To evaluate the efficacy of the change in IVIG dosing strategy. 

Intravenous immunoglobulin (IVIG) is commonly used for high priority, high acuity neurologic indications requiring hospitalization, such as MG, GBS and CIDP. Randomized controlled trials of effectiveness of IVIG in these neurologic indications called for varying dosing strategies based on actual body weight. However, in the past decade, due to the increasing cost of intravenous immunoglobulin, many hospitals and institutions have begun to use ideal body weight or adjusted body weight for intravenous immunoglobulin dosing.  This change in dosing strategy has led to a reduction of IVIG use by an estimated 20%.  The reasoning behind this change in dosing includes the pharmacokinetics of IVIG. IVIG distributes in the intravascular and extravascular fluid with minimal distribution in lipophilic material.  Additionally, change in serum IgG levels collected prior to and after IVIG had the strongest correlation to ideal body weight. 

This is an IRB approved, retrospective chart review of all patients hospitalized at Memorial Hermann Hospital Texas Medical Center who received IVIG for the indications of myasthenia gravis, GBS or CIDP from 2010-2017. 

A total of 65 patients were analyzed according to total IVIG dose given and dosing strategy (actual vs. adjusted vs. ideal body weight), dose reduction, pre- and post-IVIG treatment medical research council (MRC) score evaluating muscle strength, adverse effects, second rescue treatment (if needed), and discharge disposition

There was a higher rate of readmission for additional treatment in patients in which ideal body weight was used. IVIG dosing differences did not impact length of hospital stay, and there were no mortality events in this patient sample. MRC score evaluating pre- and post-treatment muscle strength was an important factor associated with length of stay and discharge disposition. Weaker patients on inpatient admission required longer hospital stays and rehabilitation at discharge.