Impact of Dexmedetomidine Infusion on Postoperative Acute Kidney Injury in Elderly Patients Undergoing Major Joint Replacement: A Retrospective Cohort Study

Association between albumin-corrected anion gap level and the risk of acute kidney injury in intensive care unit

PURPOSE

This study was to investigate the association between albumin-corrected anion gap (AG) (ACAG) levels and the risk of acute kidney injury (AKI) in intensive care unit (ICU) patients.

METHODS

The ICU patients of this retrospective cohort study were collected from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database between 2008 and 2019. ACAG = AG + {4.4 - [albumin (g/dl)]} × 2.5. The incidence of AKI was determined using the Kidney Disease: Improving Global Outcomes (KDIGO) definition. The logistic regression model was used to evaluate the association between ACAG levels and the risk of AKI. Subgroup analyses were applied based on age, gender, mechanical ventilation, vasopressors, the Charlson comorbidity index (CCI), and the Simplified Acute Physiology Score II (SAPS II).

RESULTS

Totally, 5586 patients were enrolled, of which 1929 patients (34.53%) occurred AKI. The higher levels of ACAG were associated with the risk of AKI in ICU patients, with the odds ratio (OR) value being 1.23 [95% confidence interval (CI): 1.22-1.24, P = 0.005] in ACAG level between 16.5 and 19.5, and OR value being 1.20 (95% CI 1.16-1.24, P = 0.016) in ACAG level > 19.5. A higher ACAG level was associated with a higher risk of AKI in ICU patients aged < 65 years, in ICU patients of female gender, in ICU patients who used mechanical ventilation, in ICU patients who did not use vasopressors, in patients without cardiogenic shock, and in ICU patients with CCI ≥ 2, and SAPS II > 31 (all P < 0.05).

CONCLUSION

There is an association between ACAG level and the risk of AKI in ICU patients. A higher ACAG value in ICU patients should therefore receive more attention.

Perioperative acute kidney injury: The renoprotective effect and mechanism of dexmedetomidine

Dexmedetomidine (DEX) is a highly selective and potent α2-adrenoceptor (α2-AR) agonist that is widely used as a clinical anesthetic to induce anxiolytic, sedative, and analgesic effects. In recent years, a growing body of evidence has demonstrated that DEX protects against acute kidney injury (AKI) caused by sepsis, drugs, surgery, and ischemia-reperfusion (I/R) in organs or tissues, indicating its potential role in the prevention and treatment of AKI. In this review, we summarized the evidence of the renoprotective effects of DEX on different models of AKI and explored the mechanism. We found that the renoprotective effects of DEX mainly involved antisympathetic effects, reducing inflammatory reactions and oxidative stress, reducing apoptosis, increasing autophagy, reducing ferroptosis, protecting renal tubular epithelial cells (RTECs), and inhibiting renal fibrosis. Thus, the use of DEX is a promising strategy for the management and treatment of perioperative AKI. The aim of this review is to further clarify the renoprotective mechanism of DEX to provide a theoretical basis for its use in basic research in various AKI models, clinical management, and the treatment of perioperative AKI.

Advances of perioperative acute kidney injury in elderly patients undergoing non-cardiac surgery

The risk of developing perioperative acute kidney injury (AKI) in elderly patients increases with age. The combined involvement of aging kidneys, coexisting multiple underlying chronic diseases, and increased exposure to potential renal stressors and nephrotoxic drugs or invasive procedures constitute susceptibility factors for AKI in elderly patients. The perioperative AKI in elderly patients undergoing noncardiac surgery has its own specific population characteristics, so it is necessary to further explore the characteristics of AKI in elderly patients in terms of epidemiology, clinical diagnosis, risk factors, and preventive and curative measures to provide meaningful clinical advice to improve prognosis, accelerate recovery, and reduce medical burden in elderly patients. Since AKI has the fastest-growing incidence in older patients and is associated with a worse prognosis, early detection, early diagnosis, and prevention of AKI are important for elderly patients in the perioperative period. Large, multicenter, randomized controlled clinical studies in elderly non-cardiac surgery patients with AKI can be conducted in the future, with the aim of providing the evidence to reduce of the incidence of AKI and to improve the prognosis of patients.

