Acute kidney injury (AKI) is a common complication following non-cardiac surgery with adverse short- and long- term morbidity and mortality. Evidence shows that hypoalbuminemia is associated with increased AKI risk in patients with infectious diseases and cancer and following cardiac surgery and transplant surgery. However, little evidence is available on non-cardiac surgery population. Thus, we investigated the association between preoperative hypoalbuminemia and AKI following non-cardiac surgery. We retrospectively assessed perioperative risk factors and preoperative serum albumin concentration in 729 consecutive adult patients who underwent non-cardiac surgery from July 1, 2017, to June 30, 2018. Each patient was categorized according to maximal Kidney Disease Improving Global Outcomes criteria based on creatinine changes and urine output within the first week after surgery. Multivariate Logistic regression models were used to analyze the association between preoperative hypoalbuminemia and postoperative AKI. Of 729 patients, 188 (25.8%) developed AKI. AKI incidence was higher in patients with preoperative serum albumin < 37.5 g/L than in those with preoperative serum albumin ≥37.5 g/L [35.9% (98/273) vs. 19.7% (90/456), P < 0.001]. Multivariate logistic regression analysis showed that preoperative serum albumin < 37.5 g/L (odds ratio 1.892; 95% confidence interval 1.238–2.891; P = 0.003) was independently associated with postoperative AKI. Patients with preoperative serum albumin < 37.5 g/L tended to have a higher but not significant ratio in AKI stage 2 (2.6% vs 1.1%, P = 0.144) and much higher ratio in AKI stage 3 (4.8% vs 0.7%, P < 0.001) than those with preoperative serum albumin ≥37.5 g/L. AKI patients had a higher in-hospital mortality rate [6.9% (13/188) vs. 0.2% (1/541), P < 0.001]. Kaplan-Meier analysis revealed that the cumulative survival rate decreased with increasing AKI severity (P < 0.001). Postoperative AKI was also associated with other worse outcomes, such as prolonged mechanical ventilation [53.4 (33.0, 73.8) vs 14.7 (11.1, 18.3) hours, P < 0.001], intensive care unit stay [4.0 (3.1, 4.9) vs 2.0 (1.8, 2.3) days, P < 0.001], postoperative hospital stay [17.8 (14.8, 20.9) vs 12.3 (11.3, 13.3) days, P < 0.001], and higher total cost [13,453 (8538, 20,228) vs 11,306 (6277, 16,400) dollars, P < 0.001]. Preoperative hypoalbuminemia was independently associated with AKI after non-cardiac surgery, and postoperative AKI was associated with poor outcomes.

Background: Sepsis is characterized by organ dysfunction resulting from a patient’s dysregulated response to infection. Sepsis-associated acute kidney injury (S-AKI) is the most frequent complication contributing to the morbidity and mortality of sepsis. The prevention and treatment of S-AKI remains a significant challenge worldwide. In the recent years, human amnion epithelial cells (hAECs) have drawn much attention in regenerative medicine, yet the therapeutic efficiency of hAECs in S-AKI has not been evaluated.Methods: Septic mice were induced by cecal ligation and puncture (CLP) operation. hAECs and their derived exosomes (EXOs) were injected into the mice via tail vein right after CLP surgery. The 7-day survival rate was observed. Serum creatinine level was measured and H&E staining of tissue sections were performed 16 h after CLP. Transmission electron microscopy was used to examine the renal endothelial integrity in CLP mice. Human umbilical vein endothelial cells (HUVECs) were treated with lipopolysaccharide (LPS) and EXOs. Zonula occludens-1 (ZO-1) localization was observed by immunofluorescence staining. Expression of phosphor-p65 (p-p65), p65, vascular cell adhesion molecule-1 (VCAM-1), and ZO-1 in the kidney were determined by Western blot.Results: hAECs decreased the mortality of CLP mice, ameliorated septic injury in the kidney, and improved kidney function. More precisely, hAECs suppressed systemic inflammation and maintained the renal endothelial integrity in septic animals. EXOs from hAECs exhibited similar renal protective effects as their parental cells. EXOs maintained endothelial cell adhesion junction in vitro and inhibited endothelial cell hyperactivation in vivo. Mechanistically, EXOs suppressed proinflammatory nuclear factor kappa B (NF-κB) pathway activation in LPS-treated HUVECs and in CLP mice kidneys.Conclusion: Our results indicate that hAECs and their derived EXOs may ameliorate S-AKI via the prevention of endothelial dysfunction in the early stage of sepsis in mice. Stem cell or exosome-based therapy targeting endothelial disorders may be a promising alternative for treatment of S-AKI.

Background: Sleep disturbances are prevalent in patients requiring invasive mechanical ventilation in the intensive care unit (ICU) and are associated with worse outcomes. Sedative-dose dexmedetomidine may improve sleep quality in this patient population but is associated with adverse events. Herein, we tested the effect of low-dose dexmedetomidine infusion on nighttime sleep quality in postoperative ICU patients with invasive ventilation.Methods: In this pilot randomized trial, 80 adult patients who were admitted to the ICU after non-cardiac surgery and required invasive mechanical ventilation were randomized to receive either low-dose dexmedetomidine (0.1 to 0.2 μg/kg/h, n = 40) or placebo (n = 40) for up to 72 h. The primary endpoint was overall subjective sleep quality measured using the Richards–Campbell Sleep Questionnaire (score ranges from 0 to 100, with a higher score indicating better quality) in the night of surgery. Secondary outcomes included sleep structure parameters monitored with polysomnography from 9:00 PM on the day of surgery to the next 6:00 AM.Results: All 80 patients were included in the intention-to-treat analysis. The overall subjective sleep quality was median 52 (interquartile 20, 66) with placebo vs. 61 (27, 79) with dexmedetomidine, and the difference was not statistically significant (median difference 8; 95% CI: −2, 22; P = 0.120). Among 68 patients included in sleep structure analysis, those in the dexmedetomidine group tended to have longer total sleep time [median difference 54 min (95% CI: −4, 120); P = 0.061], higher sleep efficiency [median difference 10.0% (95% CI: −0.8%, 22.3%); P = 0.060], lower percentage of stage N1 sleep [median difference −3.9% (95% CI: −11.8%, 0.5%); P = 0.090], higher percentage of stage N3 sleep [median difference 0.0% (95% CI: 0.0%, 0.4%); P = 0.057], and lower arousal index [median difference −0.9 (95% CI −2.2, 0.1); P = 0.091] but not statistically significant. There were no differences between the two groups regarding the incidence of adverse events.Conclusion: Among patients admitted to the ICU after surgery with intubation and mechanical ventilation, low-dose dexmedetomidine infusion did not significantly improve the sleep quality pattern, although there were trends of improvement. Our findings support the conduct of a large randomized trial to investigate the effect of low-dose dexmedetomidine in this patient population.Clinical trial registration: ClinicalTrial.gov, identifier: NCT03335527.

Glutamine on critical-ill patients: a systematic review and meta-analysis Yueming Sun, Sainan Zhu, Shuangling Li, Hong Liu