Automated vs Conventional Perioperative Glycemic Control in Diabetic Patients Undergoing Cardiopulmonary Bypass Surgery
Condition: Diabetes; Cardiopulmonary Bypass
Study type: Interventional

Summary: 
      The purpose of this randomized controlled trial is to evaluate a fully automated algorithm
      for the establishment of glycemic control in diabetic patients and to compare the results
      with routine management of hyperglycemia in patients undergoing cardiopulmonary bypass
      surgery.
    

Detailed description: 
      Upon admission of the patients to the hospital, demographic and physiological data will be
      collected including waist circumference and BMI. A set of baseline laboratory tests will be
      done for each patient including: glucose level, Hba1c, lipid profile, creatinine level, liver
      enzymes and micro albumin/creatinine urinary ratio.

      Patients will be asked about the presence of any diabetes complications: nephropathy,
      retinopathy and/or neuropathy.

      In the induction room, an intravenous cannula will be inserted by an experienced
      anesthesiology staff or resident. A three way stopcock will be connected directly to the
      cannula. Standard monitors (ECG, non-invasive blood pressure and oxygen saturation) will be
      connected to the patient. An arterial line will be inserted by the anesthesia resident under
      sterile conditions using 20 gauge angiocatheter.

      General anesthesia will be started. A baseline glucose level will be taken from a blood gas
      sample, from the arterial line inserted at the beginning of the surgery.

      In the Control group, patients' glucose levels will be managed as per the anesthesiologist
      and/or the anesthesia resident in charge of intraoperative anesthesia management of the
      patients. The patient will be given actrapid insulin using the glucose sliding scale for
      diabetic patients as set by the protocol set at AUBMC (mentioned in methodology).

      The anesthesia resident will be just asked to take a blood gas sample for the patient every
      30 minutes without telling him/her about the purpose of the study, so he/she will be blinded
      and will act accordingly (including administering insulin to the patient or just monitoring
      the blood glucose levels without intervening). At the end of the surgery a copy of the blood
      gas samples and chart of the patients will be collected.

      In the Experimental group, patients will be treated using an automated protocol consisting of
      an insulin infusion pump named The Space Glucose Control System by B. Braun, in Melsungen,
      Germany. The Space Glucose Control system is a Class IIb medical device. The manufacturer, B.
      Braun, received the first CE mark in June 2004. The most recent renewal was in May 2013. At
      the bottom of this system, a central user interface is connected with a touch screen
      interface in order to enter the data. The glucose reading as measured has to be entered
      manually by the medical house staff (anesthesia resident) via the touch screen display. Based
      on this input the system gives advice on the insulin infusion rate. The suggested insulin
      infusion is displayed on the screen, but has to be entered manually and therefore confirmed
      by the medical staff.

      For glucose measurement, a sample of blood gas will be taken every half an hour. Actrapid HM
      will be used in a 4IU/ ml concentration for infusion in a 50 ml syringe.

      The range of glucose will be recorded throughout the intra-operative period. The number of
      hypoglycemic (<70mg/dl) and hyperglycemic (> 200mg/dl) events will be recorded.

      Insulin allergy in patients with diabetes mellitus is a rare condition. Signs and symptoms
      including angioedema, hypotension, urticaria and rash, if present, are usually noticed
      immediately following the injection. Patients suspected of having insulin allergy will be
      treated by stopping the infusion, administering antihistaminic H2 and H1 blockers,
      corticosteroids and pressors depending on the magnitude of the allergic reaction.

      Hypoglycemia defined as blood glucose level less than 70 mg/dl, will be detected and treated
      promptly to provide a rise in blood glucose to a safe level in order to eliminate any
      potential harm. The intervention will include intravenous infusion of 100 to 200 ml of D5
      water over 1 to 3 minutes and repeating blood glucose level after 15 minutes to reach a
      target blood sugar of 100. The same intervention will be repeated in case this level wasn't
      reached and patient will be withdrawn from the study after two failed correction and will be
      treated more aggressively with an infusion of D10W.
    

Intervention name(s): Space Glucose Control
Intervention type(s): Device
Intervention description(s): Development of a closed loop control system via Space Glucose Control that automatically infuses insulin on the basis of an automated algorithm, which integrates a continuous glucose signal, could help overcome these obstacles and permit strict glycemic control without increasing the workload.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Participant)
Primary purpose: Treatment