Abstract:

Objective To investigate the correlation between single-breath counting (SBC) and standard measures of pulmonary function in patients with spinal cord injury, to evaluate the value for predicting pulmonary function.
Methods Forty-two patients (24 with cervical injury and 18 with thoracic injury) were selected from October, 2018 to February, 2019 in outpatients and inpatients. SBC and standard laboratory spirometer tests were performed separately. The correlation of the outcome of SBC and lung function indicators including forced vital capacity (FVC), forced respiratory capacity in the first second (FEV1), FEV1/FVC, slow expiratory vital capacity (EVC) and all the predicted values on the percentage (%pred) were analyzed. A receiver operating characteristic (ROC) curve was constructed according to the lung function classification criteria.
Results The outcome of SBS was correlated with FVC, EVC as well as the percentage of predicted values (r= 0.723 to 0.760, P< 0.01 for the whole patients;r= 0.549 to 0.657, P < 0.01 for cervical ones; r= 0.623 to 0.847, P < 0.01 for thoracic ones), and was also correlated with FEV1 as well as the percentage of predicted values ( r = 0.622 to 0.760, P< 0.01 for whole patients and cervical ones). The area under the ROC curve was 0.864 to 0.941.
Conclusion There is a good correlation between SBC and standard lung function for patients with spinal cord injury, suggesting an assistive diagnostic value for patients with reduced lung function.

Key words: spinal cord injury, pulmonary function, assessment, single-breath counting