Anesthetics attenuate ischemia–reperfusion induced renal injury: Effects and mechanisms

Intraoperative application of low-dose dexmedetomidine or lidocaine for postoperative analgesia in pediatric patients following craniotomy: a randomized double-blind placebo-controlled trial

Background

Postoperative pain is a common occurrence in pediatric patients following craniotomy, often leading to negative outcomes. Intravenous dexmedetomidine and lidocaine are commonly used adjuvant medicines in general anesthesia to reduce perioperative opioid consumption and relieve postoperative pain in adults. While they show promise for use in pediatrics, the evidence of their application in pediatric craniotomy patients is limited. Therefore, we aimed to compare the effects of dexmedetomidine and lidocaine on postoperative pain in pediatric patients following craniotomy.

Methods

We conducted a randomized, double-blind, single-center trial on children scheduled for craniotomy. The 255 recruited participants aged 1-12 years were randomly assigned to intraoperatively receive a loading intravenous dose of either dexmedetomidine 1 μg·kg-1 or lidocaine 2 mg·kg-1 or normal saline for 15 min followed by dexmedetomidine 0.5 μg·kg-1·h-1 or lidocaine 1 mg·kg-1·h-1 or normal saline until the sutures of endocranium were completed. The primary outcome was the cumulative sufentanil consumption within 24 h post-surgery.

Results

A total of 241 patients were included in the statistical analysis. The primary outcome did not show any significant differences among the three groups (median (IQR) lidocaine group: 3.36 (1.32-5.64) μg vs. dexmedetomidine group: 3.12 (1.36-6.39) μg vs. control group 3.46 (1.77-7.62) μg, p = 0.485). Among the secondary outcomes, there was a statistically significant but small reduction in sufentanil consumption within 2 h, postoperative FLACC/WBFS/NRS pain scores within 4 h after surgery and postoperative Ramsay sedation scores in dexmedetomidine group (p < 0.05). Regarding postoperative complications, the incidence of electrolyte disturbance within 24 and 48 h after surgery was significantly higher in control group compared to the other two groups. There were no significant differences in intraoperative opioid consumption, postoperative frequency of remedy medication, or length of hospitalization among the three groups. No adverse events related to lidocaine or dexmedetomidine were observed.

Conclusions

There were no significant differences in the primary outcome among the three groups. Although dexmedetomidine showed some benefits in reducing postoperative opioid consumption within the first 2 h and pain intensity within the first 4 h post-surgery, these findings should be interpreted with caution. Further research is required to comprehensively assess the outcomes and determine the optimal administration strategy.

Clinical Trial Registration

[http://www.chictr.org.cn/index.aspx], identifier [ChiCTR1800019411].

Effect of hydrogen sulfide on ischemia-reperfusion injury of kidney: A systematic review and meta-analysis of in vivo animal studies

Hydrogen sulfide (H₂S) has been shown to be effective against kidney ischemia-reperfusion injury (IRI) in animal studies. We aimed to evaluate the current evidence from in vivo animal studies for the protective effects of H₂S against kidney IRI by systematically reviewing the literature and performing a meta-analysis. Based on the preregistered protocol (PROSPERO: CRD42021295469); PubMed, Medline, Embase, Web of Science, and Scopus were searched to identify in vivo animal studies evaluating the effect of H₂S against kidney IRI. Standardized mean difference (SMD) with 95% confidence interval (CI) was calculated and pooled using random-effects meta-analysis. Twenty-two articles complied with eligibility criteria, from which the creatinine levels of 152 control animals and 182 animals treated with H₂S from 27 individual experiments were pooled. H₂S treatment significantly decreased serum creatinine (SMD = -1.82 [95% CI -1.12, -2.51], p < 0.0001), blood urea nitrogen (-2.50 [-1.46, -3.54], p < 0.0001), tissue malondialdehyde (-2.59 [-3.30, -1.88], p < 0.0001), tunel positive cells (-3.16 [-4.38, -1.94], p < 0.0001), and tubular damage score (-2.01 [-3.03, -0.99], p < 0.0001). There was a high heterogeneity across studies (I² = 83.5% for serum creatinine level). In meta-regression analysis, the type of H₂S donor and its application time accounted for 11.3% (p = 0.025) and 16.6% (p = 0.039) of heterogeneity, respectively. Accordingly, H₂S protects the kidney against IRI only if it is given as GYY4137 before or during ischemia. Although H₂S is a potential candidate against kidney IRI, further well-designed preclinical studies focusing on GYY4137 are warranted before clinical implication.

