Continuous Glucose Monitoring in Critically Ill Surgical Patients

Patients:

This study will be conducted in the surgical intensive care unit (SICU) at Yale New Haven Hospital in a prospective observational fashion. As this is a pilot study to determine the accuracy of CGM in our patient population we have based our enrollment projection to complete the study within an approximately 8 month time frame. We will identify three groups of 15 patients who are candidates for enrollment. The primary outcome is the degree of correlation between the continuous glucose monitor and capillary or arterial blood samples.

The first group will be patients who present to the SICU and are hemodynamically unstable. Hemodynamic instability will be defined as systolic blood pressure less than 90 mmHg or the requirement of continuous infusion of vasopressors to maintain the systolic blood pressure over 90 mmHg. The second group of patients will be a similar group that is expected to require massive fluid or blood resuscitation (>6L crystalloid or >6 units of blood) to maintain systolic blood pressure over 90 mmHg. This second group of patients will consist mainly of trauma patients. These patients or their closest available relative will be approached for consent to participate in the trial. For patients enrolled through a surrogate who regain their decision making capacity they will be informed of their participation in the study by one of the investigators.

The third group will be patients undergoing elective surgical procedures that will likely require a post-operative admission to the SICU. This group will include patients undergoing open abdominal aortic aneurysm repair, esophagectomy, or other major abdominal or thoracic operation that will likely require a SICU stay of more than 24 hours. At least half of this group will consist of diabetic patients. These patients will be selected by one of the investigators based on their likelihood of requiring more than 24 hours of SICU care. Based on the experience of the investigators we believe we will be able to accurately predict which patients will require an ICU stay of at least 24 hours. Most commonly these patients will have significant co-morbid medical conditions including coronary artery disease, hypertension, hypercholesterolemia, obesity, etc. An attempt will be made to contact these patients pre-operatively by telephone within 1 week of their planned surgery at which time details of the research will be explained. Their willingness to participate will be ascertained and they will be formally enrolled and sign consent on the morning of surgery if possible. On some occasions patients will require ICU stays post-operatively that were not predicted pre-operatively. These patients and any patients that were not identified pre-operatively by the research team will be enrolled post-operatively often through their surrogate similar to the other study groups. Similarly if patient are enrolled pre-operatively and subsequently do not require SICU admission they will not undergo any of the study procedures and not be counted towards the total enrollment.

Study Procedures: