Myocardial protective and anti-inflammatory effects of dexmedetomidine in patients undergoing cardiovascular surgery with cardiopulmonary bypass: a systematic review and meta-analysis

Global trend of review articles focused on cardiopulmonary bypass: Perspectives from bibliometrics

BACKGROUND

Cardiopulmonary bypass (CPB) is a life-support technology widely used in surgery. Review articles reflect research advances in a certain topic or field within a certain period of time.

AIM

To perform a bibliometric analysis of the review articles that focused on CPB for cardiovascular surgery.

METHODS

This study was based on a bibliometric analysis. Data were acquired from the Web of Science and basic bibliometric parameters were analyzed and visualized using VOSviewer and Excel.

RESULTS

We identified 141 review articles on CPB. Generally, the number of publications increased, and most of them were published in the 2010s (n = 57, 40.4%) and the 2020s (n = 45, 31.9%). There were 113 (80.1%) narrative review articles, 21 (14.9%) meta-analysis studies and 7 (5.0%) systematic review papers. The United States (n = 25, 17.7%) and China (n = 21, 14.9%) were the leading countries in terms of publication number. The articles were published in 98 different journals. The Journal of Cardiothoracic and Vascular Anesthesia (n = 14, 10.0%) and Perfusion-United Kingdom (n = 11, 7.8%) were preferred by the authors. The high-frequency keywords included inflammatory response, children, acute kidney injury, meta-analysis and off-pump, except for CPB and cardiac surgery. Inflammatory response had the closest relationship with CPB during cardiac surgery. The complications of CPB, including inflammatory response, kidney injury and ischemia, caught lots of concern.

CONCLUSION

The rapid increase of review papers shows that the research on CPB in cardiac surgery is increasingly being emphasized by scholars and clinical staff worldwide. Meta-analysis has been widely conducted to analyze clinical controversies and further guide clinical practice. Strategies to improving the outcomes of patients undergoing cardiac surgery with CPB are the hot spots in this field.

Research status and advances in dexmedetomidine for sepsis‑induced multiple organ dysfunction syndrome (Review)

Sepsis‑induced organ dysfunction syndrome (ODS) arises from a dysregulated response to infection, leading to multiple life‑threatening organ dysfunctions, and is a common complication in critically ill patients. Sepsis results in varying degrees of injury to the brain, lungs, kidneys and liver, culminating in immune dysfunction and multiple ODS (MODS). Current evidence indicates a direct correlation between the severity of organ injury and the prognosis of septic patients. Understanding the mechanisms of MODS in sepsis and developing effective management strategies are vital research areas. The protective effects of dexmedetomidine (DEX) on sepsis are well established, demonstrating its capacity to mitigate injuries to the brain, lungs, kidneys, liver and immune system. The present study reviews recent research progress on the role and mechanisms of action of DEX in the treatment of sepsis.

Early sedation with dexmedetomidine in patients with acute myocardial infarction requiring mechanical ventilation

AIMS

Patients with acute myocardial infarction (AMI) who require invasive mechanical ventilation (IMV) represent a critically ill population with limited data on optimal sedative and analgesic use. Clinical trials assessing dexmedetomidine use exclude poorly represent patients with AMI. This study aimed to compare the use of early sedation with dexmedetomidine with usual care sedation in patients with AMI requiring IMV.

METHODS AND RESULTS

We utilized the Vizient® Clinical Data Base to identify patients aged ≥18 years admitted between 2015 and 2019 with a primary diagnosis of AMI who required IMV. Patients receiving dexmedetomidine on the first day of IMV were included in the early dexmedetomidine group, while the remaining patients were assigned to the usual care group. Inverse probability of treatment weighting (IPTW) was used to estimate adjusted risk differences between groups. We identified 15 928 patients, of which 1620 (10.2%) received early dexmedetomidine. Patients who received early dexmedetomidine were more likely to present with cardiogenic shock (52.0 vs. 47.7%, P = 0.001). In unadjusted analyses, patients receiving early dexmedetomidine had lower in-hospital mortality (33.0 vs. 42.1%) and more ventilator-free days (13.6 vs. 12.1) compared with usual care (both, P < 0.05). After IPTW, patients receiving early dexmedetomidine had an 11.0% [95% confidence interval (CI): 8.6-13.5%] lower mortality and more ventilator-free days (mean difference: +2.2 days, 95% CI: 1.6-2.8 days).

CONCLUSION

Early sedation with dexmedetomidine was associated with lower mortality compared with usual care in patients with AMI requiring IMV. A randomized controlled trial of sedative agents in this population is warranted.

Somatostatin and N-acetylcysteine on testicular damage triggered by ischemia reperfusion: cellular protection and antioxidant effects

