Sarah
My sick day 'rules' for ketones say that if BG is below 8.3mmol/l . To check ketones every 2 hours and if present to take insulin (specified amounts depending on the ketone level) and to drink a glass of a sugary drink or fruit juice
You use relatively large amounts of insulin to get rid of ketones and the danger of taking insulin and no glucose at this level is a hypo. Your body also needs some fuel to function properly in fighting any infection.
(flat coke is suggesting if you are vomiting . They also say to call doctor if you have ketones and vomiting persists ... even if glucose levels aren't high)
Above 8.3mmol/l my 'rules' say to drink water, plus of course the necessary insulin (other diabetics on the course suggested Evian water for the bicarb, the doctors seemed to agree with that)
You need to get a set of rules, especially for you, for if you are sick and have ketones again. Have them written out so you can refer to them (easier than trying to remember when you feel ill) You need a lot more insulin when you have ketones than normally but you really need individual guidance as to how much and when.