A patient is having persistent methaemoglobinaemia after nitrobenzene poisoning, 10 days old. The patient right now is on ventilatory support due low sp02 levels and dyspnea. Gave 3 doses of 100mg methylene blue infusions along with ascorbic acid.

Any guidelines for dosage methylene blue infusions for persistent methaemoglobinaemia after nitrobenzene poisoning? Give your suggestion please.