Ischemia-reperfusion (I/R) injury is a significant cause of testicular damage, leading to infertility and other reproductive dysfunctions. Antioxidant therapies have emerged as a potential intervention to mitigate oxidative stress and cellular damage. This study investigates the effects of somatostatin (SST) and N-acetylcysteine (NAC) on testicular damage induced by I/R, focusing on their antioxidant and cellular protective effects. Twenty-four male rats were divided into four groups, as follows: sham operated, I/R injury, I/R + somatostatin treatment, and I/R + NAC treatment. A testicular I/R injury was induced surgically, followed by either SST or NAC administration. Testicular tissues were assessed histopathologically using hematoxylin and eosin staining and employing Johnson's biopsy scoring. Immunohistochemical analyses were performed for caspase- 3, 8-hydroxy- 2'-deoxyguanosine (8-OHdG), testis-specific histone 2B, and testosterone to evaluate apoptosis, oxidative DNA damage, cellular proliferation, and steroidogenesis, respectively. Serum levels of testosterone and follicle-stimulating hormone (FSH) were measured by biochemical analysis. The results showed that both SST and NAC treatments significantly ameliorated histopathological damage and reduced the levels of caspase- 3 and 8-OHdG, indicating reduced apoptosis and oxidative DNA damage. Furthermore, increased testis-specific histone 2B positivity suggested enhanced cellular proliferation. Notably, administration of SST decreased testosterone positivity in the testis, whereas NAC treatment increased it. However, no significant differences in serum testosterone levels were observed between the NAC and SST groups. In addition, serum FSH levels of the I/R + SST group were found to be significantly higher than those of the control group. SST and NAC exhibit protective effects against testicular damage induced by I/R, as evidenced by their antioxidant and anti-apoptotic properties. The differential impact on testosterone positivity in the testis tissue highlights distinct underlying mechanisms, warranting further investigation. Despite these promising findings, the lack of significant changes in serum hormone levels calls for additional studies to fully elucidate the therapeutic potential and mechanistic pathways of SST and NAC in the context of testicular I/R injury.

A review of recent advances in anesthetic drugs for patients undergoing cardiac surgery

Inducing and maintaining general anesthesia requires a diverse set of medications. Currently, heart surgery anesthetic management does not adhere to any one standard protocol or set of drugs. To ensure steady circulatory function while providing sufficient sedation, anesthetic medications are carefully selected for cardiovascular operations. Among the opioids used most often in cardiac surgery are fentanyl, sufentanil, and remifentanil. As a cardiac anesthesiologist, your key responsibilities will be to maintain your patient's blood pressure (BP) and oxygen levels, reduce the frequency and intensity of ischemia events, and make it easy for them to get off of cardiopulmonary bypass (CPB) and supplemental oxygen fast. Additionally, new knowledge gaps have been identified as a result of developments in cardiac anesthetics, which must be addressed. The goal of the most recent developments in cardiac anesthesia has been to decrease risks and increase accuracy in patient outcomes during cardiac surgeries. Furthermore, new methods and tools are contributing to the evolution of cardiovascular anesthesia toward a more dynamic, patient-centered approach, with an eye on boosting safety, decreasing complications, and facilitating better recovery for patients. New medications and methods have emerged in the field of anesthetic pharmacology, aiming to improve anesthesia management, particularly for patients who have cardiovascular disease. Optimal cardiovascular stability, fewer side effects, and enhanced surgical recovery are achieved by use of these medications. We have reviewed all the different kinds of cardiac anesthetic techniques and medications in this research. We have also examined the many new anesthetic medicines that have been produced and used for individuals with cardiovascular issues. Next, we covered prospects in the realm of cardiovascular anesthesia and novel cardiac anesthetic drugs.

Dexmedetomidine improves clinical outcomes in sepsis-induced myocardial injury: a retrospective cohort study

Background

The efficacy of dexmedetomidine (DEX) in treating sepsis-induced myocardial injury (SIMI) remains unclear. In this study, we explored the relationship between DEX use and clinical outcomes of patients with SIMI, focusing on the dosage and treatment duration.

Methods

In this retrospective cohort analysis, we identified patients with SIMI from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database and categorized them into the DEX and non-DEX groups based on intensive care unit treatment. The baseline bias was reduced through propensity score matching (PSM). The primary outcome was 28-day mortality, whereas the secondary outcomes were in-hospital mortality and mortality rates at 7 days, 90 days, and 1 year. The association between DEX use and in-hospital mortality was assessed using Kaplan-Meier analysis and Cox proportional hazards models.

Results

After PSM, 373 patients in the DEX group were matched with 579 patients in the non-DEX group to achieve a balanced distribution of the covariates. The Cox regression model demonstrated a significant reduction in the 28-day mortality associated with DEX use, yielding a hazard ratio (HR) of 0.61 (95% confidence interval [CI]: 0.47-0.78, P < 0.001). In-hospital mortality also significantly decreased (HR = 0.43, 95% CI: 0.33-0.57, P < 0.001). Lower mortality rates were observed at 7 days, 90 days, and 1 year. DEX doses >0.4 μg/kg/h, particularly in the range of 0.400-0.612 μg/kg/h, total doses >3.113 mg during hospitalization, and treatment durations exceeding 72 h were associated with improved mortality risk at all intervals. Regarding DEX efficacy at 28 days, our subgroup analyses indicated a significant interaction between the Sequential Organ Failure Assessment score and invasive mechanical ventilation.

Conclusion

DEX administration was associated with improved in-hospital mortality and reduced mortality rates at 7 days, 28 days, 90 days, and 1 year in patients with SIMI. These findings require validation in future studies.

Short term outcomes of the first pediatric cardiac surgery program in Rwanda

BACKGROUND

While the number of cardiac surgery programs in sub-Saharan Africa are increasing, it is still insufficient. With only 0.08 pediatric cardiac surgeons per million people, few cardiac centers routinely perform pediatric cardiac surgery. This has led to reliance on humanitarian medical missions or referral abroad for most African nations. This study outlines the outcomes of Rwanda's first sustainable pediatric cardiac surgery program.

METHODS

A retrospective chart review was performed for all pediatric patients who received cardiac surgery between October 2022 and April 2024. Patient demographics, procedures, operative times, length of stay, complications, and 30-day mortality were synthesized. Perioperative factors associated with complications and prolonged intensive care unit length of stay were evaluated using logistic and linear regression analysis, respectively.

