The Theory is Out There: The Use of ALPHA-2 Agonists in Treatment of Septic Shock

Evaluation of the efficacy of silymarin and dexmedetomidine on kidney and lung tissue in the treatment of sepsis in rats with cecal perforation

Sepsis is a systemic inflammatory response syndrome that develops in the host against microorganisms. This response develops away from the primary infection site and results in end-organ damage. The present study aimed to investigate the protective and therapeutic effects on lung and kidney tissue of silymarin (S) and dexmedetomidine (DEX) applied 1 h before and after sepsis induced by the cecal ligation and puncture (CLP) method in rats. A total of 62 rats was randomly divided into eight groups: i) Control (n=6); ii) cecal perforation (CLP; n=8); iii) S + CLP (n=8; S + CLP; S administered 1 h before CPL); iv) CLP + S (n=8; S administered 1 h after CLP); v) DEX + CLP (n=8; D + CLP; DEX administered 1 h before CLP); vi) CLP + D (n=8; DEX administered 1 h after CLP); vii) SD + CLP (n=8; S and DEX administered 1 h before CLP) and viii) CLP + SD (n=8; S and DEX administered 1 h after CLP). After the cecum filled with stool, it was tied with 3/0 silk under the ileocecal valve and the anterior surface of the cecum was punctured twice with an 18-gauge needle. A total of 100 mg/kg silymarin and 100 µg/kg DEX were administered intraperitoneally to the treatment groups. Lung and kidney tissue samples were collected to evaluate biochemical and histopathological parameters. In the histopathological examination, all parameters indicating kidney injury; interstitial edema, peritubular capillary dilatation, vacuolization, ablation of tubular epithelium from the basement membrane, loss of brush border in the proximal tubule epithelium, cell swelling and nuclear defragmentation; were increased in the CLP compared with the control group. Silymarin administration increased kidney damage, including ablation of tubular epithelium from the basement membrane, compared with that in the CLP group. DEX significantly reduced kidney damage compared with the CLP and silymarin groups. The co-administration of DEX + silymarin decreased kidney damage, although it was not as effective as DEX-alone. To conclude, intraperitoneal DEX ameliorated injury in CLP rats. DEX + silymarin partially ameliorated injury but silymarin administration increased damage. As a result, silymarin has a negative effects with this dosage and DEX has a protective effect. In the present study, it was determined that using the two drugs together had a greater therapeutic effect than silymarin and no differences in the effects were not observed any when the application times of the agents were changed.

The efficacy of dexmedetomidine for septic shock: A meta-analysis of randomized controlled trials

INTRODUCTION

The efficacy of dexmedetomidine was elusive for septic shock. This meta-analysis aimed to explore the efficacy of dexmedetomidine for septic shock.

METHODS

PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases have been searched through October 2022 and we included randomized controlled trials reporting the effect of dexmedetomidine in patients with septic shock.

RESULTS

Five randomized controlled trials were included in the meta-analysis. Compared with control group for septic shock, dexmedetomidine treatment was able to substantially decrease Sequential Organ Failure Assessment score (mean difference [MD] = -0.99; 95% confidence interval [CI] = -1.14 to -0.84; P < .00001) and duration of mechanical ventilation (MD = -0.90; 95% CI = -1.27 to -0.54; P < .00001), but showed no obvious influence on morality at 28 days (odds ratio = 0.79; 95% CI = 0.38 to 1.66; P = 054), hospital mortality (odds ratio = 0.66; 95% CI = 0.35 to 1.24; P = .20) or intensive care unit length of stay (MD = -1.47; 95% CI = -4.60 to 1.66; P = .36).

CONCLUSIONS

Dexmedetomidine administration may help treat patients with septic shock.

Dexmedetomidine only regimen for long-term sedation is associated with reduced vasopressor requirements in septic shock patients: A retrospective cohort study from MIMIC-IV database

Background

Previous studies have shown that dexmedetomidine (DEX) may be associated with reduced vasopressor requirements in septic shock patients, however, long-term DEX-only sedation in reducing vasopressor requirements is still controversial.

