Remote Ischemic Preconditioning Group Research Articles

ИССЛЕДОВАНИЕ ЭФФЕКТА ДИСТАНЦИОННОГО ИШЕМИЧЕСКОГО ПРЕКОНДИЦИОНИРОВАНИЯ НА МЕТАБОЛОМ У ПАЦИЕНТОВ, ПЕРЕНЕСШИХ СОСУДИСТУЮ ХИРУРГИЮ

The aim was to investigate the effect of remote ischemic preconditioning (RIPC) on the metabolic profile of patients undergoing elective vascular surgery 24 hours after the intervention. Materials and methods. A randomized, double-blind, placebo-controlled trial was conducted at the Republican Clinical Hospital in Makhachkala from January 1, 2023 to March 1, 2024. We studied patients who had to undergo surgery for an infrarenal abdominal aortic aneurysm, carotid endarterectomy, or revascularization of the lower extremities. Participants received RIPC or placebo, after which 103 metabolites and metabolic ratios were analyzed using the AbsoluteIDQ®p180 kit. Results. The study included 26 patients, 12 of them in the RIPC group and 14 in the control group. In the RIPC group, significant correlations were found between changes in metabolites (for example, the kynurenine/tryptophan ratio) and cardiomarkers (hs-TnT, NT-proBNP), which were absent in the control group. In the control group, blood pressure correlated with creatinine and beta-2-microglobulin levels. Conclusions. RIPC can affect specific metabolic changes after vascular surgery, which is confirmed by correlations with cardiomarkers not found in the control group.

Remote ischemic preconditioning on perioperative autonomic nervous system function and postoperative recovery in patients undergoing cholecystectomy

Background Cholecystectomy often disrupts autonomic balance, impacting recovery. Remote ischemic preconditioning (RIPC) may enhance ANS function and protect organs, but its role in cholecystectomy is unclear. Methods In this randomized controlled trial, 80 patients aged 45 to 65 years, scheduled for elective laparoscopic cholecystectomy, were randomly assigned to either the RIPC group or the control group. The primary outcomes were mean arterial pressure (MAP), heart rate variability (HRV), and the low-frequency to high-frequency ratio (LF/HF) measured at various time points during the perioperative period. Secondary outcomes included liver and kidney function markers, postoperative hospital stay, and 30-day mortality rates. Results RIPC group significantly improved HRV compared to the control group at 5 minutes post-anesthesia induction (42.5 ± 9.8 ms vs. 36.4 ± 10.1 ms, P = 0.02) and at the end of surgery (44.8 ± 10.5 ms vs. 37.1 ± 9.3 ms, P = 0.01). The LF/HF ratio was significantly lower in the RIPC group at 30 minutes into surgery (1.25 ± 0.35 vs. 1.67 ± 0.42, P = 0.04) and at the end of surgery (1.19 ± 0.31 vs. 1.71 ± 0.39, P = 0.03), indicating improved autonomic balance. There were no significant differences in MAP, liver function markers (ALT), or kidney function (SCr) between groups at any time point. Conclusions RIPC may improve ANS function and MAP stability during cholecystectomy, as shown by better HRV and lower LF/HF ratios. Though the impact on recovery was not significant.

Direct effects of remote ischemic preconditioning on post-exercise-induced changes in kynurenine metabolism.

Tryptophan (TRP) degradation through the kynurenine pathway is responsible for converting 95% of free TRP into kynurenines, which modulate skeletal muscle bioenergetics, immune and central nervous system activity. Therefore, changes in the kynurenines during exercise have been widely studied but not in the context of the effects of remote ischemic preconditioning (RIPC). In this study, we analyzed the effect of 14-day RIPC training on kynurenines and TRP in runners after running intervals of 20 × 400 m. In this study, 27 semi-professional long-distance runners were assigned to two groups: a RIPC group performing 14 days of RIPC training (n = 12), and a placebo group, SHAM (n = 15). Blood was collected for analysis before, immediately after, and at 6 h and 24 h after the run. After the 14-day RIPC/SHAM intervention, post hoc analysis showed a significantly lower concentration of XANA and kynurenic acid to kynurenine ratio (KYNA/KYN) in the RIPC group than in the SHAM group immediately after the running test. Conversely, the decrease in serum TRP levels was higher in the RIPC population. RIPC modulates post-exercise changes in XANA and TRP levels, which can affect brain health, yet further research is needed.