RESULTS

207 patients received 240 cardiac procedures. At time of surgery, 45% of patients were 1-5 years old (n = 95). The top five procedures were repair of Ventricular Septal Defect, Patent Ductus Arteriosus, Atrial Septal Defect, Tetralogy of Fallot and Coarctation of the Aorta. 30-day mortality was 1.9% (n = 4) and 6.3% (n = 13) experienced a major complication. Additionally, 24% (n = 50) experienced minor complications, most commonly, pneumonia. The linear combination of surgery duration, cross clamp and bypass time was significantly associated with having complications (aOR = 0.67, p = 0.01). Younger age, longer operative times, number of inotropes and the presence of complications were associated with an increased intensive care unit stay.

CONCLUSIONS

The 30-day surgical outcomes are favorable compared to programs with a similar case mix, showing that pediatric cardiac surgery can be safely performed in developing countries with local cardiac teams. Prolonged bypass and cross clamp times were associated with higher complication rates and increased inotrope use was associated with longer intensive care unit stay.

The Effect of Dexmedetomidine and Levobupivacaine in an Experimental Ischemia Reperfusion Model

BACKGROUND/AIM

Although it has been reported that different molecules are effective in preventing ischemia-reperfusion (I/R) injury, the most effective treatment is still unknown.

MATERIALS AND METHODS

The rats were divided into four groups of eight rats each. Group C: 1 ml intraperitoneal (IP) isotonic + laparotomy + IP 2 ml isotonic +I/R. Group D: 100 μg kg-1/1 ml IP dexmedetomidine + laparotomy + IP 2 ml isotonic +I/R. Group L: 1 ml IP isotonic + laparotomy + IP levobupivacaine (2.5 mg kg-1/2 ml) +I/R. Group DL: 100 μg kg-1/1 ml IP dexmedetomidine + laparotomy + IP levobupivacaine (2.5 mg kg-1/2 ml) +I/R. Brain, heart, lung, and liver tissue samples were collected for histopathological examination. Biochemically, levels of aspartate amino transaminase, alanine amino transaminase, serum glucose, total antioxidant status (TAS), total oxidant status, ischemia modified albumin, and malondialdehyde were measured in blood samples.

RESULTS

Group D mean blood TAS levels were found to be statistically significantly higher than those in Group C and Group L (p=0.037, p=0.048 respectively). Group DL oxidative stress index (OSI) value was found to be statistically significantly lower than that of Group C (p=0.010).

CONCLUSION

Both dexmedetomidine and levobupivacaine demonstrated protective effects in I/R injury. When used in combination, the effects of these treatments were further enhanced, reaching statistical significance. As our literature review found no studies on the combined use of dexmedetomidine and levobupivacaine in I/R injury, it is anticipated that supporting these results with clinical studies may significantly contribute to clinical practice.

Protective Effects of Trimetazidine and Dexmedetomidine on Liver Injury in a Mesenteric Artery Ischemia-Reperfusion Rat Model via Endoplasmic Reticulum Stress

BACKGROUND/OBJECTIVES

Acute mesenteric ischemia can lead to severe liver damage due to ischemia-reperfusion (I/R) injury. This study investigated the protective effects of trimetazidine (TMZ) and dexmedetomidine (DEX) against liver damage induced by mesenteric artery I/R via endoplasmic reticulum stress (ERS) mechanisms.

METHODS

Twenty-four rats were divided into four groups: control, I/R, I/R+TMZ, and I/R+DEX. TMZ (20 mg/kg) was administered orally for seven days, and DEX (100 µg/kg) was given intraper-itoneally 30 min before I/R induction. Liver tissues were analyzed for creatinine, alanine ami-notransferase (ALT), aspartate aminotransferase (AST), thiobarbituric acid reactive substances (TBARS), and total thiol (TT) levels.

RESULTS

Compared with the control group, the I/R group presented significantly increased AST, ALT, TBARS, and TT levels. TMZ notably reduced creatinine levels. I/R caused significant liver necrosis, inflammation, and congestion. TMZ and DEX treatments reduced this histopathological damage, with DEX resulting in a more significant reduction in infiltrative areas and vascular congestion. The increase in the expression of caspase-3, Bax, 8-OHdG, C/EBP homologous protein (CHOP), and glucose-regulated protein 78 (GRP78) decreased with the TMZ and DEX treatments. In addition, Bcl-2 positivity decreased both in the TMZ and DEX treatments.

CONCLUSIONS

Both TMZ and DEX have protective effects against liver damage. These effects are likely mediated through the reduction in ERS and apoptosis, with DEX showing slightly superior protective effects compared with TMZ.

Dexmedetomidine administration is associated with improved outcomes in critically ill patients with acute myocardial infarction partly through its anti-inflammatory activity

Background

Dexmedetomidine (DEX) is a commonly used sedative in the intensive care unit and has demonstrated cardioprotective properties against ischemia-reperfusion injury in preclinical studies. However, the protective effects of early treatment of DEX in patients with acute myocardial infarction (AMI) and its underlying mechanism are still not fully understood. This study aims to investigate the association between early DEX treatment and in-hospital mortality in patients with AMI, and to explore the potential mediating role of white blood cell (WBC) reduction in this relationship.

Methods

A retrospective cohort analysis was conducted using the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. Patients with AMI were divided into the DEX and non-DEX group, based on whether they received DEX treatment in the early stage of hospitalization. The primary outcome measured was in-hospital mortality. The study evaluated the association between DEX use and in-hospital mortality using the Kaplan-Meier (KM) method and Cox proportional hazards model. Additionally, 1:1 propensity score matching (PSM) was conducted to validate the results. Furthermore, causal mediation analysis (CMA) was utilized to explore potential causal pathways mediated by WBC reduction between early DEX use and the primary outcome.

