The Problem:Hyperglycemia
in critical illness is common even in persons not previously diabetic.
There is often concurrent insulin resistance. Hyperglycemia may lead to
important complications in critical illness and prolong the ICU stay and
ventilator dependency. Strict glycemic control reduces mortality for ICU
patients.1 Diabetics with acute MI showed improved
outcome if blood glu kept< 215 mg/dl = 11.9 mmol/l.2 Conversion:
glucose mmol/l = (0.05551)* mg/dl Remember that hospitalization for
neuro problems brings many changes to activity and intake so insulin need
will probably be different too.Neuro impairments can especially modify
diabetes manifestations and management: Motivation, initiation, attention,
power, oral continence, swallowing, etc. Parenteral feedings very often
are interrupted whether intentionally or not.In the ICU IV insulin R or H is used while on the ward a regime that
combines short and medium insulins such as NPH and R or H will normally
work best.
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What We Do:
Strive for steady blood glucose numbers in the 4 – 8 range.
Prolonged NPO states are best minimized of course. Nausea, anorexia,
absorption or motility problems due to meds or other factors can make frequent
CBS checks necessary. The Glycemic Index is interesting (on the web) but we
usually defer to dietary dept to bring meals with X calories, often 1800
For patients in the ICU
IV insulin infusions of Humulin
R are run with up to 30 U/hour with CBS q 2 h or q 1 h if infusion rate is >
10U/hour. Insulin dosing and CBS testing QID
is best giving 40 % of total daily dose of insulin as N @HS and 20% of TDD as H
or R with meals TID. Add metformin unless contraindicated. Use of sliding scale
H or R alone tends not to give good control of glusose but may be justified for
the first 2 days after new injury, illness, surgery. A reasonable slicing scale
order would include CBS QID with CBS > 11 -> 5 Units
Humulin R SQ and CBS > 17 -> 7Units.
Links:
CLICK
HERE for INSULIN CHART
Evidence Footnotes:
1.
NEJM
345:1359, 20012.
DIGAMI
Study
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