Up to 30% of patients with Guillain–Barré syndrome require mechanical ventilation and 5% die due to acute complications of mechanical ventilation. There is a considerable group of patients that will need prolonged mechanical ventilation (considered as >14 days) and should be considered for early tracheostomy. The objective of this study is to identify risk factors for prolonged mechanical ventilation.

We prospectively analyzed patients with Guillain–Barré diagnosis with versus without prolonged mechanical ventilation. We considered clinical and electrophysiological characteristics and analyzed factors associated with prolonged mechanical ventilation.

Three hundred and three patients were included; 29% required mechanical ventilation. When comparing the groups, patients with prolonged invasive mechanical ventilation (IMV) have a lower score on the Medical Research Council score (19.5 ± 16.2 vs 27.4 ± 17.5, p = 0.03) and a higher frequency of dysautonomia (42.3% vs 19.4%, p = 0.037), as well as lower amplitudes of the distal compound muscle action potential (CMAP) of the median nerve [0.37 (RIQ 0.07–2.25) vs. 3.9 (RIQ1.2–6.4), p = <0.001] and ulnar nerve [0.37 (RIQ0.0–3.72) vs 1.5 (RIQ0.3–6.6), p = <0.001], and higher frequency of severe axonal damage in these nerves (distal CMAP ≤ 1.0 mV). Through binary logistic regression, severe axonal degeneration of the median nerve is an independent risk factor for prolonged IMV OR 4.9 (95%CI 1.1–21.5) p = 0.03, AUC of 0.774, (95%CI 0.66–0.88), p = < 0.001.

Severe median nerve damage is an independent risk factor for prolonged mechanical ventilation.