Impact of Paired Remote Ischemic Preconditioning on Postreperfusion Syndrome in Living-Donor Liver Transplantation: A Propensity-Score Matching Analysis.

Background and Objectives: Postreperfusion syndrome (PRS) is a significant challenge in liver transplantation (LT), leading to severe circulatory and metabolic complications. Ischemic preconditioning (IPC), including remote IPC (RIPC), can mitigate ischemia-reperfusion injury, although its efficacy in LT remains unclear. This study evaluated the impact of paired RIPC, involving the application of RIPC to both the recipient and the living donor, on the incidence of PRS and the need for rescue epinephrine during living-donor LT (LDLT). Materials and Methods: This retrospective observational cohort analysis included 676 adult patients who had undergone elective LDLT between September 2012 and September 2022. After applying exclusion criteria and propensity score matching (PSM), 664 patients were categorized into the paired RIPC and non-RIPC groups. The primary outcomes were the occurrence of PRS and the need for rescue epinephrine during reperfusion. Results: The incidence of PRS and the need for rescue epinephrine were significantly lower in the paired RIPC group than in the non-RIPC group. Furthermore, the incidence of postoperative acute kidney injury was lower in the paired RIPC group. Multivariable logistic regression adjusted for propensity scores indicated that paired RIPC was significantly associated with a reduced occurrence of PRS (odds ratio: 0.672, 95% confidence interval: 0.479-0.953, p = 0.021). Conclusions: Paired RIPC, involving both the recipient and the living donor, effectively reduces the occurrence of PRS and the need for rescue epinephrine during LDLT. These findings suggest that paired RIPC protects against ischemia-reperfusion injury in LDLT. Future randomized controlled trials are needed to verify our results and to explore the underlying mechanisms of the protective effects of RIPC.

Daily Remote Ischaemic Preconditioning for Intermittent Claudication: A Sham Controlled Randomised Trial

Remote ischaemic preconditioning (RIPC) is a promising non-invasive strategy in which brief episodes of ischaemia and reperfusion can increase skeletal muscle resistance to ischaemia and improve mobility. This study aimed to determine whether 28 consecutive days of RIPC improved intermittent claudication (IC) symptoms compared with sham intervention. This single centre, parallel, randomised, sham controlled, double blind trial was conducted from January 2022 to April 2023 in outpatient settings. Forty two patients with stable IC Fontaine stage IIa or IIb were randomised to RIPC or sham for 28 days. The pre-specified primary outcome was a change in the maximum walking distance (MWD) after 28 days measured with a treadmill test. A > 10% change in MWD was considered clinically significant. Change in intermittent claudication distance (ICD), time to relief from claudication (TRC), and health related quality of life (HRQoL) measured with the VascuQoL-6 questionnaire were the secondary outcomes (ClinicalTrials.gov ID: NCT05084066). Forty one men (RIPC= 23, sham= 18) aged 64.9 ± 7.4 years were analysed. A change of > 10% in MWD occurred in 14 patients in the RIPC group vs. eight patients in the sham group (relative risk 1.37, 95% confidence interval 0.74 - 2.25; p= .35). Changes in ICD, TRC, and HRQoL between the groups were not statistically significant. In this trial, RIPC did not significantly improve MWD, ICD, or TRC compared with treatment with a sham device.

