Role of angiotensin-converting enzyme (ACE and ACE2) imbalance on tourniquet-induced remote kidney injury in a mouse hindlimb ischemia-reperfusion model

In this study, the relationship between the local imbalance of angiotensin converting enzymes ACE and ACE2 as well as Ang II and Ang (1-7) and renal injury was observed in the different genotypes mice subjected to tourniquet-induced ischemia-reperfusion on hind limbs. In wild-type mice, renal ACE expression increased while renal ACE2 expression decreased significantly after reperfusion, accompanied by elevated serum angiotensin II (Ang II) level and lowered serum angiotensin (1-7) (Ang (1-7)) level. However, renal Ang (1-7) also increased markedly while renal Ang II was elevated. Renal injury became evident after limb reperfusion, with increased malondialdehyde (MDA), decreased super-oxide dismutase (SOD) activity and increased serum blood urea nitrogen (BUN) and creatinine (Cr), compared to control mice. These mice also developed severe renal pathology including infiltration of inflammatory cells in the renal interstitium and degeneration of tubule epithelial cells. In ACE2 knock-out mice with ACE up-regulation, tourniquet-induced renal injury was significantly aggravated as shown by increased levels of MDA, BUN and Cr, decreased SOD activity, more severe renal pathology, and decreased survival rate, compared with tourniquet-treated wild-type mice. Conversely, ACE2 transgenic mice with normal ACE expression were more resistant to tourniquet challenge as evidenced by decreased levels of MDA, BUN and Cr, increased SOD activity, attenuated renal pathological changes and increased survival rate. Our results suggest that the deregulation of ACE and ACE2 plays an important role in tourniquet-induced renal injury and that ACE2 up-regulation to restore the proper ACE/ACE2 balance is a potential therapeutic strategy for kidney injury.     

Skeletal muscle damage during tourniquet-induced ischaemia The initial step towards atrophy after orthopaedic surgery?

Muscle biopsies from the vastus lateralis muscle of patients who had undergone anterior cruciate ligament surgery under conditions of tourniquet-induced ischaemia were examined under the electron microscope at different periods of time up to 90 min of ischaemia. The severity of the alterations in ultrastructure appeared to depend on the period of ischaemia. The pathological changes consisted of accumulation of lysosomes, persistent intrafibre oedema, and some extracellular oedema. Signs of fibre necrosis were found after 90 min of ischaemia. Capillary ultrastructure was only altered with regard to some swelling of the endothelium and marked thickening of the basement membrane. It was concluded that skeletal muscle could be severely affected even during relatively short periods of ischaemia, which might facilitate the development of muscle atrophy during immobilization after orthopaedic surgery.     

Tourniquet-induced ischemia-reperfusion injuries during extremity surgery at children's age: impact of anesthetic chemical structure

Abstract

Objectives

The aim of this study was to determine the relationship between the antioxidant profile of anesthetics and its relation to total antioxidant capacity (TAC) of plasma in children who underwent tourniquet-induced ischemia-reperfusion (IR) injury during extremity operations.

Methods

Children were randomized into three groups: general inhalational anesthesia with sevoflurane (group S), total intravenous anesthesia (TIVA) with propofol (group T), and regional anesthesia (group R). Venous blood samples were obtained before peripheral nerve block and induction of general anesthesia (baseline), 1 minute before tourniquet release (BTR), and 5 and 20 minutes after tourniquet release (ATR). Plasma TAC as well as antioxidant potential of propofol, thiopental, and bupivacaine were measured using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay.

Results

Plasma TAC in group T was increased significantly at 20 minutes ATR in comparison with basal and BTR values, and also was significantly higher in comparison with plasma TAC in groups S and R measured at the same time point. The radical scavenging activity of anesthetics in vitro indicated that only propofol possessed a significant antioxidative activity in the reaction with DPPH radical in comparison with thiopental and bupivacaine.

Discussion

These data confirm that TIVA with propofol attenuates oxidative stress related to tourniquet-induced ischaemia-reperfusion injury in children.     

