Diabetic Ketoacidosis — MCQs

10 questions

Which ketone body is primarily responsible for the metabolic acidosis seen in diabetic ketoacidosis?

A 55 year old male presents with tachypnea and mental confusion. Blood glucose 350 mg/dl, pH = 7.0. What is the most likely acid base disorder?

A 24 year old male presents with altered sensorium and rapid shallow breathing. ABG shows:pH 7.2, sodium 140, bicarbonate 10 and chloride 98. Probable diagnosis is -

Diabetic ketoacidosis is said to be present if:

A 15-year-old girl with type 1 diabetes is brought to the emergency department complaining of dizziness. Laboratory findings include severe hyperglycemia, ketoacidosis, and a blood pH of 7.15. To achieve rapid control of severe ketoacidosis, which of the following is the most appropriate drug?

In a patient presenting with diabetic ketoacidosis (DKA), what is the most appropriate immediate treatment?

An obese patient presented in casualty in an unconscious state, with a blood glucose level of 400 mg/dL and urine testing positive for sugar and ketones. Which drug is most useful in his management?

A 27-year-old female is brought in by ambulance with altered mental status. She is in a comatose state, but is breathing spontaneously with deep and rapid respirations. Her vital signs are as follows: T 100.2F, BP 92/54 mmHg, HR 103 bpm, RR 28, and SpO2 97% on room air. Complete blood count reveals: WBC 12.7, hemoglobin 11.3, platelets 254. Basic metabolic panel reveals: sodium 137, potassium 4.2, chloride 100, bicarbonate 16, creatinine 1.78 An ABG is performed which showed pH 7.38, PaO2 94, PaCO2 26. Which of the following is the most likely cause of this patient’s presentation?

All of the following are selective indications for the use of hypotonic solutions, except:

Q10

A patient presents with the following arterial blood gas (ABG) and electrolyte values: pH: 7.34, Na: 135 mEq/L, Cl: 93 mEq/L, HCO3: 20 mEq/L, Random Blood Sugar (RBS): 420 mg/dl. What is the most likely acid-base disturbance?

Diabetic Ketoacidosis Indian Medical PG Practice Questions and MCQs

Question 1: Which ketone body is primarily responsible for the metabolic acidosis seen in diabetic ketoacidosis?

A. Carbonic acid
B. Beta hydroxybutyric acid (Correct Answer)
C. Acetoacetic acid
D. Lactic acid

Explanation: ***Beta hydroxybutyric acid*** - While both acetoacetic acid and beta-hydroxybutyric acid are ketone bodies, **beta-hydroxybutyric acid** is the most abundant and thus the primary contributor to the **acidosis** in DKA. - In diabetic ketoacidosis, the liver produces an excess of ketone bodies from **fatty acid metabolism**, and beta-hydroxybutyrate comprises approximately **75-80%** of total ketone bodies (with a β-hydroxybutyrate:acetoacetate ratio of **3:1 or higher**, compared to 1:1 normally). - This quantitative predominance makes it the **primary acid** responsible for the anion gap metabolic acidosis in DKA. *Acetoacetic acid* - **Acetoacetic acid** is indeed a ketone body and contributes to acidosis, but it is typically present in **lower concentrations** (approximately 20%) compared to beta-hydroxybutyric acid. - It can be converted to **acetone**, another ketone body, but neither is the primary cause of severe metabolic acidosis. *Carbonic acid* - **Carbonic acid** (H2CO3) is part of the **bicarbonate buffering system** and is derived from carbon dioxide and water, playing a role in respiratory acidosis or alkalosis. - It is not a ketone body and is not directly responsible for the **anion gap metabolic acidosis** observed in DKA. *Lactic acid* - **Lactic acid** accumulation can cause **lactic acidosis**, which is another form of metabolic acidosis often seen in conditions of tissue hypoxia or liver failure. - However, it is fundamentally different from the **ketone body accumulation** that defines DKA.

Question 2: A 55 year old male presents with tachypnea and mental confusion. Blood glucose 350 mg/dl, pH = 7.0. What is the most likely acid base disorder?

