Diabetic in hospital over 600, should she have been on dextrose IV 5%?

My Mother is 74 years old, diabetic with pneumonia and elevated liver enzymes. Yesterday, Friday, we called the EMS as she was incoherent, unable to respond to normal questions (where are you, etc). We found out her blood sugar level was 56, she's normally at 155 - 255 depending on fasting or eating. We had never experienced this before but with the pneumonia, she was unable to feed herself and her levels dropped. The EMS immediately found her levels were low and got sugar in her. After stabilizing her sugar, they took her to the hospital for the pneumonia. 9.5 hours later in ER they finally admitted her and the family went home, with stable sugar. Saturday ... When I arrived at the room, they had her on a drip of Dextrose 5% solution, and when they checked her sugar it was unreadable ... meaning over 600. When I left, it was 590. I just called ~ 10:45 pm on Sat. night and she's in the 300's and stable. Question should she have been put on dextrose drip in the first place?

Thank you for your answers. Her husband (my step-father) had not given her any nourishment, thinking she "probably" ate, and she was still taking the diabetic pills, even though she hadn't eaten because she didn't have the strength to make herself anything. (I don't live in the same city as her, so I'm not able to be there all the time.) I appreciate your feedback as this is the first time I've used the forum. Thank you.

It sounds like she wasn't eating. Since she wasn't eating, it is O.K. to do this. The body, if not eating, does need some form of sugar. That type of sugar I.V. is the smallest amount made. The way sugar metabolism works when not eating is
once the sugar is introduced into the body and metabolized, an adrenalin rush happens and the blood sugar soars, then it
falls, such the crash. This continues until the person eats. This is how my doctor explained it to me. If she just received some other type of I.V. solution, it probably wouldn't of helped her get over her illness.

diabetics in such situations are given neutralising doses of insulin with 5% dextrose and constantly monitored for blood sugar levels.