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Centre for Evidence-
Based Medicine

Diagnosis: Clinical Scenario

A five week old baby boy has been admitted with projectile vomiting. You are unable to palpate a pyloric tumour. You decide to admit the child and observe him at least for the next 24 hours. However, the parents are keen to take their child home now.

You ask for an ultrasound of the pylorus and the radiologist reports the result as negative. Do you send the child home? You pose the question, in young infants with projectile vomiting and no palpable pyloric tumour, what is the probability of pyloric stenosis with a negative or a positive ultrasound of the pylorus?

You search Medline using the terms "pyloric stenosis" and "ultrasound" and find the following paper:

Neilson D, Hollman AS.
The ultrasonic diagnosis of infantile hypertrophic pyloric stenosis: technique and accuracy.
Clinical Radiology 1994;49:246-7.

Read the article and decide:

  1. Are the results of this diagnostic article valid?
  2. Are the valid results of this diagnostic study important?
  3. Can you apply this valid, important evidence about a diagnostic test in caring for your patient?

Continue to completed worksheet