A 52-year-old man from Delhi presents to the emergency department with acute onset flaccid paralysis of both lower limbs and loss of sensation below the T10 dermatome following a road traffic accident with spinal trauma. His vital signs are stable. Neurological examination reveals absent deep tendon reflexes and sphincter involvement. An MRI spine shows a complete transection of the spinal cord at the T10 level. The patient's muscle membrane potential is measured at −60 mV (normal: −70 to −90 mV). Which is the most appropriate immediate next step in management?