A. Metabolic acidosis (Correct Answer)
B. Metabolic alkalosis
C. Respiratory alkalosis
D. Respiratory acidosis

Explanation: Metabolic acidosis - A **pH of 7.0** indicates significant acidemia, and **hyperglycemia (350 mg/dL)** in conjunction with clinical symptoms (tachypnea, mental confusion) strongly suggests **diabetic ketoacidosis (DKA)**, a common cause of high anion gap metabolic acidosis [1]. - Tachypnea is often a **compensatory mechanism** (Kussmaul breathing) to blow off carbon dioxide and raise pH in metabolic acidosis [1], [2]. Metabolic alkalosis - This would present with an **elevated pH (alkalemia)**, which is opposite to the patient's measured pH of 7.0 [2]. - It is typically caused by conditions like severe vomiting or diuretic use, which are not suggested by the clinical presentation [3]. Respiratory alkalosis - This condition involves a **high pH** and a **low PCO2**, often due to hyperventilation [2]. - While the patient is tachypneic, the profound acidemia (pH 7.0) contradicts a primary respiratory alkalosis. Respiratory acidosis - While leading to a low pH, respiratory acidosis is characterized by **elevated PCO2** due to hypoventilation. - The patient's **tachypnea** indicates hyperventilation, which would tend to lower PCO2, making primary respiratory acidosis unlikely.

Question 3: A 24 year old male presents with altered sensorium and rapid shallow breathing. ABG shows:pH 7.2, sodium 140, bicarbonate 10 and chloride 98. Probable diagnosis is -

A. Amphetamine toxicity
B. DKA (Correct Answer)
C. Renal tubular acidosis
D. Ethylene glycol poisoning

Explanation: ***DKA*** - The patient presents with **altered sensorium** and **rapid shallow breathing** (Kussmaul breathing), consistent with severe metabolic acidosis [1]. - The ABG results show **pH 7.2** (acidosis), **bicarbonate 10** (metabolic component), and an **elevated anion gap** (Na - (Cl + HCO3) = 140 - (98 + 10) = 32), which are characteristic findings in **diabetic ketoacidosis (DKA)** [1], [2]. *Amphetamine toxicity* - Amphetamine toxicity typically causes **sympathomimetic effects** such as tachycardia, hypertension, hyperthermia, and agitation, rather than directly leading to a high anion gap metabolic acidosis of this severity. - While it can cause some metabolic derangements, the primary acid-base disturbance is usually different or less pronounced in this manner compared to DKA. *Renal tubular acidosis* - Renal tubular acidosis (RTA) typically presents with a **normal anion gap metabolic acidosis** (hyperchloremic metabolic acidosis), where the anion gap would not be significantly elevated. - The calculated anion gap of 32 in this patient rules out RTA as the primary cause of this severe acidosis. *Ethylene glycol poisoning* - Ethylene glycol poisoning also causes a **high anion gap metabolic acidosis** and altered mental status. - However, it is typically associated with additional specific symptoms like **flank pain**, **oliguria**, and detection of **calcium oxalate crystals** in the urine, which are not mentioned in this case.

Question 4: Diabetic ketoacidosis is said to be present if:

A. Hyperglycemia, glycosuria, hyperkalemia, and hypocalcemia are present.
B. Hypoglycemia, hypokalemia, hypercalcemia, and ketonemia are present.
C. Hypoglycemia, ketonemia, ketonuria, and hypokalemia are present.
D. Hyperglycemia, heavy glycosuria, ketonemia, ketonuria, and acidosis are present. (Correct Answer)

