Vanessa De Azevedo, RN - PhD Student
College of Nursing
University of Utah
College of Nursing
University of Utah
What is Stress Induced Hyperglycemia?
Stress Induced
Hyperglycemia (SIH) is characterized by level of blood glucose of 140 mg/dl or
higher in patients receiving treatment in Intensive Care Unit (ICU) from
surgery, traumatic injury, and critical or acute medical illnesses. Regarding
the reason for admission in ICU, the presence of hyperglycemia is associated
with increased morbidity and mortality. Patients with or without previous
diagnose of Diabetes are also susceptible to present hyperglycemia when
involved in critical scenarios.
Excessive
counter regulatory hormones (e.g. glucagon, growth hormone, catecholamine and
endogenous or exogenous glucocorticoid), and high circulation or tissue levels
of cytokine are the causes of SIH. Such a condition makes insulin incapable of
combating hepatic gluconeogenesis (the formation of glycose by the liver) responsible
for blood glucose levels, and also makes the absorption of glucose into
skeletal muscles impaired. In addition, intravenous nutrition therapy commonly
received in critical settings is also responsible for events of hyperglycemia.
It is well known
in medicine that controlling SIH in critical patients is a challenge for health
care providers. The ideal blood sugar target range is 70-110 mg/dl; however,
the high risk of hypoglycemia is eminent when such a target is applied. Researchers
are trying to find a safer ways to control patients’ glycemic level without producing
adverse hypoglycemia events. Insulin protocols, randomized control trials
(RCT), and revision of guidelines have been done to solve such an important
issue.
What happens if
a patient presents hyper or hypoglycemia when in ICU?
Hyperglycemia is characterized by
blood sugar level higher or equal to 110 mg/dl in a healthy person. Considering
critical patients, high levels of blood sugar (< 140 mg/dl) can result in mitochondrial
damage, endothelial dysfunction, and immune suppression, leading to an
increased risk of infection. Indeed, SIH can result in polyneuropathy which requires
a longer use of mechanical ventilation and longer hospitalization in ICU.
Hypoglycemia is defined as blood glucose
level below or equal to 70 mg/dl. Glucose is not a villain for our body, it is
also a metabolic fuel for the brain. Lack of glucose in the human body can be the
consequence of a tight glucose control in ICU, in other words, excessive amount
of insulin administrated when restrictive insulin protocols are applied. Other
causes of hypoglycemia are inadequate nutrition, and insufficient provision of
glucose. If untreated, hypoglycemia can result in permanent brain damage and
death.
Both hyperglycemia and hypoglycemia if
not properly treated can result in poor care outcomes and even death.
What has been
done to avoid SIH in ICU settings?
After a detection of blood sugar
elevated, physicians prescribe an insulin protocol which consists of an
intravenous administration of regular insulin (fast acting) through a pump. The
dose of insulin is calculated by the level of glucose measured at the moment of
administration. Through a simple but reliable glucometer, the blood glucose
level is measured. The blood sample can be collect through finger sticks, and
venous or arterial line. Arterial blood is the most accurate source for
accessing glycemic level.
The insulin protocol requires hourly glycemic assessments in
order to manage the insulin dose administrated. Such approach causes a delay in
treatment which might result in adverse events such as hypoglycemia. The
American Diabetes Association (ADA), the American College of Critical Care
Medicine (ACCM), and the American Association of Clinical Endocrinologists
(AACE) recommend a target glucose range of 140-180mg/dl. They also
recommend the use of paper-based or computerized protocols that allow for predefined
adjustments in infusion rate based on glycemic fluctuations and insulin dose,
and initiation of intravenous insulin protocol at 180 mg/dl. Furthermore,
hypoglycemia protocols should be established for each patient. The goal of
the guidelines above is to avoid hypoglycemia and hyperglycemia and to mitigate
adverse outcomes.
What is the role of nurses taking care of patients with insulin protocol
in ICU?
Nurses play a crucial role in
glycemic management. They assess glycemic level from the beginning to the end
of the therapy, making critical decisions that will impact the evolution of the
therapy, and patient care outcomes.
Such responsibilities require time,
attention, dedication, and application of scientific knowledge. Once insulin
therapy is initiated, nursing workload will increase.
Why do we need a change?
Hourly glycemic assessment is not
enough when managing insulin protocols. The need for a more tight control is
essential to avoid adverse events such as hyper or hypoglycemia.
