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SA JOURNAL OF DIABETES & VASCULAR DISEASE
92
VOLUME 9 NUMBER 2 • JUNE 2012
Hands on
PRACTICAL GUIDANCE ON INSULIN
USAGE IN THE HOSPITAL SETTING
S Afr J Diabetes Vasc Dis
2012;
9
:
92–96.
Adri Kok
Specialist physician, Union Hospital, Gauteng,
CEO of Faculty of Consulting Physicians of
South Africa, chairperson of the Medical
Advisory and Ethics Committee of Netcare,
and a director of the South African Private
Practitioners’ Forum
e-mail: jakok@mweb.co.za
Introduction
In recent years, there has been much debate and
controversy about the correct use of insulin in the
hospital setting. There is little debate however on
the impaired glucose metabolism present in the
majority of critically ill patients, often aggravated by
parenteral feeding, infections, inotrope support and/
or pre-existent diabetes.
Insulin resistance is common and even a single
elevated blood glucose level has been associated
with adverse outcomes. Intensive insulin therapy has
been shown to reduce mortality and morbidity, with-
out the risk of hypoglycaemia, if it is done safely by
informed, educated nursing staff. It has also been
shown to be cost-effective.
The correct target level of glucose which can be
achieved safely has been the discussion point for
some years and the new American Diabetes Asso-
ciation (ADA) practice guidelines recommend a safe
level of 7.8–10 mmol/l but not to exceed a threshold
of 10 mmol/l in selected patients (consensus state-
ment of ADA/AACE 2012) in the intensive care unit
setting.
1
There are other situations where hyper-
glycaemia in the in-patient setting may significantly
affect the outcome of the illness. Many patients may
be diagnosed as being new-onset diabetics during a
hospital admission for another reason.
An understanding of factors affecting the indi-
vidual patient must be considered when a protocol
is developed. The nursing staff must understand
clearly defined goals for blood glucose levels, have
clear action points to avoid hypoglycaemia and must
be educated on how anti-diabetic medication works
and what the pitfalls of treatment are.
All patients with diabetes admitted for whatever
reason must have their diabetic status prominently
identified in the patient file and be automatically
monitored at mealtimes, with a record of glucose lev-
els available to all members of the healthcare team.
Specific issues will be discussed in depth below.
Monitoring
The usual bedside glucometer readings are adequate
in the non-critically ill patient. If there is any doubt,
a laboratory glucose test can be done to confirm an
abnormal result, especially if a patient has never been
diagnosed with diabetes before. If a random level is
elevated, a fasting laboratory glucose test should be
done to confirm the diagnosis at a time when there
are no confounding factors present that could influ-
ence the glucose level, e.g. infection, trauma, sur-
gery. This is usually done in an out-patient setting six
to eight weeks following discharge from hospital.
In the intensive care unit (ICU), continuous glucose-
monitoring devices are used by some but are costly. In
South African ICUs, glucometer readings may be used
but it is preferred to use glucose levels on the arterial
blood gas analysis to determine action points.
If a patient is shocked with poor peripheral per-
fusion, an arterial line will facilitate accurate deter-
mination of glucose levels, as poor capillary filling
will affect the accuracy of finger-prick glucose levels.
Capillary blood may overestimate actual blood glu-
cose levels and if strict targets are set, it may result
in hypoglycaemia. These limitations must be consid-
ered when organising a hospital insulin protocol.
New glucometers are able to compensate for
changes in haematocrit level, they can adjust for
reducing agents such as vitamin C and acetami-
nophen, require only a small amount of capillary
blood, and provide a rapid glucose level, often within
six seconds, thus saving on nursing time.