Explanation: ***Hyperglycemia, heavy glycosuria, ketonemia, ketonuria, and acidosis are present.*** [1], [3] - **Diabetic ketoacidosis (DKA)** is characterized by **uncontrolled hyperglycemia** (blood glucose > 250 mg/dL), metabolic acidosis (pH < 7.3, bicarbonate < 18 mEq/L), and the presence of **ketones** in the blood (ketonemia) and urine (ketonuria). - The heavy glycosuria reflects the body's attempt to excrete excess glucose through the kidneys. *Hyperglycemia, glycosuria, hyperkalemia, and hypocalcemia are present.* - While **hyperglycemia** and **glycosuria** are present in DKA, **hyperkalemia** is often seen due to the acidosis shifting potassium out of cells, but it is not a defining diagnostic criterion. [2] - **Hypocalcemia** is not a primary diagnostic feature of DKA; calcium levels are generally normal or may even be slightly elevated due to hemoconcentration. *Hypoglycemia, hypokalemia, hypercalcemia, and ketonemia are present.* - **Hypoglycemia** contradicts the definition of DKA, which is characterized by **hyperglycemia**. - While **ketonemia** is a feature, **hypokalemia** and **hypercalcemia** are not defining diagnostic criteria for DKA. Hypokalemia may develop during treatment, but patients often present with normal or high potassium. [2] *Hypoglycemia, ketonemia, ketonuria, and hypokalemia are present.* - **Hypoglycemia** is a direct contradiction to the diagnostic criteria of DKA, which requires **hyperglycemia**. - Although **ketonemia** and **ketonuria** are features of DKA, **hypokalemia** is not a defining characteristic at presentation and typically develops during insulin therapy. [2]

Question 5: A 15-year-old girl with type 1 diabetes is brought to the emergency department complaining of dizziness. Laboratory findings include severe hyperglycemia, ketoacidosis, and a blood pH of 7.15. To achieve rapid control of severe ketoacidosis, which of the following is the most appropriate drug?

A. NPH insulin
B. Tolbutamide
C. Ultralente insulin
D. Regular insulin (Correct Answer)

Explanation: ***Regular insulin*** - **Regular insulin** is a **short-acting insulin** that can be administered intravenously, allowing for rapid onset and precise titration, which is crucial for managing severe **ketoacidosis**. - Intravenous regular insulin is the cornerstone of **diabetic ketoacidosis (DKA)** treatment, as it quickly lowers blood glucose and suppresses ketogenesis. *NPH insulin* - **NPH (Neutral Protamine Hagedorn) insulin** is an **intermediate-acting insulin** and is not suitable for the rapid control required in DKA. - Its delayed onset and prolonged duration make it inappropriate for acute emergency management of severe hyperglycemia and ketoacidosis. *Tolbutamide* - **Tolbutamide** is an oral sulfonylurea used to stimulate insulin secretion in patients with **type 2 diabetes** who still have some pancreatic beta-cell function. - It is ineffective in **type 1 diabetes** where there is an absolute insulin deficiency, and it does not provide rapid insulin action for DKA. *Ultralente insulin* - **Ultralente insulin** is a **long-acting insulin** that is no longer widely used and has a very slow onset and prolonged duration of action. - It is unsuitable for the acute management of severe ketoacidosis, which requires rapid and titratable insulin delivery.

Question 6: In a patient presenting with diabetic ketoacidosis (DKA), what is the most appropriate immediate treatment?

A. Administration of an oral hypoglycemic agent
B. Administration of bicarbonate
C. Administration of insulin (Correct Answer)
D. Close observation only

Explanation: ***Administration of insulin*** - **Insulin therapy** is critical in DKA to reverse the underlying metabolic abnormalities by stopping ketogenesis and facilitating glucose uptake into cells [1]. - It is typically administered intravenously at a continuous rate, after initial **fluid resuscitation**, to gradually lower blood glucose and resolve acidosis [1]. *Administration of an oral hypoglycemic agent* - **Oral hypoglycemic agents** are ineffective in DKA because these patients typically have an absolute or relative **insulin deficiency** and **profound insulin resistance** due to stress hormones [3]. - Moreover, they are not suitable for acutely ill patients who may have impaired gastrointestinal absorption. *Administration of bicarbonate* - **Bicarbonate administration** is generally not recommended in DKA unless the **pH is extremely low** (e.g., < 6.9 or 7.0) due to potential risks like paradoxical central nervous system acidosis and fluid overload. - The acidosis usually resolves with **insulin therapy** and **fluid resuscitation** as ketone body production ceases and they are metabolized [1]. *Close observation only* - **Diabetic ketoacidosis** is a medical emergency requiring urgent and aggressive intervention, not just observation [2]. - Delaying treatment can lead to severe complications, including **cerebral edema**, **coma**, and **death** [2].