Results

This study analyzed data from 2,781 patients, with 355 in the DEX group and 2,426 in the non-DEX group. KM survival analysis revealed a significantly lower in-hospital mortality rate in the DEX group compared to the non-DEX group. After adjusting for multiple confounding factors, the Cox regression model demonstrated a significant positive impact of DEX on the risk of in-hospital mortality in patients with AMI, with hazard ratios (HR) of 0.50 (95% confidence interval (CI): 0.35-0.71, p < 0.0001). PSM analysis confirmed these results, showing HR of 0.49 (95% CI: 0.31-0.77, p = 0.0022). Additionally, CMA indicated that 13.7% (95% CI: 1.8%-46.9%, p = 0.022) of the beneficial effect of DEX on reducing in-hospital mortality in patients with AMI was mediated by the reduction in WBC.

Conclusion

The treatment of DEX was associated with a lower risk of in-hospital mortality in patients with AMI, potentially due to its anti-inflammatory properties.

Enhanced recovery after surgery program for patients undergoing isolated elective coronary artery bypass surgery improves postoperative outcomes

OBJECTIVE

To evaluate the effect of a perioperative systematic standardized enhanced recovery after surgery (ERAS) program for patients undergoing isolated elective coronary artery bypass grafting (CABG) in terms of mortality, hospital morbidities, and length of stay.

METHODS

From January 2015 to September 2020, 1101 patients underwent isolated elective CABG. Our standardized systematic ERAS program was implemented in November 2018. Propensity score matching resulted in well-matched pairs of 362 patients receiving standard perioperative care (control group) and 362 patients on the ERAS program (ERAS group). There were no significant intergroup differences in preoperative and operative data except for the normothermia rate, which was significantly greater in the ERAS group (P < .001). The primary outcome was 3-year mortality. The secondary outcomes were hospital morbidities and length of stay.

RESULTS

In-hospital and 3-year mortality did not differ between the 2 groups. The ERAS program was associated with a significant relative risk decrease in mechanical ventilation duration (-53.1%, P = .003), length of intensive care unit stay (-28.0%, P = .015), length of hospital stay (-10.5%, P = .046), bronchopneumonia (-51.5%, P < .001), acute respiratory distress syndrome (-50.8%, P = .050), postoperative delirium (-65.4%, P = .011), moderate-to-severe acute kidney injury (-72.0%, P = .009), 24-hour chest tube output (-26.4%, P < .001), and overall red blood cell transfusion rate (-32.4%, P = .005) compared with the control group.

CONCLUSIONS

A systematic standardized ERAS program for low-risk patients undergoing isolated elective CABG was associated with a significant improvement in postoperative outcomes, reduction in red blood cell transfusion, shorter lengths of intensive care unit and hospital stays, and comparable long-term mortality.

Dexmedetomidine Inhibits Hippocampal Neuronal Damage Caused by Persistent Isoflurane-Induced Hypotension in Rat Model of Chronic Cerebral Hypoperfusion

Purpose The purpose of this study was to investigate the effect of dexmedetomidine (DEX) on hypotension-induced neuronal damage in a chronic cerebral hypoperfusion (CCH) model of rats, an established model of cerebral white matter lesions (WML) in humans, which is prevalent in the elderly and closely related to cognitive decline. Methods The CCH model rats were randomly assigned to one of four groups: normotension + no DEX (NN) group (n = 6), normotension + DEX (ND) group (n = 6), hypotension + no DEX (HN) group (n = 6), or hypotension + DEX (HD) group (n = 6). Under isoflurane anesthesia, mean arterial blood pressure was maintained at or above 80 mmHg (normotension) or below 60 mmHg (hypotension) for a duration of two hours. The DEX groups received 50 μg of DEX intraperitoneally. Two weeks later, the Y-maze test and, after preparing brain slices, immunohistochemical staining were performed using antibodies against neuronal nuclei (NeuN), microtubule-associated protein 2 (MAP2), glial fibrillary acidic protein (GFAP), and Ionized calcium-binding adapter molecule 1 (Iba1). Results Behavioral observations showed no significant differences among the groups. Significant reductions of both NeuN-positive cells and the MAP2-positive area were found in the hippocampal CA1 in the HN group compared with NN and ND groups, but not in the HD group. GFAP and Iba-1-positive areas were significantly increased in the HN group, but not in the HD group. Conclusion DEX significantly ameliorated hypotension-induced neuronal damage and both astroglial and microglial activation in the CA1 region of CCH rats.

Dexmedetomidine for reducing succinylcholine-induced myalgia in patients undergoing electroconvulsive therapy: A randomised controlled trial

Background and Aim

Electroconvulsive therapy (ECT) is an effective intervention for psychiatric patients. Succinylcholine is considered the drug of choice for muscle relaxation for ECT. Significant adverse effects of succinylcholine include fasciculation and myalgia. Dexmedetomidine is a highly selective α-2 adrenergic agonist. This study aims to determine the efficacy of a low dose of dexmedetomidine in reducing succinylcholine-induced myalgia in patients receiving ECT.

Methods

This randomised controlled trial was conducted on 100 patients, aged 18-65 years, undergoing ECT, who were randomly allocated into two groups with an allocation ratio of 1:1. Group D received intravenous (IV) dexmedetomidine 0.25 µg/kg, and Group C received IV normal saline (0.9%). Patients' self-reported myalgia scores were measured after 60 min of the procedure. Fasciculations were noted after IV succinylcholine administration. Heart rate (HR) and mean blood pressure (MBP) were measured at baseline, after infusion (5 min) and after ECT (0, 2.5, 5, 10, 15, 30 min). Continuous data were analysed using a Student's t-test for two-group comparisons, a mixed model analysis of variance for group comparisons and various time point analyses. Categorical data were analysed using the Chi-square/Fisher's exact test.