患肢加压溶栓治疗下肢深静脉血栓形成的临床疗效及护理效应

目的:探讨止血带结扎患肢,从足背浅静脉推注尿激酶治疗下肢深静脉血栓形成的临床疗效及护理效应。方法:对62例下肢深静脉血栓患者经患肢足背静脉穿刺,踝关节上用止血带阻断浅静脉后,推注中等剂量尿激酶.通过测量腿围和彩超结果来评价是否有效。并采用多种护理辅助手段辅助治疗。结果:临床症状迅速改善,有效率22.5%,显效率77.5%。结论:此方法操作简单,所用材料价格便宜,临床效果明显,值得推广应用。     

全膝关节置换术中不同止血带使用方法的疗效比较及对患者凝血功能、炎症反应和生活质量的影响

摘要 目的：探讨全膝关节置换术（TKA）中不同止血带使用方法的疗效比较及对患者凝血功能、炎症反应和生活质量的影响。方法：选取2019年1月至2022年2月间来我院接受治疗的256例TKA患者,根据止血带使用方法的不同将患者分为A组（n=124,全程使用止血带）和B组（n=132,安装假体至切口缝合包扎完毕间使用止血带）。对比两组临床指标、凝血功能指标、炎症因子指标和生活质量评分。结果：两组术中出血量组间对比差异无统计学意义（P>0.05）。B组的下肢深静脉血栓的发生率低于A组,美国特种外科医院（HSS）评分高于A组,视觉疼痛模拟量表（VAS）评分低于A组（P<0.05）。两组术后1 d 纤维蛋白原含量（FIB）升高,且B组低于A组（P<0.05）。凝血酶原时间（PT）、凝血酶时间（TT）、活化部分凝血酶时间（APTT）均缩短,且B组大于A组（P<0.05）。两组术后1 d白介素-1β（IL-1β）、白介素-6（IL-6）、白介素-8（IL-8）、C反应蛋白（CRP）均升高,且B组低于A组（P<0.05）。两组术后3个月健康调查量表（SF-36）各维度评分均升高,且B组高于A组（P<0.05）。结论：TKA术中安装假体至切口缝合包扎完毕间使用止血带,可减轻对机体炎症反应、凝血功能的影响,有助于膝关节功能恢复,改善患者术后生活质量。     

右美托咪定对下肢手术患者止血带诱发肢体缺血-再灌注损伤的影响

目的:探讨右美托咪定对下肢手术患者因止血带诱发肢体缺血-再灌注损伤的影响。方法:选取2015年1月-2016年5月我院行下肢手术治疗的患者90例,按照数字随机法分为观察组及对照组,每组各45例。两组均给予蛛网膜下腔阻滞联合硬膜外麻醉,观察组在穿刺成功15 min内静脉输注1μg/kg的右美托咪定,维持剂量0.5μg/kg·h直至手术结束,对照组患者则给予同等剂量的生理盐水。对比两组止血带前(T0)、止血带充气30 min(T1)、止血带充气1 h(T2)、止血带释放后30 min(T3)、止血带释放后1 h(T4)时的超氧化物歧化酶(SOD)、丙二醛(MDA)、肿瘤坏死因子-α(TNF-α)、白介素-6(IL-6)、平均动脉压(MAP)、心率(HR)水平以及不良反应发生情况。结果:T3、T4时点观察组SOD水平显著高于对照组,MDA水平显著低于对照组(P0.05)。T1、T2、T3、T4时点观察组TNF-α水平显著低于对照组,T4时点IL-6水平也显著低于对照组(P0.05)。T1、T2时点观察组MAP、HR水平均显著低于对照组(P0.05)。观察组术中止血带疼痛、高血压发生率均显著低于对照组(P0.05)。结论:右美托咪定可显著抑制下肢手术患者止血带诱发氧化应激反应以及炎症反应,进而降低肢体缺血-再灌注损伤,具有较好的安全性。