Predictive Value of Substance P for Pulmonary Infection in Patients With Acute Cerebral Infarction During Hospitalization.

Background and purpose: This study aimed to evaluate the predictive value of serum substance P (SP) levels at hospital admission for the development of pulmonary infection during hospitalization in patients with acute cerebral infarction. Additionally, the study explored the association between SP levels and the severity of inflammation following pulmonary infection.

Methods: A total of 340 patients with acute cerebral infarction were retrospectively analyzed. Serum SP concentrations were measured upon hospital admission. During hospitalization, 96 patients developed pulmonary infections of varying severity, while 244 patients remained free of pulmonary infection. In patients who developed infection, serum levels of high-sensitivity C-reactive protein, procalcitonin, and interleukin-6 were also measured.

Results: Invasive procedures, dysphagia, admission National Institutes of Health Stroke Scale (NIHSS) score, age, and serum SP concentration at admission were identified as significant risk factors for pulmonary infection in patients with acute cerebral infarction. Receiver operating characteristic curve analysis showed that serum SP concentration at admission had a sensitivity of 65.63% and specificity of 85.66% for predicting pulmonary infection (area under the curve=0.81, p<0.001). Moreover, SP levels at admission were positively correlated with NIHSS scores and the levels of inflammatory markers.

Conclusions: Serum SP concentration at the time of admission has predictive value for the development of pulmonary infection during hospitalization in patients with acute cerebral infarction and may serve as an early indicator of infection risk.