Survival benefits of dexmedetomidine used for sedating septic patients in intensive care setting: A systematic review

Dexmedetomidine Improves Microcirculatory Alterations in Patients With Initial Resuscitated Septic Shock

BACKGROUND

The study was to investigate the effects of dexmedetomidine on microcirculation in patients with early septic shock despite initial resuscitation.

METHODS

This was a single-center prospective study. Patients with early septic shock despite initial fluid resuscitation who still required norepinephrine to maintain target arterial pressure were enrolled. Hemodynamic and gas analysis variables, sublingual microcirculatory parameters were measured at baseline, and during the infusion of dexmedetomidine for 1 h (0.7mcg/kg/h). To elucidate the possible mechanisms of the effect of dexmedetomidine on microcirculation, after interim analysis, the dose-effect relationship of dexmedetomidine on microcirculation and catecholamine level were investigated at baseline, 1h after stabilization at different doses of dexmedetomidine (0.7 and 0.3 mcg/kg/h), and 2h after dexmedetomidine cessation.

RESULTS

Forty-four patients with septic shock were enrolled after initial resuscitation. Compared with baseline, total and perfused vascular densities were statistically increased after infusion of dexmedetomidine, which was correlated with the dose of dexmedetomidine. During dexmedetomidine infusion, plasma norepinephrine, and dopamine level were significantly decreased. Changes in plasma norepinephrine level contributed to dexmedetomidine infusion were well correlated with changes in total and perfused vascular densities.

CONCLUSIONS

In adult patients with resuscitated septic shock, dexmedetomidine improved microcirculation, which might be associated with plasma catecholamine level. However, double-blinded large sample studies should be performed to verify the results.

Trial registration: Clinicaltrials.gov NCT02270281. Registered October 16, 2014.

The significant mechanism and treatments of cell death in heatstroke

With global warming, extreme environmental heat is becoming a social issue of concern, which can cause adverse health results including heatstroke (HS). Severe heat stress is characterized by cell death of direct heat damage, excessive inflammatory responses, and coagulation disorders that can lead to multiple organ dysfunction (MODS) and even death. However, the significant pathophysiological mechanism and treatment of HS are still not fully clear. Various modes of cell death, including apoptosis, pyroptosis, ferroptosis, necroptosis and PANoptosis are involved in MODS induced by heatstroke. In this review, we summarized molecular mechanism, key transcriptional regulation as for HSF1, NRF2, NF-κB and PARP-1, and potential therapies of cell death resulting in CNS, liver, intestine, reproductive system and kidney injury induced by heat stress. Understanding the mechanism of cell death provides new targets to protect multi-organ function in HS.

The Effect of Dexmedetomidine as a Sedative Agent for Mechanically Ventilated Patients With Sepsis: A Systematic Review and Meta-Analysis

Purpose: Dexmedetomidine has been shown to improve clinical outcomes in critically ill patients. However, its effect on septic patients remains controversial. Therefore, the purpose of this meta-analysis was to assess the effect of dexmedetomidine as a sedative agent for mechanically ventilated patients with sepsis. Methods: We searched PubMed, Embase, Scopus, and Cochrane Library from inception through May 2021 for randomized controlled trials that enrolled mechanically ventilated, adult septic patients comparing dexmedetomidine with other sedatives or placebo. Results: A total of nine studies involving 1,134 patients were included in our meta-analysis. The overall mortality (RR 0.97, 95%CI 0.82 to 1.13, P = 0.67, I² = 25%), length of intensive care unit stay (MD -1.12, 95%CI -2.89 to 0.64, P = 0.21, I² = 71%), incidence of delirium (RR 0.95, 95%CI 0.72 to 1.25, P = 0.70, I² = 0%), and delirium free days (MD 1.76, 95%CI -0.94 to 4.47, P = 0.20, I² = 80%) were not significantly different between dexmedetomidine and other sedative agents. Alternatively, the use of dexmedetomidine was associated with a significant reduction in the duration of mechanical ventilation (MD -0.53, 95%CI -0.85 to -0.21, P = 0.001, I² = 0%) and inflammatory response (TNF-α: MD -5.27, 95%CI -7.99 to -2.54, P<0.001, I² = 0%; IL-1β: MD -1.25, 95%CI -1.91 to -0.59, P<0.001, I² = 0%). Conclusions: For patients with sepsis, the use of dexmedetomidine as compared with other sedative agents does not affect all-cause mortality, length of intensive care unit stay, the incidence of delirium, and delirium-free days. But the dexmedetomidine was associated with the reduced duration of mechanical ventilation and inflammatory response.

