The Hands-on Guide to Practical Paediatrics

Rebecca Hewiston
Caroline Fertleman


Scenario 8: Tonsillitis

Shelly Graves is a 12-year-old girl who has presented to the emergency department with painful throat and difficulty swallowing. She has been unable to eat or drink for the past 2 days because of the pain in her throat and has been having fevers.
On examination you find that she has very enlarged and erythematous tonsils covered with purulent exudate. She also has many enlarged and tender lymph nodes palpable in her neck. She is febrile, but her heart rate, capillary refill time, oxygen saturations and respiratory rate are all normal.
Her blood tests reveal a lymphocytosis and you are awaiting the results of a monospot test. Her weight is 60 kg and height is 159 cm which puts her on 98th centile for weight and 75th centile for height for her age. Looking at the growth chart and her calculated BMI, you estimate that her ideal body weight is 43 kg. Her current BMI is between the 98th and 99.6th centiles which means that she is classified as being obese.
She takes no regular medications and has no known allergies. Her details are as follows:
DOB: 12/11/2001
Address: 123 Park Lane, Bolton, Lancashire BL3 4DG
Weight: 60 kg
Hospital Number: 3240619

  • 1. What will you prescribe on her drug chart?

    Correct answer:

    • Intravenous fluids. She will need intravenous maintenance fluids as she is still currently unable to take anything orally. If you calculate this based on her weight this gives you the following:

      100 × 10 = 1000 mL + 50 × 10 = 500 mL + 20 × 40 = 800 mL = 2300 mL in total

      However, this volume is in excess of the maximum amount of maintenance fluid that you should be prescribing for a girl (maximum 2 L in 24 hours). This is because she is obese and you will need to use her ideal body weight to calculate the doses of her medications. Her ideal body weight based on the growth chart is 43 kg.

      100 × 10 = 1000 mL + 50 × 10 = 500 mL + 20 × 23 = 460 mL = 1960 mL in 24 hours

      Rate = 82mL/hour

      Do not prescribe the whole volume for the 24 hours, but instead just prescribe one bag initially as this will last for 6 hours, and after this time she could be re-assessed and may be able to drink sufficient volumes and no longer require intravenous fluids.

    • Analgesia. She will need analgesia for her sore throat – you can prescribe paracetamol regularly orally as she may be able to swallow small volumes of fluid. Prescribe a solution rather than a tablet to make it easier for her to swallow.

      Her ideal body weight is 43 kg, so you should prescribe paracetamol based on this weight. The dose range for her age is 480–750 mg up to four times a day. Generally, 15 mg/kg is used as a safe dose – for her this is 15 × 43 = 645 mg. The solution comes in a strength of 250 mg/5 mL and therefore it is sensible to round up to 650 mg for ease of measuring the dose.

      You may also wish to prescribe PRN ibuprofen as additional pain relief. For her age, the dose is 300 mg up to three times daily.

    • Antibiotics. She also may have a supra-added bacterial infection of her tonsils and an antibiotic may help with this. Her history is consistent with infectious mononucleosis and therefore you should avoid prescribing amoxicillin because it can cause a rash in these patients. Penicillin V is the recommended treatment. This should also be given as a solution in order to aid swallowing. The dose for her age range is 250–500 mg, four times daily.

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