A 14-year old boy who is known to have type 1 diabetes is admitted to hospital with a history of nausea, vomiting and abdominal pain over the previous 24 hours. On examination he is dehydrated and drowsy. The following results are obtained:

Serum:                sodium         130 mmol/L [135-145]

                            potassium     5.8 mmol/L [3.6-5.0]

                            bicarbonate     5 mmol/L [22-30]

                            urea                18 mmol/L [3.3-5.0]

                            creatinine     136 µmol/L [55-120]

Plasma:              glucose          30 mmol/L

Urine:                  strongly positive for glucose and ketones