Is the Sympathetic System Detrimental in the Setting of Septic Shock, with Antihypertensive Agents as a Counterintuitive Approach? A Clinical Proposition

Mortality in the setting of septic shock varies between 20% and 100%. Refractory septic shock leads to early circulatory failure and carries the worst prognosis. The pathophysiology is poorly understood despite studies of the microcirculatory defects and the immuno-paralysis. The acute circulatory distress is treated with volume expansion, administration of vasopressors (usually noradrenaline: NA), and inotropes. Ventilation and anti-infectious strategy shall not be discussed here. When circulation is considered, the literature is segregated between interventions directed to the systemic circulation vs. interventions directed to the micro-circulation. Our thesis is that, after stabilization of the acute cardioventilatory distress, the prolonged sympathetic hyperactivity is detrimental in the setting of septic shock. Our hypothesis is that the sympathetic hyperactivity observed in septic shock being normalized towards baseline activity will improve the microcirculation by recoupling the capillaries and the systemic circulation. Therefore, counterintuitively, antihypertensive agents such as beta-blockers or alpha-2 adrenergic agonists (clonidine, dexmedetomidine) are useful. They would reduce the noradrenaline requirements. Adjuncts (vitamins, steroids, NO donors/inhibitors, etc.) proposed to normalize the sepsis-evoked vasodilation are not reviewed. This itemized approach (systemic vs. microcirculation) requires physiological and epidemiological studies to look for reduced mortality.

Modulation of microglial phenotypes by dexmedetomidine through TREM2 reduces neuroinflammation in heatstroke

No FDA approved pharmacological therapy is available to reduce neuroinflammation following heatstroke. Previous studies have indicated that dexmedetomidine (DEX) could protect against inflammation and brain injury in various inflammation-associated diseases. However, no one has tested whether DEX has neuro-protective effects in heatstroke. In this study, we focused on microglial phenotypic modulation to investigate the mechanisms underlying the anti-inflammatory effects of DEX in vivo and in vitro. We found that DEX treatment reduced the expression of CD68, iNOS, TNF-α, and IL-1β, and increased the expression of CD206, Arg1, IL-10 and TGF-β in microglia, ameliorating heatstroke induced neuroinflammation and brain injury in mice. TREM2, whose neuro-protective function has been validated by genetic studies in Alzheimer's disease and Nasu-Hakola disease, was significantly promoted by DEX in the microglia. TREM2 esiRNA reversed the DEX-induced activation of PI3K/Akt signalling. Overall these findings indicated that DEX may serve, as a potential therapeutic approach to ameliorate heatstroke induced neuroinflammation and brain injury via TREM2 by activating PI3K/Akt signalling.

Dexmedetomidine use and mortality in mechanically ventilated patients with severe burns: A cohort study using a national inpatient database in Japan

BACKGROUND

Dexmedetomidine is an alpha 2-adrenergic receptor agonist. Apart from its sedative effects, dexmedetomidine can potentially reduce mortality through its anti-inflammatory effect. However, the impact of dexmedetomidine on in-hospital outcomes of patients with severe burns remains unclear. Therefore, we aimed to elucidate the association between dexmedetomidine use and mortality in mechanically ventilated patients with severe burns, using a Japanese nationwide database of in-hospital patients.

METHODS

We included adults with severe burns (burn index ≥ 10) who were registered in the Japanese Diagnosis Procedure Combination national inpatient database from 2010 to 2018, started mechanical ventilation within 3 days of admission, and received any sedative drug (dexmedetomidine, midazolam, or propofol). One-to-one propensity score matching was performed between patients who received dexmedetomidine on the day of mechanical ventilation initiation (dexmedetomidine group) and those who did not receive dexmedetomidine (control group). The primary outcome was all-cause 30-day in-hospital mortality. Secondary outcomes were length of hospital stay and duration of mechanical ventilation in patients and survivors.