Perioperative dexmedetomidine administration does not reduce the risk of acute kidney injury after non-cardiac surgery: a meta-analysis

BACKGROUND

Post-operative acute kidney injury (AKI) is one of the most common and serious complications after major surgery and is significantly associated with increased risks of morbidity and mortality. This meta-analysis was conducted to evaluate the effects of perioperative dexmedetomidine (Dex) administration on the occurrence of AKI and the outcomes of recovery after non-cardiac surgery.

METHODS

The PubMed, Embase, Web of Science, and Cochrane Library databases were systematically searched for studies comparing the effects of Dex vs. placebo on kidney function after non-cardiac surgery, and a pooled fixed-effect meta-analysis of the included studies was performed. The primary outcome was the occurence of post-operative AKI. The secondary outcomes included the occurence of intra-operative hypotension and bradycardia, intensive care unit (ICU) admission, duration of ICU stay, and hospital length of stay (LOS).

RESULTS

Six studies, including four randomized controlled trials (RCTs) and two observational studies, with a total of 2586 patients were selected. Compared with placebo, Dex administration could not reduce the odds of post-operative AKI (odds ratio [OR], 0.44; 95% confidence interval (CI), 0.18-1.06; P  = 0.07; I2  = 0.00%, P  = 0.72) in RCTs, but it showed a significant renoprotective effect (OR, 0.67; 95% CI, 0.48-0.95; P  = 0.02; I2  = 0.00%, P  = 0.36) in observational studies. Besides, Dex administration significantly increased the odds of intra-operative bradycardia and shortened the duration of ICU stay. However, there was no significant difference in the odds of intra-operative hypotension, ICU admission, and hospital LOS.

CONCLUSIONS

This meta-analysis suggests that perioperative Dex administration does not reduce the risk of AKI after non-cardiac surgery. However, the quality of evidence for this result is low due to imprecision and inconsistent types of non-cardiac operations. Thus, large and high-quality RCTs are needed to verify the real effects of perioperative Dex administration on the occurrence of AKI and the outcomes of recovery after non-cardiac surgery.

Dexmedetomidine infusion for emergence coughing prevention in patients undergoing an endovascular interventional procedure: A randomized dose-finding trial

OBJECTIVE

Dexmedetomidine has been introduced in emergence coughing, agitation, and shivering prevention. This study aimed to investigate the optimal dose of dexmedetomidine for emergence cough prophylaxis.

METHODS

In this randomized, double-blinded, and prospective trial, 356 patients scheduled for an endovascular interventional procedure were randomly assigned to 0.3 (D 0.3), 0.4 (D 0.4), 0.5 (D 0.5), and 0.6 (D 0.6) μg·kg^-1·h^-1 dexmedetomidine rate, or saline control (C), from anesthesia induction until the end of surgery. The primary outcomes measured were cough grade and frequency. Additionally, groups were compared according to mean arterial pressure (MAP), heart rate, agitation, shivering, postoperative nausea and vomiting (PONV), extubation time, sedation scores, and postoperative first night sleep quality (secondary outcomes).

RESULTS

A total of 351 patients were included in the analysis. The respective incidences of D 0.3, D 0.4, and D 0.5 versus C group were: 78.6%, 68.6%, 53.4% and 42.9% vs 89.7% for cough (p = 0.002, p < 0.001, and p < 0.001 between group D 0.4, D 0.5 and D 0.6 vs C, respectively); 30%, 27.1%, 20.5%, 15.7% vs 44.1% for agitation (p = 0.04, p = 0.003, and p < 0.001 between group D 0.4, D 0.5 and D 0.6 vs C, respectively); 8.6%, 7.1%, 6.8%, 5.7% vs 22.1% for shivering (p = 0.027, p = 0.013, p = 0.01, and p = 0.01 between D 0.3, D 0.4, D 0.5 and D 0.6 vs C, respectively); and 52.9%, 57.1%, 42.5%, 44.3% vs 61.8% for poor sleep quality (p = 0.02 and p = 0.04 between group D 0.5 and D 0.6 vs C, respectively). D 0.4, D 0.5 and D 0.6 showed lower MAP during extubation, compared with the C group. Also, D 0.5 and D 0.6 presented a slight delay in extubation (3.1 and 3.3 min longer than C; p = 0.002 and p < 0.001, respectively). Meanwhile, the frequency of atropine, vasopressor administration, PONV and dizziness were similar to the control.