Methods

A retrospective study was conducted among patients with septic shock on mechanical ventilation using the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. The primary outcome was the ratio of norepinephrine equivalent dose to mean arterial pressure (NEq/MAP) in the first 72 h after DEX or other sedatives for sedation. The secondary outcomes were key organ function parameters, 28-day mortality, and 90-day mortality. Univariate, propensity score matching (PSM), and generalized linear mixed model (GLMM) analyses were performed.

Results

DEX was associated with decreased NEq/MAP in the first 72 h (difference = 0.05, 95% CI = -0.02-0.08, p = 0.002) after adjusting for confounders in the GLMM analysis. The DEX group was also associated with a lower heart rate, cardiac output (CO), lactate level, aspartate transaminase (AST) level, and higher PaO2/FiO2 ratio (p < 0.0125). Moreover, DEX only sedation was associated with reduced 90-day mortality (OR = 0.60, 95% CI = 0.37-0.94, p = 0.030).

Conclusion

DEX may be associated with decreased vasopressor requirements, improved AST and PaO2/FiO2 levels, and reduced 90-day mortality in patients with septic shock, which warrants further study.

Association between dexmedetomidine administration and outcomes in critically ill patients with sepsis-associated acute kidney injury

STUDY OBJECTIVE

To investigate the association between dexmedetomidine administration and outcomes in critically ill patients with sepsis-associated acute kidney injury (SA-AKI).

DESIGN

A single-center, retrospective, cohort study.

SETTING

Intensive care unit (ICU).

PATIENTS

A total of 2192 critically ill patients with SA-AKI were included in the analysis, which identified from the Medical Information Mart for Intensive Care (MIMIC-IV) database between 2008 and 2019.

INTERVENTIONS

Intravenous infusion of dexmedetomidine.

MEASUREMENTS

The primary outcome was recovery of renal function. In-hospital mortality, vasopressor requirements, length of ICU and hospital stay were considered secondary outcomes. The Cox proportional hazards, logistic regression, and linear regression models were used to assess the association between dexmedetomidine and outcomes. Propensity score matching (PSM) analysis was used to match patients receiving dexmedetomidine to those without treatment.

MAIN RESULTS

After PSM, 719 matched patient pairs were derived from patients who received dexmedetomidine and those who did not. The administration of dexmedetomidine was associated with a higher rate of renal recovery [61.8% vs. 55.8%, hazard ratio (HR) 1.35; P = 0.01], reduced in-hospital mortality [28.3% vs. 41.3%, HR 0.56; P < 0.001], and prolonged intensive care unit (ICU) stay [15.8d vs 12.6d, HR 2.34; P < 0.001] and hospital stay [23.7d vs 19.7d, HR 4.47; P < 0.001]. No significant difference was found in vasopressor requirements in patients with SA-AKI. Nevertheless, results illustrated that dose receiving between 0.30 and 1.00 μg/kg/h and duration using under 48 h of dexmedetomidine was associated with improvements in renal function recovery in SA-AKI patients.

CONCLUSION

Dexmedetomidine administration was associated with improvements in renal function recovery and in-hospital survival in critically ill patients with SA-AKI. The results need to be verified in further randomized controlled trials.

The effect of dexmedetomidine on vasopressor requirements in patients with septic shock: a subgroup analysis of the Sedation Practice in Intensive Care Evaluation [SPICE III] Trial

BACKGROUND

Septic shock is associated with decreased vasopressor responsiveness. Experimental data suggest that central alpha2-agonists like dexmedetomidine (DEX) increase vasopressor responsiveness and reduce catecholamine requirements in septic shock. However, DEX may also cause hypotension and bradycardia. Thus, it remains unclear whether DEX is hemodynamically safe or helpful in this setting.

METHODS

In this post hoc subgroup analysis of the Sedation Practice in Intensive Care Evaluation (SPICE III) trial, an international randomized trial comparing early sedation with dexmedetomidine to usual care in critically patients receiving mechanical ventilation, we studied patients with septic shock admitted to two tertiary ICUs in Australia and Switzerland. The primary outcome was vasopressor requirements in the first 48 h after randomization, expressed as noradrenaline equivalent dose (NEq [μg/kg/min] = noradrenaline + adrenaline + vasopressin/0.4).