RESULTS

Eligible patients (n = 1888) were classified into the dexmedetomidine group (n = 371) or the control group (n = 1517). After one-to-one propensity score matching, we compared 329 patients from both groups. No significant difference was observed in the 30-day mortality between patients in the dexmedetomidine and control groups (22.8% vs. 22.5%, respectively; odds ratio, 1.02; 95% confidence interval, 0.71-1.46). Moreover, there were no significant differences between patients in the dexmedetomidine and control groups in terms of the length of hospital stay or the duration of mechanical ventilation.

CONCLUSIONS

We found no significant association between dexmedetomidine use and in-hospital outcomes (mortality, length of hospital stay, and length of mechanical ventilation) in mechanically ventilated patients with severe burns. Dexmedetomidine use may not improve the aforementioned outcomes; therefore, its selection should be based on the patient's general condition and the target level of sedation.

Sedation in the Intensive Care Unit

PURPOSE OF REVIEW

This narrative review illustrates literature over the last 5 years relating to sedation delivery to mechanically ventilated adult patients in intensive care units.

RECENT FINDINGS

There has been an increase in dexmedetomidine-related publications but although systematic reviews suggest dexmedetomidine reduces delirium, agitation, and length of stay, clinical trials have not supported these findings. It is likely to be useful for the managing patients with persisting agitation. Guidelines continue to recommend lightly sedating patients but considerable variation remains in clinical practice and in research trials. Protocols with no sedative infusions and morphine boluses as needed are feasible and safe, while educational interventions can decrease sedation-related adverse events.

SUMMARY

Research trials have mainly focused on individual drugs rather than practice. Given evidence is slow to translate into practice; work is needed to understand and respond to the concerns of clinicians regarding deep sedation and agitation.

Comparative Effectiveness of Midazolam, Propofol, and Dexmedetomidine in Patients With or at Risk for Acute Respiratory Distress Syndrome: A Propensity Score-Matched Cohort Study

Background: Sedatives are commonly used in patients with or at risk for acute respiratory distress syndrome (ARDS) during mechanical ventilation. To systematically compare the outcomes of sedation with midazolam, propofol, and dexmedetomidine in patients with or at risk for ARDS.

Methods: We developed a dataset of real-world data to enable the comparison of the effectiveness and safety of sedatives and the associated outcomes from the MIMIC-III database and the eICU Collaborative Research database. We performed a systematic study with six cohorts to estimate the relative risks of outcomes among patients administered different sedatives. Propensity score matching was performed to generate a balanced 1:1 matched cohort and to identify potential prognostic factors. The outcomes included hospital mortality, duration of mechanical ventilation, length of intensive care unit stay, length of hospitalization, and likelihood of being discharged home.

Results: We performed 60 calibrated analyses among all groups and outcomes with 17,410 eligible patients. Sedation with dexmedetomidine was associated with a lower in-hospital mortality rate than sedation with midazolam and propofol or sedation without dexmedetomidine (p < 0.001). When compared with no sedation, the use of midazolam, propofol or dexmedetomidine was associated with a longer ICU stay and longer hospitalization duration (p < 0.01). Patients treated with midazolam were relatively less likely to be discharged home (p < 0.05).

Conclusion: Patients treated with dexmedetomidine had a reduced risk of mortality. These data suggest that dexmedetomidine may be the preferred sedative in patients with or at risk for ARDS.

Effect of dexmedetomidine on inflammation in patients with sepsis requiring mechanical ventilation: a sub-analysis of a multicenter randomized clinical trial

BACKGROUND

Administration of dexmedetomidine has been reported to improve inflammatory response in animals. We explored the effects of administering dexmedetomidine on the levels of C-reactive protein (CRP) and procalcitonin, and thus on inflammation, in patients with sepsis enrolled in a randomized clinical trial.

METHODS

The DESIRE trial was a multicenter randomized clinical trial in which adult patients with sepsis were sedated with (DEX group) or without (non-DEX group) dexmedetomidine while on mechanical ventilators. As a prespecified sub-analysis, we compared CRP and procalcitonin levels during the first 14 days of treatment between the two groups. The 14-day mortality rate, albumin level, and the number of patients with disseminated intravascular coagulation (DIC) were also assessed. We used generalized linear models to estimate the differences in these outcomes between groups. We also used the Kaplan-Meier method to estimate the 14-day mortality rate and the log-rank test to assess between-group differences.

