Cough in spinal cord injured patients: the relationship between motor level and peak expiratory flow

Pulmonary complications remain a major cause of morbidity and mortality in patients with higher level spinal cord injury. Neurologically intact individuals can cough in order to clear their air passage of lung secretions and foreign material. Patients with higher level cord injuries, with paralysis of the trunk and abdominal muscles, may not have the ability to generate an effective cough. If coughing is dependent on a caregiver, these patients will cough with reduced frequency. Because the innervation to the muscles involved in cough consists of nerves that arise from varying levels of the spinal cord, some patients with spinal cord injury have partial control over these muscles and thus can cough, though with reduced efficacy. Two hundred patients with varying levels of spinal cord injury were studied to determine if motor level and cough ability are correlated. Cough efficacy was measured using a peak expiratory flowmeter while patients were seated at 90 degrees. We concluded that there is indeed a direct relationship between motor level and peak expiratory flow produced during coughing.