Glucose levels of patients
kept in ICUs are continuously monitored and controlled. However, this intensive
control of glucose makes the patient more prone to hypoglycemia or low glucose
levels. Hypoglycemia in turn could affect mortality of these patients.
A study evaluated mortality
associated with hypoglycemia in critically-ill patients admitted in the ICU.
The data for the study was obtained from the NICE-SUGAR study database. This
study obtained data on 6104 adults admitted to the ICUs of 42 hospitals between
the years 2004 and 2008 for 3 or more days.
The participants either underwent intensive blood glucose
control, with glucose levels maintained between 81 to 108 mg per deciliter, or
conventional glucose control, with a glucose level of 180 mg per deciliter or
less. The patients were monitored for several parameters until they were
discharged, till 90 days after the beginning of the study or until they died.
Data was obtained at 28 days
for 6026 patients and at 90 days for 6022 patients. Analyzing the data obtained
at 28 days, the researchers found moderate hypoglycemia (blood glucose levels between
41 and 70 mg per deciliter) in 74.2% patients in the intensive-control group
and 15.8% in the conventional-control group. Severe hypoglycemia (blood glucose
value of 40 mg per deciliter) was observed in 6.9% patients in the intensive-control
group and 0.5% patients in the conventional-control group.
Patients with moderate and severe hypoglycemia were hospitalized for a
longer duration as compared to those who did not have hypoglycemia
. Deaths were more common in
patients who suffered from hypoglycemia. Moderate
hypoglycemia was associated with a 40% increased risk of death, while the risk
was doubled with severe hypoglycemia
. Among the patients with moderate
hypoglycemia, the risk for death was higher in patients who had hypoglycemia
for more than a day.
Hypoglycemia can increase
the chances of death through a number of ways like altering blood flow and
causing cardiac arrhythmias. However, this study was not designed to evaluate
whether hypoglycemia was the cause of death in these patients. This question
therefore remains unanswered.
Thus, in critically ill patients, it is important to avoid
hypoglycemia, which may be linked to increased risk for death
Hypoglycemia and Risk of Death in Critically Ill Patients; The
NICE-SUGAR Study Investigators; N Engl J Med 2012; 367:1108-1118