RESULTS

Our study comprised 201 patients: 100 in the DEX group and 101 in the non-DEX group. CRP and procalcitonin levels were lower in the DEX vs. non-DEX group during the 14-day treatment period [CRP-range, 5.6-20.3 vs. 8.3-21.1 mg/dL (P = 0.03); procalcitonin-range, 1.2-37.4 vs. 1.7-52.9 ng/mL (P = 0.04)]. Albumin levels were higher in the DEX group (range, 2.3-2.6 g/dL) than in the non-DEX group (range, 2.1-2.7 g/dL; P = 0.01). The percentage of patients with DIC did not significantly differ between the groups (range, 21-59% and 17-56% for the DEX and non-DEX groups, respectively; P = 0.49). The 14-day mortality rates in the DEX and non-DEX groups were 13 and 21%, respectively (P = 0.16).

CONCLUSION

Sedation using dexmedetomidine reduced inflammation in patients with sepsis requiring mechanical ventilation.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01760967 . Registered on 4 January 2013.

Effect of Dexmedetomidine on duration of mechanical ventilation in septic patients: a systematic review and meta-analysis

Background

Because of its analgesic and light sedative properties, the highly selective alpha-2 adrenergic receptor agonist dexmedetomidine (DEX) has been suggested for the treatment of septic patients, but its effect on the duration of mechanical ventilation remains unclear. The present study was conducted to review the extant literature in DEX and determine its influence on ventilation time in adult septic patients.

Methods

Databases of PubMed, Cochrane, and EMBASE were applied till 20th January 2019 without language restriction. The searching strategy as following: sepsis OR septic AND mechanical ventilation AND dexmedetomidine. Two authors screened titles, abstracts, and even articles to meet the including criterion independently. In addition, references of related articles or reviews were also referred. Data was recorded in a table and analyzed using the software of Review Manager 5.0.

Results

Four studies with a total of 349 patients were included. Three trials with 267 patients revealed the effect of DEX on duration of mechanical ventilation, two trials with 264 patients on ventilator-free days and four trials with 334 patients on 28-day mortality. The analyzed results indicated that DEX was not associated with significantly different durations of mechanical ventilation (MD 0.65, 95% CI, − 0.13 to 1.42, P = 0.10). However, there were significant differences in ventilator-free days (MD 3.57, 95% CI, 0.26 to 6.89, P = 0.03) and 28-day mortality (RR 0.61, 95% CI, 0.49 to 0.94, P = 0.02) in the septic patients.

Conclusion

Administration of DEX for sedation in septic patients was not associated with the duration of mechanical ventilation, but it increased the ventilator-free days and reduced 28-day mortality.

Circulatory effects of dexmedetomidine in early sepsis: a randomised controlled experimental study

We designed this experimental study with a view to evaluate the effects of dexmedetomidine (DEX) on cardiac performance and systemic and peripheral hemodynamics in healthy and early-stage endotoxemia swine models. Our study hypothesis was that DEX can ensure hemodynamic stability during the course of endotoxemia. Thirty-two male pigs (25-27 kg) were assigned into four groups: (1) no intervention (group A), (2) DEX 0.8 μg/kg was administered in non-septic animals (group B), (3) sepsis induced by intravenous Escherichia coli endotoxin (group C) and (4) DEX 0.8 μg/kg was administered in septic animals (group D). Hemodynamic parameters such as heart rate, mean blood pressure, central venous pressure, pulmonary artery pressures, pulmonary artery occlusion pressure, pulmonary vascular resistance and cardiac output were continuously recorded. Central venous oxygen saturation was also measured in order to obtain a complete evaluation of cardiovascular response to sepsis. Heart rate was decreased, whilst mean arterial pressure decrease was alleviated after DEX administration in septic animals. In addition, central venous pressure was stable in animals with sepsis after DEX infusion. Sepsis dramatically elevated pulmonary function indicators but DEX succeeded in ameliorating this effect. The important decrease measured in central venous oxygen saturation in both sepsis groups reflected the decreased perfusion of tissues that takes place at the end of early sepsis. Our findings support the hypothesis that DEX has beneficial effects on heart rate and pulmonary artery pressure, whilst reduction in systemic blood pressure occurs at acceptable levels.