CONCLUSIONS

Both 0.5 and 0.6 μg·kg^-1·h^-1 dexmedetomidine infusion rates effectively mitigated emergence coughing with prolonged extubation time, besides sleep disturbance. D 0.4, D 0.5, and D 0.6 reduced agitation and sustained hemodynamic stability. Finally, the four doses applied were effective in shivering attenuation.

The Intersection of Acute Kidney Injury and Non-Coding RNAs: Inflammation

Acute renal injury (AKI) is a complex clinical syndrome, involving a series of pathophysiological processes, in which inflammation plays a key role. Identification and verification of gene signatures associated with inflammatory onset and progression are imperative for understanding the molecular mechanisms involved in AKI pathogenesis. Non-coding RNAs (ncRNAs), involved in epigenetic modifications of inflammatory responses, are associated with the aberrant expression of inflammation-related genes in AKI. However, its regulatory role in gene expression involves precise transcriptional regulation mechanisms which have not been fully elucidated in the complex and volatile inflammatory response of AKI. In this study, we systematically review current research on the intrinsic molecular mechanisms of ncRNAs that regulate the inflammatory response in AKI. We aim to provide potential research directions and strategies for developing ncRNA-targeted gene therapies as an intervention for the inflammatory damage in AKI.

A Stepwise Targeting Curcumin Derivative, Ser@TPP@CUR, for Acute Kidney Injury

Based on the pathological mechanisms of acute kidney injury (AKI), a stepwise targeting curcumin derivative, Ser@TPP@CUR, was developed in this study. Ser@TPP@CUR can be specifically internalized by renal tubular epithelial cells via KIM-1 receptor-mediated endocytosis and then actively distributed in mitochondria under the effect of TPP, a mitochondrial targeting molecule. Both in vitro and in vivo results showed that Ser@TPP@CUR effectively ameliorated injured renal tubular epithelial cells and improved renal functions of AKI mice.

Identification of inflammatory response and alternative splicing in acute kidney injury and experimental verification of the involvement of RNA‑binding protein RBFOX1 in this disease

An increasing number of inflammatory responses and alternative splicing (AS) have been recently reported to be associated with various kidney diseases. The effect of inflammatory response on acute kidney injury (AKI) has not been fully clarified. In the present study, a mouse model of AKI induced by cisplatin and ischemia-reperfusion (IR) was established and genome-wide profiling analysis and identification of differentially expressed genes (DEGs) in kidney tissue was conducted by Gene Ontology (GO) functional analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, protein-protein interaction (PPI) network analysis and RT-qPCR. The results revealed that common DEGs in AKI induced by cisplatin and IR were enriched in the inflammatory response pathway, including hub genes CSF-1, CXCL1, CXCL10, IL-1β, IL-34, IL-6 and TLR2. AS in AKI was initially reported. Cisplatin-induced AS was enriched in the phosphorylation pathway, involving regulated AS genes CSNK1A1, PAK2, CRK, ADK and IKBKB. IR-induced AS was enriched in apoptosis and proliferation pathways, including DEGs ZDHHC16, BCL2L1 and FGF1 regulated by AS. The ability of RNA-binding proteins (RBPs) to regulate AS was coordinated with the function of context-dependent genetic mechanisms. A total of 49 common differentially expressed RBP genes were screened. RNA binding fox-1 homolog 1 (RBFOX1) was revealed to be the top downregulated gene. The relative levels of RBFOX1 in the nuclei of mouse renal tubular epithelial cells in mRNA and proteins were downregulated by cisplatin and IR. Moreover, the biological functions of RBFOX1 were investigated in human renal proximal tubular epithelial cells (HK-2 cells). Results of in vitro experiments revealed that exogenous RBFOX1 inhibited inflammation and oxidative stress to reduce hypoxia/reoxygenation-induced apoptosis of HK-2 cells. This phenomenon may be related to the inhibition of NF-κB and the activation of the NRF2/HO-1 signaling pathway. In conclusion, the inflammatory cytokines, AS and RBPs in AKI were analyzed in the present study via whole transcriptome sequencing. It was revealed that the RBP gene RBFOX1 was involved in the pathogenesis of AKI. Thus, the present study provided novel insights into the mechanism of AKI pathogenesis.

