Intraoperative Low-Dose Dexmedetomidine Administration Associated with Reduced Hepatic Ischemia-Reperfusion Injury in Pediatric Deceased Liver Transplantation: A Retrospective Cohort Study

Current status and perspective on molecular targets and therapeutic intervention strategy in hepatic ischemia-reperfusion injury

Hepatic ischemia‒reperfusion injury (HIRI) is a common and inevitable complication of hepatic trauma, liver resection, or liver transplantation. It contributes to postoperative organ failure or tissue rejection, eventually affecting patient prognosis and overall survival. The pathological mechanism of HIRI is highly complex and has not yet been fully elucidated. The proposed underlying mechanisms include mitochondrial damage, oxidative stress imbalance, abnormal cell death, immune cell hyperactivation, intracellular inflammatory disorders and other complex events. In addition to serious clinical limitations, available antagonistic drugs and specific treatment regimens are still lacking. Therefore, there is an urgent need to not only clarify the exact etiology of HIRI but also reveal the possible reactions and bottlenecks of existing drugs, helping to reduce morbidity and shorten hospitalizations. We analyzed the possible underlying mechanism of HIRI, discussed various outcomes among different animal models and explored neglected potential therapeutic strategies for HIRI treatment. By thoroughly reviewing and analyzing the literature on HIRI, we gained a comprehensive understanding of the current research status in related fields and identified valuable references for future clinical and scientific investigations.

Effect of Dexmedetomidine Combined with Remifentanil on Emergence Agitation During Awakening from Sevoflurane Anesthesia for Pediatric Liver Surgery

BACKGROUND We aimed to assess the effect of dexmedetomidine (Dex) combined with remifentanil on emergence agitation (EA) during awakening from sevoflurane anesthesia for pediatric liver surgery. MATERIAL AND METHODS Sixty children who underwent liver surgery in our hospital were prospectively selected and randomly allocated into group A (placebo+remifentanil+sevoflurane) or group B (Dex+remifentanil+sevoflurane). Mean arterial pressure (MAP) and heart rate (HR) at different time points, agitation score during awakening, behavioral status, pain level, and the incidence of postoperative adverse effects were compared in both groups. RESULTS Children in group B had lower HR and MAP levels immediately after tracheal extubation and 5 min after tracheal extubation than those in group A. The Aono's scores, PAED agitation scores, and CHIPP scores at 15 min and 30 min of admission to the PACU were lower in group B than in group A. The incidence of agitation during postoperative anesthesia awakening was lower in group B in contrast to group A. There was no significant difference in postoperative adverse reactions between group A and group B. CONCLUSIONS In pediatric liver surgery, the use of Dex+remifentanil+sevoflurane anesthesia can reduce the incidence of EA during the awakening period, stabilize hemodynamic levels, and relieve postoperative pain, and has fewer postoperative adverse effects, which warrants clinical application.

Effect of dexmedetomidine on liver transplantation: a meta-analysis

Background: Dexmedetomidine (DEX), an adjuvant anesthetic, may improve the clinical outcomes of liver transplantation (LT). Methods: We summarized the relevant clinical trials of DEX in patients undergoing LT. As of 30 January 2023, we searched The Cochrane Library, MEDLINE, EMBASE, Clinical Trial.gov and the WHO ICTRP. The main outcomes were postoperative liver and renal function. The random effect model or fixed effect model was used to summarize the outcomes across centers based on the differences in heterogeneity. Results: The meta-analysis included nine studies in total. Compared with the control group, the DEX group had a reduced warm ischemia time (MD-4.39; 95% CI-6.74--2.05), improved postoperative liver (peak aspartate transferase: MD-75.77, 95% CI-112.81--38.73; peak alanine transferase: MD-133.51, 95% CI-235.57--31.45) and renal function (peak creatinine: MD-8.35, 95% CI-14.89--1.80), and a reduced risk of moderate-to-extreme liver ischemia-reperfusion injury (OR 0.28, 95% CI 0.14-0.60). Finally, the hospital stay of these patients was decreased (MD-2.28, 95% CI-4.00--0.56). Subgroup analysis of prospective studies showed that DEX may have better efficacy in living donors and adult recipients. Conclusion: DEX can improve short-term clinical outcomes and shorten the hospital stay of patients. However, the long-term efficacy of DEX and its interfering factors deserves further study. Systematic Review: identifier CRD42022351664.

Dexmedetomidine ameliorates liver injury and maintains liver function in patients with hepatocellular carcinoma after hepatectomy: a retrospective cohort study with propensity score matching

Background

Although dexmedetomidine (DEX) is widely used during the perioperative period in patients with hepatocellular carcinoma (HCC), its clinical effects on liver function and postoperative inflammation are unclear. This study aimed to explore effects of DEX on postoperative liver function and inflammation in patients with HCC after hepatectomy.

