DISCUSSION
Hospital hyperglycemia which is defined as random blood glucose
> 7.8 mmol/L with or without diabetes history occurs
frequently in inpatients 14-16. Inpatient
hyperglycemia has been associated with an increase in mortality,
complications, hospital stay length, and overall hospital cost17,18. Previous reports have indicated that the
inpatient hyperglycemia incidence is around 32.2% of ICU patients and
32% of patients admitted to non-ICU wards in the U.S.19. The reported incidence of hyperglycemia was 45.7%
in China 20. In our study, 26.1% of total adult
inpatients were noted to experience hyperglycemia (> 7.8
mmol/L) with 12.8% having a significant episode of hyperglycemia
(> 10 mmol/L). The HH and SHH prevalence of ICU inpatients
are as high as 73.6% and 30.6%, respectively. Meanwhile, there are
20.7% of non-ICU inpatients with HH and 10.8% with SHH. The inpatient
wards with higher hyperglycemia rates can be divided into two
categories: the first category is those who tend to admit more patients
with pre-existing diabetes history who are at risk for developing
excursions in blood glucose control, such as the Cardiology ward; the
second category consists of patients without a history of diabetes but
who experience illness, stress, and/or medication related hyperglycemia.
Surgical and ICU wards typically represent patients falling into the
latter category 21,22. As is known, medications other
than glucocorticoids can induce hyperglycemia, such as lipid-modifying
agents, antidepressants and estrogen 23-26. In our
hospital, patients following craniocerebral operations who are admitted
to the Neurosurgery ward regularly receive dexamethasone therapy.
However, episodes of hyperglycemia were low which appeared to be related
to intensive glucose monitoring whenever glucocorticoid therapy was
prescribed. This finding seems to support the belief that intensive
monitoring of blood glucose is of benefit for inpatient glycemic control9,27,28. Illness associated stress which occurs in 12
-22% of inpatients has been reported to induce hyperglycemia which a
resultant increase in both morbidity and mortality5,22,29-31. Stress-induced hyperglycemia is felt to be
related to over activation of the hypothalamic–pituitary–adrenal axis
and/or the sympathetic autonomic nervous system thereby causing insulin
resistance followed by hyperglycemia 32. Sleep loss
which is common in inpatients is considered as an independent risk
factor which can disrupt glycemic homeostasis 33,34.
Our study also indicates that thoracic surgery is unique in character as
the rate of mild hyperglycemia (7.8-10mmol/L) is nearly three times
higher than the rate of pre-existing diabetes history. This association
may be related to the fact that many thoracic surgery cases were for a
malignant tumor, and both lung cancer itself and its treatment have been
associated with the development of hyperglycemia35-37. Traditional inpatient glycemic care is
typically passive in nature and not very efficient14,20,38. Lack of timely reaction to glucose
excursions, delayed treatment, and undiagnosed new onset diabetes or
pre-diabetes have all been identified as common factors related to poor
inpatient glycemic control 39. Our facility developed
an alert system for glucose excursions which sent real time cellphone
message to the hospitalized patient’s designated inpatient team
physician with the aim of improving the reaction time and intervention
for episodes of hypo- or hyperglycemia. Previously studied glucose alert
systems have shown improvement of inpatient glycemic control40,41. With the HMA system, the monthly glycemia
related consultation rate for all inpatients increased nearly 66%.
While the HMA system was not noted to reduce the rate of total inpatient
hyperglycemic episodes, the HH rate for the surgical wards was
decreased. These findings indicate that the effect of HMA system on
utilization of formal consultations for blood glucose excursions varied
by the specialty service of the ward. The surgical wards actively
utilized the alert by requesting endocrinology team consultation. It
should be noted that two kinds of endocrinologist consultation are
performed in our hospital: 1) individual endocrinology consults and 2)
glycemic care team (GCT) assessments. The former is the traditional way
to deal glucose excursions in Chinese hospitals, and is performed during
a single visit by an endocrine physician to the inpatient with
recommendations being provided to fulfill the consultation requirement.
The GCT is composed of a nurse, a diabetes educator, nutritionist and an
endocrinologist. GCT assessment is led by the endocrinologist who takes
the initiative to follow-up the patient during the period that glucose
excursions are occurring. In order to cover the entire complement of
hospitalized patients, the GCT would require a large number of
endocrinologists which presently is beyond the capacity of our facility.
Therefore, at present, GCT assessments are only available to a select
number of inpatients in our hospital. The GCT glucose assessments were
noted to correlate with a reduced rate of hyperglycemia and a shorter
length of hospital stay, while individual endocrinologist consults were
noted to decrease the average length of hospital stay and medical care
expenses for inpatients experiencing hyperglycemia 42.
However, the HMA system was found to reduce the HH rate for the surgical
wards even when just individual endocrinologist consultations were
utilized. Within internal medicine wards, a quite different response to
HMA alerts was noted. Nephrology was the fourth highest ward receiving
HMA alerts but the third lowest ward in increased utilization of
endocrinologist consults. The glycemia related consultation rate for
Cardiology + CCU ward even declined by 20%. There is rare previous
report describing the relationship between inpatient ward response to
glycemic alert, hyperglycemia episodes and glycemia related
consultations. We postulate that the less active response to the glucose
excursions alerts may lead to suboptimal glycemic control secondary to a
delay in endocrinologist consultation, or possibly that individual
endocrinologist consults were not felt to be effective enough for
internal medicine wards patients with more complicated glucose control
issues. Future investigation is warranted as to determine the exact
causes for variations in utilization of consultations for HMA alerts.
In conclusion, inpatient hyperglycemia which is associated with inferior
outcomes and longer hospital stays is commonly encountered in
hospitalized adults, and real time glycemic alert systems for inpatients
hold the potential to improve glycemic control thereby reducing
complications, morbidity and mortality related to excursions in glucose
from either hyper- or hypoglycemia. This study revealed the prevalence
of hospital hyperglycemia at 26.1% overall, 20.7% in non-ICU
inpatients, and 73.6% in ICU inpatients. It is noted that real time
glycemic alert cellphone messages to the team physician who is directly
responsible for the inpatient with the glucose excursions can increase
the glycemia related consultation rate overall and also appears to
decrease hyperglycemia episodes in patients on the surgical wards.