Pneumoperitoneum and Acute Kidney Injury-An Integrative Clinical Concept Review

An increased intraabdominal pressure, particularly when occurring during periods of hemodynamic instability or fluid overload, is regarded as a major contributor to acute kidney injury (AKI) in intensive care units. During abdominal laparoscopic procedures, intraoperative insufflation pressures up to 15 mmHg are applied, to enable visualization and surgical manipulation but with the potential to compromise net renal perfusion. Despite the widely acknowledged renal arterial autoregulation, net arterial perfusion pressure is known to be narrow, and the effective renal medullary perfusion is disproportionately impacted by venous and lymphatic congestion. At present, the potential risk factors, mitigators and risk-stratification of AKI during surgical pneumoperitoneum formation received relatively limited attention among nephrologists and represent an opportunity to look beyond mere blood pressure and intake-output balances. Careful charting and reporting duration and extent of surgical pneumoperitoneum represents an opportunity for anesthesia teams to better communicate intraoperative factors affecting renal outcomes for the postoperative clinical teams. In this current article, the authors are integrating preclinical data and clinical experience to provide a better understanding to optimize renal perfusion during surgeries. Future studies should carefully consider intrabdominal insufflation pressure as a key variable when assessing outcomes and blood pressure goals in these settings.

Effects of Diazepam on Hematological and Histological Parameters in Rats / in Vivo and Unbiased Stereological Investigation

Diazepam-based drugs are widely used today in human treatment. Diazepam may be a primary drug aimed at treating neurological diseases or an associated drug in the treatment of other diseases in the purpose of symptomatic therapy. The sedative effect of diazepam characterizes it as a drug that people usually use on their own and without a doctor’s supervision. Directly, but also through influencing the nervous system, diazepam disrupts proper functioning of all body organs. The purpose of this paper was to examine the effects of diazepam on blood and cytohistological parameters of rats in an in vivo experiment. Mallory-Azan and immunochistochemical staining methods BLX-CX and Survivin tissues of liver, kidney and spleen of rats were used to achieve the set goal. Cytometric analysis of rats detected cells in apoptosis and measurements of stereological parameters were made using a system according to Cavalier’s principle. Results of analysis of hematological and histological parameters indicate a detrimental effect of diazepam on blood parameters, as well as on structure and functioning of the liver, kidneys and spleen of rats. This paper is a foundation for further detailed scientific research with the aim of elucidating all harmful effects that diazepam has on all organs in the body of rats. This data could serve as a starting point for future studies in clinical pharmacology on therapeutic protocols for usage of diazepam-based sedatives.

Mediators of Regional Kidney Perfusion during Surgical Pneumo-Peritoneum Creation and the Risk of Acute Kidney Injury—A Review of Basic Physiology

Acute kidney injury (AKI), especially if recurring, represents a risk factor for future chronic kidney disease. In intensive care units, increased intra-abdominal pressure is well-recognized as a significant contributor to AKI. However, the importance of transiently increased intra-abdominal pressures procedures is less commonly appreciated during laparoscopic surgery, the use of which has rapidly increased over the last few decades. Unlike the well-known autoregulation of the renal cortical circulation, medulla perfusion is modulated via partially independent regulatory mechanisms and strongly impacted by changes in venous and lymphatic pressures. In our review paper, we will provide a comprehensive overview of this evolving topic, covering a broad range from basic pathophysiology up to and including current clinical relevance and examples. Key regulators of oxidative stress such as ischemia-reperfusion injury, the activation of inflammatory response and humoral changes interacting with procedural pneumo-peritoneum formation and AKI risk will be recounted. Moreover, we present an in-depth review of the interaction of pneumo-peritoneum formation with general anesthetic agents and animal models of congestive heart failure. A better understanding of the relationship between pneumo-peritoneum formation and renal perfusion will support basic and clinical research, leading to improved clinical care and collaboration among specialists.