There is consensus among researchers
that the more tight the glucose levels (70 -110 mg/dl) the more benefits
patients will have. However, such a tight control is not recommended due to
high incidence of hypoglycemia it may cause.
Hourly measurement with glucometers and
finger sticks will result in hematomas, and consequently poor quality of a
blood sample. Indeed, such an approach will increase nursing workload which can
drive nurses away from other critical care conditions that might require
special attention.
Where innovation and technology can help?
Currently in the market we have
devices such as continuous glucose monitoring and bionic pancreas that are
helping patients with Diabetes types 1 and 2 to self-manage their blood
glucose. Even though, critically ill patients are not necessarily in the scope
of diabetes, they will certainly be beneficiated with such technology in ICUs.
What is CGM?
Illustration of a continuous glucose
monitoring Dexcom G4, retrieved from: https://diatribe.org/issues/48/test-drive
Continuous
Glucose Monitoring (CGM) is a device that was initially designed with the
purpose of helping Diabetes Type 1 patients to self-manage their blood sugar.
Such an equipment contains a glucose sensor, a transmitter, and a display. The
sensor captures and measures in real-time glucose fluid in the subcutaneous
tissue. Connected to a transmitter, glucose levels are send wirelessly via radio
frequency to the monitor display device.
What is Bionic pancreas?
Top figure represents a
bionic pancreas monitor, retrived from:
https://diatribe.org/introducing-beta-bionics-bringing-ilet-bionic-pancreas-market
.
Bottom figure respresents an ilustration of how artificial pancreas works. Retrieved from: http://discovermagazine.com/2016/may/13-priming-the-pump
Bionic
pancreas is a device that aims at imitating the human pancreas delivering
insulin and glucagon hormones based on a blood sugar result measured every five
minutes. The system consists of a dual pump (one for insulin and one for
glucagon) that receives information from a separate sensor –CGM- and automatically
calculates the exact dose of hormone a patient needs.
What to expect using CGM and Bionic Pancreas in ICU?
In conclusion,
the addition of the new technology in ICU settings will lead to a real-time
management of glycemic levels, reduction of nursing workload, and more accurate
and safe levels of glucose. CGM and bionic pancreas will help prevent/manage
SIH by simulating an almost real and effective human pancreas resulting in
reduction of incidence of infection, hospital length of stay, and better patient
outcomes.
References and suggested links for further reading:
http://inpatient.aace.com/strategies-for-achieving-glycemic-control-management-of-hyperglycemia-in-the-critical-care-setting
McCowen,K.C., Malhotra, A., Bistrian, B.R. (2001).
Stress-Induced Hyperglycemia. Critical Care
Clinics, 17(1), 107-124. Doi http://dx.doi.org/10.1016/S0749-0704(05)70154-8
Harp, J. B., Yancopoulos, G. D., & Gromada, J. (2016). Glucagon orchestrates stress-induced hyperglycaemia. Diabetes,
Obesity and Metabolism, 18(7), 648-653. doi: 10.1111/dom.12668
Godinjak, A., Iglica, A., Burekovic, A., Jusufovic, S.,
Ajanovic, A., Tancica, I., & Kukuljac, A. (2015). Hyperglycemia in
Critically Ill Patients: Management and Prognosis. Medical Archives, 69(3),
157-160. doi: 10.5455/medarh.2015.69.157-160
Lacherade, J.-C.,
Jacqueminet, S., & Preiser, J.-C. (2009). An Overview of
Hypoglycemia in the Critically Ill. Journal of Diabetes Science and Technology,
3(6), 1242–1249.
Brunner, R.,
Kitzberger, R., Miehsler, W., Herkner, H., Madl, C., & Holzinger, U.
(2011). Accuracy and reliability of a subcutaneous continuous
glucose-monitoring system in critically ill patients. Critical Care
Medicine, 39(4), 659-664. doi: 10.1097/CCM.0b013e318206bf2e
De Block, C.,
Manuel, Y. K. B., Van Gaal, L., & Rogiers, P. (2006). Intensive insulin
therapy in the intensive care unit: assessment by continuous glucose
monitoring. Diabetes Care, 29(8), 1750-1756.
Harris, D. L.,
Battin, M. R., Weston, P. J., & Harding, J. E. (2010). Continuous glucose
monitoring in newborn babies at risk of hypoglycemia. Journal of Pediatrics,
157(2), 198-202.e191. doi: 10.1016/j.jpeds.2010.02.003
No comments:
Post a Comment