RECOVER-AUTONOMIC: Platform Protocol, Appendix A (IVIG)

Participants will receive IVIG for 9 months (36 weeks) with a follow-up period for an additional 3 months (total study duration for 12 months).

"Normal saline given intravenously will be the control (placebo) product. Blinding IV bag and tubing covers will be used for both IVIG and Placebo.~Participants will receive placebo for 9 months (36 weeks) with a follow-up period for an additional 3 months (total study duration for 12 months)."

Participants will receive coordinated non-pharmacologic care for a duration of 3 months, concurrent with IVIG administration. Coordinated non-pharmacologic care involves volume expansion through high salt diet, water intake, abdominal binder, exercise/rehabilitation, motivation, education, and assisted care through care coordinator.

Participants will receive usual non-pharmacologic care (control) for a duration of 3 months, concurrent with IVIG administration.