Mrs Mac said:
Quick question to all of you:- yesterday I had a hypo (only mild 3.6) around lunchtime. I wasn't hungry but decided it would probably be wise to have lunch. I had a sip or two of lucazade to and then made lunch. I was confused about whether I should take my novo rapid. I didn't on the end as I thought it would defeat the object of eating the food. Was this the right or the wrong thing to do? BG not too bad afterwards so I guess I got away with it? This may sound like a really stupid question!!
Thanks again for your input.
Before each meal these are the basic steps and calculations you need to do, but you must first know what your particular insulin-carb ratios and sensitivity values are in order to get good control. Note that my comments assume your basal dose has been established as being correct.
Insulin-Carb Ratio (how many carbs does 1u bolus cover), and you need to know this for each meal since it will be different. Most adults tend to start with a ratio of around 1u of bolus for every 10g of carbs (1:10). My values below are very non-typical since I am insensitive to insulin.
The correct ratio can only be worked out by carefully recording the carbs, bolus dose given and resulting BG after 3.5 to 4 hours, assuming no further carb or bolus taken. You should review the data from last 3 days before making an adjustment so that a clear trend can be observed. You MUST record every bit of data needed to make a good judgement i.e. BG pre-meal, bolus given, carbs eaten and then BG after 3.5 or 4 hours. If you have access to an Excel spreadsheet this is ideal, but I believe there are smartphone apps that can be used also.
My IC Ratios:- breakfast: 1:1 (35g carbs needs 35u bolus)
lunch: I don't have any lunch carbs to keep weight in check)
dinner: 1:3 (45g carbs needs 15u bolus)
Correction Dose (how many mmol/l your BG will fall for each unit bolus given). Most people have a ratio of 1 unit of bolus to reduce BG by 2– 3 mmol/l.
My Correction Dose: 1u reduces my BG by 1 mmol/l (once again very non-typical, since I need a lot more insulin than most)
Carb count of next meal: this is absolutely vital, since if you don't know fairly accurately the carb content of the next meal, how can you know how much bolus to inject? Establish a food database for the meals that you usually eat which clearly shows the carbs per portion size (weight), so you can refer back when ever you need to. In the early days don't worry about what type of carb you are eating, but just concentrate on total carb content in order to establish the IC Ratios
I have established a detailed Excel spreadsheet with all my meals and can quickly work out the total carb count for the next meal. Eating out is not so easy and requires a certain amount of guesswork. It also predicts what bolus dose I should have for next meal based on results of previous day and also average results of previous 3 days .. very powerful!
Basic Steps before meal:-
1) Measure BG. If too high, work out bolus Correction Dose required to reduce BG to target e.g. 6 mmol/l
2) Work out carbs in next meal.
3) What IC Ratio should I use to ensure BG returns to 4 - 6 mmol/l after about 3.5 to 4 hours?
4) Bolus insulin dose = correction dose (if needed) + carbs/IC Ratio
5) Note: I have not included any adjustment for planned exercise, but will be needed if required.
An example:
BG was 12, correction ratio is 1:3, so correction dose = (12 - 6)/3 = 2u
Carb count for meal is 45g, ICR is 1:5, so carb bolus dose = 45/5 = 9u
Total bolus to inject = 2u + 9u = 11u
Note that it is the IC Ratio that is the key to working out the Bolus dose, and so it is this ratio that needs to be changed if resulting BG are not in the target range. This is because you may have different carb levels, for the same meal, but on different days.
If you regularly experience hypos shortly after your meals, you may want to consider increasing the ICR for those meals the next day. So a ratio of 1:5 may need to be changed to 1:7 (in example above this would mean the bolus was (45/5) 9u needs to be reduced to (45/7) 6u, assuming the same carb count).
I hope this helps, and remember to keep reading the books and documents I referred to earlier .... knowledge is real power in controlling diabetes. It takes time, but gradually you will get a good understanding of what needs to be done, and if in doubt always check with your DSN.
Jonty