Question 7: An obese patient presented in casualty in an unconscious state, with a blood glucose level of 400 mg/dL and urine testing positive for sugar and ketones. Which drug is most useful in his management?

A. Glibenclamide
B. Troglitazone
C. Insulin (Correct Answer)
D. Chlorpropamide

Explanation: Insulin - The patient presents with **hyperglycemia**, **ketonuria**, and an **unconscious state**, suggestive of **diabetic ketoacidosis (DKA)** or at least severe uncontrolled diabetes requiring urgent glucose management [1], [4]. - **Insulin therapy** is crucial for DKA management, as it lowers blood glucose, resolves ketosis, and helps correct electrolyte imbalances [3]. *Glibenclamide* - This is a **sulfonylurea** that stimulates insulin release from pancreatic beta cells. - It is **contraindicated in DKA** because the pancreas is often severely stressed or non-functional, and it can worsen hypoglycemia if given inappropriately [2]. *Troglitazone* - This is a **thiazolidinedione** (glitazone) which improves insulin sensitivity in peripheral tissues. - It is **not used for acute hyperglycemia or DKA** and was withdrawn from the market due to liver toxicity. *Chlorpropamide* - This is an older **first-generation sulfonylurea**, similar to glibenclamide, that stimulates insulin secretion. - It has a **long half-life** and a higher risk of **hypoglycemia**, making it unsuitable for acute, severe hyperglycemia like DKA [2].

Question 8: A 27-year-old female is brought in by ambulance with altered mental status. She is in a comatose state, but is breathing spontaneously with deep and rapid respirations. Her vital signs are as follows: T 100.2F, BP 92/54 mmHg, HR 103 bpm, RR 28, and SpO2 97% on room air. Complete blood count reveals: WBC 12.7, hemoglobin 11.3, platelets 254. Basic metabolic panel reveals: sodium 137, potassium 4.2, chloride 100, bicarbonate 16, creatinine 1.78 An ABG is performed which showed pH 7.38, PaO2 94, PaCO2 26. Which of the following is the most likely cause of this patient’s presentation?

A. Acute renal failure
B. Severe sepsis
C. Alcohol binging
D. Medication overdose
E. Undiagnosed type 1 diabetes mellitus (Correct Answer)

Explanation: Detailed analysis is as follows: ***Undiagnosed type 1 diabetes mellitus*** - The patient presents with **altered mental status**, **deep and rapid respirations** (Kussmaul breathing), **metabolic acidosis** (low bicarbonate), and **compensatory respiratory alkalosis** (low PaCO2 with near normal pH), all highly suggestive of **diabetic ketoacidosis (DKA)** [1], [2]. - The elevated creatinine of 1.78 suggests **dehydration**, a common finding in DKA due to osmotic diuresis [1]. *Acute renal failure* - While the elevated **creatinine** of 1.78 suggests kidney dysfunction, **acute renal failure** alone typically causes a metabolic acidosis with **oliguria or anuria**, which is not explicitly mentioned, and the respiratory compensation would be different [3]. - The primary symptoms of DKA (Kussmaul respiration, mental status changes, significant metabolic acidosis) are not directly explained by isolated acute renal failure [2]. *Severe sepsis* - **Severe sepsis** can cause altered mental status, **hypotension**, and **tachycardia**, but commonly presents with **fever**, which is only mild (100.2F), and an uncontrolled **metabolic acidosis** is less specific than the DKA picture. - While there is **leukocytosis**, common in infection, the specific **metabolic derangements** like Kussmaul respirations and profound acidosis point away from sepsis as the primary unifying diagnosis; leukocytosis in this context may instead represent a stress response to DKA [2]. *Alcohol binging* - **Alcohol binging** can lead to altered mental status and **metabolic acidosis** (e.g., alcoholic ketoacidosis), but it typically presents with a history of recent heavy alcohol intake, and **hypoglycemia** or alcoholic hepatitis are more common. - While this might explain some symptoms, the specific constellation of lab findings (elevated creatinine, profound metabolic acidosis with respiratory compensation) is more consistent with DKA. *Medication overdose* - A **medication overdose** could cause altered mental status, but the specific pattern of **metabolic acidosis** with **respiratory compensation** and signs of dehydration is not characteristic of most common overdoses [3]. - The other clinical and lab findings (e.g., Kussmaul respirations, elevated creatinine) would need to be explained by specific pharmacological effects not commonly seen with typical overdoses.

