Abstract
RATIONALE: Oxygen consumption may be impaired in critically ill patients. OBJECTIVES: To evaluate the effect of intravenous thiamine on oxygen consumption ([Formula: see text]o2) in critically ill patients. METHODS: This was a small, exploratory open-label pilot study conducted in the intensive care units at a tertiary care medical center. Critically ill adults requiring mechanical ventilation were screened for enrollment. Oxygen consumption ([Formula: see text]o2) and cardiac index (CI) were recorded continuously for 9 hours. After 3 hours of baseline data collection, 200 mg of intravenous thiamine was administered. The outcome was change in [Formula: see text]o2 after thiamine administration. MEASUREMENTS AND MAIN RESULTS: Twenty patients were enrolled and 3 were excluded because of incomplete [Formula: see text]o2 data, leaving 17 patients for analysis. There was a trend toward increase in [Formula: see text]o2 after thiamine administration (16.3 ml/min, SE 8.5; P = 0.052). After preplanned adjustment for changes in CI in case of a delivery-dependent state in some patients (with exclusion of one additional patient because of missing CI data), this became statistically significant (16.9 ml/min, SE 8.6; P = 0.047). In patients with average CI greater than our cohort's mean value of 3 L/min/m(2), [Formula: see text]o2 increased by 70.9 ml/min (±16; P < 0.0001) after thiamine. Thiamine had no effect in patients with reduced CI (< 2.4 L/min/m(2)). There was no association between initial thiamine level and change in [Formula: see text]o2 after thiamine administration. CONCLUSIONS: The administration of a single dose of thiamine was associated with a trend toward increase in [Formula: see text]o2 in critically ill patients. There was a significant increase in [Formula: see text]o2 in those patients with preserved or elevated CI. Further study is needed to better characterize the role of thiamine in oxygen extraction. Clinical trial registered with www.clinicaltrials.gov (NCT01462279).