Objective: To study the incidence of acute kidney injury (AKI) in patients with septic shock, evaluate the impact of AKI stage on the prognosis of septic shock and explore the role of hemodynamics in the incidence of AKI.
Methods: We retrospectively investigated the patients of septic shock who had been placed pulmonary artery catheter (PAC) continuously admitted in Peking Union Medical College Hospital from January, 2001 to June, 2008. Mortality and incidence of AKI were compared between groups of different AKI stages, survival analysis and prognosis evaluation were performed. The impacts of hemodynamics on the incidence of AKI were studied.
Results: Altogether 158 cases of septic shock were enrolled in this retrospective study. Of all the patients, the incidences of all AKI and stage 1 - 3 were 79.7% (126/158), 16.5% (26/158), 16.5% (26/158) and 46.8% (74/158) respectively; 45.6% (72/158) of all the patients needed renal alternative therapy. Ninety-four patients died within 28 days (59.5%). The mortality in the patients without AKI was 12.5%, while those with AKI and those at stages 1-3 of AKI were 38.5%, 69.2%, 83.8% and 71.4% (P < 0.05), with OR values at 4.38, 15.75, 36.17 and 17.50 respectively. The survival analysis showed that the survival rate decreased as AKI stage increasing. The ROC curve showed that the area under curve (AUC) was 0.811, with 95%CI at 0.738 - 0.883 (P < 0.001). The incidences of AKI in patients with different levels of mean arterial pressure (mAP) were 76.2% (90 - 100 mm Hg), 71.8% (80 - 90 mm Hg) and 94.4% (65 - 80 mm Hg) respectively. The incidences of AKI in patients with different levels of cardiac index (CI) were 76.7% (> 4.0 L x min(-1) x m(-2)), 71.2% (2.5 - 4.0 L x min(-1) x m(-2)) and 96.6% (< 2.5 L x min(-1) x m(-2)).
Conclusion: Septic shock is highly associated with AKI and has poor prognosis. AKI stage of AKI net is an independent predictor of prognosis of septic shock. The change of hemodynamics has an important role on the development of septic AKI. It's useful to decrease the incidence of AKI by elevating the blood pressure and CI, but super-normal goal won't work better.