Ouch!
I've been in the 20s before, but not that high or for that long.
Apart from the immediate threat of ketones and feeling rubbish and as long as you know the cause, if this is a one-off it shouldn't cause any long-term issues.
My super highs are normally caused by missing or under dosing a bolus or a very high fat and carb meal such as an Indian takeaway. And beige party food - my term for a finger buffet comprising mostly of pork pies, sausage rolls, scotch eggs, quiches and the like - they are a killer and defy any amount of fast acting insulin. My tactic is to dose every two to three hours until the BG stops rising after the previous dose wears off.
We can only see from about 2am on the graph - did you go to bed high? I can see you have a high glucose alarm set for about 22 - did it not go off?
I know even without the alarm I'd have been up for the toilet once an hour, so at least you know your bladder is in good shape if you slept through that.