Effect of remote ischemic preconditioning on cerebral circulation time in severe carotid artery stenosis: Results from the RIC-CCT trial

In patients with severe internal carotid artery stenosis (sICAS), cerebral circulation time (CCT) is associated with cerebral hyperperfusion syndrome. This study aims to investigate the effect of remote ischemic preconditioning (RIC) on CCT in patients with sICAS. Patients are randomly assigned to the RIC group (RIC twice daily, for 2-4days before carotid artery stenting [CAS] as an adjunct to standard medical therapy) and the control group. The results show that RIC produces a significant decrease in CCT of the stenosis side (sCCT) from baseline to pre-CAS, and the occurrence of contrast staining on brain computed tomography (CT) is lower in RIC versus control group after CAS. In addition, significant changes in some serum biomarkers suggest that anti-neuroinflammation, anti-oxidative stress, protecting endothelial injury, and improving cerebral autoregulation may be associated with the effect of RIC. These findings provide supporting evidence that RIC can modulate cerebral circulation in patients with sICAS. This study was registered at ClinicalTrials.gov (NCT05451030).

Short cycles of remote ischemic preconditioning had no effect on tensile strength in small intestinal anastomoses: an experimental animal study

PurposeThis study aimed to investigate the effect of remote ischemic preconditioning (RIPC) on the healing of small intestinal anastomoses, evaluated by tensile strength and histologic wound healing on postoperative day 5. MethodsA total of 22 female pigs were randomized 1:1 into either an intervention or control group. The intervention group received 5 cycles of 3-minute ischemia followed by 3-minute reperfusion on the right forelimb. Two end-to-end anastomoses, a distal and a proximal, were created in the small intestine 30 and 60 min after RIPC, respectively. On postoperative day 5, the anastomoses were harvested and underwent a maximal anastomotic tensile strength (MATS) test (MATS 1–3) followed by histologic analyses. ResultsMATS 1, when a tear became visible in the serosa, was significantly increased in the proximal anastomoses of the RIPC group compared with the control group (4.91 N vs 3.83 N; P = .005). No other significant differences were found when comparing these 2 groups. ConclusionOur study showed no convincing results of RIPC on intestinal anastomotic healing to recommend its use in a general clinical setting. Further animal studies on RIPC’s effect after relative or absolute intestinal ischemia may be recommended.

Remote Ischemic Preconditioning Before Drug-Coated Balloon Implantation can Improve the Long-Term Prognosis of Patients with CAD.

Drug-coated balloons (DCBs) have become increasingly vital to percutaneous coronary intervention, offering many advantages. However, a significant challenge is that many patients are intolerant to the myocardial ischemia caused by DCB dilation. Remote ischemic preconditioning (RIPC) is known to enhance heart's tolerance to ischemia and hypoxia. This study investigated whether preoperative RIPC could extend the tolerated DCB inflation time and improve the long-term prognosis of patients with coronary artery disease (CAD). A total of 653 patients with CAD were recruited and randomized into a RIPC group (n = 323) and a control (n = 330) group. The RIPC group underwent RIPC on the left upper limb twice daily, starting three days before the DCB implantation. The patients were followed up for one year after the operation, and 197 patients returned for coronary angiography (CAG) examination where the quantitative flow ratio (QFR) of the target vessels was measured. The primary endpoint of the study was the incidence of target lesion failure (TLF), which included target lesion revascularization (TLR), target vessel myocardial infarction, and cardiac death. The secondary endpoint was the rate of QFR loss in the target vessels. The findings revealed a significantly lower incidence of TLR in the RIPC group compared to the control group. Additionally, at the one-year follow-up, the rate of QFR loss in target vessels was lower in the RIPC group than in the control group. The preoperative application of RIPC effectively extended the duration patients could tolerate DCB inflation. Furthermore, this approach positively impacted the long-term prognosis of CAD patients undergoing DCB treatment. NCT04766749.

Association between Ranolazine, Ischemic Preconditioning, and Cardioprotection in Patients Undergoing Scheduled Percutaneous Coronary Intervention.