Impact of perioperative pain management on cancer recurrence: an ASRA/ESRA special article

Cancer causes considerable suffering and 80% of advanced cancer patients experience moderate to severe pain. Surgical tumor excision remains a cornerstone of primary cancer treatment, but is also recognized as one of the greatest risk factors for metastatic spread. The perioperative period, characterized by the surgical stress response, pharmacologic-induced angiogenesis, and immunomodulation results in a physiologic environment that supports tumor spread and distant reimplantation.In the perioperative period, anesthesiologists may have a brief and uniquewindow of opportunity to modulate the unwanted consequences of the stressresponse on the immune system and minimize residual disease. This reviewdiscusses the current research on analgesic therapies and their impact ondisease progression, followed by an evidence-based evaluation of perioperativepain interventions and medications.

The influence of dexmedetomidine and propofol on circulating cytokine levels in healthy subjects

Background

Surgery and diseases modify inflammatory responses and the immune system. Anesthetic agents also have effects on the human immune system but the responses they induce may be altered or masked by the surgical procedures or underlying illnesses. The aim of this study was to assess how single-drug dexmedetomidine and propofol anesthesia without any surgical intervention alter acute immunological biomarkers in healthy subjects.

Methods

Thirty-five healthy, young male subjects were anesthetized using increasing concentrations of dexmedetomidine (n = 18) or propofol (n = 17) until loss of responsiveness (LOR) was detected. The treatment allocation was randomized. Multi-parametric immunoassays for the detection of 48 cytokines, chemokines and growth factors were used. Concentrations were determined at baseline and at the highest drug concentration for each subject.

Results

The changes in the concentration of eotaxin (decrease after dexmedetomidine) and platelet-derived growth factor (PDGF, increase after propofol) were statistically significantly different between the groups. Significant changes were detected within both groups; the concentrations of monocyte chemotactic protein 1, chemokine ligand 27 and macrophage migration inhibitory factor were lower in both groups after the drug administration. Dexmedetomidine decreased the concentration of eotaxin, interleukin-18, interleukin-2Rα, stem cell factor, stem cell growth factor and vascular endothelial growth factor, and propofol decreased significantly the levels of hepatocyte growth factor, IFN-γ-induced protein 10 and monokine induced by IFN-γ, and increased the levels of interleukin-17, interleukin-5, interleukin-7 and PDGF.

Conclusions

Dexmedetomidine seemed to have an immunosuppressive effect on the immune system whereas propofol seemed to induce mixed pro- and anti-inflammatory effects on the immune system. The choice of anesthetic agent could be relevant when treating patients with compromised immunological defense mechanisms.

Trial registration

Before subject enrollment, the study was registered in the European Clinical Trials database (EudraCT number 2013–001496-21, The Neural Mechanisms of Anesthesia and Human Consciousness) and in ClinicalTrials.gov (Principal Investigator: Harry Scheinin, number NCT01889004, The Neural Mechanisms of Anesthesia and Human Consciousness, Part 2, on the 23rd of June 2013).

Effect of propofol, midazolam and dexmedetomidine on ICU patients with sepsis and on arterial blood gas

Effects of propofol, midazolam and dexmedetomidine on patients with sepsis in intensive care unit (ICU) and on arterial blood gas (ABG) were studied. In total 429 ICU patients with sepsis, admitted to Renji Hospital, School of Medicine, Shanghai Jiaotong University from May 2015 to January 2019, were selected as research subjects for a prospective analysis. All patients received basic treatment, such as anti-infection treatment, correction of shock and improvement of microcirculation. One hundred and fifty-two patients who were treated with propofol for sedation served as group A, 146 patients who were treated with midazolam for sedation served as group B, and 131 patients who were treated with dexmedetomidine for sedation served as group C. The three groups of patients were compared in terms of diastolic blood pressure (DBP), systolic blood pressure (SBP), heart rate (HR), arterial partial pressure of oxygen (PaO₂), arterial partial pressure of carbon dioxide (PaCO₂), cardiac troponin T (cTnT) and creatine kinase-MB (CK-MB) before and after treatment. APACHE II score was used to evaluate the sedative effects. The wake-up time of the patients, the length of ICU stay and the adverse reactions were recorded. There was no significant difference among groups A, B and C in terms of HR, SBP, DBP, PaO₂, PaCO₂, cTnT, CK-MB and APACHE II score before treatment, and SBP, DBP, cTnT and HR after treatment (P>0.050). After treatment, there was no significant difference between groups A and B with respect to CK-MB and APACHE II score (P>0.050). The wake-up time in group A was significantly longer than that in groups B and C (P<0.001). In conclusion, propofol, midazolam and dexmedetomidine are effective and safe in the sedative treatment of ICU patients with sepsis, but dexmedetomidine has the best effect on protecting blood pressure and cardiac functions, which is worthy of use in the clinic.

