Pediatric Critical Care, Fluids, Electrolytes and Dehydration Management MCQs

Pediatrics · 35 free questions with answers & explanations.

1. A 6-month-old infant with acute gastroenteritis is assessed: sunken eyes, absent tears, dry mouth, skin turgor reduced with 3-second return, HR 164/min, BP 68/42 mmHg, and weak pulse. She is not tolerating oral fluids. Which is the MOST appropriate initial fluid management?
2. A 10-year-old (weight 35 kg) requires maintenance IV fluids after abdominal surgery. Using the Holliday-Segar method, what is the correct maintenance fluid rate per hour?
3. A 3-year-old presents with seizures. Serum sodium is 116 mEq/L. He was receiving only free water feeds for 5 days for gastroenteritis. What is the SAFEST rate of sodium correction?
4. A 6-month-old infant with acute watery diarrhoea and moderate dehydration (estimated 7% loss of body weight) weighs 7 kg. Using the Holliday-Segar method, what is the daily maintenance fluid requirement for this infant?
5. A 2-year-old with severe hypernatraemic dehydration (serum Na 168 mEq/L) after several days of inadequate fluid intake is being rehydrated. Which is the MOST important principle guiding fluid therapy?
6. In the PICU, a 4-year-old with meningococcal meningitis on mechanical ventilation develops hyponatraemia (Na 122 mEq/L) with concentrated urine (urine Na 65 mEq/L), urine osmolality > plasma osmolality, and no evidence of oedema or volume depletion. What is the most likely diagnosis?
7. A premature neonate at 28 weeks gestation develops oliguria, rising creatinine, and metabolic acidosis on day 3. The urine output is 0.3 mL/kg/hr despite adequate fluid resuscitation. Serum potassium is 6.8 mEq/L with peaked T waves on ECG. What is the FIRST priority in management?
8. A 6-month-old with rotavirus gastroenteritis is assessed as having 8% dehydration (moderate). He is alert, has mildly sunken fontanelle, reduced skin turgor, and serum Na 145 mEq/L. The preferred initial rehydration approach is:
9. A 4-year-old with acute diarrhea develops hyponatremic dehydration: Na 118 mEq/L, serum osmolality 248 mOsm/kg, and is now seizing. The correct management of symptomatic severe hyponatremia in this child is:
10. A 2-year-old post-neurosurgery develops polyuria (urine output 8 mL/kg/hr), urine specific gravity 1.003, serum Na 152 mEq/L, and serum osmolality 310 mOsm/kg. Which finding best differentiates central DI from nephrogenic DI in this child?
11. A 5-year-old with salicylate poisoning has arterial blood gas: pH 7.50, PaCO2 26, HCO3 20, and plasma salicylate level 65 mg/dL. Urine is being alkalinized. Which acid-base pattern is characteristic of moderate-to-severe salicylate toxicity in this age group?
12. A 4-year-old, 16 kg child with severe dehydration due to diarrhea requires IV fluid resuscitation. After initial 20 mL/kg NS bolus, his deficit is estimated at 8% (about 1280 mL). Using the Holliday-Segar method, his daily maintenance is 1100 mL. How should the remaining deficit be replaced over 24 hours?
13. A 3-year-old child with hypernatremic dehydration (serum Na 165 mEq/L) is being rehydrated. The rate of correction of sodium must not exceed which value to prevent cerebral edema during treatment?
14. A 6-month-old infant is admitted with severe pneumonia and is noted to have serum sodium of 124 mEq/L with urine sodium >40 mEq/L and urine osmolality >100 mOsm/kg. The most likely mechanism of hyponatremia in this child is:
15. A 9-year-old child in the PICU is on mechanical ventilation for septic shock. He has oliguric AKI. Serum potassium is 6.8 mEq/L with peaked T waves on ECG. The immediate first step in management of this hyperkalemia is:
16. A 2-year-old child weighing 12 kg is assessed to have 10% dehydration. What is the total fluid required in the first 24 hours using the standard calculation (deficit replacement + daily maintenance by Holliday-Segar), assuming no ongoing losses?
