Maximum Inspiratory Pressure is a Discriminator of Pneumonia in Individuals With Spinal-Cord Injury.

BACKGROUND Respiratory complications remain a major cause of mortality among individuals with spinal-cord injury (SCI). The present study investigated whether respiratory function is a discriminator of pneumonia in individuals with SCI and is aimed to determine the best predictive parameter. METHODS This was a retrospective cohort study. Individuals with traumatic SCI, level C3 to T12, complete and incomplete lesions, were included. Data on respiratory function were extracted from medical records. The receiver operating characteristic curve was calculated for each parameter (forced vital capacity, FEV1, peak expiratory flow, and maximum inspiratory and expiratory pressure [PImax and PEmax]) to determine the discriminator with the largest area under the curve between individuals with and without pneumonia. RESULTS Data of 307 subjects were analyzed. PImax was identified as the best discriminator between individuals with and without pneumonia, both in motor complete (area under the curve 0.86, 95% CI 0.78-0.93, P < .001) and incomplete individuals (area under the curve 1.0, 95% CI 1.00-1.00, P < .001). In individuals with motor complete lesions, the threshold value for PImax was 115% of the lesion-specific reference value (sensitivity 74.4%, specificity 83.4%). In motor incomplete individuals, the PImax threshold value was 93.5 cm H2O (sensitivity 100%, specificity 100%). CONCLUSIONS PImax is the best discriminator between spinal cord-injured individuals with versus those without pneumonia. Individuals with a PImax below threshold values are at risk of pneumonia.