[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"health-study-detail:100625950":3},{"organization":4,"armGroups":7,"interventions":18,"overallOfficials":25,"centralContacts":24,"locations":29,"responsibleParty":43,"collaborators":24,"id":45,"slug":46,"hasResults":47,"nctId":48,"briefTitle":49,"officialTitle":50,"acronym":51,"eligibilityCriteria":52,"healthyVolunteers":53,"sex":54,"minAge":55,"maxAge":56,"enrollmentInfo":57,"targetDuration":24,"studyType":60,"phases":61,"briefSummary":63,"conditions":64,"keywords":67,"overallStatus":72,"whyStopped":24,"lastUpdateSubmitDate":73,"lastUpdatePostDateStruct":74,"startDateStruct":77,"completionDateStruct":79,"leadSponsor":81,"locationsCount":82},{"fullName":5,"class":6},"Duke University","OTHER",[8,14],{"label":9,"type":10,"description":11,"interventionNames":12},"Left Wrist Block","EXPERIMENTAL","Ultrasound-guided periarterial block with 2% lidocaine at left wrist.",[13],"Drug: Lidocaine 2%",{"label":15,"type":10,"description":16,"interventionNames":17},"Right Wrist Block","Ultrasound-guided periarterial block with 2% lidocaine at right wrist.",[13],[19],{"type":20,"name":21,"description":22,"armGroupLabels":23,"otherNames":24},"DRUG","Lidocaine 2%","Small-volume injection (5 mL) of 2% lidocaine around radial artery under ultrasound guidance.",[9,15],null,[26],{"name":27,"affiliation":5,"role":28},"David MacLeod","PRINCIPAL_INVESTIGATOR",[30],{"facility":31,"status":24,"city":32,"state":33,"zip":34,"country":35,"countryCode":36,"cosmosGeoPoint":37,"geoPoint":42,"contacts":24},"Duke University Medical Center","Durham","North Carolina","27710","United States","US",{"type":38,"coordinates":39},"Point",[40,41],-78.89862,35.99403,{"lat":41,"lon":40},{"type":44,"investigatorFullName":24,"investigatorTitle":24,"investigatorAffiliation":24,"oldNameTitle":24,"oldOrganization":24},"SPONSOR","100625950","phase-4-spark-study---sympathetic-periarterial-radial-block-in-healthy-volunteers-100625950",false,"NCT07429292","SPARK Study - Sympathetic Periarterial Radial Block in Healthy Volunteers","SPARK Study - Sympathetic PeriArterial Radial blocK Study","SPARK","Inclusion Criteria:\n\n* Age 18-50 years\n* ASA physical status I-II\n* Able to understand and provide informed consent\n* Able to comply with study procedures and follow-up\n* Two hands with 5 intact digits and no significant upper extremity injury\n\nExclusion Criteria:\n\n* Allergy to lidocaine or similar anesthetics\n* Allergy to adhesives or ultrasound gel\n* Neuromuscular, autonomic, or major vascular disorders affecting upper extremities\n* Peripheral neuropathy\n* Raynaud's phenomenon or digital ischemia\n* Coagulopathy or anticoagulation\n* Active skin infection near block site\n* Pregnancy\n* BMI \\> 35 kg\u002Fm²\n* Inability to tolerate cold exposure\n* Any condition interfering with study conduct",true,"ALL","18 Years","50 Years",{"count":58,"type":59},20,"ESTIMATED","INTERVENTIONAL",[62],"PHASE4","The SPARK Study evaluates changes in peripheral sympathetic vasomotor activity following a targeted, ultrasound-guided periarterial sympathetic block of the distal radial artery in healthy volunteers. Autonomic reactivity will be assessed before and after the block using digit-specific pulse-amplitude index and infrared thermography during standardized cold pressor testing.",[65,66],"Healthy Volunteers","Sympathetic Activity",[68,69,70,71],"Sympathetic Block","Radial Artery","Cold Pressor Test","Periarterial block","NOT_YET_RECRUITING","2026-06-16",{"date":75,"type":76},"2026-06-17","ACTUAL",{"date":78,"type":59},"2026-09",{"date":80,"type":59},"2027-04",{"name":5,"class":6},1]