A 4 week old baby is brought to ED with a history of vomiting over 1 week. The vomiting initially thought to be normal, has increased and baby appears to be hungry all the time. The baby’s weight gain over this week has been around 100 grams.  Prior to this the baby had been feeding well and gaining weight. Birth and antenatal history unremarkable. VBG was done:

pH 7.51                                      Na 137mmol/l

pCO2 50mmHg                          K 3.9mmol/l

HCO3 36 mmol/l                        Cl 90mmol/l

B/E 11                                         BSL 4.6 mmol/l

Lactate 1.3mmol/l                       Cr 28 umol/l

1. Describe and interpret the VBG
2. What is the normal weight gain for an infant?