Incidence and Risk Factors of Pneumonia in Individuals With Acute Spinal Cord Injury: A Multi-national, Multi-center, Prospective Cohort Study

Abstract

ObjectiveTo describe the occurrence of pneumonia in individuals with acute spinal cord injury (SCI) and identify its key predictors. DesignMulti-centric, longitudinal cohort study. Setting10 specialized SCI rehabilitation units in Europe and Australia. ParticipantsEligible were 902 men and women with acute SCI, aged 18 years or older, with cervical or thoracic lesions and not dependent on 24-hour mechanical ventilation; 503 participated in the study (N=503). InterventionsNot applicable. Main Outcome MeasuresWe assessed demographics and lesion related parameters at study entry, and any pneumonia events throughout inpatient rehabilitation. Respiratory function, decubitus, and urinary tract infections were assessed at 1, 3, and 6 months post injury as well as at discharge from inpatient rehabilitation. Time to event (pneumonia) analyses were done using the Kaplan-Meier method, and potential predictors for pneumonia were analyzed with multivariable survival models. ResultsFive hundred three patients with SCI were included, with 70 experiencing at least 1 pneumonia event. 11 participants experienced 2 or more events during inpatient rehabilitation. Most events occurred very early after injury, with a median of 6 days. Pneumonia risk was associated with tetraplegia (hazard ratio [HR]=1.78; 95% confidence interval [CI] 1.00-3.17) and traumatic etiology (HR=3.75; 95% CI 1.30-10.8) American Spinal Injury Impairment Scale (AIS) A (HR=5.30; 95% CI 2.28-12.31), B (HR=4.38; 95% CI 1.77-10.83), or C (HR=4.09; 95% CI 1.71-9.81) lesions. For every 10 cmH2O increase in inspiratory muscle strength, pneumonia risk was reduced by 13% (HR=0.87; 95% CI 0.78-0.97). ConclusionPneumonia is a major complication after SCI with the highest incidence very early after injury. Individuals with traumatic or AIS A, B, or C tetraplegia are at highest risk for pneumonia.