Plasma exchange for Guillain-Barré syndrome.

BACKGROUND: Guillain-Barré syndrome is an acute symmetric, usually ascending and usually paralysing illness, due to inflammation of peripheral nerves. It is thought to be caused by autoimmune factors, such as antibodies. Plasma exchange removes antibodies and other potentially injurious factors from the blood stream. It involves connecting the patient's blood circulation to a machine which exchanges the plasma for a substitute solution, usually albumin. Several studies have evaluated plasma exchange for Guillain-Barré syndrome.
OBJECTIVES: To systematically review the evidence concerning the efficacy of plasma exchange for treating Guillain-Barré syndrome. SEARCH STRATEGY: Search of the Cochrane Neuromuscular Disease Trial Register for randomised trials concerning plasma exchange in Guillain-Barré syndrome, search of the bibliographies of identified papers and enquiry from the authors of the papers. SELECTION CRITERIA: Randomised and quasi-randomised trials of plasma exchange versus sham exchange or supportive treatment. DATA COLLECTION AND ANALYSIS: Potentially relevant papers were scrutinised by two reviewers and the selection of eligible studies was agreed by them and a third reviewer. Data were extracted by one reviewer and checked by a second reviewer. Some missing data were obtained from the authors of studies. MAIN
RESULTS: Six eligible trials concerning 649 patients were identified, all comparing plasma exchange versus supportive treatment alone. Primary outcome measures ~bullet~Time to recover walking with aid In the only two trials for which this measure was reported, the median time to recover this ability was faster in the plasma exchange than the control group. ~bullet~Time to onset of motor recovery in mildly affected patients In the one trial for which this measure was available, the time was significantly shortened in the plasma exchange group. Secondary outcome measures ~bullet~Improvement in disability grade at four weeks In five trials, there were significantly more patients who had improved by one disability grade or more in the plasma exchange group as compared to the control group. Patients treated with plasma exchange fared significantly better in the following secondary outcome measures: time to recover walking without aid, percentage of patients requiring artificial ventilation, duration of ventilation, full muscle strength recovery after one year, and severe sequelae after one year. There were less patients with infectious events and cardiac arrhythmias in the plasma exchange than the control group. Subgroup analyses Plasma exchange was beneficial in patients with mild, moderate and severe (needing ventilation) Guillain-Barré syndrome. It was beneficial in patients with a disease duration of seven or less days and also in those with disease lasting more than seven days. However, in the only trial that enrolled patients up to 30 days from disease onset, the benefit of plasma exchange in patients treated after seven days was less apparent. Type of treatment Single studies showed that two plasma exchanges were significantly superior to none for mild Guillain-Barré syndrome and four to two for moderate Guillain-Barré syndrome, but that six were not superior to four for severe Guillain-Barré syndrome requiring ventilation. One study suggested that continuous flow plasma exchange was significantly superior to intermittent flow. Another study found no significant difference between the two techniques. The same study found a significantly higher rate of adverse events with fresh frozen plasma as the replacement fluid than albumin. Plasma exchange compared with cerebrospinal fluid filtration A single trial comparing these two treatments did not show any difference in outcomes but was too small to demonstrate equivalence. REVIEWER'S
CONCLUSIONS: Plasma exchange is the first and only treatment that has been proven to be superior to supportive treatment alone in Guillain-Barré syndrome. Consequently, plasma exchange should be regarded as the treatment against which new treatments, such as intravenous immunoglobulin, should be judged. In mild Guillain-Barré syndrome two sessions of plasma exchange are superior to none. In moderate Guillain-Barré syndrome four sessions are superior to two. In severe Guillain-Barré syndrome six sessions are no better than four. Continuous flow plasma exchange machines may be superior to intermittent flow machines and albumin to fresh frozen plasma as the exchange fluid. Plasma exchange is more beneficial when started within seven days after disease onset rather than later, but was still beneficial in patients treated up to 30 days after disease onset. The value of plasma exchange in children less than 12 years old is not known. There is insufficient evidence to determine whether cerebrospinal fluid filtration is equivalent to plasma exchange.