17. A 6-month-old infant is found to have serum sodium of 158 mEq/L with clinical signs of 5% dehydration. What type of fluid is most appropriate as initial replacement to safely lower the sodium?
18. In pediatric septic shock refractory to initial fluid resuscitation with 60 mL/kg isotonic crystalloid, which vasoactive agent is recommended as first-line according to Surviving Sepsis Campaign pediatric guidelines?
19. A 3-year-old post-operative child develops low urine output, lethargy, and a serum sodium of 124 mEq/L after receiving 0.18% saline with dextrose at maintenance rates. What is the most likely cause of this hyponatraemia?
20. A 10 kg, 18-month-old child has moderate dehydration (estimated 10% deficit) secondary to acute gastroenteritis. Using the Holliday-Segar method for maintenance fluids, calculate the total 24-hour maintenance fluid requirement for this child.
21. A 3-year-old child with severe hypernatremic dehydration (Na+ 168 mEq/L) is being rehydrated. Over what period should sodium be corrected, and what is the maximum safe rate of serum sodium reduction?
22. A ventilated 4-year-old in PICU develops acute pulmonary edema and decreased urine output (0.3 mL/kg/hr for 12 hours) 48 hours after cardiac surgery. Serum creatinine is 1.8 mg/dL (baseline 0.4 mg/dL). According to KDIGO criteria, what is the AKI staging?
23. A 5-year-old on mechanical ventilation for ARDS has worsening hypoxemia despite FiO2 0.8. ABG shows PaO2 52 mmHg. The pediatric intensivist calculates the oxygenation index (OI). Which OI value meets the definition for SEVERE pediatric ARDS (per PALICC 2015)?
24. A 6-month-old infant with severe dehydration (estimated 10% dehydration) secondary to acute gastroenteritis is brought in. Weight is 7 kg. Using the Holliday-Segar method, what is the total 24-hour maintenance fluid requirement for this infant?
25. A 5-year-old child with meningococcal septicemia has BP 65/40 mmHg, HR 160/min, prolonged capillary refill of 5 seconds, and altered consciousness. Following initial fluid resuscitation, which vasopressor is recommended as first-line for fluid-refractory septic shock in children?
26. A 2-year-old with severe diarrhea has serum sodium of 162 mEq/L, indicating hypernatremic dehydration. The plan is to correct the sodium deficit over 48 hours. Which fluid is most appropriate for initial resuscitation in this child?
27. A 4-year-old with viral gastroenteritis has depressed fontanelle, dry mucous membranes, skin pinch retracts slowly (>2 sec), and sunken eyes. He is irritable but responds to voice. He is classified as having severe dehydration. What is the WHO-recommended initial treatment?
28. Using the Holliday-Segar method, what is the daily maintenance fluid requirement for a 25 kg child?
29. A 15 kg child has 10% dehydration due to acute gastroenteritis. How much total fluid (in mL) should be administered in the first 24 hours (including maintenance and deficit replacement)?
30. A 2-year-old child presents with hyponatremic dehydration (serum Na 118 mEq/L) and lethargy. Which of the following is the MOST appropriate initial correction strategy?
31. Which of the following is the MOST reliable clinical sign for assessing 5–10% dehydration in a 6-month-old infant?
32. A 2-year-old child (weight 12 kg) with severe dehydration and a serum sodium of 168 mEq/L is being rehydrated. The most important principle governing the rate of sodium correction in hypernatremic dehydration is:
33. A 4-year-old child is intubated and mechanically ventilated for ARDS following pneumonia. The plateau pressure on the ventilator is 34 cmH2O. Which lung-protective strategy is most appropriate?
34. An 8-month-old exclusively breastfed infant presents with severe hyponatremia (Na+ 118 mEq/L), seizures and no signs of dehydration. The mother has been diluting formula with excessive water. The immediate treatment for symptomatic hyponatremia is:
35. According to Holliday-Segar method, what is the daily maintenance fluid requirement for a 25 kg child?