Results

There were no differences between the groups regarding demographics. Myalgia and fasciculations were less in Group D than in Group C (P < 0.001). MBP and HR changes were comparable (P > 0.05).

Conclusion

A low dose of dexmedetomidine (0.25 µg/kg) effectively reduces myalgia and fasciculations due to succinylcholine in patients undergoing electroconvulsive therapy.

Ferroptosis Exists in Ischemia Reperfusion Injury after Cardiac Surgery with Cardiopulmonary Bypass

Ischemia-reperfusion (IR) injury commonly arises during cardiac surgery involving Cardiopulmonary Bypass (CPB), and it has relationship with ferroptosis in mice. However, the exact role of ferroptosis in the human cardiac damage caused by cardiac surgery remains unclear. Basic patient data and perioperative period information were collected, and clinic indicators related to cardiac function were detected to assess the extent of cardiac injury. Cardiac tissue samples were collected to determine histopathological changes, ultrastructure of mitochondrial and hallmarks of ferroptosis. 25 patients were involved in this study. In the present study, we observed a significant increase in the clinical indicator hs-cTnT, with levels rising more than 1393 ± 242 folds (P < 0.0001) following the cardiac surgery. Masson staining revealed a notable increase in fibrosis levels by 2.282 ± 0.259% (P = 0.0009). Furthermore, there was a significant elevation in lipid peroxidation, as evidenced by a 61.42 ± 17.33% increase in MDA (P = 0.0006). Additionally, we observed notable swelling, decreased mitochondrial crista, and even fragmented mitochondria. Notably, changes in the marker gene of ferroptosis were observed, with PTGS2 showing a 6.437 ± 0.81 folds increase (P < 0.0001). Furthermore, key regulators such as SLC7A11 and GPX4 proteins exhibited a reduction of 97.33 ± 25.78% (P = 0.0068) and 60.59 ± 14.93% (P = 0.0071), respectively, indicating the occurrence of ferroptosis following the surgery. Ferroptosis exists in myocardial IR injury caused by cardiac surgery with CPB, indicating that targeting ferroptosis could serve as a potential strategy for myocardial protection against CPB-induced IR injury. The trial has been registered in Chinese Clinical Trial Registry (ChiCTR, No. ChiCTR2200061995) on July 16th, 2022.

Effects of dexmedetomidine on postoperative pain and early cognitive impairment in older male patients undergoing laparoscopic cholecystectomy

The primary aim of the present study was to investigate the effect of dexmedetomidine (DEX) on postoperative pain and early cognitive impairment in old male patients, who underwent laparoscopic cholecystectomy (LC). A total of 97 old patients, subjected to LC at the 980 Hospital of the Joint Service Support Force of the People's Liberation Army of China, were randomly divided into two groups, namely the DEX and normal saline groups. Patients in the DEX group received an intravenous infusion of 0.8 µg/kg DEX within 10 min following general anesthesia, followed by a maintenance infusion of 0.5 µg/(kg/h). Furthermore, patients in the normal saline group were treated with an equivalent volume of normal saline. Cognitive function was assessed using the Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA) tests at 6 h, 1, 2 and 3 days, postoperatively. The incidence of postoperative cognitive dysfunction (POCD) and postoperative adverse events were recorded for both groups. In addition, the Visual Analogue Scale (VAS) pain score was utilized to assess the pain level of all patients, while the Quality of Recovery-15 (QoR-15) scale was employed to analyze the postoperative recovery results. Therefore, the MoCA score was higher in the DEX group compared with the normal saline group at 6 h and day 1 postoperatively. Additionally, the MMSE score was higher at 6 h postoperatively in the DEX group compared with the normal saline group. Correspondingly, the incidence of POCD was lower in the DEX group compared with the normal saline group at 6 h and day 1, after LC (P<0.05). VAS score in resting state for patients in the DEX group was significantly lower compared with the normal-saline group (P<0.05). Furthermore, the QoR-15 scale score in patients in the DEX group was notably increased compared with the normal saline group on the first and second days after the operation (P<0.05). Overall, the present study verified that the continuous infusion of DEX at a rate of 0.5 µg/(kg/h) during LC could effectively reduce the incidence of early POCD and alleviate postoperative pain in old male patients, thus facilitating postoperative recovery.

Perioperative Glycemic Management in Cardiac Surgery: A Narrative Review

Diabetes and hyperglycemic events in cardiac surgical patients are associated with postoperative morbidity and mortality. The causes of dysglycemia, the abnormal fluctuations in blood glucose concentrations, in the perioperative period include surgical stress, surgical techniques, medications administered perioperatively, and patient factors. Both hyperglycemia and hypoglycemia lead to poor outcomes after cardiac surgery. While trying to control blood glucose concentration tightly for better postoperative outcomes, hypoglycemia is the main adverse event. Currently, there is no definite consensus on the optimum perioperative blood glucose concentration to be maintained in cardiac surgical patients. This review provides an overview of perioperative glucose homeostasis, the pathophysiology of dysglycemia, factors that affect glycemic control in cardiac surgery, and current practices for glycemic control in cardiac surgery.

Dexmedetomidine Pretreatment Confers Myocardial Protection and Reduces Mechanical Ventilation Duration for Patients Undergoing Cardiac Valve Replacement under Cardiopulmonary Bypass

PURPOSE

The study aims to assess the effects of dexmedetomidine (Dex) pretreatment on patients during cardiac valve replacement under cardiopulmonary bypass.

