The Effect of Plasmapheresis on Respiratory Muscle Strength in Patients with Guillain-Barré Syndrome

Abstract

STUDY OBJECTIVES: To evaluate the effect of plasmapheresis on respiratory muscle function in patients with Guillain-Barré Syndrome (GBS). DESIGN: A prospective study. SETTING: A university hospital. PATIENTS: Fifteen consecutive patients with GBS. MEASUREMENTS: Vital capacity (VC) and negative inspiratory force (NIF) immediately prior to and 6, 12, and 24 hours after each plasmapheresis treatment. RESULTS: For each plasmapheresis session, there was no significant difference (p > 0.1) between the baseline (preplasmapheresis) and any of the 6-, 12-, or 24-hour postplasmapheresis VC measurements. When serial baseline measurements of VC were compared, there were significant differences between the baseline value (standard deviation, SD) for Session 1 [1.61 (0.95) L] and baseline values (SD) for Session 4 [1.89 (1.1) L, p < 0.05], Session 5 [1.88 (1.1) L, p < 0.01], and Session 6 [1.89 (1.2) L, p < 0.01]. As with the VC, the baseline NIF did not differ significantly from the acute postplasmapheresis values for any session. When the serial baseline NIF measurements were compared, the only significant difference (p < 0.05) was between Session 1 [46.8 (24.7) cm] and Session 5 [57.5 (23.9) cm]. CONCLUSION: While each individual plasmapheresis has no immediate effect upon respiratory muscle strength (RMS) in patients with GBS, there does appear to be a cumulative beneficial effect with improvement in RMS apparent by the start of the fourth session. However without a randomized controlled trial, spontaneous improvement cannot be excluded as the cause for the changes observed over time.