Objective: To assess the relationship between plasma cortisol level and Guillain-Barré syndrome-related complications, notably respiratory failure. One third of patients with Guillain-Barré syndrome develop respiratory failure, which is predicted by few early indicators. Adrenal function has rarely been studied in Guillain-Barré syndrome.
Design: Prospective study.
Setting: Intensive care unit in a teaching hospital.
Patients: Patients with Guillain-Barré syndrome referred to our unit (n = 102).
Interventions: Plasma cortisol levels were measured before baseline and 60 mins after corticotrophin test in 93 patients with Guillain-Barré syndrome at admission, 16 (17%) of whom were ventilated within 24 hrs from admission, 17 (18%) ventilated after the 24th hr and 60 (65%) never ventilated.
Measurements and main results: Mean plasma cortisol levels at baseline and 60 mins after corticotrophin test were 22.9 +/- 11.3 ng/mL and 45.4 +/- 16.1 ng/mL. At baseline, the plasma cortisol levels were significantly higher in 17 (18%) patients, who developed respiratory failure at least 24 hrs later (28.5 +/- 12.1 ng/mL vs. 20.4 +/- 9.6 ng/mL; p = .003) and dysautonomia (33.1 +/- 14.3 ng/mL vs. 21.4 +/- 10.2 ng/mL, p = .003). When adjusting on only validated clinical predictors (i.e., delay between onset and admission <7 days, inability to lift head and vital capacity <60%), baseline cortisol level was the only independent risk factor for respiratory failure (odds ratio: 2.45 per 10 ng/mL [1.23-4.88 ng/mL], p = .01). Fifty-nine patients underwent electrophysiological testing. When adjusting on a validated electrophysiological model (i.e., peroneal proximal/distal compound muscle action potential ratio and vital capacity), baseline cortisol level remained an independent predictor (odds ratio: 2.50 per 10 ng/mL [1.14-5.51 ng/mL], p = .02).
Conclusion: Measurement of baseline plasma cortisol levels can be helpful for early detection of patients with Guillain-Barré syndrome at risk for respiratory failure at least 24 hrs later.