Sick day rules

Sick day rules are guidelines for patients with diabetes providing advice on how to manage blood sugars and insulin/tablets during times of illness, especially illnesses that lead to reduced food intake and/or vomiting. It is essential that all patients with diabetes are aware of sick day rules and that these are regularly re-enforced as part of routine on going diabetes care.

What are sick day rules?

Sick day rules are guidelines for patients with diabetes providing advice on how to manage blood sugars and insulin/tablets during times of illness, especially illnesses that lead to reduced food intake and/or vomiting.

During these times, the cardinal advice is that patients should NEVER STOP THEIR INSULIN.

Insulin requirements often actually rise during inter-current illness, even if food intake has significantly fallen. Thus, patients are advised to regularly check BMs (two to four hourly), continue their regular doses of insulin, counter any falling blood sugars with frequent small sips of sugary drinks and maintain a high fluid intake (ideally 3 litres per day).

What advice should be given to a patient with T1DM, an inter-current illness and who is 'off their food'? 

The advice given should include: 

1. Continuing to take all doses of insulin. 

2. Monitoring BMs two to four hourly. 

3. Maintaining a high fluid intake. 

4. Trying to substitute normal meals with sips of lucozade/cola (not diet), a scoop of ice cream, soup and bread, breakfast cereal and milk or an other carbohydrate-containing food stuff that they would find palatable.

5. Any BMs less than four or a trend of falling blood sugars should be countered by taking frequent small sips of lucozade, cola (not diet) or fruit juice. Hypoglycaemia in this situation is however unusual and the normal problem is rising blood sugars.

6. If their BM is above 15 they should test their urine for ketones.

What advice should be given to a patient with T1DM, an inter-current illness, and urinary ketones? 

They should maintain a good fluid intake and continue to test BMs two to four hourly. In addition, they should act according to the degree of ketonuria as follows:

1. If the ketones are only trace or small, they should continue their usual doses of insulin and take additional rapid acting insulin every four hours and continue to monitor the ketones. The dose of additional insulin should be 10% of their total usual daily dose.

2. If the ketones are moderate or large, they should continue their usual doses of insulin and take additional rapid acting insulin every four hours and continue to monitor the ketones. The dose of additional insulin should be 20% of their total usual daily dose.

3. If the ketones are moderate or large and the patient is vomiting, they should present themselves to hospital. 

What advice should be given to a patient with T1DM, an inter-current illness and, despite taking all their usual insulin doses, BMs of between 10-15 mmol/L?

They should test urine for ketones, if they have ketonuria, they should follow the advice as for urinary ketones (see above Q&A).

If there are no urinary ketones, all doses of insulin should be increased by 10% above normal doses and they should continue to monitor BMs two to four hourly and test urine ketones if blood sugar goes above 15.

What advice should be given to a patient with T1DM, an inter-current illness and, despite taking all their usual insulin doses, BMs of >15 mmol/L? 

They should test urine for ketones, if they have ketonuria, they should follow the advice as for urinary ketones (see Q&A above).

If there are no urinary ketones, they should follow advice as for trace or small urinary ketones (see Q&A above).

What advice should be given to a patient who has tablet- and/or GLP1 agonist-treated T2DM and an inter-current illness?

They should be advised to stop their metformin if they take this medication, to continue their other usual hypoglycaemic medication, to check their BM two to four hourly and to seek medical attention if it rises inexorably.

What should a patient do as their inter-current illness resolves?

In the majority of cases, it will be possible to avoid hospital admission.

As the inter-current illness resolves, the patient should continue to monitor their blood sugars closely and if they have increased the doses of insulin, these should be brought back to normal or there will be an increased risk of hypoglycaemia.

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