Chronic Paediatric Conditions — MCQs

Question 161: A 7-year-old boy with type 1 diabetes mellitus is brought to the emergency department with a 12-hour history of vomiting and abdominal pain. His mother reports he has been unwell with a cold for 2 days. On examination, he is drowsy but responsive to verbal commands. His temperature is 37.8°C, heart rate 130 bpm, respiratory rate 32/min with deep sighing respirations, blood pressure 95/60 mmHg, and capillary refill time 3 seconds. Blood glucose is 28 mmol/L. What is the most appropriate initial fluid resuscitation?

• A. 0.9% sodium chloride 10 mL/kg over 1 hour (Correct Answer)
• B. 0.9% sodium chloride 20 mL/kg bolus over 15 minutes
• C. 0.45% sodium chloride with 5% dextrose 10 mL/kg over 1 hour
• D. Hartmann's solution 20 mL/kg bolus over 15 minutes
• E. 0.9% sodium chloride with 5% dextrose 10 mL/kg over 1 hour

Explanation: ***0.9% sodium chloride 10 mL/kg over 1 hour***- The patient presents with **diabetic ketoacidosis (DKA)** and signs of dehydration (tachycardia, reduced BP, prolonged CRT, drowsiness, Kussmaul respirations). Initial fluid resuscitation in pediatric DKA should be with **isotonic saline (0.9% sodium chloride)**.- Current guidelines (e.g., ISPAD) recommend a cautious bolus of **10 mL/kg over 1 hour** to gradually correct dehydration and reduce the risk of **cerebral edema**, a serious complication of rapid fluid shifts in DKA.*0.9% sodium chloride 20 mL/kg bolus over 15 minutes*- While 0.9% sodium chloride is the correct fluid, a rapid **20 mL/kg bolus over 15 minutes** is typically reserved for patients in profound **hypovolemic shock** or circulatory collapse, which is not indicated here.- In DKA, rapid fluid administration can significantly increase the risk of **cerebral edema** due to rapid changes in serum osmolality.*0.45% sodium chloride with 5% dextrose 10 mL/kg over 1 hour*- **Hypotonic solutions** like 0.45% sodium chloride are contraindicated for initial resuscitation in DKA as they can exacerbate fluid shifts into the intracellular space, increasing the risk of **cerebral edema**.- **Dextrose** should not be included in initial resuscitation fluids when blood glucose is as high as 28 mmol/L; it is added later when glucose levels fall to prevent hypoglycemia during insulin therapy.*Hartmann's solution 20 mL/kg bolus over 15 minutes*- Hartmann's solution (Lactated Ringer's) is a balanced crystalloid, which can be considered in some DKA protocols, but a **20 mL/kg bolus over 15 minutes** is still too aggressive for initial management unless the patient is in severe shock.- The **rapid administration rate** is a primary concern in pediatric DKA due to the risk of **cerebral edema**, favoring slower initial rehydration.*0.9% sodium chloride with 5% dextrose 10 mL/kg over 1 hour*- While 0.9% sodium chloride is the correct base fluid and 10 mL/kg over 1 hour is an appropriate rate, the inclusion of **5% dextrose** is inappropriate at this stage.- The patient's **blood glucose is 28 mmol/L**, and adding dextrose would worsen hyperglycemia, delaying the metabolic correction of DKA. Dextrose is only added once glucose levels drop significantly.