Is there an alarm to warn me i might be slipping into a diabetic coma?

Yes: You are probably referring to low blood sugar episodes. Warning signs ususally begin wiht a sense of "jitter" or "shakiness" and a feeling of hunger and irritability. One usually becomes sweaty. This can progress to mild confusion (drunkiness characteristics) and progressing to frank confusion, slurred speech, seizure and coma. Know your body and your diabetes. Get diabetic educaton. See pcp.

Check your sugar: Check your sugar levels. Diabetic coma is the result of extreme low or extreme high sugar levels. You should never get to these extremes. You need to check not only to avoid the coma but to avoid the serious longterm consequences of uncontrolled diabetes (infections, blindness, neuropathy, renal failure, early demise). It helps to be on top of your hba1c.