Remifentanil-dexmedetomidine Anesthesia With a Caudal for Elective Surgery. (Remi-dex)

Study Overview
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Brief Summary
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This study intends to show the efficacy of remifentanil-dexmedetomidine infusions in combination with a caudal block for patients ages 1 year to 3 years old receiving elective surgery to investigate alternatives to the currently used volatile anesthetics.

Detailed Description
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In light of the concern for potential anesthetic neurotoxicity in infants and toddlers, it is prudent to start investigating alternative methods to decrease the amount of volatile anesthetic being utilized in this patient population. The US Food and Drug Administration has been asked to evaluate the data showing the neurotoxic effects of multiple anesthetic agents in animal models and humans. These studies have shown that N-methyl-D-aspartate (NMDA) receptor blockers such as ketamine,and gamma-Aminobutyric acid receptor (GABA) modulators like benzodiazepines, nitrous, propofol, barbiturates and isoflurane have been shown to cause brain cell apoptosis in animal models. Regional anesthesia provides both intraoperative and postoperative analgesia may play a major role in effectively reducing the amount of general anesthetic used. Caudal anesthesia has been proven be both safe, effective and is applied widely in the pediatric population. Dexmedetomidine is a selective alpha2-adrenergic agonist that acts in the brainstem by inhibiting norepinephrine release. Dexmedetomidine is commonly used off-label, including use for duration greater than 24 hours and any use in pediatrics. Dexmedetomidine has relatively few adverse events when compared to other sedative agents, with hypotension and bradycardia being most common. Remifentanil has a rapid onset, rapid offset, small volume of distribution, rapid clearance, and a short elimination half-life, It may be a useful anesthetic for pediatric outpatient surgery. While the current standard of care involves a volatile general anesthetic with a caudal block, anesthesiologists have alternative methods that can be utilized to allow an elective surgery to be performed. In summary, this study intends to show the efficacy and safety of a remifentanil-dexmedetomidine infusion and caudal block for patients ages 1 year-3 years old receiving elective circumcision, hydrocele repair, orchidopexy, mild hypospadias or inguinal hernia repair. This alternative anesthetic is already being studied in children under 12 months.

Official Title
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Remifentanil-dexmedetomidine Anesthesia as an Alternative Anesthetic for Elective Pediatric Surgery: a Pilot Study.

Conditions
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Anesthesia

Intervention / Treatment
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* Drug: Remifentanil
* Drug: Dexmedetomidine
* Drug: Ropivacaine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Children aged 1 - 3 years undergoing urologic surgery (circumcision, hydrocele repair, orchidopexy, mild hypospadias) or inguinal hernia repair American Society of Anesthesiologist Physical Status (ASA-PS) I or II Eligible for caudal block Parental/legal guardian consents for study ' Exclusion Criteria: Allergy to remifentanil, dexmedetomidine or ropivacaine Family history of malignant hyperthermia Parental/legal guardian refusal ASA-PS ≥ 3 Symptoms of upper respiratory infection (URI) within the 2 weeks prior to surgery Known spinal deformity, presence of sacral dimple, or signs of infection at the site of the caudal block (e.g. diaper rash, skin redness or tenderness).

Ages Eligible for Study
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Minimum Age: 1 Year
Maximum Age: 3 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
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Remifentanil-dexmedetomidine and caudal<br>Anesthesia will be induced with inhaled sevoflurane which will be discontinued once IV access is obtained and the airway is secured with an endotracheal tube. Patients will receive remifentanil loading dose of 1mcg/kg over 1 min followed by an infusion (0.05-0.5 mcg/kg/min) and dexmedetomidine load at 1mcg/kg over 10 mins followed by and infusion (0.2-0.7 mcg/kg/hr) A caudal block with 0.2% ropivacaine will be performed in all patients for intraoperative and postoperative pain control. | Drug: Remifentanil<br>* 1mcg/kg over 1 min followed by an infusion (0.05-0.5 mcg/kg/min)<br>* Other names: Ultiva;Drug: Dexmedetomidine<br>* 1mcg/kg over 10 mins followed by and infusion (0.2-0.7 mcg/kg/hr)<br>* Other names: Precedex;Drug: Ropivacaine<br>* Caudal anesthesia block with Ropivicaine 0.2% 1ml/kg injected into the caudal space<br>* Other names: Naropin;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of patients requiring intervention for light anesthesia | Identified by patient movement, change in mean arterial pressure >80 at surgical incision, need to change anesthetic plan | 90-120 mins (length of surgery) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time to recovery after anesthesia | Time from end of surgery to: extubation; time to discharge from post-anesthesia care unit (PACU) | 10 mins; 1- 4 hours | 
| Number of patients requiring rescue analgesia in PACU | Use of Fentanyl, Morphine, Ketorolac in recovery unit, | 30 mins to 4 hours after surgery | 
| Number of patients with pain after surgery | Pain is assessed after recovery on Face, Legs, Activity, Cry, Consolability (FLACC) scale 0 to 10. Average score will be noted. | 1 to 4 hours | 
| Number of patients with respiratory event | Bronchospasm, laryngospasm and pulse oximetry desaturation to less than 90% | Anesthesia start to discharge from PACU usually 2- 6 hours |