The objective of this study is to demonstrate that the OptiScanner® is safe and can provide accurate blood glucose levels in critically ill subjects.

Accuracy Hypothesis:

The assessment of blood glucose level that results from the OptiScanner is comparable to the YSI 2300 STAT Plus™ Glucose and Lactate Analyzer ("YSI Analyzer"; YSI Life Sciences, Yellow Springs, OH).

Safety Hypothesis:

The OptiScanner has an acceptable risk/benefit profile for a system that can provide repeated automated blood glucose levels for critically ill subjects.

Inclusion Criteria:

• Signed informed consent by participant or his/her legally authorized representative
• At least 18 years old
• Admitted to the ICU or CCU
• Expected ICU or CCU stay of at least 18 hours at the time of enrollment (as judged by Investigator)
• Requires blood glucose monitoring; and
• A vascular access device that can be dedicated for connection to the OptiScanner is either already in-place, is planned to be placed for another purpose or can, in the opinion of the Investigator be safely placed exclusively for use in this study, and another access device is in place or can be placed for manually drawing samples to be evaluated using the YSI Analyzer. Note that CVCs should not be placed solely for the purposes of conducting this study. Refer to section 1.2.7 for details regarding vascular access devices and guidelines for selection and placement.

Exclusion Criteria:

• Pregnant or nursing

• In the Investigator's opinion the subject cannot safely tolerate the amount of saline required to be given to the subject (up to 360 mL per day)

• Hematocrit less than 15% or greater than 60%

• Subjects that require placement of an additional vascular access line will be excluded if they do not have a suitable access site free from any of the following conditions:

  • Peripheral vascular disease
  • History of placement site neuropathy or chronic pain
  • History of placement extremity coagulopathy or clot formation
  • History of vascular surgery on the same extremity as catheter placement

• Any medical condition that, in the Investigator's opinion, would warrant exclusion from the study or prevent the subject from completing the study, including but not limited to a high risk of complications associated with vascular access; or

• Participation in any other investigational drug or device study in the last 30 days and/or while enrolled in this study.