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VOLUME 11 NUMBER 4 • NOVEMBER 2014
173
SA JOURNAL OF DIABETES & VASCULAR DISEASE
LEARNING FROM PRACTICE
Can pre-operative carbohydrate loading be used in diabetic
patients undergoing colorectal surgery?
AFFIFA FARRUKH, KATH HIGGINS, BALJIT SINGH, ROBERT GREGORY
Correspondence to: Dr Affifa Farrukh
Department of Digestive Diseases, Leicester General Hospital, Gwendolen
Road, Leicester, UK
Tel: +44 (0)1162 584787
e-mail:
farrukh_affi@yahoo.comKath Higgins, Baljit Singh, Robert Gregory
Departments of Digestive Diseases and Diabetes, University Hospitals of
Leicester NHS Trust, Leicester, UK
Previously published in
Br J Diabetes Vasc Dis
2014;
14
: 102–104
S Afr J Diabetes Vasc Dis
2014;
11
: 173–175
Abstract
The introduction of enhanced recovery after surgery
(ERAS) has been associated with shortening post-operative
recovery. It achieves such outcomes by minimising the
physical and physiological trauma of surgery. Benefits include
superior pain control, reduced duration of ileus, improved
pulmonary function and a reduction in thrombo-embolic
and cardiac events. Within the ERAS approach, the role of
oral carbohydrate supplements is based on dealing with
insulin resistance which characterises periods of stress.
Aggressive control of blood glucose levels has been shown
to benefit both diabetic and non-diabetic patients admitted
to intensive care units, however original studies in this area
have not been consistently reproducible. The development
of low-osmolality carbohydrate drinks during the mid-1990s
opened up the possibility of extending these benefits to
surgical patients by providing them with a carbohydrate
load two to three hours prior to anaesthesia. The benefits
of the ERAS approach to colorectal surgery has been
confirmed in several reports. However, its role in diabetic
patients has, as yet, received limited attention. This review
examines this limited number of publications and considers
the potential benefit of pre-operative carbohydrate loading
in all diabetic patients.
Keywords:
diabetes, surgery, carbohydrate loading, pre-operative
Introduction
The introduction of ERAS has been associated with shortening
post-operative recovery. It achieves such outcomes by minimising
the physical and physiological trauma of surgery. It is claimed that
such an approach will benefit all patients.
1
The overall strategy
requires that patients are given partnership and responsibility
for their care, health is optimised prior to surgery and care and
rehabilitation are evidence based. Such an approach has called
into question the traditional pre-operative overnight fast and
the use of bowel preparation for colonic surgery among other
aspects of care. The benefit of such an approach for patients
undergoing colorectal surgery is recognised throughout the
world.
1,2
Benefits include superior pain control, reduced duration
of ileus, improved pulmonary function and a reduction in
thromboembolic and cardiac events. Within the ERAS approach
the role of oral carbohydrate supplements is based on dealing with
insulin resistance which characterises periods of stress. It improves
post-operative glycaemic control through endogenous insulin
release, not only by reducing the risk of hyperglycaemia during
post-operative nutrition but also by improving nitrogen economy
and therefore maintaining muscle strength.
3
Historic background
In 1877 Bernard demonstrated that stress disturbed glucose
homeostasis when he reported hyperglycaemia in association with
haemorrhage.
4
This was the first recognition of the existence of
insulin resistance. Although this physiological response in which
glucose reserves are directed to non-insulin-dependent tissues,
such as the brain, may be beneficial after trauma, Ljungqvist
et al.
questioned whether this was true following surgery.
5
These doubts
arose following work on insulin resistance as a marker of surgical
stress.
6
Elevated blood glucose level is associated with an increased
incidence of infections following surgery.
7
Improved glycaemic
control was associated with fewer deep sternal infections in diabetic
patients who underwent cardiac surgery.
8
Aggressive control of
blood glucose levels has been shown to be of benefit to both
diabetic and non-diabetic patients admitted to an intensive care
unit, with significant reductions in death rates from multiple organ
dysfunction.
9
However, since this study was published in 2001,
these results have been difficult to reproduce and the NICE-SUGAR
study
10
and a meta-analysis
11
have informed consensus opinion
that ‘aggressive’ blood glucose control is potentially harmful. The
main issue is that an ‘aggressive’ approach to glycaemic control
increases the likelihood of hypoglycaemic episodes. For this reason
moderate control is associated with lower mortality amongst
diabetic patients, although this is probably not true for people
without diabetes.
12
Indeed a recent study of non-diabetic patients
undergoing hepatobiliary surgery again demonstrated the benefits
of aggressive control of blood sugar levels leading to reduced
incidence of infections and shorter hospital stays, and none of the
patients in the study had any episodes of hypoglycaemia.
13
Clearly
the need to ensure that blood glucose is kept within an acceptable
range is crucial to the success of any intensive insulin regime.
14
Against this background, Ljungqvist
et al.
5
interpreted their own
and other work as showing the need to shorten the catabolic phase
related to surgical stress and to achieve this by minimising insulin
resistance in the post-operative period.
Current approaches
The novel approach adopted has been to challenge the conventional
wisdom of fasting prior to surgical procedures. The traditional
basis for fasting had been to prevent aspiration, but this view