Dexmedetomidine protects against high mobility group box 1-induced cellular injury by inhibiting pyroptosis

Dexmedetomidine (DEX) is a widely used clinical anesthetic with proven anti-inflammatory effects. Both high mobility group box 1 (HMGB1) and pyroptosis play an important role in the inflammatory response to infection and trauma. Thus far, there have been no studies published addressing the effect of DEX on HMGB1 and pyroptosis. In order to fill this gap in the literature, bone marrow-derived macrophages (BMDMs) were exposed to HMGB1 (4 µg/mL) with or without DEX (50 μM) pretreatment. The production of pro-inflammatory cytokines [such as tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), and IL-18], phosphorylation of extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) and P38, and the activation of caspase-1 were measured by enzyme immunosorbent assay, western blot analysis, confocal microscope, and flow cytometry, respectively. We found that DEX protected against HMGB1-induced cell death of BMDMs. In addition, DEX suppressed the generation of TNF-α, IL-1β, and IL-18 as well as the phosphorylation of ERK1/2 and P38. Moreover, DEX inhibited caspase-1 activation and decreased pyroptosis. Taken together, these findings demonstrate the protective effect of DEX in mediating HMGB1-induced cellular injury, thus indicating that DEX may be a potential therapeutic candidate for the management of infection and trauma-derived inflammation.

Targeting the Blood-Brain Barrier to Prevent Sepsis-Associated Cognitive Impairment

Sepsis is a systemic inflammatory disease resulting from an infection. This disorder affects 750 000 people annually in the United States and has a 62% rehospitalization rate. Septic symptoms range from typical flu-like symptoms (eg, headache, fever) to a multifactorial syndrome known as sepsis-associated encephalopathy (SAE). Patients with SAE exhibit an acute altered mental status and often have higher mortality and morbidity. In addition, many sepsis survivors are also burdened with long-term cognitive impairment. The mechanisms through which sepsis initiates SAE and promotes long-term cognitive impairment in septic survivors are poorly understood. Due to its unique role as an interface between the brain and the periphery, numerous studies support a regulatory role for the blood-brain barrier (BBB) in the progression of acute and chronic brain dysfunction. In this review, we discuss the current body of literature which supports the BBB as a nexus which integrates signals from the brain and the periphery in sepsis. We highlight key insights on the mechanisms that contribute to the BBB's role in sepsis which include neuroinflammation, increased barrier permeability, immune cell infiltration, mitochondrial dysfunction, and a potential barrier role for tissue non-specific alkaline phosphatase (TNAP). Finally, we address current drug treatments (eg, antimicrobials and intravenous immunoglobulins) for sepsis and their potential outcomes on brain function. A comprehensive understanding of these mechanisms may enable clinicians to target specific aspects of BBB function as a therapeutic tool to limit long-term cognitive impairment in sepsis survivors.

Perioperative application of dexmedetomidine for postoperative systemic inflammatory response syndrome in patients undergoing percutaneous nephrolithotomy lithotripsy: results of a randomised controlled trial

OBJECTIVE

Our previous retrospective study demonstrated that perioperative dexmedetomidine (Dex) administration was associated with low systemic inflammatory response syndrome (SIRS) incidence. The present study was designed to investigate whether perioperative administration of Dex decreases the incidence of postpercutaneous nephrolithotomy lithotripsy (PCNL) SIRS in patients who undergo PCNL.

DESIGN

A randomised controlled trial was designed.