METHODS

For patients in the Dex group (n = 52), 0.5 μg/kg Dex was given before anesthesia induction, followed by 0.5 μg/kg/h pumping injection before aortic occlusion. For patients in the control group (n = 52), 0.125 ml/kg normal saline was given instead of Dex.

RESULTS

The patients in the Dex group had longer time to first dose of rescue propofol than the control group (P = 0.003). The Dex group required less total dosage of propofol than the control group (P = 0.0001). The levels of cardiac troponin I (cTnI), creatine kinase isoenzyme MB (CK-MB), malondialdehyde (MDA), and tumor necrosis factor-α (TNF-α) were lower in the Dex group than the control group at T4, 8 h after the operation (T5), and 24 h after the operation (T6) (P <0.01). The Dex group required less time for mechanical ventilation than the control group (P = 0.003).

CONCLUSION

The study suggests that 0.50 µg/kg Dex pretreatment could reduce propofol use and the duration of mechanical ventilation, and confer myocardial protection without increased adverse events during cardiac valve replacement.

Intra-operative anesthetic induced myocardial protection during cardiothoracic surgery: a literature review

Background and Objective

Myocardial protection involves limiting the metabolic activity and oxygen consumption of the heart, thus enabling surgery to proceed with minimal blood loss while reducing the level of ischemic injury. It was this concept that allowed for the development of the open-heart surgical technique. We know myocardial ischemia and reperfusion injury are both detrimental, thus developing strategies to mitigate this can help reduce peri-operative morbidity and mortality. In this review, we will mainly be addressing the anesthetic considerations for myocardial protection, along with discussing potential future research which can help expand the field.

Methods

We searched the PubMed database for relevant studies dating from 2004-2022. In total, 18 studies were deemed suitable for this literature review.

Key Content and Findings

Studies have demonstrated cardioprotective effects with use of the volatile agents and propofol, mainly with respect to lower levels of inflammatory markers such as creatine kinase (CK)-MB and troponin I (TnI)/troponin T (TnT). The data is lacking regarding protective effects of dexmedetomidine and lidocaine, hence we cannot recommend either agent at present.

Conclusions

Myocardial protection with respect to the anesthetic agents have been extensively studied over the past two decades, some routinely used drugs such as the volatile agents, propofol and opiates have demonstrated a cardioprotective role. The ideal dosing regimen and duration are areas of research that can be studied further. The data for the other anesthetic adjuncts such as lidocaine, dexmedetomidine along with use of regional anesthesia is still equivocal. Alongside advances in anesthesia, we believe surgical research looking into optimal cardioplegia solutions will also help improve myocardial protection in the future.

Dexmedetomidine as a cardioprotective drug: a narrative review

Dexmedetomidine (DEX), a highly selective alpha2-adrenoceptors agonist, is not only a sedative drug used during mechanical ventilation in the intensive care unit but also a cardio-protective drug against ischemia-reperfusion injury (IRI). Numerous preclinical in vivo and ex vivo studies, mostly evaluating the effect of DEX pretreatment in healthy rodents, have shown the efficacy of DEX in protecting the hearts from IRI. However, whether DEX can maintain its cardio-protective effect in hearts with comorbidities such as diabetes has not been fully elucidated. Multiple clinical trials have reported promising results, showing that pretreatment with DEX can attenuate cardiac damage in patients undergoing cardiac surgery. However, evidence of the post-treatment effects of DEX in clinical practice remains limited. In this narrative review, we summarize the previously reported evidence of DEX-induced cardio-protection against IRI and clarify the condition of the hearts and the timing of DEX administration that has not been tested. With further investigations evaluating these knowledge gaps, the use of DEX as a cardio-protective drug could be further facilitated in the management of patients undergoing cardiac surgery and might be considered in a broader area of clinical settings beyond cardiac surgery, including patients with acute myocardial infarction.

Effects of interventions targeting the systemic inflammatory response to cardiac surgery on clinical outcomes in adults

BACKGROUND

Organ injury is a common and severe complication of cardiac surgery that contributes to the majority of deaths. There are no effective treatment or prevention strategies. It has been suggested that innate immune system activation may have a causal role in organ injury. A wide range of organ protection interventions targeting the innate immune response have been evaluated in randomised controlled trials (RCTs) in adult cardiac surgery patients, with inconsistent results in terms of effectiveness.

OBJECTIVES

The aim of the review was to summarise the results of RCTs of organ protection interventions targeting the innate immune response in adult cardiac surgery. The review considered whether the interventions had a treatment effect on inflammation, important clinical outcomes, or both.

SEARCH METHODS

CENTRAL, MEDLINE, Embase, conference proceedings and two trial registers were searched on October 2022 together with reference checking to identify additional studies.

SELECTION CRITERIA

RCTs comparing organ protection interventions targeting the innate immune response versus placebo or no treatment in adult patients undergoing cardiac surgery where the treatment effect on innate immune activation and on clinical outcomes of interest were reported.

DATA COLLECTION AND ANALYSIS

Searches, study selection, quality assessment, and data extractions were performed independently by pairs of authors. The primary inflammation outcomes were peak IL-6 and IL-8 concentrations in blood post-surgery. The primary clinical outcome was in-hospital or 30-day mortality. Treatment effects were expressed as risk ratios (RR) and standardised mean difference (SMD) with 95% confidence intervals (CI). Meta-analyses were performed using random effects models, and heterogeneity was assessed using I2.

