Bronchodilatory effects of ipratropium bromide in patients with tetraplegia

Airway hyperresponsiveness was recently described in patients with chronic cervical spinal cord injury (tetraplegia). The response was attributed to unopposed cholinergic broncho- constrictor activity due to loss of sympathetic innervation of the airway. To determine if the administration of a cholinergic antagonist alters resting airway tone in these patients, ipratropium bromide (72 f.ig) was administered by aerosol to 25 tetraplegic patients. We found that 12 of 25 patients (48%) had significant improvement (defined as ≥12%) in forced expired volume in 1 s (FEV)) and/or forced vital capacity (FVC). A significant correlation between airway responsiveness and complaints of dyspnea at rest, completeness of injury (sensory), or smoking history was not found. These findings of improved airflow after the use of an anticholinergic bronchodilator agent provides further evidence that transection of the cervical cord results in unopposed parasympathetic activity and a resultant increase in resting airway tone.