• To learn if The Guardian® blood-sugar monitoring device can be used reliably in patients with high blood sugar who are receiving care in the ICU. [ Time Frame: 3 years ] [ Designated as safety issue: No ]
  

• Compare blood-sugar measurements from the study device with blood-sugar measurements from the standard "fingerstick" method of blood-sugar testing. [ Time Frame: 3 Years ] [ Designated as safety issue: No ]
  

The Study Device:

The Guardian® blood-sugar monitoring device is designed to automatically record blood sugar levels many times per hour, without requiring multiple fingersticks. It uses a blood sugar "sensor" (an electronic measuring device) that is about the size of a beeper. The sensor is attached to a small catheter that has a small needle in it. Once the catheter is inserted in the skin, the needle is removed right away.

Use of Study Device:

If you agree to take part in this study, while you are in the ICU, the catheter and needle part of the study device will be inserted under the skin of your abdomen or thigh. The device will automatically measure your blood sugar every 10 seconds so the data can be reviewed by the research staff. The needle will be removed right away. The catheter must be changed every 3 days by the research staff. You will have the study device in place for 15 days (or until you leave the ICU, whichever comes first).

Standard Monitoring of Blood Sugar Levels:

While you are on study, your blood sugar will also be monitored according to the standard of care. This will be in the form of having your blood sugar checked by using a small needle to prick the tip of your finger every hour or more, as necessary.

The blood sugar measurements from the study device will not be used in any way to affect any decisions about your blood sugar monitoring or care.

Length of Study Participation:

After the study device is removed from your body for the last time (after 15 days or when you leave the ICU), you will be considered off study. If intolerable side effects occur, or an infection occurs that seems to have been caused by the study device, you will be taken off study early.

This is an investigational study. The study device is commercially available and FDA approved for monitoring blood sugar levels for outpatient (outside of the hospital) use. Using the device in patients who are in the hospital is considered experimental. At this time, it is only being used in this way in research.

Inclusion Criteria:

1. Patients in any of our University of Texas collaborative intensive care units.
2. Critically ill patients on an insulin infusion protocol

Exclusion Criteria:

1. Patients or their legal representatives who do not consent
2. Patients with large areas of skin affected so as not to allow implantation of device.
3. Patients < 18 years of age