MAIN RESULTS

A total of 40,255 participants from 328 RCTs were included in the synthesis. The effects of treatments on IL-6 (SMD -0.77, 95% CI -0.97 to -0.58, I2 = 92%) and IL-8 (SMD -0.92, 95% CI -1.20 to -0.65, I2 = 91%) were unclear due to heterogeneity. Heterogeneity for inflammation outcomes persisted across multiple sensitivity and moderator analyses. The pooled treatment effect for in-hospital or 30-day mortality was RR 0.78, 95% CI 0.68 to 0.91, I2 = 0%, suggesting a significant clinical benefit. There was little or no treatment effect on mortality when analyses were restricted to studies at low risk of bias. Post hoc analyses failed to demonstrate consistent treatment effects on inflammation and clinical outcomes. Levels of certainty for pooled treatment effects on the primary outcomes were very low.

AUTHORS' CONCLUSIONS

A systematic review of RCTs of organ protection interventions targeting innate immune system activation did not resolve uncertainty as to the effectiveness of these treatments, or the role of innate immunity in organ injury following cardiac surgery.

Dexmedetomidine as an anesthetic adjunct is associated with reduced complications and cardiac intensive care unit length of stay after heart valve surgery

BACKGROUND

We sought to explore the relationship between dexmedetomidine as an anesthetic adjuvant in cardiac surgery and postoperative complications and length of stay (LOS) in the cardiac intensive care unit (CICU).

METHODS

We conducted a retrospective study of patients aged 18 years and older who underwent heart valve surgery between October 2020 and June 2022. The primary endpoint of the study was major postoperative complications (cardiac arrest, atrial fibrillation, myocardial injury/infarction, heart failure) and the secondary endpoint was prolonged CICU LOS (defined as LOS > 90th percentile). Multivariate logistic regression analysis was performed for variables that were significant in the univariate analysis.

RESULTS

A total of 856 patients entered our study. The 283 patients who experienced the primary and secondary endpoints were included in the adverse outcomes group, and the remaining 573 were included in the prognostic control group. Multivariate logistic regression analysis revealed that age > 60 years (odds ratio [OR], 1.68; 95% confidence interval [CI], 1.23-2.31; p < 0.01), cardiopulmonary bypass (CPB) > 180 min (OR, 1.62; 95% CI, 1.03-2.55; p = 0.04) and postoperative mechanical ventilation time > 10 h (OR, 1.84; 95% CI, 1.35-2.52; p < 0.01) were independent risk factors for major postoperative complications; Age > 60 years (OR, 3.20; 95% CI, 1.65-6.20; p < 0.01), preoperative NYHA class 4 (OR, 4.03; 95% CI, 1.74-9.33; p < 0.01), diabetes mellitus (OR, 2.57; 95% CI, 1.22-5.41; p = 0.01), Intraoperative red blood cell (RBC) transfusion > 650 ml (OR, 2.04; 95% CI, 1.13-3.66; p = 0.02), Intraoperative bleeding > 1200 ml (OR, 2.69; 95% CI, 1.42-5.12; p < 0.01) were independent risk factors for prolonged CICU length of stay. Intraoperative use of dexmedetomidine as an anesthetic adjunct was a protective factor for major complications (odds ratio, 0.51; 95% confidence interval, 0.35-0.74; p < 0.01) and prolonged CICU stay. (odds ratio, 0.37; 95% confidence interval, 0.19-0.73; p < 0.01).

CONCLUSIONS

In patients undergoing heart valve surgery, age, duration of cardiopulmonary bypass, and duration of mechanical ventilation are associated with major postoperative complication. Age, preoperative NYHA classification 4, diabetes mellitus, intraoperative bleeding, and RBC transfusion are associated with increased CICU length of stay. Intraoperative use of dexmedetomidine may improve such clinical outcomes.

Radioprotective effects of α2-adrenergic receptor agonist dexmedetomidine on X-ray irradiation-induced pancreatic islet cell damage

Comprehensive epidemiological analyses conducted in the last 30 years have revealed a link between radiation and DM. We aimed to determine the effects of dexmedetomidine pretreatment on radiation-induced pancreatic islet cell damage. Twenty-four rats were divided into three groups: group 1 (control group), group 2 (only X-ray irradiation group), and group 3 (X-ray irradiation + dexmedetomidine). We observed necrotic cells with vacuoles accompanying loss of cytoplasm in the islets of Langerhans, extensive edematous areas, and vascular congestions in group 2. In group 3, we observed a decrease in necrotic cells in the islets of Langerhans, and edematous areas and vascular congestion was also reduced. We determined a decrease in β-cells, α-cells, and D-cells in the islets of Langerhans in group 2 compared to the control group. In group 3, β-cells, α-cells, and D-cells were elevated compared to group 2. Ionizing radiation may induce DM. Dexmedetomidine appears to exert a radioprotective effect.

The Effects of Dexmedetomidine on Abdominal Aortic Occlusion-Induced Ovarian Injury via Oxidative Stress and Apoptosis

Ischemia/reperfusion (I/R) induced ovarian damage is caused by various diseases such as ovarian torsion, ovarian transplantation, cardiovascular surgery, sepsis, or intra-abdominal surgery. I/R-related oxidative damage can impair ovarian functions, from oocyte maturation to fertilization. This study investigated the effects of dexmedetomidine (DEX), which has been shown to exhibit antiapoptotic, anti-inflammatory, and antioxidant effects, on ovarian I/R injury. We designed four study groups: group 1 (n = 6): control group; group 2 (n = 6): only DEX group; group 3 (n = 6): I/R group; group 4 (n = 6): I/R + DEX group. Then, ovarian samples were taken and examined histologically and immunohistochemically, and tissue malondialdehyde (MDA) and glutathione (GSH) levels were measured. In the I/R group MDA levels, caspase-3, NF-κB/p65, 8-OHdG positivity, and follicular degeneration, edema, and inflammation were increased compared to the control group (p = 0.000). In addition, GSH levels were significantly decreased in the I/R group compared to the control group (p = 0.000). On the other hand, in the I/R + DEX treatment group MDA levels, caspase-3, NF-κB/p65, 8-OHdG positivity, follicular degeneration, edema, and inflammation findings were decreased than in the I/R group (p = 0.000, p = 0.005, p = 0.005, p = 0.001, p = 0.005, respectively). However, GSH levels increased significantly in the I/R + DEX treatment group compared to the I/R group (p = 0.000). DEX protects against ovarian I/R injury through antioxidation and by suppressing inflammation and apoptosis.