Background and Objectives: Remote ischemic preconditioning (RIPC) has demonstrated efficacy in protecting against myocardial ischemia-reperfusion injury when applied before percutaneous coronary revascularization. Ranolazine, an anti-ischemic drug, has been utilized to minimize ischemic events in chronic angina patients. However, there is a lack of trials exploring the combined effects of ranolazine pretreatment and RIPC in patients undergoing percutaneous coronary interventions (PCIs). Materials and Methods: The present study is a prospective study which enrolled 150 patients scheduled for nonemergent percutaneous coronary revascularization. Three groups were formed: a control group undergoing only PCIs, an RIPC group with RIPC applied to either upper limb before the PCI (preconditioning group), and a group with RIPC before the PCI along with prior ranolazine treatment for stable angina (ranolazine group). Statistical analyses, including ANOVAs and Kruskal-Wallis tests, were conducted, with the Bonferroni correction for type I errors. A repeated-measures ANOVA assessed the changes in serum enzyme levels (SGOT, LDH, CRP, CPK, CK-MB, troponin I) over the follow-up. Statistical significance was set at p < 0.05. Results: The ranolazine group showed (A) significantly lower troponin I level increases compared to the control group for up to 24 h, (B) significantly lower CPK levels after 4, 10, and 24 h compared to the preconditioning group (p = 0.020, p = 0.020, and p = 0.019, respectively) and significantly lower CPK levels compared to the control group after 10 h (p = 0.050), and (C) significantly lower CK-MB levels after 10 h compared to the control group (p = 0.050). Conclusions: This study suggests that combining RIPC before scheduled coronary procedures with ranolazine pretreatment may be linked to reduced ischemia induction, as evidenced by lower myocardial enzyme levels.

Protective effect of remote ischemic preconditioning on blood pressure control in magnetic resonance-guided focused ultrasound operations

Backrgound. Magnetic resonance-guided focused ultrasound (MR-FUS) is a new non-invasive technology for the surgical treatment of extrapyramidal movement disorders for such pathologies as essential tremor, Parkinson’s disease, etc. In these cases, the brain is injured and a zone of ischemia is formed. Arterial hypertension (AH) is one of the most common pathologies, which is often accompanied by neurological diseases. Objective. To investigate the effect of the remote ischemic preconditioning (RIPC) on blood pressure (BP) during MR-FUS surgery. Design – blinded, randomized, controlled, 2-group study with sham preconditioning. Materials and Methods. Patients were randomized into the RIPC group (cuff systolic BP (SBP) &gt;50 mmHg, n=42) and the group with sham RIPC (cuff diastolic BP (DBP), n=39) before surgery in regime 3 cycles each 5 min with 5 min rest between cycles. Results. While there was a decrease in SBP and DBP before and after the operation in the RIPC group, there was an increase (p&lt;0.001) in the sham RIPC group. Using the Difference-in-Difference equation for SBP, SBP was 8.9 (5.9–11.9) mm Hg higher in the sham RIPC group than in the RIPC group (p&lt;0.01). Conclusion. As a result, MR-FUS operations showed a significant decrease in BP during RIPC compared to the imitation, which confirms the angioprotective effect of preconditioning.

Pretreatment with remote ischemic conditioning attenuates testicular damage after testicular ischemia and reperfusion injury in rats.

Testicular torsion is a urological emergency. However, surgical detorsion of the torsed spermatic cord can cause testicular reperfusion injury. Although remote ischemic preconditioning (RIPC) has been convincingly shown to protect organs against ischemia/reperfusion (I/R) injury, little is known regarding the effect of RIPC on testicular torsion/detorsion-induced reperfusion injury. Therefore, we aimed to evaluate the effect of RIPC on testes after testicular I/R injury in a rat model in vivo. Male Sprague-Dawley rats were randomly classified into 4 groups: sham-operated (sham), testicular I/R (TI/R), or remote liver (RIPC liver) and limb (RIPC limb) ischemic preconditioning groups. Testis I/R was induced by 3 h of right spermatic cord torsion (720° clockwise), and reperfusion was allowed for 3 hours. In the RIPC group, four cycles of 5 min of ischemia and 5 min of reperfusion were completed 30 min prior to testicular torsion. The ERK1/2 inhibitor U0126 was administered intravenously at the beginning of reperfusion (1 mg/kg). The testes were taken for the oxidative stress evaluations, histology, apoptosis, immunohistochemical and western blotting analysis. Remote liver and limb ischemic preconditioning attenuated ipsilateral and contralateral testicular damage after testicular I/R injury. For example. RIPC reduced testicular swelling and oxidative stress, lessened structural damage, and inhibited the testicular inflammatory response and apoptosis. Furthermore, RIPC treatment enhanced testicular ERK1/2 phosphorylation postI/R. Inhibition of ERK1/2 activity using U0126 eliminated the protection offered by RIPC. Our data demonstrate for the first time that RIPC protects testes against testicular I/R injury via activation of the ERK1/2 signaling pathway.

