Thiamine Administration and Prevalence of Delirium in the Intensive Care Unit: A Before-after Study
Condition: Delirium
MeSH terms: Delirium
Study type: Observational

Summary: 
      Delirium is a very common condition among ICU-admitted patients, and its prevalence is
      estimated between 30-40%. Delirium is associated with increased morbidity and mortality and
      future cognitive decline, along with increased ventilation-dependency and other
      complications.

      There are multiple risk factors for delirium, including deficiencies of micronutrients.
      Thiamine deficiency is associated with specific neurological syndromes, including Wernicke
      and Korsakoff syndromes and Delirium Tremens. Several studies demonstrated significant
      thiamine deficiency among ICU-admitted patients (prevalence of 30-70%) without known risk
      factors, such as alcohol dependency. Thiamine deficiency may cause delirium in those
      patients.

      Intravenous thiamine had been safely used for decades, for several indications. Lately,
      thiamine has been advocated for therapy in patients with septic shock, and its use in
      intensive care units has increased worldwide.

      Since 2016, thiamine has been routinely administered in our intensive care unit. Considering
      the theoretical association between thiamine deficiency and ICU-related delirium, the
      investigators aim to investigate whether the routine use of thiamine has been associated with
      decreased prevalence of delirium among ICU patients when compared to the pre-routine thiamine
      administration era.
    

Detailed description: 
      Delirium is a very common condition among ICU-admitted patients, and its prevalence is
      estimated between 30-40%. Delirium is associated with increased morbidity and mortality and
      future cognitive decline, along with increased ventilation-dependency and other
      complications.

      There are multiple risk factors for delirium, including deficiencies of micronutrients.
      Thiamine deficiency is associated with specific neurological syndromes, including Wernicke
      and Korsakoff syndromes and Delirium Tremens. Several studies demonstrated significant
      thiamine deficiency among ICU-admitted patients (prevalence of 30-70%) without known risk
      factors, such as alcohol dependency. Thiamine deficiency may cause delirium in those
      patients.

      Intravenous thiamine had been safely used for decades, for several indications. Lately,
      thiamine has been advocated for therapy in patients with septic shock, and its use in
      intensive care units has increased worldwide.

      Since 2016, thiamine has been routinely administered in our intensive care unit. Considering
      the theoretical association between thiamine deficiency and ICU-related delirium, the
      investigators aim to investigate whether the routine use of thiamine has been associated with
      decreased prevalence of delirium among ICU patients when compared to the pre-routine thiamine
      administration era.

      Primary endpoint: Average delirium score during ICU-hospitalization before and after the
      routine intravenous thiamine administration.

      Secondary endpoints: ICU and hospital admission times, duration of ventilation, need for
      tracheostomy, need for anti-delirium therapy and 28-day mortality.

      Study design: Retrospective before-after interventional study. Inclusion criteria: All
      patients, aged 18-99, admitted to the intensive care unit in our medical facility between the
      years 2014-2018 (two years before and after intervention).

      Exclusion criteria: Patients who were treated with thiamine prior to ICU admission, and
      patients who did not receive thiamine in the ICU.

      Data collection: Data will be collected from the patients' electronic management file (iMD
      soft, Ofek and Chameleon software). Data collection will be anonymous.

      Data: Age, gender, ICU and hospital admission times, duration of ventilation, 28-day
      mortality, need for tracheostomy. Need for anti-delirium therapy, cause for ICU admission,
      medical history, regular medication therapy, APACHE-2 score, SOFA score, lactate levels, need
      for inotropic or vasopressor support, need for physical restraints, need for renal
      replacement therapy, use of medication which may increase risk for delirium, RASS score.

      Cohort size: 1000 patients overall, 500 in each study group (before and after intervention).
    

Intervention name(s): intravenous Thiamine
Intervention type(s): Drug
Intervention description(s): patients who received Thiamine,100-500 mg/day for at least one day
Intervention MeSH terms: Thiamine
Observational model: Case-Control
Time perspective: Retrospective
Sampling method: Non-Probability Sample
Study population: 
        All patients, aged 18-99, admitted to the intensive care unit in our medical facility
        between the years 2014-2018 (two years before and after intervention).