Lethargic Child – OSCE Case

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A 5-year-old girl is brought to the emergency department by her father due to lethargy. Work through the case to reach a diagnosis.

UK Medical Licensing Assessment (UKMLA)

This clinical case maps to the following UKMLA presentations:

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Presenting complaint

“She’s been really tired and had this weird heavy breathing for the last few days, she just doesn’t seem right. I’m really worried.”

History of presenting complaint

When did this start?

β€œShe has been tired and weak for the last 5 days”

Before this, has she been complaining of anything?

β€œFor the last week, she has been drinking lots of water throughout the day”

Has she been unwell recently?

β€œShe had a bit of a cold around 2 weeks ago”

Has she come in contact with anyone who is sick?

β€œI don’t think so”

Does she have any other symptoms?

“She started complaining of tummy pain today”

Has she had a fever?


Has she complained of any urinary difficulties?

β€œShe’s been passing urine more frequently I think. The last few days she’s been waking up 3-4 times at night to use the toilet”

How have her bowel movements been?

β€œNormal. No constipation, no diarrhoea”

Has she lost any weight?

“About 1kg in the last week”

How is her appetite?

β€œReduced. She prefers to drink lots of water and juice”

Clinical examination

As this child looks unwell in the ED, you decide to assess and stabilise her condition before continuing the rest of the history.

Examination findings

  • She is responding to you but looks lethargic
  • HR 140, RR 28, BP 96/48, oxygen saturation 94% on air, temperature 37oC
  • Respirations are deep, with sub-costal retractions
  • No nasal flaring
  • No cyanosis
  • Heart sounds normal
  • Normal vesicular breath sounds bilaterally, equal air entry
  • Abdomen soft and non-tenderΒ 

Kussmaul’s respirations

Several signs may be found in dehydration:

  • Dry mucous membranes
  • Dry skin/cracked lips
  • Altered mental status
  • Irritability/listlessness
  • Sunken eyes/cheeks
  • Tachycardia
  • Oliguria/anuria
  • Crying without tears


ABG results

The results of the patient’s ABG are shown below:

  • pH: 7.17
  • pO2: 80 mmHg
  • PCO2: 24 mmHg
  • HCO3: 12 mEq/L
  • Lactate: 7.37 mmol/L
  • Anion gap: 12
  • Ketones: 6.2

This ABG shows metabolic acidosis with respiratory compensation.

The presence of academia (blood pH <7.35) confirms an acidotic process. The low levels of HCO3 with elevated lactate confirm a metabolic cause (lactic acidosis). Finally, the low levels of pCO2 (24mmHg) indicate this child has respiratory compensation, trying to normalise blood pH by blowing off CO2.


Diabetic ketoacidosis (DKA) secondary to a new diagnosis of type I diabetes

  • Hyperglycaemia (glucose >11.0mmol/L)
  • Ketonaemia (>3.0mmol/L or >2+ on urine dipstick)
  • Acidosis (HCO3 <15 and/or pH <7.3)

Autoimmune destruction of the beta islet cells in the pancreas which leads to an absolute insulin deficiency.


Deficit (mL) = weight (kg) x percent dehydration (%) x 10

The fluid deficit should be corrected gradually over 12-24 hours.

Fixed-rate IV insulin infusion – the exact regime would follow local guidelines.


Cerebral oedema – a potentially fatal complication due to rapid changes in serum osmolality. This is the cause of most of the deaths in DKA in children.


Dr Jess Speller


  1. National Institute for Health and Care Excellence (NICE).Β Intravenous Fluid Therapy in Children and Young People in Hospital [NG29]. Published in June 2020. Available from: [LINK]
  2. Holliday M.Β Maintenance Fluids Calculations. MDCalc. Available from: [LINK]
  3. Diabetes UK with the Joint British Diabetes Societies Inpatient Care Group. Management of diabetic ketoacidosis in adults. Available from: [LINK].
  4. NICE guidelines. Diabetes (type 1 and type 2) in children and young people: diagnosis and management. Published August 2015. Available from: [LINK].


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