially those with head injuries, as it helps maintain gut integrity and reduces complications compared to parenteral nutrition.
- The patient's **hemodynamic stability** (blood pressure and pulse are within a reasonable range for a ventilated patient) suggests he can tolerate enteral feeding, and there are no signs of gut ischemia or ileus that would contraindicate it.
*Enteral feeding using a percutaneous endoscopic gastrostomy (PEG) tube*
- While a PEG tube provides enteral nutrition, it is typically reserved for patients requiring **long-term enteral support** (usually more than 4-6 weeks) or those who cannot tolerate a nasogastric tube.
- Given that it has only been 3 days post-injury, a **less invasive method** like a nasogastric tube is initially preferred.
*Oral feeding*
- The patient is described as **somnolent** and on a ventilator, meaning he is not awake enough or able to protect his airway to safely receive oral feeding.
- Attempting oral feeding in this state carries a high risk of **aspiration pneumonia**.
*Keep patient NPO*
- Keeping the patient NPO (nil per os) for an extended period in critical illness is associated with several negative outcomes, including **gut mucosal atrophy, increased infection risk**, and poorer clinical outcomes.
- After 3 days, initiating nutritional support is crucial to prevent these complications.
*Total parenteral nutrition*
- **Total parenteral nutrition (TPN)** is generally considered a last resort when the gastrointestinal tract is non-functional or enteral feeding is contraindicated.
- TPN is associated with a **higher risk of complications**, such as central line infections, liver dysfunction, and metabolic disturbances, compared to enteral feeding.
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