Effect of remote ischemic preconditioning on lung function after surgery under general anesthesia: a systematic review and meta-analysis

Remote ischemic preconditioning (RIPC) protects organs from ischemia–reperfusion injury. Recent trials showed that RIPC improved gas exchange in patients undergoing lung or cardiac surgery. We performed a systematic search to identify randomized controlled trials involving RIPC in surgery under general anesthesia. The primary outcome was the PaO2/FIO2 (P/F) ratio at 24 h after surgery. Secondary outcomes were A-a DO2, the respiratory index, duration of postoperative mechanical ventilation (MV), incidence of acute respiratory distress syndrome (ARDS), and serum cytokine levels. The analyses included 71 trials comprising 7854 patients. Patients with RIPC showed higher P/F ratio than controls (mean difference [MD] 36.6, 95% confidence interval (CI) 12.8 to 60.4, I2 = 69%). The cause of heterogeneity was not identified by the subgroup analysis. Similarly, A-a DO2 (MD 15.2, 95% CI − 29.7 to − 0.6, I2 = 87%) and respiratory index (MD − 0.17, 95% CI − 0.34 to − 0.01, I2 = 94%) were lower in the RIPC group. Additionally, the RIPC group was weaned from MV earlier (MD − 0.9 h, 95% CI − 1.4 to − 0.4, I2 = 78%). Furthermore, the incidence of ARDS was lower in the RIPC group (relative risk 0.73, 95% CI 0.60 to 0.89, I2 = 0%). Serum TNFα was lower in the RIPC group (SMD − 0.6, 95%CI − 1.0 to − 0.3 I2 = 87%). No significant difference was observed in interleukin-6, 8 and 10. Our meta-analysis suggested that RIPC improved oxygenation after surgery under general anesthesia.Clinical trial number: This study protocol was registered in the University Hospital Medical Information Network (registration number: UMIN000030918), https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000035305.

Effects of remote ischemic preconditioning in severe traumatic brain injury: A single-center randomized controlled trial.

Traumatic brain injury (TBI) is a significant contributor to global mortality and impairment. Experimental data has shown the advantages of remote ischemic preconditioning (RIPC) in treating brain injury, however, there is a lack of evidence-based medicine regarding its clinical effectiveness and safety. In this study, we investigated whether RIPC could enhance outcomes in patients with severe TBI. Between January 2019 and December 2022, a comprehensive assessment was conducted on 392 individuals with severe TBI. Out of these, 304 patients were initially included and randomly assigned to receive either RIPC treatment (n = 153) or a control treatment (n = 151). The main measures of results included Glasgow Outcome Scale scores at 6 months, the occurrence of cerebral infarction during hospitalization, mortality rate within 30 days, levels of neuron-specific enolase and S-100β, any adverse effects, expenses incurred during hospitalization, and duration of hospital stay. The 2 groups did not show any statistically significant differences in baseline clinical data. The Glasgow Outcome Scale scores at 6 months in the RIPC group showed significant improvement when compared with the control group. Additionally, the application of RIPC therapy can reduce the concentrations of neuron-specific enolase and S-100β. There was no notable distinction observed between the 2 groups regarding the adverse reactions of RIPC-induced objective indications of tissue or neurovascular harm. In the RIPC group, there was a significant reduction in both the duration of hospital stays and the expenses associated with hospitalization. The results of this study suggest that RIPC has the potential to enhance clinical outcomes, mitigate nerve damage, and reduce both hospital expenses and length of stay in patients with severe TBI. The use of RIPC is a reliable and efficient method for managing severe TBI.

