Effect of Dexmedetomidine vs Esmolol or Placebo on Cerebral Hemodynamics in Septic Shock

Study Overview
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Brief Summary
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Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. Some researchers proposed that the dysregulated response or organ dysfunction can be lessened by reducing the stress response, which further reduce complication and mortality rates of sepsis. Dexmedetomidine is alpha adrenergic receptor agonist, presenting sympatholytic action in certain parts of the brain with anxiolytic, sedative, and pain killing effects. In the experiments of sepsis animal model, dexmedetomidine have been proved to improve serum lactate clearance and the microcirculation. Dexmedetomidine may inhibit inflammation, as it enhances the activity of the immune system while reducing its systemic reaction and lowering cytokine concentrations. There are also evidences in clinical trials with definite safety that dexmedetomidine reduced inflammation, reduced vasopressor requirements and improved organ function. The beta antagonist esmolol has been proposed as a therapy to lower heart rate, thereby improving diastolic filling time, and improving cardiac output, resulting in a reduction in vasopressor support. A recent meta-analysis of 8 randomized studies using esmolol suggested that the 32% risk ratio decreased 28-day mortality, and a meta-analysis of 7 studies using esmolol in patients with sepsis and septic shock was associated with 32% lower 28-day mortality. However, the effect of anti-stress drugs on cerebral hemodynamics is unknown. In this study, investigators are going to apply the technique of transcranial Doppler to assess the reaction of cerebral blood flow in anti-stress group and control group.

Detailed Description
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It is a single-blinded, single-center, randomized trial. Patients with septic shock established within 24 hours in the ICU of Tibet Autonomous Region People's Hospital will be screened for recruitment. After adequate fluid resuscitation, continuous infusion of norepinephrine is given to the patients to maintain a mean arterial pressure (MAP) of 65-75 millimeter of mercury (mmHg). Midazolam and fentanyl are given to achieve the goal sedation of bispectral index (BIS) 40-60, patients who are still with tachycardia (heart rate over 100 b.p.m.) will be recruited. After recruitment, patients in accordance with the random number table are divided into dexmedetomidine group, esmolol group and control group (T0). Patients in the two experimental groups are required to achieve the heart rate goal of 75-95 b.p.m. in one hour by adjusting the dose of dexmedetomidine or esmolol every twenty minutes. All patients acquired the hemodynamic evaluation at T1, T2, T3, T4 (6, 12, 18, 24hours after enrollment). The hemodynamic evaluation including transcranial Doppler of middle cerebral artery(MCA), deep middle cerebral vein (DMCV), basal vein Rosenthal (BVR) and transverse sinus (TS), hemodynamic parameters acquired by the pressure-recording analytical method through peripheral arterial with Mostcare. Demographic characteristics, diagnosis, laboratory reports and drug dose are collected during the study.

Official Title
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Effect of Dexmedetomidine vs Esmolol or Placebo on Cerebral Hemodynamics in Septic Shock: A Randomized Clinical Trial.

Conditions
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Septic Shock, Stress Response, Cerebral Hemodynamics

Intervention / Treatment
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* Drug: Dexmedetomidine Hydrochloride
* Drug: Esmolol Hydrochloride


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 18   80 years old. Patients established septic shock according to sepsis 3.0 criteria. Under deep sedation of BIS 40-60 with midazolam and fentanyl. After achieving the goal sedation, patients are still with tachycardia (heart rate over 100 b.p.m.. Exclusion Criteria: Pregnancy. Patients with severe arrhythmia. Patients with aortic or aortic valve disease. Patients with mechanical circulatory assist device (e.g. extracorporeal membrane oxygenation (ECMO), intra-aortic balloon pump (IABP), etc). Patients with cerebral trauma. Any contraindication to the use of transcranial doppler.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: dexmedetomidine group<br> | Drug: Dexmedetomidine Hydrochloride<br>* The continuous intravenous infusion of dexmedetomidine (0.1mg/ml) will start at 0.1ug/kg/h, increasing every 20 minutes by a step change of 0.05-0.2ug/kg/h to reach the target heart rate with the expectation that this should be within 12 hours. The infusion will be reduced by step change, and if necessary, ultimately stopped if the heart rate fall below 80b.p.m..<br>|
| Experimental: esmolol group<br> | Drug: Esmolol Hydrochloride<br>* The continuous intravenous infusion of esmolol (10mg/ml) will start at 20mg/h, increasing every 20 minutes by a step change of 20mg/h to reach the target heart rate with the expectation that this should be within 12 hours. The infusion will be reduced by step change, and if necessary, ultimately stop if the heart rate fall below 80b.p.m..<br>|
| No Intervention: control group<br> | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The cerebral hemodynamic change caused by the anti-stress therapy | The cerebral hemodynamics will be evaluated according to the features of the blood flow of MCA, DMCV, BVR and TS measured by transcranial doppler, as well as regional cerebral oxygen saturation measured by the near infrared spectroscopy at Hour 0, Hour 6, Hour 12, Hour 18 and Hour 24. The difference will be acquired by contrasting between two intervention group and one control group. | Hour 0, Hour 6, Hour 12, Hour 18 and Hour 24. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The systemic hemodynamic change caused by anti-stress therapy | The systemic hemodynamic changes will be acquired through the pressure-recording analytical method with Mostcare, blood pressure and electro cardiac monitor, central venous pressure (CVP) monitor, trans thoracic echocardiography, and blood gas at Hour 0, Hour 6, Hour 12, Hour 18 and Hour 24. The difference will be acquired by contrasting between two intervention group and one control group | Hour 0, Hour 6, Hour 12, Hour 18 and Hour 24 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Septic shock, Stress response, Trans-cranial Doppler