After a telephone consultation on Saturday, we see a 5 month old girl 2 days later on Monday for the evaluation of failure to thrive combined with repetitive vomiting.
The clinical examination shows a girl in good general condition with normal vital signs for her age and no fever. The weight is 5.68kg (P 5) with a height of 65.5cm (P 72). We see a relevant percentile decline in weight from P 80 at the age of 1 month to P 33 at the age of 4 months.
In the patient history, repetitive vomiting is described from around birth until the third month of life. In the last 3 weeks, the vomiting has started again, usually 10 minutes after breastfeeding, resulting in the mother feeding her child with a mixture of water, salt and sugar.
Initially blood gas analysis including the electrolytes is performed: