Evidence from Van den Berghe et al., a trial of glycemic control in cardiac ICU patients, [1] demonstrates that control of blood glucose can reduce a patient’s risk for infections and mortality.  There is no reason to believe these results cannot be generalized to other critically ill patients and no evidence supports that this strategy is not generalizable.

Blood glucose maintained between 80 mg/dl and 110 mg/dl showed a 3.4 percent reduction in one-year mortality.  In addition, patient survival rates improved when a continuous infusion of insulin was used to maintain blood glucose as described above.  The reductions in mortality occurred regardless of a patient’s history of diabetes or hyperglycemia.  Intensive insulin therapy reduced the risk of complications from critical illness such as sepsis and prolonged antibiotic therapy.  However, overly aggressive protocols may lead to hypoglycemia, which must be avoided.

Numerator: Number of ICU patient days with median patient glucose values between 80 mg/dl and 110 mg/dl.

Denominator: Total number of ICU patient days.

Reference:

[1] Van den Berghe G, Wouters PJ, Bouillon R, et al. Outcome benefit of intensive insulin therapy in the critically ill: Insulin dose versus glycemic control. Critical Care Medicine. 2003;31:359–366.

Achieve glucose control between 80 mg/dl and 110 mg/dl in 100 percent of critically ill patients within one year.

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 calculate the median glucose value for every patient on the days selected for sampling in the ICU.  The median glucose value must be calculated each day for those patients as well.

Median Glucose Calculation:

The value in a median glucose collection (as opposed to an average) is that newly critically ill patients with elevated glucoses just begun on a continuous insulin infusion will have the outlier critically high values de-emphasized in assessment of glucose control. 

The median glucose value is the central tendency of the series of glucoses (serum and fingerstick) samples collected for that patient on a particular day.  The median value is obtained by listing the values in increasing order and eliminating the highest and lowest values until the central value is obtained.  If the total number of values is even the central tendency is the average of the middle two values.  If the total number of values is odd, the single middle value is the central tendency.

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 median glucose values for each patient on the day of sample.  The number of patients on each day with a median glucose value between 80 mg/dl and 110 mg/dl is added to the overall tally.  This is completed for each day of sampling during the collection period.  The tally result over the time of the collection period is the number of compliant patients (CP).

Denominator:

Gather the number of patients in the unit on each day of sampling for the sample period.  The total of the number of patients in the unit on each collection day is the total number for the collection period (Patient Days, or PD).

Example:

A particular ICU samples data twice weekly for the month.  On each sample day there are 4 ICU patients.  One patient’s median gluose level is compliant with 80 mg/dl to 110 mg/dl range during the first week, two patients are compliant during the second week, three patients are compliant during the third week, all four patients are compliant during the fourth week. 

CP =  1+1+2+2+3+3+4+4 = 20 compliant patients

PD =  4+4+4+4+4+4+4+4=  32 patient days

CP/PD x 100 = Percent of patients with glucose between 80 mg/dl and 110 mg/dl = 62.5 percent