Neuromuscular respiratory failure in Guillain-Barre Syndrome: evaluation of clinical and electrodiagnostic predictors.

UNLABELLED Guillain-Barre Syndrome (GBS) has an unpredictable clinical course with up to 30% of patients requiring assisted ventilation during the course of their illness. Successful management mandates anticipation, prompt recognition and optimal treatment of neuromuscular respiratory failure in GBS. AIMS To identify clinical and electrodiagnostic predictors of neuromuscular respiratory paralysis in GBS. MATERIALS AND METHODS Forty six patients of GBS were studied over a 6 year period, the study being 2 year retrospective and 4 year prospective. Clinical and electrodiagnostic data were compared between ventilated (28) and non-ventilated (18) patients. The clinical parameters assessed were median age, gender, antecedent infection, prior lung disease, time to peak disability, bifacial weakness, upper limb weakness, bulbar paralysis, neck weakness and autonomic dysfunction. Electrodiagnostic studies included motor nerve conduction studies in 11 ventilated and 13 non-ventilated patients, done prior to maximum disability in each group. Multiple logistic regression analysis was used to compare the two groups. RESULTS Comparing the clinical data in the ventilated and non-ventilated groups, 'early peak disability', autonomic dysfunction and bulbar weakness predicted the onset of respiratory paralysis. Age, gender, neck or bifacial weakness, upper limb paralysis, or preceding infection did not influence the development of neuromuscular respiratory weakness. Electrodiagnostic testing revealed abnormal H reflex and F waves to be the commonest abnormality in either group. Although data was not sufficient for statistical analysis, the presence of markedly attenuated Compound Muscle Action Potentials inexcitable motor nerves and denervation changes on the electromyography, was commoner in the ventilated group. Thirty six patients received treatment with either plasmapheresis (12) or intravenous immunoglobulin (24). Overall mortality was 5, all 5 patients being on assisted ventilation. CONCLUSION Early progression to peak disability, bulbar dysfunction and autonomic instability predicted the development of neuromuscular respiratory paralysis in GBS. Early electrodiagnostic studies in this series suggest axonopathic GBS as a predictor of respiratory paralysis, a finding that needs to be evaluated with sufficient data to permit statistical analysis.