Effects of Remote Ischemic Preconditioning on Delirium and Neurological Function in Patients Undergoing Cardiac Surgery: A Multicenter Randomized Controlled Trial.

Postoperative delirium (POD) and neurological dysfunction are very common following cardiac surgery and deteriorate the patient's prognosis and the outcome of surgical procedures. A clinically effective management strategy or drug is not yet available for POD. Additionally, it is unknown whether remote ischemic preconditioning (RIPC) has neuroprotective and anti-delirium benefits in patients who undergo cardiac surgery. This study examined whether RIPC can improve POD and neurological function in cardiac surgery patients. We screened 510 consecutive adult patients aged 18 and older who underwent cardiac surgery between January 2018 and December 2022. Then, 448 of these patients were recruited in the trial as the intention to treat (ITT) group, who were then randomly assigned to receive either a control (n = 223) or RIPC treatment (n = 225). The primary outcome measures were hospitalization postoperative delirium, six-month modified Rankins scale (mRS), hospital cerebral infarction, 30-day overall mortality, neuron-specific enolase (NSE) and S-100b levels, related adverse effects, hospital costs, and hospital stay. A statistically significant variation was not observed between the two groups in terms of the baseline clinical data. In contrast to the control group, the POD in the RIPC group was considerably alleviated. RIPC treatment also decreased the levels of NSE and S-100b, which alleviated nerve injury. The adverse impacts of RIPC-induced objective indicators of tissue or neurovascular damage were similar in both groups, showing no significant variations between the two. The hospital stays and hospitalization costs also decreased significantly in the RIPC-treated patients. The study findings suggested that RIPC may benefit cardiac surgery patients by reducing POD, alleviating injury, and lowering hospital expenditures and length of stay. Cardiac surgery patients can be treated with RIPC, which is an effective and safe technique.

Remote ischemic preconditioning and hypoxia-induced biomarkers in acute myocardial infarction: study on a porcine model

Objectives. Remote ischemic preconditioning (RIPC) mitigates acute myocardial infarction (AMI). We hypothesized that RIPC reduces the size and severity of AMI and explored molecular mechanisms behind this phenomenon. Design. In two series of experiments, piglets underwent 60 min of the circumflex coronary artery occlusion, resulting in AMI. Piglets were randomly assigned into the RIPC groups (n = 7 + 7) and the control groups (n = 7 + 7). The RIPC groups underwent four 5-min hind limb ischemia-reperfusion cycles before AMI. In series I, the protective efficacy of RIPC was investigated by using biomarkers and echocardiography with a follow-up of 24 h. In series II, the heart of each piglet was harvested for TTC-staining to measure infarct size. Muscle biopsies were collected from the hind limb to explore molecular mechanisms of RIPC using qPCR and Western blot analysis. Results. The levels of CK-MBm (p = 0.032) and TnI (p = 0.007) were lower in the RIPC group. Left ventricular ejection fraction in the RIPC group was greater at the end of the follow-up. The myocardial infarct size in the RIPC group was smaller (p = 0.033). Western blot indicated HIF1α stabilization in the skeletal muscle of the RIPC group. PCR analyses showed upregulation of the HIF target mRNAs for glucose transporter (GLUT1), glucose transporter 4 (GLUT4), phosphofructokinase 1 (PFK1), glyceraldehyde 3-phosphate dehydrogenase (GAPDH), enolase 1 (ENO1), lactate dehydrogenase (LDHA) and endothelial nitric oxidate synthase (eNOS). Conclusions. Biochemical, physiologic, and histologic evidence confirms that RIPC decreases the size of AMI. The HIF pathway is likely involved in the mechanism of the RIPC.

