Nurse Call Systems

I am a registered nurse. I work in a general systems intensive care unit. Today I had a seriously ill patients and has been with her during my lunch break two hours late. I decided my friends house (across the street) will once again have 15 minutes nap. It was three hours, I went back - the patient was good;! For the nurse was pale and charge nurse called my boss. I know what I did was irresponsible and I have no idea what to expect, what type of punishment or what to tell my boss. Any input would be appreciated. PS I love my job and I said (to have an intensive care nurse for 10 years has been) I'm good at what I do. I would think that if this behavior is not an ordinary repetition is likely to increase by an impairment in your file, and if it happens again, it should be removed in three years. If it would have serious consequences, you already know. Get an alarm clock and go to bed on time at night. An episode in 10 years - the ICU nurses are in demand. You will probably receive a warning is all If sleepiness is a chronic problem, get a sleep study .