Anesthetic for Guillain-Barré Syndrome – Do we need neuromuscular blocking agents? A case report
Background: Guillain-Barré (GB) syndrome is a challenge for the anesthesiologist. Our purpose is to report and discuss the anesthesia of a GB patient for major orthopedic surgery, managed without neuromuscular blocking agents.
Case report: Male, 43 years old, ASA II, proposed for a total hip replacement. History of complete paralysis caused by GB 4 years ago with partial recovery after therapy. On admission, moderate muscular weakness without apparent respiratory compromise. We induced anesthesia with fentanyl 100μg and propofol 200mg and we inserted an orotracheal tube without difficulties. During surgery we administerd desflurane 4.1 to 6.0% endtidal,  fentanyl 200μg, paracetamol 1g and parecoxib 40mg. Surgery lasted for 2 hours and was accomplished uneventfully. Patient was hemodynamically stable (Fig 1) and the tracheal tube was removed at the end of the surgery without complications.
Discussion: Our case shows that GB patients can be successfully submitted to major orthopedic surgery under general anesthesia without any neuromuscular blocker. Previous reports of anesthesia in GB, published by others, stressed three points: first, the potential of neuroaxis anesthesia to worsen the disease; second, the risks of hyperkalemia and cardiac arrest with succinylcholine, third, the increased sensivity of these patients to non-depolarizing drugs [1-2]. As neuromuscular blockers are not absolutely precluded, a point that is usually missed is why patients with muscular weakness need relaxants. As far as we know, in an evidence based anesthesia, we do not find any support to use relaxants in GB and our case also suggested its futility in patients with muscular weakness. In consequence we recommend its use only as rescue in cases where muscular function is enough to produce difficult surgical conditions. 
References: 1. Regional anesthesia in the patient with preexisting neurologic disorders. Adv Anesth 2011 2. Succinylcholine-induced Hyperkalemia in Acquired Pathologic states: Etiologic Factors and Molecular Mechanisms. The Journal of the American Society of Anesthesiologists.
Learning points: In GB patients, depolarizing drugs have the risk of hyperkalemia and non-depolarizing drugs the risk of prolonged blockage and post-operative ventilatory support. What evidence supports the need of neuromuscular blockers during general anesthesia for GB? Our case suggests that we do not need neuromuscular blockers to anaesthetize GB patients with muscular weakness.

Anaesthesia for Guillain-Barré Syndrome - do we need neuromuscular blocking agents? A case report