Identification Of Acute Kidney Injury Phenotypes For Critically Ill Patients Based On Mimic-Ⅲ Database

Objective By analyzing the clinical data of patients with acute kidney injury in the MIMIC-Ⅲ database,this study assessed whether AKI could be subtyped using latent class analysis.Methods The electronic medical record data in MIMIC-Ⅲ database were extracted by diagnostic codes,and clinical data were exported.This study included patients ≥18 years who developed AKI within 24 hours of intensive care unit admission.Then use latent class analysis to utilize all available laboratory variables,vital signs,and comorbidities to identify phenotypes.Select the best classification model based on the model fit metrics.Clinical outcomes of phenotypes assessed by mortality at discharge and need for renal replacement therapy.Results According to the criteria,680 patients were enrolled in this study.Independent latent class models indicated that a three-class（i.e.three phenotype）model was optimal.Phenotype 1 had 182 patients,and phenotype 2 had 354 patients,whereas phenotype 3 had 144 patients.There was no significant gender difference among the three phenotypes.Compared with phenotype 1 and 3,phenotype2 was the oldest and had the largest proportion of HIV-infected patients（P<0.001）.Phenotype 3 had a worse prognosis compared to phenotype 1 and phenotype2—higher mortality（17.4% vs 9.3% [phenotype 2] vs 5.5% [phenotype 1],P<0.001）.Phenotype 3 was significantly higher in patients with coagulation disorders 、hemorrhagic anemia and Sepsis or septic shock,and higher rates of norepinephrine use（P<0.001）.The blood pressure and heart rate of the three phenotypes were not significantly different,presumably related to the use of norepinephrine.In addition,phenotype 3 had a higher proportion of mechanically ventilated patients（58.1% vs40.3%[phenotype 2] vs 33.0%[phenotype 1],P<0.001）.More patients in phenotype 3received renal replacement therapy compared to phenotype 1 and phenotype 2（11.8%vs 6.3% [phenotype 2] vs 2.3% [phenotype 1],P<0.001）.Phenotype 3 had higher median bilirubin levels,aspartate aminotransferase,and alanine aminotransferase and the highest proportion of liver disease compared with phenotypes 2 and 1.Patients in phenotype 3 also had higher median lactate,white blood cell count than patients in phenotypes 1 and 2.Phenotype 3 also had higher creatinine and BUN than phenotype2 and 3.Among the three phenotypes,the difference in KDIGO AKI stage was statistically significant,with a higher proportion of stage 3 AKI in phenotype 3（58%vs 32%[phenotype 2] vs 20%[phenotype 1],P<0.001）.Conclusion Utilizing routinely collected laboratory variables,vital signs,and comorbidities,we were able to identify three distinct phenotypes of AKI with different outcomes.Future studies are warranted to validate the suggested phenotypes of acute kidney injury.