Failure to effectively clear the tracheobronchial airways and the need for prolonged mechanical ventilation are the usual indications for tracheostomy. In most cases, this procedure can be postponed until the third week of intubation. However, patients who become rapidly quadriplegic and ventilator-dependent benefit from tracheostomy earlier. Once tracheostomy is performed, careful tracheal toilet and treatment of pulmonary and urinary tract infections by the use of appropriate antibiotics are required; prophylactic antibiotic treatment is not recommended. With tracheostomy and intensive care, the mortality from the disease can be reduced to approximately 3 percent (Ropper and Kehne; see further on under “Prognosis”).
The decisions to wean and then discontinue respiratory aid and to remove the endotracheal or tracheostomy tube are based on the degree and timing of recovery of respiratory function. The weaning process generally begins when the vital capacity reaches approximately 10 mL/kg and comfortable breathing can be sustained for a few minutes. The relative merits of the numerous methods of delivering positive-pressure volume-cycled ventilation and its gradual withdrawal are not covered here, but there is little to favor one over the other and the reader is referred to the monograph Neurological and Neurosurgical Intensive Care by Ropper and colleagues.
Physical therapy (passive movement and positioning of limbs to prevent pressure palsies and, later, mild resistance exercises) can begin once they can be comfortably undertaken.
Plasma exchange and immune globulin Specific treatment of the presumed immune disorder that underlies GBS includes plasma exchange and IVIg. Our practice has been to observe patients who are still able to walk unaided rather than institute treatment immediately. If the patient becomes unable to walk, shows a reduction in vital capacity, or signs of oropharyngeal weakness, plasma exchange or IVIg is instituted promptly. This typically occurs at the fifth to tenth day after the appearance of the first symptoms, but may be as early as 1 day or as late as 3 weeks.
Three large randomized trials comprising more than 500 patients have established the efficacy of plasma exchange administered during the evolving phase of GBS. In patients who are treated within 2 weeks of onset, there is an approximate halving of the period of hospitalization, of the duration of mechanical ventilation, and of the time required to achieve independent ambulation. However, in the largest trial, if the first plasma exchange was delayed for 2 weeks or longer after the onset of the disease, the procedure was of little value. Nonetheless, if a patient continues to progress in the third or fourth week of illness, it is probably still appropriate to institute the exchanges. The most important predictors of responsiveness to plasma exchange treatment are the same as for the overall prognosis, namely the patient’s age (responders are younger) and the preservation of motor compound muscle action potential amplitudes prior to instituting treatment (McKhann et al). One study has found that the condition of patients was better at 6 and 12 months after treatment as compared to untreated patients; other studies have been equivocal on this point and demonstrated mainly accelerated improvement.