Hyperglycaemia

 

Three kinds of patient

1.       Hyperglycaemia despite no diabetes

2.       Hyperglycaemia with undiagnosed diabetes – hidden risk of HONK or DKA.

3.       Hyperglycaemia with diagnosed diabetes

 

Peri-operative hyperglycaemia:

Cause

·      ↑Hepatic glucose production (mainly this)

·      ↑Insulin resistance

Bad effects

·      ↑Mortality

·      ↑Morbidity of various sorts

·      ↑↑Infection risk (even if >6)

Lower risk (paradoxical) in diabetics because their cells are used to it

Good effects

·      Whatever reason the stress response evolved for

·      Makes cardiac myocytes resistant to ischaemia

Unknowns

·      Which is more important – the good of the bad?

·      Which is more important for the bad – the high sugar or its cause?

 

NICE-SUGAR trial:

Background

·      In sick diabetics, high sugar is associated with bad outcome

Groups

·      Aggressive vs lax control

Outcome

·      Aggressive group had higher mortality

Explanation

·      Cells of diabetic patient become accustomed to hyperglycaemia

 

Clinical implications:

Target BSL

·      Rule of thumb 6-10

o  Lower end if non-diabetic

o  Higher end if diabetic

·      Need HbA1c to know which of the three groups a patient belongs to

·      Should we be checking this in all patients having major surgery?

Elective cancellation

·      HbA1c >9%: cancel

·      BSL ↑↑↑: cancel (but safe threshold is unknown)

 

 

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