Reduced microRNA-744 expression in mast cell-derived exosomes triggers epithelial cell ferroptosis in acute respiratory distress syndrome.

Acute respiratory distress syndrome (ARDS) is a critical disorder characterized by immune-related damage to epithelial cells; however, its underlying mechanism remains elusive. This study investigated the effects of alterations in microRNA (miRNA) expression in mast cell-derived exosomes on human bronchial epithelial (HBE) cells and ARDS development in cellular and mouse models challenged with lipopolysaccharide. Lipopolysaccharide-treated mast cell-derived exosomes reduced glutathione peroxidase 4 (GPX4) expression and increased long-chain acyl-CoA synthetase 4 (ACSL4), 15-lipoxygenase (ALOX15), and inflammatory mediator levels in HBE cells. miRNA sequencing revealed a reduction in mast cell-derived exosomal miR-744 levels, which was associated with the regulation of ACSL4, ALOX15, and GPX4 expression. This downregulation of exosomal miR-744 expression reduced miR-744 levels and promoted ferroptosis in HBE cells, whereas the experimental upregulation of miR-744 reversed these adverse effects. Down-regulation of miR-744 induced the expression of markers for ferroptosis and inflammation in HBE cells and promoted pulmonary ferroptosis, inflammation, and injury in LPS-stimulated mice. In vivo, treatment with ACSL4, ALOX15, and GPX4 inhibitors mitigated these effects, and experimental miR-744 expression rescued the lipopolysaccharide-induced changes in HBE cells and mouse lungs. Notably, miR-744 levels were reduced in the plasma and exosomes of patients with ARDS. We concluded that decreased mast cell-derived exosomal miR-744 levels trigger epithelial cell ferroptosis, promoting lung inflammation and damage in ARDS. This study provides new mechanistic insights into the development and sustained pulmonary damage associated with ARDS and highlights potential therapeutic strategies.

Nocturnal Infusion of Low-dose Dexmedetomidine and Propofol for Prevention of Delirium Occurring in the ICU after Hip Fracture Surgery in Elderly Patients.

How to cite this article: Cong N, Wang D, Xue F. Nocturnal Infusion of Low-dose Dexmedetomidine and Propofol for Prevention of Delirium Occurring in the ICU after Hip Fracture Surgery in Elderly Patients. Indian J Crit Care Med 2024;28(9):894-895.

The addition of peripheral nerve blocks to routine spinal or general anesthesia was associated with decreased risks of major adverse events after total hip or knee arthroplasty: A retrospective, propensity score-matched cohort study.

Background: Although total joint arthroplasty is the most effective procedures for end-stage arthritis, the incidence of postoperative death and complications remains high. The association of additional peripheral nerve blocks (PNBs) to routine spinal or general anesthesia with major adverse events (including mortality and complication rates) in elective total hip arthroplasty (THA) or total knee arthroplasty (TKA) has been subject to inconclusive findings. Methods: This retrospective observational single institution study included all patients ≧ 18 years undergoing their first elective THA or TKA from January 1, 2012 to December 31, 2021. A 1:2 propensity score matching (PSM) was performed to account for the baseline differences between two groups that were accepted to PNB or not. Kaplan-Meier curves were employed to estimate the effects of PNB on mortality. The associations of PNB and the complications were assessed by logistic regression models. Results: We identified 1328 patients, among whom 197 had PNB and 1131 had not. The 90-day all-cause mortality was significantly reduced in patients with PNBs (0 % vs 2.79 %, P = 0.041) after THA or TKA, when compared to the non-PNB group. PNB was also associated with a lower risk of pulmonary complications (odds ratio [OR], 0.430; 95%confidence interval [CI],0.216-0.857) and deep vein thrombosis (OR, 0.103; 95%CI, 0.011-0.954). Interpretation: The results of this observational, propensity score-matched cohort study suggested a strong association between the addition of PNBs to routine spinal or general anesthesia and decreased risks of major adverse events.

Short-term inhalation of xenon during anesthesia for prevention of postoperative delirium in elderly patients undergoing laparoscopic radical colectomy: study protocol for a randomized controlled clinical trial.

