Pulmonary edema and hemorrhage, possible causes of pulmonary infection and respiratory failure in the early stage of lower spinal cord injury.

Pulmonary infection and respiratory failure are frequently encountered in the early stage of acute spinal cord injury (SCI) and are thought of as the chief causes of death. Unfortunately, there is little knowledge concerned with the pathogenesis of pulmonary infection, respiratory failure and other pathological changes in the lung in the early stage of SCI. Pulmonary embolism, respiratory muscle dysfunction, poor expectoration caused by position, and decreased ability to cough up respiratory secretions were the main causes. These explanations may be beyond criticism in high-level paraplegia in SCI, but are unconvincing in lower SCI such as in low-thoracic cord injury where the phenomenon of pneumonia and respiratory dysfunction remains. There might be some more important factors that lead to pulmonary infection and respiratory failure in the early stage of SCI. In SCI rats, pulmonary edema and hemorrhage were occurred in the early stage of SCI while the other organs were almost normal. And the location of lung edema and hemorrhage were the same as that of pulmonary infection. The purpose of this paper is to propose pathological changes in the lung and possible causes for pulmonary infection and respiratory failure. We hypothesize that pulmonary edema and hemorrhage in the early stage of SCI might be the chief factor contributing to pulmonary infection and respiratory failure in lower SCI.