Control of glucose can reduce a patient’s risk for infections and mortality.  However, the most common complication of aggressive glucose control is hypoglycemia, which can be life threatening.  Careful measurement of the frequency of hypoglycemia allows clinicians to pace the aggressiveness of their control efforts as they develop a safe protocol.

Numerator: Number of hypoglycemic episodes per patient day.

Denominator: Total number glucose measurements per patient day.

Achieve glucose control between 80 mg/dl and 110 mg/dl in 100 percent of critically ill patients within one year without increased incidence of hypoglycemia.

Definition of Hypoglycemia:

Hypoglycemia is most easily defined as a value less than the lower limit of normal at your institution.  Individual labs calibrate their parameters based upon the patient populations that they treat, therefore the lower limit of normal at your institution should represent values below the standard deviation from normal.

Frequency of Collection:

Ideally, data collection would occur daily with calculation of results monthly for the most accurate assessment of performance.  However, this is an ambitious collection effort requiring more time than may be available.  The frequency of sample collection may be twice weekly or even once weekly.  Trends become more difficult to interpret reliably as the interval between collection periods increases, however.

It will be necessary to tally the number of hypoglycemic events on all ICU patients on the days selected for sampling as well as the total number of glucose measurements (serum and fingerstick) on those patients. 

Patient Days:

Patient days are the number of days for each patient in the ICU with glucose measurements.  Patient days as the denominator include the total number of days of exposure to glucose measurement by all patients in the selected population during the selected time period.

Numerator:

Gather the glucose values (serum and fingerstick) for each patient on the day of sample.  The total number of glucose values less than the lower limit of normal at your institution is the numerator.

Denominator:

Gather the glucose values (serum and fingerstick) for each patient on the day of sample.  The total number of glucose values collected regardless of result is the denominator.

Example:

A particular ICU samples data twice weekly for the month.  On each sample day the number of hypoglycemic episodes is as follows:

Numerator =  5+3+3+2+1+2+2+1 = 19

Denominator =  40+45+35+39+55+49+45+39 = 347

Numerator/Denominator x 100 = percent of hypoglycemic episodes per glucose check = 0.05 x 100 = 5 percent