Clinical Trial: Intraoperative Cell Salvage and Postoperative Acidosis

Study Status: Not yet recruiting
Recruit Status: Not yet recruiting
Study Type: Observational

Official Title: The Contribution of Intraoperative Mechanical Red Cell Salvage to Acidosis in the Immediate Postoperative Period After Cardiac Surgery

Brief Summary:

Metabolic acidosis is a common complication that patients experience in the early postoperative period following cardiac surgery. Increasingly, the composition and volume of intravenous fluids administered during surgery have been implicated in the development of postoperative acidosis. Intraoperative Cell Salvage (ICS), an autologous blood transfusion technique employed by Cardiac/Perfusion Units to minimize blood loss during surgery, involves the infusion of of one such fluid, 0.9% sodium chloride. The rapid infusion of large volumes of 0.9% sodium chloride has previously been linked with the development of hyperchloraemic acidosis. We hypothesize that the volume of mechanically salvaged of red blood cells re-infused into patients undergoing heart surgery contributes to the acidosis that occurs in the early postoperative period.

To test this, we have designed an observational cohort study to check for correlation between the volume of cell salvaged blood infused during surgery and the severity of postoperative acidosis (which will be assessed using data from routine arterial blood gas samples).

Detailed Summary:
Sponsor: University of Edinburgh

Current Primary Outcome: plasma hydrogen ion concentration [ Time Frame: at the start of surgery (before fluid infusion) and immediately after surgery (after fluid infusion) ]

Original Primary Outcome: Same as current

Current Secondary Outcome:

• plasma chloride concentration [ Time Frame: at the start of surgery (before fluid infusion) and immediately after surgery (after fluid infusion) ]

  Plasma chloride concentration is measured by the arterial blood gas analyzer machine.

  Data from two routine blood gas samples are of interest:

  T1 - baseline measurement taken on insertion of an arterial line immediately after the induction of anaesthesia (i.e. before any fluid infusion has commenced); T2 - postoperative measurement made immediately after patient arrives in ICU (i.e. once all the cell salvaged blood has been transfused)

• plasma strong ion difference [ Time Frame: at the start of surgery (before fluid infusion) and immediately after surgery (after fluid infusion) ]

  Plasma strong ion difference can be computed from routine arterial blood gas electrolyte measurements (chloride, lactate, sodium, potassium) using a formula.

  Strong ion difference serves as an indirect measure of plasma acidity.

  Data from two routine blood gas samples are of interest:

  T1 - baseline measurement taken on insertion of an arterial line immediately after the induction of anaesthesia (i.e. before any fluid infusion has commenced); T2 - postoperative measurement made immediately after patient arrives in ICU (i.e. once all the cell salvaged blood has been transfused)

Original Secondary Outcome: Same as current

Information By: University of Edinburgh

Dates:
Date Received: June 10, 2016
Date Started: July 2016
Date Completion: August 2016
Last Updated: June 10, 2016
Last Verified: June 2016