Sick children can have electrolyte abnormalities at levels not often seen by 'adult' nephrologists - the levels of derangement in this case were eye-watering, and far in excess of what I usually see. Nearly 20 years ago, Webster and Kulkarni observed that metabolic alkalosis was commoner in the critically ill than acidosis (1), but most of us might more readily remember patients with Kussmaul respiration in metabolic acidosis than the hypercapnic response to alkalosis. Nonetheless, as this case graphically shows, severe alkalosis can be life threatening.