Evaluation of Thiamine as Adjunctive Therapy in COVID-19 Critically Ill Patients

A Two-Center Propensity Score Matched Study

Khalid Al Sulaiman; Ohoud Aljuhani; Maram Al Dossari; Asma Alshahrani; Aisha Alharbi; Rahmah Algarni; Majed Al Jeraisy; Shmeylan Al Harbi; Abdulmalik Al Katheri; Fahad Al Eidan; Abdulkareem M. Al Bekairy; Nouf Al Qahtani; Mashael Al Muqrin; Ramesh Vishwakarma; Ghassan Al Ghamdi


Crit Care. 2021;25(223) 

In This Article


A total of 738 critically ill patients with COVID-19 admitted to ICUs at the two governmental hospitals were included in the study. Thiamine was given to 88 patients, whereas 650 patients did not receive thiamine. A total of 166 patients were included after propensity score matching had been conducted using baseline severity scores, systemic use of corticosteroids and study centers. The median (Q1, Q3) dose of thiamine given per day was 100 mg (50, 200) with a median duration of seven days. The majority of patients received thiamine by intravenous administration (57%).

Demographic and Clinical Characteristics

Among critically ill patients admitted to ICUs, the patients' average age was 60 years (± 15). A total of 531 (72%) patients were male (Table 1, Additional file 1). Diabetes mellitus (61%) was the most common coexisting illness, followed by hypertension (56.8%) and dyslipidemia (23.2%). Coexisting illness between the two groups was not statistically significant (Table 2, Additional file 2).

The baseline severity scores (i.e., APACHE II, SOFA and NUTRIC scores), mechanical ventilation (MV) needs within 24 h of ICU admission, and laboratory tests (i.e., INR, Fibrinogen, CRP, Ferritin, HCT, pH) were significantly higher among patients who did not receive thiamine during ICU stay. On the other hand, systematic corticosteroids use during ICU stay, and phosphorus levels were higher in the thiamine group. However, after conducting propensity score matching, most of these baseline and demographic characteristics were similar between the two groups (Table 1, Additional file 1).

Study Outcomes

There were fifteen patients (18.1%) who died during ICU stay among the thiamine group, compared with thirty patients (36.1%) in the other group. In other words, patients who received thiamine as adjunctive therapy during ICU stay had a lower 30-day mortality rate by 63% [OR (95% CI): 0.37 (0.18, 0.78), P value = 0.009] (Table 1). Additionally, thiamine use was associated significantly with a lower in-hospital mortality rate by 61% [OR (95% CI): 0.39 (0.19,0.78), P value = 0.008]. The overall survival probabilities were higher during hospital stay among patients who received thiamine before and after propensity score-matched (Figure 1a, b).

Figure 1.

a Overall survival plot during the hospital stay comparing patients who received thiamine (88 patients) as adjunctive therapy versus the control group (650 patients)—before PS matching. b Overall survival plot during the hospital stay comparing patients who received thiamine (83 patients) as adjunctive therapy versus the control group (83 patients)—after PS matching

The duration of mechanical ventilation (Beta estimate − 0.13 CI − 0.54, 0.27; P value = 0.51), ICU length of stay (LOS) (Beta estimate 0.11 CI − 0.19, 0.39; P value = 0.48) and hospital LOS (Beta estimate 0.08 CI − 0.17, 0.33; P value = 0.52) did not differ significantly in patients who received thiamine as adjunctive therapy compared to patients who did not (Table 1).

Complications During ICU Stay

Critically ill patients who received thiamine as an adjunctive therapy were less likely to have thrombosis during ICU stay by 81% [OR (95% CI) 0.19 (0.04, 0.88), P value = 0.03] (Table 2). Moreover, acute kidney injury [OR (95% CI) 0.91 (0.49, 1.68)] and liver Injury [OR (95% CI) 0.93 (0.30, 2.87)] were lower in the thiamine group by 9% and 7%, respectively. However, the differences were not statistically significant (Table 2).