Minimizing Ischemia Reperfusion Injury in Xenotransplantation

The recent dramatic advances in preventing "initial xenograft dysfunction" in pig-to-non-human primate heart transplantation achieved by minimizing ischemia suggests that ischemia reperfusion injury (IRI) plays an important role in cardiac xenotransplantation. Here we review the molecular, cellular, and immune mechanisms that characterize IRI and associated "primary graft dysfunction" in allotransplantation and consider how they correspond with "xeno-associated" injury mechanisms. Based on this analysis, we describe potential genetic modifications as well as novel technical strategies that may minimize IRI for heart and other organ xenografts and which could facilitate safe and effective clinical xenotransplantation.

Adenosine kinase inhibition attenuates ischemia reperfusion-induced acute kidney injury

Acute kidney injury (AKI) has a high morbidity and mortality, and there is no targeted treatment yet. One of the main causes of AKI is ischemia-reperfusion (IR). Increased release of adenosine under stress and hypoxia exerts anti-inflammatory and antioxidant effects. Adenosine kinase (ADK) is an important enzyme that eliminates adenosine in cells, and can maintain low adenosine concentration in cells. Our previous studies have shown that pretreatment of adenosine kinase inhibitor ABT-702 could markedly attenuate cisplatin-induced nephrotoxicity both in vivo and in vitro. This study is designed to investigate the effect of ADK inhibition on IR-induced AKI. The results showed that ADK expression was positively correlated with the degree of renal tubular injury, which suggested that the degree of ADK inhibition reflected the severity of acute tubular necrosis. In vivo, ADK inhibitor could reduce IR-induced renal injury, which might play a protective role by increasing tissue adenosine level, inhibiting oxidative stress, and reducing cell apoptosis. In HK2 cells, cobaltous dichloride (CoCl₂) increased the level of oxidative stress, up-regulated the production of pro-inflammatory factor, and induced apoptosis, ADK inhibition could alleviate the above damaging effects. Moreover, the anti-apoptotic effect exerted by ADK inhibition was independent of inosine. In summary, our results support the idea that ADK inhibition has protective effects on IR-induced AKI. Adenosine kinase inhibition might provide a new target for AKI prevention and treatment.

Dexmedetomidine Reduces Atrial Fibrillation After Adult Cardiac Surgery: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Dexmedetomidine has been shown to have antiarrhythmic effects by exhibiting sympatholytic properties and activating the vagus nerve in preclinical studies. Results from clinical trials of dexmedetomidine on atrial fibrillation (AF) following adult cardiac surgery are controversial.

MATERIALS AND METHODS

We searched EMBASE, PubMed and Cochrane CENTRAL databases for randomized controlled trials (RCTs) comparing the antiarrhythmic effect of dexmedetomidine versus placebo or other anesthetic drugs in adult patients undergoing cardiac surgery. The primary outcome was the incidence of AF. The secondary outcomes were ventricular arrhythmias [ventricular fibrillation (VF), ventricular tachycardia (VT)], mechanical ventilation (MV) duration, intensive care unit (ICU) length of stay, and hospital length of stay, and all-cause mortality.

RESULTS

Thirteen trials with a total of 1684 study patients were selected. Compared with controls, dexmedetomidine significantly reduced the incidence of postoperative AF [odds ratio (OR) 0.75; 95% confidence interval (CI) 0.58-0.97; P = 0.03] and VT (OR 0.23; 95% CI 0.11-0.48; P < 0.0001). No significant difference for the incidence of VF existed (OR 0.80; 95% CI 0.21-3.03; P = 0.74). There was no significant difference between groups in MV duration [weighted mean difference (WMD) - 0.10; 95% CI - 0.42 to 0.21; P = 0.52], postoperative ICU stay (WMD - 0.49; 95% CI - 2.64 to 1.66; P = 0.65), hospital stay (WMD - 0.01; 95% CI - 0.16 to 0.13; P = 0.88) and mortality (OR 0.59; 95% CI 0.15-2.37; P = 0.46).

CONCLUSIONS

Perioperative administration of dexmedetomidine in adult patients undergoing cardiac surgery reduced the incidence of postoperative AF and VT. But there was no significant difference in incidence of VF, MV duration, ICU stay, hospital stay and mortality.