Methods

A retrospective cohort study with propensity score matching was performed. A total of 494 patients who underwent hepatectomy from June 2019 to July 2020 and fulfilled the eligibility criteria were included in this study. Baseline data, liver function indexes and inflammation-related biomarkers were collected and compared between the two groups. Survival analysis was conducted to investigate the effects of DEX on the overall survival (OS) of patients. Propensity score matching (PSM) was used to minimize bias between the two groups.

Results

The study cohort comprised 189 patients in the DEX-free group and 305 patients in the DEX group. Patients in the DEX group had lower levels of alanine transaminase (ALT, P = 0.018) and lactate dehydrogenase (LDH, P = 0.046) and higher level of serum albumin (ALB, P < 0.001) than patients in the DEX-free group before discharge. A total of 107 pairs of patients were successfully matched by PSM. Results consistently suggested that ALT and LDH levels were significantly lower (P = 0.044 and P = 0.046, respectively) and ALB levels were significantly higher (P = 0.002) in the DEX group than in the DEX-free group in the early postoperative period. No significant differences of inflammation-related biomarkers were observed between two groups after PSM. Neither the Kaplan-Meier survival analysis nor the multiple Cox regression survival analysis identified DEX as a contributing factor that would affect the OS of patients after PSM.

Conclusion

DEX exerts protective effects on liver function while has little effects on inflammation-related biomarkers in the early postoperative period in patients undergoing hepatectomy due to HCC.

What Is the Role of Dexmedetomidine in Modern Anesthesia and Critical Care?

Dexmedetomidine's unique sedative properties have led to its widespread use. Dexmedetomidine has a beneficial pharmacologic profile including analgesic sparing effects, anxiolysis, sympatholysis, organ-protective effects against ischemic and hypoxic injury, and sedation which parallels natural sleep. An understanding of predictable side effects, effects of age-related physiologic changes, and pharmacokinetic and pharmacodynamic effects of dexmedetomidine is crucial to maximize its safe administration in adults and children. This review focuses on the growing body of literature examining advances in applications of dexmedetomidine in children and adults.

Effect of intraoperative dexmedetomidine on hepatic ischemia-reperfusion injury in pediatric living-related liver transplantation: A propensity score matching analysis

Background

Hepatic ischemia-reperfusion injury (HIRI) is largely unavoidable during liver transplantation (LT). Dexmedetomidine (DEX), an α2-adrenergic agonist, exerts a variety of organ-protective effects in pediatric populations. However, evidence remains relatively limited about its hepatoprotective effects in pediatric living-related LT.

Methods

A total of 121 pediatric patients undergoing living-related LT from June 2015 to December 2018 in our hospital were enrolled. They were classified into DEX or non-DEX groups according to whether an infusion of DEX was initiated from incision to the end of surgery. Primary outcomes were postoperative liver graft function and the severity of HIRI. Multivariate logistic regression and propensity score matching (PSM) analyses were performed to identify any association.

Results

A 1:1 matching yielded 35 well-balanced pairs. Before matching, no significant difference was found in baseline characteristics between groups except for warm ischemia time, which was longer in the non-DEX group (44 [38–50] vs. 40 [37–44] min, p = 0.017). After matching, the postoperative peak lactic dehydrogenase levels decreased significantly in the DEX group than in the non-DEX group (622 [516–909] vs. 970 [648–1,490] IU/L, p = 0.002). Although there was no statistical significance, a tendency toward a decrease in moderate-to-extreme HIRI rate was noted in the DEX group compared to the non-DEX group (68.6% vs. 82.9%, p = 0.163). Patients in the DEX group also received a significantly larger dosage of epinephrine as postreperfusion syndrome (PRS) treatment (0.28 [0.17–0.32] vs. 0.17 [0.06–0.30] µg/kg, p = 0.010). However, there were no significant differences between groups in PRS and acute kidney injury incidences, mechanical ventilation duration, intensive care unit, and hospital lengths of stay. Multivariate analysis revealed a larger graft-to-recipient weight ratio (odds ratio [OR] 2.657, 95% confidence interval [CI], 1.132–6.239, p = 0.025) and intraoperative DEX administration (OR 0.333, 95% CI, 0.130–0.851, p = 0.022) to be independent predictors of moderate-to-extreme HIRI.

Conclusion

This study demonstrated that intraoperative DEX could potentially decrease the risk of HIRI but was associated with a significant increase in epinephrine requirement for PRS in pediatric living-related LT. Further studies, including randomized controlled studies, are warranted to provide more robust evidence.