RENBP and atrial fibrillation: These variables were included in stepwise Cox regression for further screening, and the results showed that atrial fibrillation (HR [95%CI]: 5.25 [1.22–22.52], p = 0.0257*), ALP (HR [95%CI]: 1.003 [1–1.005], p = 0.0160), AG (HR [95%CI]: 1.14 [1.05–1.23], p = 0.0011), LDH (HR [95%CI]: 1.001 [1.000–1.002], p = 0.0172), and sodium ion (HR [95%CI]: 1.1 [1.06–1.15], p < 0.0001) were independent predictors for the occurrence of respiratory failure in IS patients (Table 2).