Effects of remote ischemic preconditioning on coronary blood flow and microcirculation

This study aimed to determine the effect of short-term remote ischemic preconditioning (RIPC) on coronary blood flow and microcirculation function using the quantitative flow ratio (QFR) and index of microcirculatory resistance (IMR). We randomly divided 129 patients undergoing coronary angiography (CAG) into RIPC and control groups. Following the first CAG, we randomly divided the patients further into the unilateral upper limb and lower limb groups for four cycles of ischemia/reperfusion circulation; subsequently, we performed the second CAG. During each CAG, contrast-flow QFR (cQFR), fixed-flow QFR (fQFR), and IMR (in patients with cardiac syndrome X) were calculated and compared. We measured 253 coronary arteries in 129 patients. Compared to the control group, the average cQFR of the RIPC group increased significantly after RIPC. Additionally, 23 patients with cardiac syndrome X (IMR > 30) were included in this study. Compared to the control group, IMR and the difference between cQFR and fQFR (cQFR-fQFR) both decreased significantly after receiving RIPC. The application of RIPC can increase coronary blood flow and improve coronary microcirculation function.

Effects of RIPC on the Metabolomical Profile during Lower Limb Digital Subtraction Angiography: A Randomized Controlled Trial.

Remote ischemic preconditioning (RIPC) has demonstrated protective effects in patients with lower extremity arterial disease (LEAD) undergoing digital subtraction angiography (DSA) and/or percutaneous transluminal angioplasty (PTA). This study aimed to investigate the impact of RIPC on the metabolomical profile of LEAD patients undergoing these procedures and to elucidate its potential underlying mechanisms. A total of 100 LEAD patients were enrolled and randomly assigned to either the RIPC group (n = 46) or the sham group (n = 54). Blood samples were drawn before and 24 h after intervention. Targeted metabolomics analysis was performed using the AbsoluteIDQ p180 Kit, and changes in metabolite concentrations were compared between the groups. The RIPC group demonstrated significantly different dynamics in nine metabolites compared to the sham group, which generally showed a decrease in metabolite concentrations. The impacted metabolites included glutamate, taurine, the arginine-dimethyl-amide-to-arginine ratio, lysoPC a C24:0, lysoPC a C28:0, lysoPC a C26:1, PC aa C38:1, PC ae C30:2, and PC ae C44:3. RIPC exhibited a 'stabilization' effect, maintaining metabolite levels amidst ischemia-reperfusion injuries, suggesting its role in enhancing metabolic control. This may improve outcomes for LEAD patients. However, additional studies are needed to definitively establish causal relationships among these metabolic changes.

Remote ischemic preconditioning improves spatial memory and sleep of young males during acute high-altitude exposure

ObjectiveThe high-altitude hypoxia environment will cause poor acclimatization in a portion of the population. Remote ischemic preconditioning（RIPC）has been demonstrated to prevent cardiovascular and cerebrovascular diseases under ischemic or hypoxic conditions. However, its role in improving acclimatization and preventing acute mountain sickness (AMS) at high altitude has been undetermined. This study aims to estimate the effect of RIPC on acclimatization of individuals exposed to high altitude. MethodsThe project was designed as a randomized controlled trial with 82 healthy young males, who received RIPC training once a day for 7 consecutive days. Then they were transported by aircraft to a high altitude (3680 m) and examined for 6 days. Lake Louise Score(LLS) of AMS, physiological index, self-reported sleep pattern, and Pittsburgh Sleep Quality Index（PSQI）score were applied to assess the acclimatization to the high altitude. Five neurobehavioral tests were conducted to assess cognitive function. ResultsThe result showed that the RIPC group had a significantly lower AMSscore than the control group (2.43 ± 1.58 vs 3.29 ± 2.03, respectively; adjusted mean difference-0.84, 95% confidence interval-1.61 to −0.06, P = 0.036). and there was no significant difference in AMS incidence between the two groups (25.0% vs 28.57%, P = 0.555). The RIPC group performed better than the control group in spatial memory span score (11[9-12] vs 10[7.5-11], P=0.025) and the passing digit (7[6-7.5] vs 6[5-7], P= 0.001). Spatial memory was significantly higher in the high-altitude RIPC group than in the low-altitude RIPC group (P＜0.01). And the RIPC group obtained significantly lower self-reported sleep quality score (P = 0.024) and PSQI score (P = 0.031). ConclusionsThe RIPC treatment improved spatial memory and sleep quality in subjects exposed to acute hypoxic exposure and this may lead to improved performance at high altitude.