PARTICIPANTS

A total of 190 patients were randomly assigned to receive Dex (DEX group, n=95) or saline control (CON group, n=95) and completed the study. In the DEX group, Dex was loaded (1 µg/kg) before anaesthesia induction and was infused (0.5 µg/kg/h) during surgery.

OUTCOMES

The incidences of postoperative SIRS were recorded. Serum interleukin-6 (IL-6) and tumour necrosis factor α(TNF-α) were measured.

RESULTS

The incidence rates of SIRS were significantly lower in the DEX group than in the CON group (35.8% vs 50.5%, p=0.04). No patients developed sepsis in either group. These results might be attributed to inhibition of inflammatory responses and the resulting lower serum levels of IL-6 and TNF-α, caused by Dex administration. However, compared with the CON group, the lower incidence rate of SIRS in the DEX group did not result in better outcomes, such as shorter postoperative hospitalisation stays and lower costs.

CONCLUSION

The present study showed that Dex administration during PCNL might be beneficial for decreasing the incidence of SIRS through inhibiting the release of inflammatory mediators, but not clinical consequences such as postoperative hospitalisation duration and costs. Further effects of Dex administration on SIRS in patients who are scheduled for PCNL should be explored in future studies.

TRIAL REGISTRATION NUMBER

ChiCTR-ICR-15006167.

Dexmedetomidine restores septic renal function via promoting inflammation resolution in a rat sepsis model

BACKGROUND

Acute kidney injury occurred after sepsis, resulting in high mortality. This research aims to elucidate the mechanistic effect of DEX on the renal inflammation resolution during sepsis in rats.

METHODS

The rats were randomly divided into a sham group and the other three cecal ligation and puncture (CLP) model groups, based on different treatments: placebo, DEX and 2-adrenergic receptor (AR) inhibitor atipamezole (AT) treatment (DEX + AT) groups. The survival of septic rats within 24 h was recorded. Tissue pathology, plasma IL-1β, IL-6, TNF-α, lipoxygenase-5 and lipoxin A4 were evaluated. Western blotting and immunostaining was used to determine expression of TLR4, IκB, IKK, NF-κB p65 and pp65 in kidney tissue. Then qPCR was used to analyze the mRNA expression of renal α_2A-AR, α_2B-AR and α_2C-AR.

RESULTS

Rat mortality and kidney inflammation were significantly increased in septic rats. Specifically, IL-1β, IL-6 and TNF-α plasma levels, NF-κB activity, and TLR4 expression in rat kidney tissues were increased after CLP. In the DEX treatment group, mortality was reduced, histology changes were minor, and lipoxygenase-5, and lipoxin A4 expression were increased. The expression of IL-1β, IL-6 and TNF-α, NF-κB activity and TLR4 expression in rat kidney tissues were also decreased. These results indicated that DEX treatment alleviates acute kidney injury induced by CLP. However, the effects of DEX were apparently suppressed by atipamezole in the DEX + AT group.

CONCLUSION

The current study demonstrated the protective effect of DEX on CLP-induced kidney injury, which may be effective by attenuating NF-κB pathway activation with lipoxin A4.

Sonographic assessment of volaemia: development and validation of a new method in dogs

OBJECTIVES

The aims of this study were to describe a method for the sonographic assessment of volaemia, to determinate inter- and intra-operator variability and to assess the ability to detect blood loss after blood donation in healthy dogs.

MATERIALS AND METHODS

The left kidney was identified in a spleno-renal view, and transverse views of the caudal vena cava and aorta were obtained in 12 dogs. Vessel diameters were measured in B-mode, in duplicate by two operators, and the caudal vena cava:aorta ratio was calculated. Intra- and inter-operator variabilities were assessed using a Bland-Altman method by plotting the differences between the repeated measurements obtained from the same subject by the same operator and by the two operators against their means. Before and after blood donation measurements were compared using paired t-tests or one-sample t-tests, if appropriate.

RESULTS

Intra- and inter-operator variability was within the limit of agreement for the vast majority of measurements. After a blood donation of 9·8 ±2·2 mL/kg, the mean aorta measurements were not significantly different from those obtained before blood donation (1·11 versus 1·10, P=0·28), whereas the mean caudal vena cava measurements and caudal vena cava:aorta ratios were significantly lower (1·28 versus 1·01, P<0·0001; 1·17 versus 1·01, P=0·0001, respectively).