Feasibility of Intranasal Dexmedetomidine in Treatment of Postoperative Restlessness, Agitation, and Pain in Geriatric Orthopedic Patients

Objective

The aim of this study was to report preliminary data on the use of intranasal dexmedetomidine to treat postoperative restlessness, agitation, and pain in 23 patients aged > 70 years and undergoing orthopedic surgery.

Background

Postoperative agitation and delirium are common among older adult patients undergoing orthopedic surgery. Most preparations used to treat agitation and delirium carry a risk for adverse events such as respiratory failure. Moreover, mere opioid therapy may be insufficient in treatment of pain. Dexmedetomidine, an α2-adrenoreceptor agonist with sedative and analgesic properties, has been shown to reduce opioid requirement and reduce postoperative delirium in older adults.

Methods

We studied the use of post-operative intranasal dexmedetomidine in a retrospective study cohort of geriatric patients undergoing orthopedic surgery. Primary outcomes included alterations in heart rate (HR), mean arterial pressure (MAP), respiratory rate (RR), peripheral oxygen saturation (SpO2), Modified Richmond Agitation and Sedation Score (mRASS), and opioid consumption following dexmedetomidine administration.

Results

We identified 23 patients with a mean (SD) age of 79.9 (7.5) years who received dexmedetomidine 100 µg intranasally postoperatively. After dexmedetomidine administration, HR decreased by 10.4 (3.7) beats/min (95% CI 2.9–17.8; p = 0.004) and MAP by 16.2 (4.4) mmHg (95% CI 7.3–25.1; p < 0.001). HR decrease was significant at 2 h and MAP decrease at 1, 2, and 3 h following dexmedetomidine administration. Dexmedetomidine administration was associated with significant reductions in opioid consumption (p < 0.001) and mRASS score (p < 0.001). SpO₂ and RR remained unchanged.

Conclusions

These preliminary findings suggest that intranasal dexmedetomidine reduces opioid consumption without causing respiratory depression and may be used to treat postoperative restlessness, agitation, and pain in geriatric patients. However, hemodynamic effects of dexmedetomidine may require close observation for 3 hours following administration in older adult patients.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40266-021-00846-6.

Perioperative Pain Management and Opioid Stewardship: A Practical Guide

Surgical procedures are key drivers of pain development and opioid utilization globally. Various organizations have generated guidance on postoperative pain management, enhanced recovery strategies, multimodal analgesic and anesthetic techniques, and postoperative opioid prescribing. Still, comprehensive integration of these recommendations into standard practice at the institutional level remains elusive, and persistent postoperative pain and opioid use pose significant societal burdens. The multitude of guidance publications, many different healthcare providers involved in executing them, evolution of surgical technique, and complexities of perioperative care transitions all represent challenges to process improvement. This review seeks to summarize and integrate key recommendations into a "roadmap" for institutional adoption of perioperative analgesic and opioid optimization strategies. We present a brief review of applicable statistics and definitions as impetus for prioritizing both analgesia and opioid exposure in surgical quality improvement. We then review recommended modalities at each phase of perioperative care. We showcase the value of interprofessional collaboration in implementing and sustaining perioperative performance measures related to pain management and analgesic exposure, including those from the patient perspective. Surgery centers across the globe should adopt an integrated, collaborative approach to the twin goals of optimal pain management and opioid stewardship across the care continuum.