Heparin was associated with lower mortality when the model was adjusted for age and gender, with OR (95% CI) 0.55 (0.37–0.82) p = 0.003. This association remain significant when saturation of oxygen < 90%, and temperature > 37 °C were added to de model with OR 0.54 (0.36–0.82) p = 0.003, and also when all the other drugs were included as covariates OR 0.42 (0.26–0.66) p < 0.001.