Clinical Trial: Preoperative Parenteral Thiamine Supplementation in Patients Undergoing Heart Surgery

Study Status: Completed
Recruit Status: Unknown status
Study Type: Interventional

Official Title: Preoperative Parenteral Thiamine Supplementation in Patients Undergoing Heart Surgery - a Pilot Study

Brief Summary: The objective of this study is to determine whether preoperative parenteral thiamin supplementation does prevent the intra and early postoperative increase of lactate and whether this effect is related to the extent of thiamine deficiency in patients undergoing heart surgery. In addition the prevalence of major thiamin deficiency in patient undergoing heart surgery will be determined.

Detailed Summary:

Thiamine (vitamin B1) is a water-soluble vitamin and is involved in several stages of intermediate metabolism which are important for producing energy. Severe thiamin deficiency has been associated with severe lactic acidosis and clinical symptoms of life threatening heart failure.

To date, no study has evaluated thiamine levels in patients undergoing heart surgery and the prevalence of thiamine deficiency is not known. Furthermore it is unknown whether moderately reduced thiamin levels are associated with mild forms of perioperative cardiac failure necessitating prolonged inotropic support.

In this prospective double blind randomised controlled trial of the effect of a parenteral infusion of thiamin before induction of anaesthesia we will investigate the effect on perioperative lactate increase as primary outcome and extent and duration of inotropic support after cardiac surgery. In addition the pharmacokinetics of a intravenous infusion of 300 mg of thiamin on erythrocyte thiamin content and the amount of thiamine excreted in the 24 hours via the urine will be determined.

Baseline thiamin levels in erythrocytes before surgery, as well as nutrition history and body composition will be evaluated as effect modifier.


Sponsor: Medical University of Vienna

Current Primary Outcome: Thiamine status and lactate levels [ Time Frame: perioperative ]

Thiamine status: functional parameter - erythrocyte transketolase (α-ETK) expressed as TPP (thiamine pyrophosphate); quantity of vitamin B1 in urine and blood concentrations Lactate levels: lactate levels will be determined by blood gas analysis (BGA) within the routine check.


Original Primary Outcome: Same as current

Current Secondary Outcome: Prevalence of thiamine deficiency, identification of body composition and length of hospital and ICU stay [ Time Frame: 2-3 weeks ]

Thiamine status: functional parameter - erythrocyte transketolase (α-ETK) expressed as TPP (thiamine pyrophosphate); Body composition: measuring with bioelectrical impedance analysis (BIA) Length of ICU and hospital stay;


Original Secondary Outcome: Same as current

Information By: Medical University of Vienna

Dates:
Date Received: January 30, 2012
Date Started: February 2012
Date Completion: December 2013
Last Updated: May 14, 2013
Last Verified: May 2013