BACKGROUND: Postoperative delirium (POD) is a common complication that is characterized by acute onset of impaired cognitive function and is associated with an increased mortality, a prolonged duration of hospital stay, and additional healthcare expenditures. The incidence of POD in elderly patients undergoing laparoscopic radical colectomy ranges from 8 to 54%. Xenon has been shown to provide neuroprotection in various neural injury models, but the clinical researches assessing the preventive effect of xenon inhalation on the occurrence of POD obtained controversial findings. This study aims to investigate the effects of a short xenon inhalation on the occurrence of POD in elderly patients undergoing laparoscopic radical colectomy. METHODS/DESIGN: This is a prospective, randomized, controlled trial and 132 patients aged 65-80 years and scheduled for laparoscopic radical colectomy will be enrolled. The participants will be randomly assigned to either the control group or the xenon group (n = 66 in each group). The primary outcome will be the incidence of POD in the first 5 days after surgery. Secondary outcomes will include the subtype, severity, and duration of POD, postoperative pain score, Pittsburgh Sleep Quality Index (PQSI), perioperative non-delirium complications, and economic parameters. Additionally, the study will investigate the activation of microglial cells, expression of inflammatory factors in colon tissues, plasma inflammatory factors, and neurochemical markers. DISCUSSION: Elderly patients undergoing laparoscopic radical colectomy are at a high risk of POD, with delayed postoperative recovery and increased healthcare costs. The primary objective of this study is to determine the preventive effect of a short xenon inhalation on the occurrence of POD in these patients. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR2300076666. Registered on October 16, 2023, http://www.chictr.org.cn .

[Effects of Dexmedetomidine on the Recovery Quality of Donors Undergoing Pure Laparoscopic Donor Hepatectomy]. / å³ç¾Žæ‰˜å’ªå®šå¯¹è ¹è ”é•œä¾›è‚èŽ·å–æœ¯ä¾›è€ è‹é†’æœŸæ¢å¤è´¨é‡çš„å½±å“.

Objective: To investigate the effects of intraoperative intravenous administration of dexmedetomidine (DEX) on the recovery quality of donors undergoing pure laparoscopic donor hepatectomy. Methods: A total of 56 liver donors who were going to undergo scheduled pure laparoscopic donor hepatectomy were enrolled and randomly assigned to two groups, a DEX group ( n=28) and a control group ( n=28). Donors in the DEX group received DEX infusion at a dose of 1 µg/kg over 15 minutes through a continuous pump, which was followed by DEX at 0.4 µg/(kg·h) until the disconnection of the portal branch. Donors in the control group were given an equal volume of 0.9% normal saline at the same infusion rate and over the same period of time as those of the dex infusion in the DEX group. The primary outcome was the incidence of emergence agitation (EA). The Aono's Four-point Scale (AFPS) score was used to assess EA. The secondary observation indicators included intraoperative anesthesia and surgery conditions, spontaneous respiration recovery time, recovery time, extubation time, scores for the Ramsay Sedation Scale, the incidence of chills, numeric rating scale (NRS) score for pain, and blood pressure and heart rate after extubation. Results: The incidence of EA was 10.7% and 39.3% in the DEX group and the control group, respectively, and the incidence of EA was significantly lower in the DEX group than that in the control group ( P=0.014). The APFS scores after extubation in the DEX group were lower than those in the control group (1 [1, 1] vs. 2 [1, 3], P=0.005). Compared to the control group, the dosages of intraoperative propofol and remifentanil were significantly reduced in the DEX group ( P<0.05). During the recovery period, the number of donors requiring additional boluses of analgesia, the blood pressure, and the heart rate were all lower in the DEX group than those in the control group ( P<0.05). No significant differences between the two groups were observed in the spontaneous respiration recovery time, recovery time, extubation time, the incidence of chills, NRS score, scores for the Ramsay Sedation Scale, and the length-of-stay in postanesthesia care unit (PACU) ( P>0.05). Conclusion: DEX can reduce the incidence of EA after pure laparoscopic donor hepatectomy and improve the quality of recovery without prolonging postoperative recovery time or extubation time.