Stress hyperglycemia
Encyclopedia
Stress hyperglycemia is a medical term referring to transient elevation of the blood glucose
due to the stress
of illness. It usually resolves spontaneously, but must be distinguished from various forms of diabetes mellitus
.
It is often discovered when routine blood chemistry measurements in an ill patient reveal an elevated blood glucose. Blood glucose can be assessed either by a bedside ‘fingerstick’ glucose meter
or plasma glucose as performed in a laboratory (the latter being more efficacious). A retrospective cohort study by the Mayo Clinic held that bedside glucometry was a reliable estimate of plasma glucose with a mean difference of 7.9 mg/dL, but still may not coincide with every individual. The glucose is typically in the range of 140-300 mg/dl (7.8-16.7 mM) but occasionally can exceed 500 mg/dl (28 mM), especially if amplified by drugs or intravenous glucose. The blood glucose usually returns to normal within hours unless predisposing drugs and intravenous glucose are continued.
Stress hyperglycemia is especially common in patients with hypertonic dehydration
and those with elevated catecholamine
levels (e.g., after emergency department
treatment of acute asthma
with epinephrine
). Steroid diabetes
is a specific and prolonged form of stress hyperglycemia.
In some people, stress hyperglycemia may indicate a reduced insulin secretory capacity or a reduced sensitivity, and is sometimes the first clue to incipient diabetes. Because of this, it is occasionally appropriate to perform diabetes screening tests after recovery from an illness in which significant stress hyperglycemia occurred.
(ICU) and post-surgical care in recent years is the trend toward more aggressive treatment of stress-induced hyperglycemia. The 2008 guidelines from the Surviving Sepsis Campaign
recommend insulin therapy in critically ill patients.
A number of research studies have demonstrated that even mildly elevated blood glucose levels (110 mg/dL or 6.1 mmol/L) in a hospital intensive care unit (ICU) can measurably increase the morbidity and mortality of such patients. According to a randomized control trial (RCT) of over 1500 surgical ICU patients, controlling patients’ blood glucose below 110 mg/dL or 6.1 mmol/L significantly decreased mortality from 8% with conventional treatment to 4.6%, and also decreased morbidity from bloodstream infections
by 46%, acute renal failure
requiring dialysis or hemofiltration and critical illness polyneuropathy
(Van den Berghe, 2001). A subsequent RCT of 1200 medical ICU patients found that intensive insulin therapy significantly reduced morbidity but not mortality among all patients in the medical ICU. On the other hand, several studies failed to show benefit or demonstrated harmful effects (mainly from hypoglycemia
) of intensive insulin therapy in critically ill patients. A meta-analysis of studies on this topic could not demonstrate an advantage of tight glycemic control, while there was an increase in hypoglycemia. This questions the validity of current guidelines.
Most recently, the largest RCT to date (with 6104 enrolled patients) comparing the effects of intensive glucose control vs. conventional glucose control in ICU patients found that tight glucose control significantly increased mortality at 90 days after admission to the ICU as compared to conventional glucose control (2.6% increase in the absolute risk of death). In this trial (the NICE-SUGAR Study), patients randomised to the intensive glucose control group had a target blood sugar range of 4.5 to 6.0 mmol/L while those placed in the conventional glucose control group had a blood glucose target range of 8.0 to 10.0 mmol/L (as compared to 10.0 to 11.1 mmol/L in Van den Berghe, 2001). Patients were enrolled from mixed ICU wards (as compared to a surgical ICU in Van den Berghe, 2001). The NICE-SUGAR trial may very well change our approach to the management of stress-induced hyperglycemia in the ICU.
Glucose
Glucose is a simple sugar and an important carbohydrate in biology. Cells use it as the primary source of energy and a metabolic intermediate...
due to the stress
Stress (medicine)
Stress is a term in psychology and biology, borrowed from physics and engineering and first used in the biological context in the 1930s, which has in more recent decades become commonly used in popular parlance...
of illness. It usually resolves spontaneously, but must be distinguished from various forms of diabetes mellitus
Diabetes mellitus
Diabetes mellitus, often simply referred to as diabetes, is a group of metabolic diseases in which a person has high blood sugar, either because the body does not produce enough insulin, or because cells do not respond to the insulin that is produced...
.
It is often discovered when routine blood chemistry measurements in an ill patient reveal an elevated blood glucose. Blood glucose can be assessed either by a bedside ‘fingerstick’ glucose meter
Glucose meter
A glucose meter is a medical device for determining the approximate concentration of glucose in the blood. It is a key element of home blood glucose monitoring by people with diabetes mellitus or hypoglycemia...
or plasma glucose as performed in a laboratory (the latter being more efficacious). A retrospective cohort study by the Mayo Clinic held that bedside glucometry was a reliable estimate of plasma glucose with a mean difference of 7.9 mg/dL, but still may not coincide with every individual. The glucose is typically in the range of 140-300 mg/dl (7.8-16.7 mM) but occasionally can exceed 500 mg/dl (28 mM), especially if amplified by drugs or intravenous glucose. The blood glucose usually returns to normal within hours unless predisposing drugs and intravenous glucose are continued.