CLINICAL SIGNIFICANCE

The low intra- and inter-operator variabilities in the caudal vena cava, aorta and caudal vena cava:aorta ratio measurements support their reliability and operator independency. The sonographic assessment of volaemia appears to be a promising non-invasive, repeatable point-of-care ultrasound protocol for assessment and monitoring of blood loss. Further studies are needed to assess the sonographic assessment of volaemia protocol in spontaneously bleeding dogs.

The safety and efficacy of dexmedetomidine-remifentanil in children undergoing flexible bronchoscopy: A retrospective dose-finding trial

Flexible bronchoscopy is more and more used for diagnosis and management of various pulmonary diseases in pediatrics. As poor coordination of children, the procedure is usually performed under general anesthesia with spontaneous or controlled ventilation to increase children and bronchoscopists' safety and comfort. Previous studies have reported that dexmedetomidine (DEX) could be safely and effectively used for flexible bronchoscopy in both adulate and children. However, there is no trial to evaluate the dose-finding of safety and efficacy of dexmedetomidine-remifentanil (DEX-RF) in children undergoing flexible bronchoscopy.The objective of this study is to evaluate the dose-finding of safety and efficacy of DEX-RF in children undergoing flexible bronchoscopy.One hundred thirty-five children undergoing flexible bronchoscopy with DEX-RF were divided into 3 groups: Group DR1 (n = 47, DEX infusion at 0.5 μg·kg for 10 minutes, then adjusted to 0.5-0.7 μg kg h; RF infusion at 0.5 μg kg for 2 minutes, then adjusted to 0.05-0.2 μg kg min), Group DR2 (n = 43, DEX infusion at 1 μg kg for 10 minutes, then adjusted to 0.5-0.7 μg kg h; RF infusion at 1 μg kg for 2 minutes, then adjusted to 0.05-0.2 μg kg min), Group DR3 (n = 45, DEX infusion at 1.5 μg kg for 10 minutes, then adjusted to 0.5-0.7 μg kg h; RF infusion at 1 μg kg for 2 minutes, then adjusted to 0.05-0.2 μg kg min). Ramsay sedation scale of the 3 groups was maintained 3. Anesthesia onset time, total number of intraoperative children movements, hemodynamics (heart rate, arterial pressure, pulse oxygen saturation (SpO2), respiratory rate), total cumulative dose of dexmedetomidine and remifentanil, the amount of midazolam and lidocaine, time to first dose of rescue midazolam and lidocaine, postoperative recovery time, adverse events, bronchoscopist satisfaction score were recorded.Anesthesia onset time was significantly shorter in DR3 group (14.23 ± 5.45 vs 14.45 ± 5.12 vs 11.13 ± 4.51 minutes, respectively, of DR1, DR2, DR3, P = 0.003). Additionally, the perioperative hemodynamic profile was more stable in group DR3 than that in the other 2 groups. Total number of children movements during flexible bronchoscopy was higher in DR1 group than the other 2 groups (46.81% 22/47 vs 34.88% 15/43 vs 17.78% 8/45, respectively, of DR1, DR2, DR3, P = 0.012). Total doses of rescue midazolam and lidocaine were significantly higher in DR1 and DR2 groups than that of DR3 group (P = 0.000). The time to first dose of rescue midazolam and lidocaine was significantly longer in DR3 group than DR1 and DR2 groups (P = 0.000). Total cumulative dose of dexmedetomidine was more in DR2 and DR3 groups (P = 0.000), while the amount of remifentanil was more in DR1 and DR2 groups (P = 0.000). The time to recovery for discharge from the PACU was significantly shorter in DR1 group compared with the other 2 groups (P = 0.000). Results from bronchoscopist satisfaction score showed significantly higher in DR2 and DR3 groups than that of DR1 group (P = 0.025). There were significant differences among the 3 groups in terms of the overall incidence of hypertension, tachycardia, hypoxemia, and cough (P < 0.05).Though it required longer recovery time, high dose of DEX-RF, which provided better stable hemodynamic profiles and bronchoscopist satisfaction score, less amount of rescue scheme, and children movements, could be safely and efficacy used in children undergoing flexible bronchoscopy.