Clinical Case 3
• A 14 year old girl was brought to her GP’s office,
complaining of:
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weight loss,
dry mouth,
lethargy,
easy fatigability
and difficulty in catching the breath;
• The symptoms were noticed by the parents about 10
days before the visit
• However, the patient herself had noted an increased
frequency of urination (polyuria) and increased thirst
(polydipsia) about 8–10 weeks prior
• A urine analysis using reagent strips revealed positive
glucose and ketones respectively
• Her temperature was 39°C and a chest examination
revealed some congestion
• The patient was immediately admitted to hospital for
management
• Clinical examination revealed:
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a dehydration,
fruity odour to the breath,
tachycardia (120 beats/min)
and dry mouth, lips and tongue
The respiratory rate was 30/min and her blood pressure
was 110/70 mmHg
Laboratory Investigating
• Laboratory data indicated that:
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her plasma glucose level was 470 mg/dl (70-110 mg/dl)
serum acetone was positive
arterial blood pH was 7.18 (7.35–7.45)
with a bicarbonate level of 17 mmol/l (21–28 mmol/L)
Other serum values determined at this time were
Na+ 130 (136–145 mmol/L)
K+ 5.8 (3.5–5.0 mmol/L)
Cl– 92, (96–106 mmol/L)
and glycosylated haemoglobin 13.1% (< 6.8%)
blood islet cell antibodies were positive
What is the most likely diagnosis in this
patient? What are the causes of her observed
symptoms?
• This is a classical presentation of diabetic
ketoacidosis in Type I diabetes patients
• The common symptoms of diabetes mellitus
are:
– polyuria (increased urine volume and frequency)
– polydipsia (increased thirst)
– and polyphagia (increased appetite)
• Polyuria is secondary to the osmotic diuresis
(caused by excess filtered glucose in the urine)
which then triggers increased thirst
• Diabetic ketoacidosis is a serious acute complication
that requires prompt attention
– It is usually precipitated in Type I diabetes patients by a
stressful stimulus (e.g. an infection, surgery or acute
illness)
– or by omitting several insulin injections
• The characteristic sweet smell to the breath is due to
excretion of acetone (ketone body) formed by
condensation of excess acetyl CoA in the liver
• appearance of other ketone bodies in the blood
(acetoacetate and 3-hydroxybutyrate) decreases blood
pH (metabolic acidosis) which stimulates respiration
(hyperventilation)
What would be the most appropriate treatment
while in hospital, and the recommended therapy
on discharge?
• Following a diagnosis of diabetic ketoacidosis, intravenous
fluid replacement and correction of hyperglycaemia/
ketonaemia is crucial for effective hospital management
• A precipitating cause such as an infection should also be
sought and treated with appropriate antibiotics if necessary
• The patient was started on intravenous fluid (normal saline)
and soluble insulin infusion (0.2 units/kg followed by 0.1
units/kg per hour) to correct for the underlying dehydration
and metabolic abnormalities
• In the next 14 hours, the blood glucose was stabilized at
140 mg/dl and the patient rehydrated
• Serum electrolytes returned to normal
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bicarbonate level increased to 22 mmol/l
and arterial blood pH showed normalization to 7.35
Insulin infusion was continued until next morning
when ketones were no longer present in the diluted
serum
– The patient was switched to subcutaneous insulin
administered twice daily
– She was instructed in home blood glucose monitoring
methods and discharged on stable doses of insulin
three days later