Suction the client's oropharynx.
Rationale: A patent airway is the priority. The client does not have the ability to deep breathe and cough. Auscultating for breath sounds takes time and delays an intervention that will maintain an open airway. Administering oxygen via nasal cannula will take time and delay an intervention that will maintain an open airway. Oxygen administration will be useless if the airway is not patent. Placing the client in the orthopneic position is unsafe for a client with Guillain-Barré syndrome. The client will be unable to maintain this position. Muscle weakness involves the lower extremities, progressing to the upper extremities and diaphragm.