Dexmedetomidine improves lung compliance in patients undergoing lateral decubitus position of shoulder arthroscopy: A randomized controlled trial

BACKGROUND

The improvement of oxygenation and pulmonary mechanics in patients under general anesthesia can be achieved by dexmedetomidine (DEX) infusion. However, its role in patients undergoing lateral supine shoulder arthroscopy has not been thoroughly studied. This study aimed to evaluate the effect of DEX on lung compliance in patients undergoing shoulder arthroscopic surgery in a lateral decubitus position.

METHODS

The patients who underwent lateral recumbent shoulder arthroscopy under general anesthesia were randomly divided into the DEX group (group D) and the control group (group N). At the start of the trial, group D was given 0.5 μg/kg/hours continuous pumping until 30 minutes before the end of anesthesia; Group N was injected with normal saline at the same volume. The patients were recorded at each time point after intubation: supine position for 5 minutes (T0), lateral position for 5 minutes (T1), lateral position for 1 hour (T2), lateral position for 2 hours (T3), airway peak pressure, platform pressure, dynamic lung compliance, and static lung compliance, etc.

RESULTS

At the end of the drug infusion, the DEX group showed significant improved pulmonary mechanics and higher lung compliance than the control group. Compared with group N, group D's heart rate and mean arterial pressure were lower at all time points; there was no statistical difference in Tidal volume and Pressure end-tidal carbon dioxide data at each time point in Group D.

CONCLUSION

DEX can improve lung compliance and reduce airway pressure and platform pressure of patients undergoing shoulder arthroscopy in the lateral position under general anesthesia.

Effects of Dexmedetomidine on Basic Cardiac Electrophysiology in Adults; a Descriptive Review and a Prospective Case Study

Dexmedetomidine (DEX) is a commonly used sedative agent with no or minimal effects on breathing. DEX may also be beneficial in myocardial protection. Since the mechanisms of cardiac effects are not well known, we carried out a descriptive review and examined the effects of DEX on myocardial electrical conduction in a prospective and controlled manner. For the review, clinical studies exploring DEX in myocardial protection published between 2020-2022 were explored. A case study included 11 consecutive patients at a median (range) age of 48 (38-59), scheduled for elective radiofrequency ablation of paroxysmal atrial fibrillation. A bolus dose of DEX 1 µg/kg given in 15 min was followed by a continuous infusion of 0.2-0.7 µg/kg/h. Direct intracardiac electrophysiologic measurements, hemodynamics and oxygenation were measured before and after the DEX bolus. Experimental studies show that DEX protects the heart both via stabilizing cardiac electrophysiology and reducing apoptosis and autophagy after cell injury. The clinical evidence shows that DEX provides cardiac protection during different surgeries. In a clinical study, DEX increased the corrected sinus node recovery time, prolongated the atrioventricular (AV) nodal refractory period and cycle length producing AV nodal Wenckebach retrograde conduction block. DEX has a putative role in organ protection against hypoxic, oxidative and reperfusion injury. DEX slows down the firing of the sinus node and prolongs AV refractoriness.

Effects of dexmedetomidine on cardioprotection and other postoperative complications in elderly patients after cardiac and non-cardiac surgerie

BACKGROUND

After cardiac and non-cardiac surgeries, elderly patients have a high probability of developing cardiac complications and postoperative delirium. Although several clinical trials have investigated whether perioperative intravenous dexmedetomidine can protect the heart and reduce postoperative complications such as delirium in elderly patients, the obtained results have been inconsistent. We conducted a meta-analysis to investigate the effects of dexmedetomidine on cardioprotection and other postoperative complications in elderly patients undergoing cardiac or non-cardiac surgery.

AIM

To investigate the effects of dexmedetomidine on cardiac complications and delirium in elderly patients undergoing cardiac or non-cardiac surgery.

METHODS

The PubMed, Cochrane Library, web of science, and other sources were comprehensively searched for all randomized controlled trials published before May 2021 that investigated the efficacy of dexmedetomidine in the prevention of cardiac and postoperative delirium (POD).

RESULTS

In total, 18 studies involving 1025 patients were included in the meta-analysis. Intravenous dexmedetomidine significantly reduced cardiac troponin I (cTnI) and the inflammatory factor tumor necrosis factor-α (TNF-α) was comparable to the control group. Dexmedetomidine also reduced the POD and mortality rates. However, patients in the dexmedetomidine group were more likely to have a decreased heart rate (within the normal range) and hypotension during dexmedetomidine administration than those in the control group. There was no difference in the occurrence of myocardial infarction, bradycardia, or stroke between the two groups. Dexmedetomidine significantly shortened the time to extubate; however, it did not shorten the length of stay in the intensive care unit.

CONCLUSION

The administration of dexmedetomidine during cardiac and non-cardiac surgeries can provide myocardial protection by inhibiting inflammation and cTnI, which may be beneficial for the rapid recovery of patients. Meanwhile, the administration of dexmedetomidine reduced the incidence of POD and decreased mortality (in-hospital).