Renoprotective effect of edaravone in acute limb ischemia/reperfusion injury

Background

In this experimental study, we aimed to investigate the efficacy of edaravone on renal injury due to acute lower limb ischemia/reperfusion in a rat model.

Methods

Between June 2015 and August 2015, a total of 40 male Wistar rats were used in this study. The rats were randomly divided into the sham, ischemia/reperfusion, edaravone, and solvent groups (n=10 in each). The infrarenal abdominal aorta was clamped for 120 min and was, then, reperfused for 120 min after clamp removal. Edaravone was administered intravenously 30 min before the induction of ischemia. Serum and kidney tissue samples were subjected to biochemical and histopathological analyses.

Results

Edaravone decreased the serum and tissue malondialdehyde levels in the ischemia/reperfusion group. The serum superoxide dismutase activity in the edaravone group was significantly higher than the ischemia/reperfusion and solvent groups. The serum nitric oxide level in the ischemia/reperfusion group was numerically higher than the sham group. The serum nitric oxide level was decreased by edaravone. The serum nitric oxide level was lower in the edaravone group than the solvent group. The tissue nitric oxide level was significantly higher in the ischemia/reperfusion than the sham group. In the ischemia/ reperfusion group, the histopathological changes were improved by edaravone.

Conclusion

Edaravone ameliorated renal injury caused by lower-limb ischemia/reperfusion. Therefore, it can be used to ameliorate acute ischemia/reperfusion injury during aortic and peripheral vascular surgery.

Perioperative acupuncture medicine: a novel concept instead of acupuncture anesthesia

Objective:

To confirm that acupuncture applied to patients would improve the clinical curative effect and accelerate the patient's recovery by introducing the application of acupuncture in pre-operation, during operation, and post-operation.

Data sources:

Literature cited in this review was retrieved from PubMed, Web of Science, and China National Knowledge Infrastructure (CNKI) and was primarily published in English or Chinese from 2010 to 2018, with keywords of “acupuncture,” “electroacupuncture,” “perioperative period,” “sedation,” “analgesia,” and “recovery.” Relevant citations in the retrieved articles were also screened to include more data.

Study selection:

All retrieved literature was scrutinized, most typical articles related on perioperative acupuncture application in clinical study were reviewed.

Results:

Acupuncture could relieve anxiety and stress during the preoperative stage. It reduces the usage of narcotics and stress response, and maintains the respiratory stability and homeostasis during surgery. It also exerts a protective effect on vital organs, and during the postoperative stages, enhances the recovery while effectively alleviating the postoperative pain. This phenomenon prevents common postoperative discomforts such as nausea and vomiting. In addition, it might improve the patients’ long-term prognosis.

Conclusions:

The novel concept “perioperative acupuncture medicine” is to focus on the optimal treatment in the perioperative period of surgical patients. The review reveals the important role of acupuncture in enhancing rapid recovery of patients during the perioperative period.

Prevention of Acute Kidney Injury in Children Undergoing Cardiac Surgery: A Narrative Review

Children undergoing cardiac surgery are at risk of developing acute kidney injury (AKI). Preventing cardiac surgery-associated AKI (CS-AKI) is important as it is associated with increased early- and long-term mortality and morbidity. Targeting modifiable risk factors (eg, avoiding poor renal perfusion, nephrotoxic drugs, and fluid overload) reduces the risk of CS-AKI. There is currently no strong evidence for the routine use of pharmacological approaches (eg, aminophylline, dexmedetomidine, fenoldopam, and steroids) to prevent CS-AKI. There is robust evidence to support the role of early peritoneal dialysis as a nonpharmacologic approach to prevent CS-AKI.

Methods for Defining the Neuroprotective Properties of Xenon

Xenon has features that make it an ideal general anesthetic agent; cost and scarcity mitigate xenon's widespread use in the operating room. Discovery of xenon's cytoprotective properties resulted in its application to thwart ongoing acute neurologic injury, an unmet clinical need. The discovery that xenon's neuroprotective effect interacts synergistically with targeted temperature management (TTM) led to its investigation in clinical settings, including in the management of the postcardiac arrest syndrome, in which TTM is indicated. Following successful demonstration of xenon's efficacy in combination with TTM in a preclinical model of porcine cardiac arrest, xenon plus TTM was shown to significantly decrease an imaging biomarker of brain injury for out of hospital cardiac arrest victims that had been successfully resuscitated. With the development of an efficient delivery system the stage is now set to investigate whether xenon improves survival, with good clinical outcome, for successfully resuscitated victims of a cardiac arrest.