Question 9: All of the following are selective indications for the use of hypotonic solutions, except:

A. Burns (Correct Answer)
B. Free water deficit
C. Hypernatremia
D. Maintenance fluid therapy in stable patients

Explanation: ***Burns*** - **Hypotonic solutions** are generally *not* indicated for burn patients because these patients typically lose large amounts of **isotonic fluid** through damaged skin. [1] - The primary goal in burn resuscitation is to replace lost plasma volume with **isotonic crystalloids** (e.g., Lactated Ringer's) to prevent **hypovolemic shock**. [1] *Hypernatremia* - **Hypernatremia** is a condition of excess sodium relative to water, meaning the body has a **water deficit**. [1] - **Hypotonic solutions** are used to gradually lower serum sodium by providing **free water** to dilute the excess sodium. *Free water deficit* - A **free water deficit** indicates a lack of pure water relative to solutes, leading to increased plasma osmolality. [2] - **Hypotonic solutions** are specifically designed to provide **free water** to correct this deficit and restore proper fluid balance. *Maintenance fluid therapy in stable patients* - For stable patients requiring maintenance fluids, **hypotonic solutions** (e.g., D5W with 0.45% NS) are often used to cover obligatory fluid losses and provide adequate water without causing **sodium overload**. [1] - In such cases, the goal is to prevent dehydration and electrolyte imbalances over time, which often requires a balance of electrolytes and **free water**. [1]

Question 10: A patient presents with the following arterial blood gas (ABG) and electrolyte values: pH: 7.34, Na: 135 mEq/L, Cl: 93 mEq/L, HCO3: 20 mEq/L, Random Blood Sugar (RBS): 420 mg/dl. What is the most likely acid-base disturbance?

A. Normal Anion Gap Metabolic Acidosis (NAGMA)
B. Respiratory Acidosis
C. High Anion Gap Metabolic Acidosis (HAGMA) (Correct Answer)
D. Metabolic Alkalosis

Explanation: ### High Anion Gap Metabolic Acidosis (HAGMA) - The **pH (7.34)** indicates **acidemia**, and the **low bicarbonate (20 mEq/L)** suggests a metabolic acidosis [1], [2]. - Calculation of the anion gap: Na - (Cl + HCO3) = 135 - (93 + 20) = 22 mEq/L. An anion gap > 12 mEq/L is considered high, confirming **High Anion Gap Metabolic Acidosis (HAGMA)** [4]. The **RBS of 420 mg/dl** also points towards a likely cause such as **diabetic ketoacidosis** [3]. *Normal Anion Gap Metabolic Acidosis (NAGMA)* - This would be present if the calculated anion gap were within the normal range (typically 8-12 mEq/L). - Causes of NAGMA (e.g., hyperchloremic acidosis) are typically associated with increased chloride levels to compensate for the bicarbonate loss, which is not the primary finding here [4]. *Respiratory Acidosis* - This condition is characterized by a **low pH** and an **elevated PaCO2**, which is not provided but implied by the **low bicarbonate** not fitting a respiratory picture [2]. - While the pH is low, the primary disturbance given the other values (especially the low bicarbonate) is metabolic, not respiratory. *Metabolic Alkalosis* - Metabolic alkalosis is characterized by an **elevated pH** and an **elevated bicarbonate level**, which contradicts the presented values of low pH and low bicarbonate [2]. - This condition would involve a net gain of bicarbonate or a loss of acids, which is the opposite of the findings in this patient.

Want unlimited practice?

Get full access to all questions, explanations, and performance tracking.

Start For Free