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SA JOURNAL OF DIABETES & VASCULAR DISEASE
REVIEW
VOLUME 9 NUMBER 2 • JUNE 2012
53
Basal–bolus insulin regimen
Discontinue oral anti-diabetic drugs on admission
•
Calculate the starting total daily dose (TDD):
•
– 0.4 U/kg/d for admission blood glucose between 7.8 and
11.1 mmol/l
– 0.5 U/kg/d × blood glucose between 11.2 and 22.2 mmol/l
Half of TDD as insulin glargine (Lantus
•
®
) and half as rapid-acting
analogue
Insulin glargine once daily, at the same time of day
•
Rapid-acting insulin analogue three equally divided doses with meals
•
Supplemental insulin:
•
– Give supplemental insulin (rapid-acting analogue) following the
‘sliding-scale’ protocol below for blood glucose 7.8 mmol/l.
– If a patient is able and expected to eat all, give supplemental insulin
(rapid-acting analogue) before each meal and at bedtime following
the ‘usual’ column.
– If a patient is not able to eat, give supplemental insulin (rapid-
acting analogue) every six hours (6–12–6–12) following the ‘insulin
sensitive’ column.
Table 3.
An appropriate peri-operative insulin regime.
9
Blood glucose
(mmol/l)
Insulin sensitive
(units)
Usual
(units)
Insulin resistant
(units)
> 7.8–10
2
4
6
10.1–12.2
4
6
8
12.3–14.4
6
8
10
14.5–16.7
8
10
12
16.8–19.4
10
12
14
19.5–22.2
12
14
16
> 22.2
14
16
18
Insulin adjustment:
•
– If the fasting or mean blood glucose during the day is 7.8 mmol/l
in the absence of hypoglycaemia, increase insulin glargine dose by
20% every day.
– If a patient develops hypoglycaemia (3.9 mmol/l), decrease glargine
daily dose by 20%.
Blood glucose monitoring:
•
– Measure blood glucose level before each meal and at bedtime (or
every six hours if a patient is nil per os.
As hypoglycaemia has been linked to increased mortality in
hospitalised patients, especially high-risk patients, mild to moderate
hypoglycaemia should be identified and treated promptly to
avoid progression to a more severe episode, with possible severe
consequences.
General treatment principles
Diabetic patients admitted to hospital should be clearly identified
as such and this identification should trigger a pre-specified set of
standardised protocols. The identification of patients as diabetics
should be clear to all members of the care group, from food,
kitchen and dietetics staff to the ward and theatre nursing staff,
and even to the surgeons and anaesthetists involved in the surgical
procedure itself.
Protocols should be available to all staff and should be as clear
and simple as possible. They should also be able to cater for all
types of diabetics from the brittle type 1 patient to the type 2
patient normally controlled on diet alone.
Critically ill patients
Evidence, expert opinion and guidelines by most national and
international endocrine and diabetes associations recommend the
use of insulin infusions in these patients, particularly in the intensive
care unit (ICU) setting. Glucose targets should be 7.8–10 mmol/l in
most patients, however less vulnerable and surgical patients may
benefit from a slightly lower range of 6.1–10 mmol. The use of an
intravenous infusion requires frequent glucose monitoring, not less
than every two hours and preferably hourly, with adjustments made
to the infusion rate depending on the glucose levels and trends.
Non-critically ill patients
As randomised, controlled trials are lacking, guidelines in this group
are based on clinical experience and judgement. Glucose targets
in most patients controlled with insulin would be 7.8–10 mmol/l,
providing these can be achieved with a low risk of hypoglycaemia.
When glucose values frequently fall below 5.6 mmol/l, consideration
should be given to modifying the treatment to avoid hypoglycaemia.
When glucose values fall below 3.9 mmol/l, treatment must be
modified to avoid more serious hypoglycaemic episodes.
In patients using insulin who have been stable prior to admission,
in a tighter glycaemic range, lower limits may be acceptable in
hospital and peri-operatively. Conversely, patients who are critically
ill or in patient-care settings where frequent monitoring is not
possible or feasible, less tight control may be acceptable.
Clinical judgement must be used when considering an
acceptable range for patients where medications, nutritional status
and severity of illness may influence what may be considered an
acceptable glycaemic range.
Hypoglycaemic agents in peri-operative care
Insulin
This is the treatment of choice in hospitalised patients and in the
peri-operative management of diabetics (Table 3).
8
Insulin should
be given via insulin infusions in critically ill patients and in ICU care.
Non-critically ill patients should be managed with subcutaneous
insulin.
The method through which subcutaneous insulin is delivered
is very important. A sliding-scale insulin regime (SSI) to control
hyperglycaemia in hospitalised and peri-operative patients should
never be used for more than a few hours. Prolonged use of sliding-
scale insulin should be avoided for the following reasons:
It is ineffective in the majority of patients.
•
It increases the risk of both hyperglycaemia and hypoglycaemia.
•
A recent randomised trial in general surgical patients with type
•
2 diabetes has shown that its use is associated with adverse
outcomes.
9
It is potentially extremely dangerous in type 1 diabetes patients.
•
8
A safe and effective subcutaneous insulin regime should deliver
basal insulin that should be given, even in the fasting patient, to
maintain normal glucose metabolism and avoid ketogenesis. Timed
prandial doses should be given with meals. Allowance should be
made for corrective doses to be given both with meals and at
other times, should there be a need for this. A number of recently
published protocols guiding insulin use in a variety of circumstances
can be adapted for particular circumstances and patients.
Other hypoglycaemic agents
There are no safety data on the use of these agents in hospitalised
and peri-operative care of patients. For this reason, as a general
rule, these agents should be avoided and discontinued in the peri-
operative period. Exceptions may be considered for patients who