Effect of remote ischemic preconditioning on postoperative gastrointestinal function in patients undergoing laparoscopic colorectal cancer resection.

Patients undergoing laparoscopic colorectal cancer resection have a high incidence of postoperative gastrointestinal dysfunction (POGD). Remote ischemic preconditioning (RIPC) is an organ protection measure. The study investigated the effect of RIPC on postoperative gastrointestinal function. In this single-center, prospective, double-blinded, randomized, parallel-controlled trial, 100 patients undergoing elective laparoscopic colorectal cancer resection were randomly assigned in a 1:1 ratio to receive RIPC or sham RIPC (control). Three cycles of 5-min ischemia/5-min reperfusion induced by a blood pressure cuff placed on the right upper arm served as RIPC stimulus. Patients were followed up continuously for 7 days after surgery. The I-FEED score was used to evaluate the patient's gastrointestinal function after the surgery. The primary outcome of the study was the I-FEED score on POD3. Secondary outcomes include the daily I-FEED scores, the highest I-FEED score, the incidence of POGD, the changes in I-FABP and the inflammatory markers (IL-6 and TNF-α), and the time to first postoperative flatus. A total of 100 patients were enrolled in the study, of which 13 patients were excluded. Finally, 87 patients were included in the analysis, 44 patients in the RIPC group and 43 patients in the sham-RIPC group. Patients assigned to the RIPC group had a lower I-FEED score on POD3 compared with the sham-RIPC group (mean difference 0.86; 95% CI: 0.06 to 1.65; P = 0.035). And patients in the RIPC group were also associated with a lower I-FEED score on POD4 vs the sham-RIPC group (mean difference 0.81; 95% CI: 0.03 to 1.60; P = 0.043). Compared with the sham-RIPC group, the incidence of POGD within 7days after surgery was lower in the RIPC group (P = 0.040). At T1, T2, and T3 time points, inflammatory factors and I-FABP were considerably less in the RIPC group compared to the sham-RIPC group. The time to the first flatus and the first feces was similar in both groups. RIPC reduced I-FEED scores, decreased the incidence of postoperative gastrointestinal dysfunction, and lowered concentrations of I-FABP and inflammatory factors.

Effects of Remote Ischemic Preconditioning on Postoperative Cognitive Dysfunction in Elderly Patients with Laparoscopic Cholecystectomy.

We hypothesized that remote ischemic preconditioning (RIPC) could improve postoperative cognitive dysfunction (POCD) in elderly patients following laparoscopic cholecystectomy (LC). Eighty-eight patients were randomly assigned to either the control or the RIPC group. The RIPC was applied on the right upper limb using a blood pressure cuff inflating 200 mmHg, consisting of 3 cycles of 5 min ischemia and 5 min reperfusion. Serum concentrations of Neuron-specific Enolase (NSE) and Brain-Derived Neurotrophic Factor (BDNF) were collected at one-day preoperative (T0), at the end of the operation (T4) and one-day postoperative (T5). Z score was tested at T0 and 3 days after the operation (T6). POCD was determined if there were two Z scores ≥1.96 at the same time or an average Z score ≥1.96. There was no significant difference in the Z score of each test between the two groups at T0 (P > 0.05). Notably, the duration of Stroop test C was significantly shorter in the RIPC group than that in the Control group at T6 (P = 0.01). POCD occurred in 1/44 (2.3%) patients in the RIPC group and 8/44 (18.2%) patients in the control group at T6 (P=0.035). In addition, serum NSE concentration was significantly decreased, but serum BDNF concentration was increased compared with the control group at T4 and T5 (P<0.001). RIPC could reduce the incidence of POCD in elderly patients after laparoscopic cholecystectomy.