Use of Dexmedetomidine in Cardiothoracic and Vascular Anesthesia

Dexmedetomidine is a highly selective α₂-adrenergic agonist with analgesic and sedative properties. In the United States, the Food and Drug Administration approved the use of the drug for short-lasting sedation (24 h) in intensive care units (ICUs) in patients undergoing mechanical ventilation and endotracheal intubation. In October 2008, the Food and Drug Administration extended use of the drug for the sedation of nonintubated patients before and during surgical and nonsurgical procedures. In the European Union, the European Medicine Agency approved the use of dexmedetomidine in September 2011 with a single recognized indication: ICU adult patients requiring mild sedation and awakening in response to verbal stimulus. At present, the use of dexmedetomidine for sedation outside the ICU remains an off-label indication. The benefits of dexmedetomidine in critically ill patients and in cardiac, electrophysiology-related, vascular, and thoracic procedures are discussed.

Effects of dexmedetomidine on renal tissue after lower limb ischemia reperfusion injury in streptozotocin induced diabetic rats

AIM

The aim of this study was to investigate whether dexmedetomidine - administered before ischemia - has protective effects against lower extremity ischemia reperfusion injury that induced by clamping and subsequent declamping of infra-renal abdominal aorta in streptozotocin-induced diabetic rats.

MATERIAL AND METHODS

After obtaining ethical committee approval, four study groups each containing six rats were created (Control (Group C), diabetes-control (Group DM-C), diabetes I/R (Group DM-I/R), and diabetes-I/R-dexmedetomidine (Group DM-I/R-D). In diabetes groups, single-dose (55 mg/kg) streptozotocin was administered intraperitoneally. Rats with a blood glucose level above 250 mg/dl at the 72nd hour were accepted as diabetic. At the end of four weeks, laparotomy was performed in all rats. Nothing else was done in Group C and DM-C. In Group DM-I/R, ischemia reperfusion was produced via two-hour periods of clamping and subsequent declamping of infra-renal abdominal aorta. In Group DM-I/R-D, 100 μg/kg dexmedetomidine was administered intraperitoneally 30 minutes before ischemia period. At the end of reperfusion, period biochemical and histopathological evaluation of renal tissue specimen were performed.

RESULTS

Thiobarbituric acid reactive substance (TBARS), Superoxide dismutase (SOD), Nitric oxide synthase (NOS), Catalase (CAT) and Glutathion S transferase (GST) levels were found significantly higher in Group DM-I/R when compared with Group C and Group DM-C. In the dexmedetomidine-treated group, TBARS, NOS, CAT, and GST levels were significantly lower than those measured in the Group D-I/R. In histopathological evaluation, glomerular vacuolization (GV), tubular dilatation (TD), vascular vacuolization and hypertrophy (VVH), tubular cell degeneration and necrosis (TCDN), tubular hyaline cylinder (THC), leucocyte infiltration (LI), and tubular cell spillage (TCS) in Group DM-I/R were significantly increased when compared with the control group. Also, GV, VVH, and THC levels in the dexmedetomidine-treated group (Group DM-I/R-D) were found significantly decreased when compared with the Group DM-I/R.

CONCLUSION

We found that dexmedetomidine - 100 μg/kg intraperitoneally - administered 30 minutes before ischemia in diabetic rats ameliorates lipid peroxidation, oxidative stress, and I-R-related renal injury. We suggest that dexmedetomidine administration in diabetic rats before I/R has renoprotective effects.

Recent Perioperative Pharmacological Prevention of Acute Kidney Injury after Cardiac Surgery: A Narrative Review

Acute kidney injury (AKI) is a common and severe complication of cardiac surgery, and related rates of both hospitalization and long-term mortality are increasing. A number of studies have explored the preventive effects of perioperative pharmacological therapy on AKI after cardiac surgery. However, the mechanisms of AKI are multifaceted, and no universal treatment has been confirmed as beneficial. We review and analyze several current perioperative pharmacological therapies for AKI after cardiac surgery to identify promising preventive strategies.

