More insulin questions


I am a new grad in LTC, still trying to learn about diabetes/insulin...

How long does it take for the carbs in a meal to spike. We do accuchecks at 3:30, insulin due at 4:30, dinner comes up at 5:00. I only have 3 diabetics one is on regular/nph and the other two on novolin. If I find thier bs reading very high, should I give the insulin earlier? how do I know when the carbs will spike?

how can I become more proficient in diabetes management?


727 Posts

The timing of insulin is best when these three things happen almost simultaneously:

Check the blood sugar

Give the insulin

Take the first bite of food

If you check the pt's blood sugar at 3:30, you really have no idea what their blood sugar is when they begin their meal at 5:00. They could be much higher by then...or they could be very low.

For instance, let's say you check blood sugar at 3:30 and the reading is 130. Is that 130 and it's on the way down OR is that 130 and climbing. You don't know. So when you give insulin at 4:30 you may actually be encouraging the blood sugar to bottom out, particularly if the meal is delayed. Again, let's go with a 3:30 BS of 130, which is dropping. At 4:30 you give the insulin, which begins to drop the BS further. Supper trays are delayed until 5:20...that patient may be very low by that point with symptoms of sweating, mood changes, trembling, abdominal discomfort or even unconsciousness.

As for how long it takes for ingested carbs to peak, that is very individual. Depends on the composition of the meal (fats and proteins will slow down the rise of the blood sugar from the carbs eaten) and what the patient has to drink (liquid carbs hit the blood stream very quickly so things like juice, soda, milk are almost instantly turned to sugar, which is why we use them to treat hypoglycemia).

Long Term Care Columnist / Guide

VivaLasViejas, ASN, RN

142 Articles; 9,981 Posts

Specializes in LTC, assisted living, med-surg, psych. Has 26 years experience.

What mammac5 said.^

1530 is way too early to be checking FSBS. If that's the time your facility chose, you may need to become an advocate for changing it to 1630 or even later, as the short- and intermediate-acting insulins should never be given more than 30 minutes before a meal and preferably no more than 15 minutes. Since you have only three diabetics, you actually have the luxury of waiting till suppertime to do blood sugars and insulins together; when I was working LTC I routinely had ten or twelve, and it was always a mad scramble to beat them to the dining room and get all their DM care done before the meal.

Even with that many, I'd wait till about 1645 to go around and do the accu-checks first, then come back and give insulin before my unit's trays came out around 1730. I timed it to where I'd start at the end of the hall and wind up near the dining room right about the time the food cart arrived, so I'd give those residents their insulin right after doing their FSBS, then head down the hall as trays were being passed to the rooms. That way we didn't have so much lag time between accu-checks/insulin and food consumption.

Even with the best of intentions, though, strategies like this can fail. We had one resident who was so brittle that his sugars could jump from 50 to 500 and fall to 50 again---within an hour depending on how we responded to it. And you didn't EVER want to give him insulin before he'd at least gotten a few bites in or he'd bottom out and become unresponsive, and you'd have to run for the Glucagon. Forty-five minutes later he'd be upwards of 350 and climbing........yep, he was a challenge!

Good luck, and good for you for asking questions. We're happy to help where we can. :)

classicdame, MSN, EdD

2 Articles; 7,255 Posts

Specializes in Hospital Education Coordinator.

You state one is taking Novolin and one is on Reg/NPH. Are you aware that Novolin is EITHER regular or NPH? Or are you confusing Novolog and Novolin? I recommend you get online with and other sites and read read read


456 Posts

The fast acting insulins (Regular, Novolin R, or Novolog) usually start working in about 15 minutes. They'll be active in the body for 2-5 hours, depending on the individual's insulin sensitivity.

Most carbs will digest and hit blood sugar within that 15 minute - 2 hour window. But high fat or large meals take longer to digest, which causes a low blood sugar right after eating and a high later. Viva's advice seems smart. As a diabetic myself, I don't take insulin until the food is in front of me. May cause a slight high since the food gets a headstart, but prevents any problems from a delayed meal.

Know I keep adding to your reading list, but a great, easy to understand book is "Using Insulin" by John Walsh. Your library may have it.

Thank you for doing such a good job taking care of your diabetic patients. You sound like a great nurse.