RESULTS

Between November 2013 and February 2018, 417 patients were recruited into the SPICE III trial at both sites. Eighty-three patients with septic shock were included in this subgroup analysis. Of these, 44 (53%) received DEX and 39 (47%) usual care. Vasopressor requirements in the first 48 h were similar between the two groups. Median NEq dose was 0.03 [0.01, 0.07] μg/kg/min in the DEX group and 0.04 [0.01, 0.16] μg/kg/min in the usual care group (p = 0.17). However, patients in the DEX group had a lower NEq/MAP ratio, indicating lower vasopressor requirements to maintain the target MAP. Moreover, on adjusted multivariable analysis, higher dexmedetomidine dose was associated with a lower NEq/MAP ratio.

CONCLUSIONS

In critically ill patients with septic shock, patients in the DEX group received similar vasopressor doses in the first 48 h compared to the usual care group. On multivariable adjusted analysis, dexmedetomidine appeared to be associated with lower vasopressor requirements to maintain the target MAP.

TRIAL REGISTRATION

The SPICE III trial was registered at ClinicalTrials.gov ( NCT01728558 ).

Hemodynamic Effects of Propofol and Dexmedetomidine in Septic Patients Without Shock

Background: Use of nonbenzodiazepine agents propofol and dexmedetomidine are first line for sedation in the intensive care unit (ICU). These agents have been implicated in the development of bradycardia and hypotension in critical illness. Objectives: To compare the development of clinically significant hypotension and/or bradycardia (ie, negative hemodynamic event) in adults with sepsis yet to require vasopressors receiving either propofol or dexmedetomidine for continuous sedation. Methods: This was a retrospective multicenter cohort study of adults with non-vasopressor-dependent sepsis admitted to an ICU at two academic medical centers between July 2013-September 2017. Results: Patients in the propofol (n = 64) and dexmedetomidine (n = 31) groups developed a clinically significant negative hemodynamic event at statistically similar frequencies (34.4% vs 16.1%, P = 0.065). Patients receiving propofol developed a larger degree of hypotension (47.3 vs 34.7 mm Hg reduction, P = 0.031). In multivariable logistic regression modeling, independent predictors of a negative hemodynamic event were a past medical history of chronic kidney disease (odds ratio [OR] = 3.8; 95% CI = 1.17-12.2; P = 0.027) and baseline heart rate (OR = 1.02; 95% CI = 1.00-1.10; P = 0.036). Conclusions and Relevance: A minority of patients with sepsis who received either propofol or dexmedetomidine experienced an event. Patients with sepsis without shock receiving continuous infusions of propofol and dexmedetomidine experienced a negative hemodynamic event at similar frequencies, though the degree of hypotension seen with propofol was greater. The clinical significance of these adverse effects requires cautious use in sepsis and further investigation.

Effects From Continuous Infusions of Dexmedetomidine and Propofol on Hemodynamic Stability in Critically Ill Adult Patients With Septic Shock

PURPOSE

To compare the development of clinically significant hemodynamic event (ie, hypotension or bradycardia) in adults with septic shock receiving either propofol or dexmedetomidine.

MATERIALS AND METHODS

A retrospective cohort study of adults with septic shock admitted to an intensive care unit (ICU) at an academic medical center between July 2013 and July 2017.

RESULTS

Patients in the propofol (n = 35) and dexmedetomidine (n = 37) groups developed a clinically significant hemodynamic event at similar frequencies (31.4 vs 29.7%, P = .99). All patients with an event experienced hypotension, whereas 2 (5.4%) patients in the dexmedetomidine group also experienced bradycardia. Most patients in both groups (70% vs 90%) received an escalating sedative dose, and almost half (42.9%) in the dexmedetomidine group had the sedative dosage increased more frequently than every 30 minutes. Patients in both groups had similar ICU (24.1 vs 24.3 days, P = .98) and hospital (37.9 vs 29.7 days, P = .29) lengths of stay. There was no difference in median time to hemodynamic event between the groups (propofol 1 hour [interquartile range, IQR: 0.5-9.9] vs dexmedetomidine 2 hours [IQR: 1.5-11.1 hours], P = .85).

CONCLUSION

Patients with septic shock receiving propofol or dexmedetomidine experienced similar rates of clinically significant hemodynamic events. Most patients did not experience an event and those who did most frequently did so in the first couple of hours of therapy.