α2-adrenoreceptor modulated FAK pathway induced by dexmedetomidine attenuates pulmonary microvascular hyper-permeability following kidney injury

Renal ischemia-reperfusion (rI/R) could cause remote acute lung injury (ALI) and combination of these two organ injuries can remarkably increase the mortality. This study aims to determine whether dexmedetomidine, an α2-adrenoreceptor agonist sedative, can ameliorate pulmonary microvascular hyper-permeability following rI/R injury and explore the underlying mechanisms. In vivo, C57BL/6J mice received dexmedetomidine (25µg/kg, i.p.) in the absence or presence of α2-adrenergic antagonist atipamezole (250µg/kg, i.p.) or focal adhesion kinase (FAK) inhibitor (30mg/kg, i.p.) before bilateral renal pedicle clamping for 45 minutes followed by 24 hours reperfusion. The lung histopathological changes and the permeability of pulmonary microvascular were assessed respectively. In vitro, the cultured C57BL/6J mice pulmonary microvascular endothelial cells (PMVECs) were treated with serum from mice with rI/R with or without dexmedetomidine and atipamezole. Trans-endothelial permeability and phospho-tyrosine397FAK, F-actin, VE-cadherin and ZO-1 in monolayer PMVECs were measured respectively in the presence or absence of rI/R serum, dexmedetomidine and FAK inhibitor. In vivo, dexmedetomidine remarkably attenuated lung injury and pulmonary microvascular hyper-permeability caused by rI/R injury, which was abolished by atipamezole or FAK inhibitor co-administration. In vitro, the permeability of PMVECs monolayer following exposure to serum from rI/R mice was increased significantly, and decreased by dexmedetomidine. Dexmedetomidine increased phospho-tyrosine397FAK in a time- and dose-dependent manner, which was correlated with the changes in trans-endothelial permeability. Our data indicated that dexmedetomidine is able to ameliorate remote pulmonary microvascular hyper-permeability induced by rI/R, at least in part, via FAK modulation.

Cardiac and renal protective effects of dexmedetomidine in cardiac surgeries: A randomized controlled trial

BACKGROUND

Cardiac and renal injuries are common insults after cardiac surgeries that contribute to perioperative morbidity and mortality. Dexmedetomidine has been shown to protect several organs against ischemia/reperfusion-(I/R) induced injury. We performed a randomized controlled trial to assess the effect of dexmedetomidine on cardiac and renal I/R injury in patients undergoing cardiac surgeries.

MATERIALS AND METHODS

Fifty patients scheduled for elective cardiac surgeries were randomized to dexmedetomidine group that received a continuous infusion of dexmedetomidine initiated 5 min before cardiopulmonary bypass (1 μg/kg over 15 min, followed by 0.5 μg/kg/h) until 6 h after surgery, whereas the control group received an equivalent volume of physiological saline. Primary outcome measures included myocardial-specific proteins (troponin-I, creatine kinase-MB), urinary-specific kidney proteins (N-acetyl-beta-D-glucosaminidase, alpha-1-microglobulin, glutathione transferase-pi, glutathione transferase alpha), serum proinflammatory cytokines (tumor necrosis factor alpha and interleukin-1 beta), norepinephrine, and cortisol levels. They were measured within 5 min of starting anesthesia (T₀), at the end of surgery (T₁), 12 h after surgery (T₂), 24 h after surgery (T₃), 36 h postoperatively (T₄), and 48 h postoperatively (T₅). Furthermore, creatinine clearance and serum cystatin C were measured before starting surgery as a baseline, and at days 1, 4, 7 after surgery.

RESULTS

Dexmedetomidine reduced cardiac and renal injury as evidenced by lower concentration of myocardial-specific proteins, kidney-specific urinary proteins, and pro-inflammatory cytokines. Moreover, it caused higher creatinine clearance and lower serum cystatin C.

CONCLUSION

Dexmedetomidine provided cardiac and renal protection during cardiac surgery.