Stress hyperglycemia is especially common in patients with hypertonic dehydration
Dehydration
In physiology and medicine, dehydration is defined as the excessive loss of body fluid. It is literally the removal of water from an object; however, in physiological terms, it entails a deficiency of fluid within an organism...
and those with elevated catecholamine
Catecholamine
Catecholamines are molecules that have a catechol nucleus consisting of benzene with two hydroxyl side groups and a side-chain amine. They include dopamine, as well as the "fight-or-flight" hormones adrenaline and noradrenaline released by the adrenal medulla of the adrenal glands in response to...
levels (e.g., after emergency department
Emergency department
An emergency department , also known as accident & emergency , emergency room , emergency ward , or casualty department is a medical treatment facility specialising in acute care of patients who present without prior appointment, either by their own means or by ambulance...
treatment of acute asthma
Asthma
Asthma is the common chronic inflammatory disease of the airways characterized by variable and recurring symptoms, reversible airflow obstruction, and bronchospasm. Symptoms include wheezing, coughing, chest tightness, and shortness of breath...
with epinephrine
Epinephrine
Epinephrine is a hormone and a neurotransmitter. It increases heart rate, constricts blood vessels, dilates air passages and participates in the fight-or-flight response of the sympathetic nervous system. In chemical terms, adrenaline is one of a group of monoamines called the catecholamines...
). Steroid diabetes
Steroid diabetes
Steroid diabetes is a medical term referring to prolonged hyperglycemia due to glucocorticoid therapy for another medical condition...
is a specific and prolonged form of stress hyperglycemia.
In some people, stress hyperglycemia may indicate a reduced insulin secretory capacity or a reduced sensitivity, and is sometimes the first clue to incipient diabetes. Because of this, it is occasionally appropriate to perform diabetes screening tests after recovery from an illness in which significant stress hyperglycemia occurred.
Treatment
One of the most sweeping changes in intensive care unitIntensive Care Unit
thumb|220px|ICU roomAn intensive-care unit , critical-care unit , intensive-therapy unit/intensive-treatment unit is a specialized department in a hospital that provides intensive-care medicine...
(ICU) and post-surgical care in recent years is the trend toward more aggressive treatment of stress-induced hyperglycemia. The 2008 guidelines from the Surviving Sepsis Campaign
Surviving Sepsis Campaign
The Surviving Sepsis Campaign is a global initiative to bring together professional organizations in reducing mortality from sepsis. The purpose of the SSC is to create an international collaborative effort to improve the treatment of sepsis and reduce the high mortality rate associated with the...
recommend insulin therapy in critically ill patients.
A number of research studies have demonstrated that even mildly elevated blood glucose levels (110 mg/dL or 6.1 mmol/L) in a hospital intensive care unit (ICU) can measurably increase the morbidity and mortality of such patients. According to a randomized control trial (RCT) of over 1500 surgical ICU patients, controlling patients’ blood glucose below 110 mg/dL or 6.1 mmol/L significantly decreased mortality from 8% with conventional treatment to 4.6%, and also decreased morbidity from bloodstream infections
Sepsis
Sepsis is a potentially deadly medical condition that is characterized by a whole-body inflammatory state and the presence of a known or suspected infection. The body may develop this inflammatory response by the immune system to microbes in the blood, urine, lungs, skin, or other tissues...
by 46%, acute renal failure
Acute renal failure
Acute kidney injury , previously called acute renal failure , is a rapid loss of kidney function. Its causes are numerous and include low blood volume from any cause, exposure to substances harmful to the kidney, and obstruction of the urinary tract...
requiring dialysis or hemofiltration and critical illness polyneuropathy
Critical illness polyneuropathy
Critical illness polyneuropathy and critical illness myopathy are overlapping syndromes of widespread muscle weakness and neurological dysfunction that can develop in critically ill patients receiving intensive care...
(Van den Berghe, 2001). A subsequent RCT of 1200 medical ICU patients found that intensive insulin therapy significantly reduced morbidity but not mortality among all patients in the medical ICU. On the other hand, several studies failed to show benefit or demonstrated harmful effects (mainly from hypoglycemia
Hypoglycemia
Hypoglycemia or hypoglycæmia is the medical term for a state produced by a lower than normal level of blood glucose. The term literally means "under-sweet blood"...
) of intensive insulin therapy in critically ill patients. A meta-analysis of studies on this topic could not demonstrate an advantage of tight glycemic control, while there was an increase in hypoglycemia. This questions the validity of current guidelines.
Most recently, the largest RCT to date (with 6104 enrolled patients) comparing the effects of intensive glucose control vs. conventional glucose control in ICU patients found that tight glucose control significantly increased mortality at 90 days after admission to the ICU as compared to conventional glucose control (2.6% increase in the absolute risk of death). In this trial (the NICE-SUGAR Study), patients randomised to the intensive glucose control group had a target blood sugar range of 4.5 to 6.0 mmol/L while those placed in the conventional glucose control group had a blood glucose target range of 8.0 to 10.0 mmol/L (as compared to 10.0 to 11.1 mmol/L in Van den Berghe, 2001). Patients were enrolled from mixed ICU wards (as compared to a surgical ICU in Van den Berghe, 2001). The NICE-SUGAR trial may very well change our approach to the management of stress-induced hyperglycemia in the ICU.