The Effect of Thiamine vs. Placebo on VO2 in Critical Illness (TVO2_RCT)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01985685
Recruitment Status : Completed
First Posted : November 15, 2013
Results First Posted : October 2, 2017
Last Update Posted : October 2, 2017
Information provided by (Responsible Party):
Katherine Berg, Beth Israel Deaconess Medical Center

Brief Summary:
The objective of this study is to determine the effect of thiamine therapy on oxygen consumption (VO2) in critically-ill patients. We will evaluate this by measuring VO2 before and after thiamine or placebo administration in patients admitted to the ICU and requiring mechanical ventilation. A secondary aim is to evaluate the effect of thiamine vs. placebo on the metabolic profile of the patients.

Condition or disease Intervention/treatment Phase
Critically Ill Respiratory Failure Drug: Thiamine Phase 2

Detailed Description:

Extensive research has been done over the past two decades looking at the role of oxygen delivery (DO2) and oxygen utilization (VO2) in critical illness. VO2 depends on cardiac output, arterial oxygen content, and the body's ability to extract oxygen effectively from the blood. Oxygen demand rises in critical illness as the body goes into a catabolic state, and lower VO2 has been associated with higher lactate levels and with poorer outcomes. Although increasing DO2 was shown in past studies to raise VO2 in some patients, other investigators have found that many critically-ill patients failed to demonstrate a rise in VO2 in spite of achieving supranormal values of cardiac index (CI) and DO2. This group, in contrast to patients whose VO2 rose with the increase in CI and DO2, had exceedingly poor outcomes, suggesting that an inability to extract oxygen from the blood confers a poorer prognosis.

Thiamine deficiency can manifest in several ways, but the syndrome of wet beriberi, caused by thiamine deficiency, includes lactic acidosis, cardiac decompensation and vasodilatory shock, similar to sepsis and other forms of critical illness. The mechanism by which thiamine deficiency causes dysfunction rests upon the vitamin's essential role in the Krebs cycle and Pentose Phosphate Pathway. Lack of adequate thiamine results in the failure of pyruvate to enter the Krebs Cycle, thus preventing aerobic metabolism. The resulting decrease in aerobic metabolism and increase in anaerobic metabolism leads to decreased oxygen consumption by the tissues and increased lactic acid production.

Our group has found previously that upwards of 20% of critically ill patients with sepsis are thiamine deficient within 72 hours of presentation. In a dog model of septic shock, Lindenbaum et al have shown that, regardless of thiamine levels, supplementation with thiamine improved not only lactate clearance and mean arterial pressure, but increased VO2 as well. An increase in VO2 max after administration of thiamine to healthy volunteers has also been described. In our prior open-label study, we found that the administration of a single dose of 200mg of intravenous thiamine to critically ill patients led to a statistically significant increase in VO2 in those with normal or elevated cardiac output, suggesting that thiamine may increase the extraction component of VO2, even in the absence of absolute thiamine deficiency. This effect was not seen in patients with low cardiac output.

VO2 is known to rise in inflammatory states, reflecting increased energy expenditure. Prior studies have shown that VO2 will decrease with interventions such as fever control. In spite of VO2 being higher than normal in critically-ill patients, however, the end-organ damage and lactic acidosis suggest that it is not high enough to meet the metabolic demands of the critically-ill body. If we are able to increase VO2 further in critically-ill patients, we could potentially help maintain aerobic metabolism and decrease tissue hypoxia and the resulting end-organ damage. Our hypothesis is that administering thiamine intravenously to critically-ill patients who do not have abnormally low cardiac index will increase VO2.

We will use an anesthesia monitor with a gas exchange module to measure VO2 continuously over a 9 hour period. After 3 hours of baseline VO2 data are collected, baseline thiamine level, lactate, and central venous O2 saturation will be obtained. A single dose of 200mg of IV thiamine will then be given, and 6 hours of post-thiamine data will then be collected. We will screen all consenting patients for whom we do not know the cardiac index with a non-invasive cardiac index measurement using the Cheetah non-invasive cardiac output monitor (NICOM). We will not include patients with a cardiac index less than or equal to 2.4L/min/m2, due to our preliminary data showing these patients did not increase VO2 in response to thiamine. All patients enrolled will have cardiac index monitored continuously during the study by the NICOM, in order to assess whether or not there is any relationship between VO2 and cardiac index. Patients will also have blood drawn for a metabolomic panel before and after thiamine or placebo to assess whether thiamine has an effect on the metabolome.

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 66 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: The Effect of Thiamine vs. Placebo on VO2 in Critical Illness
Study Start Date : October 2013
Actual Primary Completion Date : May 2016
Actual Study Completion Date : December 2016

Resource links provided by the National Library of Medicine

U.S. FDA Resources

Arm Intervention/treatment
Experimental: Thiamine
200mg intravenous thiamine in 50ml 5% dextrose, single dose
Drug: Thiamine
200 mg IV thiamine
Placebo Comparator: Placebo
50ml intravenous 5% dextrose, single dose
Drug: Thiamine
200 mg IV thiamine

Primary Outcome Measures :
  1. Change in VO2 Over Time [ Time Frame: 6 hrs ]
    The primary outcome will be the change in VO2 over the 6 hours after administration of the study medication, adjusted for baseline VO2.

Secondary Outcome Measures :
  1. Percentage Change in Serum Lactate [ Time Frame: 6 hrs ]
    Percentage change in serum lactate

  2. Change in Central Venous Oxygen Saturation [ Time Frame: 6 hrs ]
    Change in central venous oxygen saturation

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  1. Adult patients (age > 18 yrs) admitted to an ICU
  2. Mechanically ventilated for an acute illness, with stable respiratory status (no changes in ventilator settings in the 3 hours prior to enrollment)
  3. Cardiac index >2.4L/min/m2 as measured by Noninvasive Cardiac Output Monitor(NICOM) by Cheetah Medical or, if being used clinically, by PA catheter or Vigileo device.
  4. Upper central venous line in place

Exclusion Criteria:

  1. Unstable ventilator settings during measurement of VO2
  2. Temperature >100.5
  3. FIO2>60%
  4. Endotracheal cuff leak, chest tube, or other evident source of air leak
  5. Positive end expiratory pressure > 12cmH2O
  6. Intravenous thiamine supplementation within 2 weeks of enrollment, or oral supplementation more than that found in a multivitamin.
  7. Protected populations (pregnant woman, prisoners, cognitively impaired)

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT01985685

United States, Massachusetts
Beth Israel Deaconess Medical Center
Boston, Massachusetts, United States, 02215
Sponsors and Collaborators
Beth Israel Deaconess Medical Center
Principal Investigator: Katherine Berg, MD Beth Israel Deaconess Medical Center

Responsible Party: Katherine Berg, Assistant Professor of Medicine, Beth Israel Deaconess Medical Center Identifier: NCT01985685     History of Changes
Other Study ID Numbers: 2013P000240
First Posted: November 15, 2013    Key Record Dates
Results First Posted: October 2, 2017
Last Update Posted: October 2, 2017
Last Verified: September 2017
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: Undecided

Keywords provided by Katherine Berg, Beth Israel Deaconess Medical Center:
VO2, critically ill, oxygen consumption

Additional relevant MeSH terms:
Critical Illness
Respiratory Insufficiency
Disease Attributes
Pathologic Processes
Respiration Disorders
Respiratory Tract Diseases
Vitamin B Complex
Growth Substances
Physiological Effects of Drugs