Clinical Trials Logo

Clinical Trial Summary

The purpose of this study is to assess cerebral blood flow velocity (CBFV) following regional anesthesia for shoulder surgery. The results of this study will help to further understand the physiologic effect of the interscalene nerve block on cerebral blood flow.


Clinical Trial Description

Traditionally, cerebral blood flow (CBF) is believed to decline when mean arterial pressure (MAP) is below the lower limit of cerebral autoregulation. Cerebral blood flow autoregulation refers to the capacity of the central nervous system to maintain blood flow within a wide range of mean arterial blood pressure. The habitual thinking is that the brain is perfused merely dependent by the blood pressure and that above or below the limits of cerebral autoregularion CBF is pressure passive. Despite this notion, there is evidence showing that parameters other than MAP influence cerebral hemodynamics independent of cerebral autoregulation. One of the physiologic processes that contribute to CBF regulation is cardiac output (CO). However, exactly how an alteration in CO, in the face of a stable blood pressure, leads to a change in CBF is not entirely clear. One of the suggested mechanisms in play is the sympathetic nervous system (SNS)-mediated vasoconstriction of extracranial and proximal intracranial vessels. Cerebral arteries are abundantly innervated by sympathetic nerve fibers originating from the superior cervical ganglion. Studies have shown that CBF reduction is attenuated by pharmacologic blockade or extirpation of the cervical sympathetic chain. The anesthetic protocol for patients undergoing major shoulder surgery include an interscalene nerve block (ISNB) combined with general anesthesia in the sitting position. The ISNB involves injecting local anesthetic at the level of the cervical spinal roots. One of the most common side effects encountered after ISNB is Horner syndrome, which is characterized by ptosis, myosis, and enopthalmia. Horner's syndrome results from the diffusion of the local anesthetic solution to the ipsilateral sympathetic cervical chain (stellate ganglion). The presence of Horner's syndrome indicates spread of local anesthetic to the sympathetic chain. Whether this degree of sympatholytic following interscalene block is associated with an observable change in CBF is unknown. Studies in baboon have shown that cervical surgical sympathectomy maintained CBF in the face of hemorrhagic hypotension and CBF did not decrease until MAP was 35% of the baseline value. These results suggest that sympathectomy induced by the block of the sympathetic chain by the local anesthetic injected for the ISNB might alter CBF. Therefore, the aim of our study is to evaluate the effect of unilateral interscalene nerve block on CBF by measuring CBF velocity non-invasively with Transcranial doppler (TCD). ;


Study Design


Related Conditions & MeSH terms


NCT number NCT04642612
Study type Observational
Source Stanford University
Contact
Status Terminated
Phase
Start date March 4, 2021
Completion date July 30, 2021

See also
  Status Clinical Trial Phase
Recruiting NCT05944393 - Erector Spine Plane (ESP) Block for Analgesia in Pediatric Scoliosis Surgery N/A
Recruiting NCT05589246 - Regional Analgesia in Combination With Cryoanalgesia to Prevent Acute Pain Following Nuss Procedure N/A
Not yet recruiting NCT03978780 - Erector Spinae Block vs. Placebo Block Study N/A
Terminated NCT02846610 - Registry for Acute Pain Treatment
Completed NCT03679897 - Comparison of 0.375% Ropivacaine and 0.25% Levobupivacaine for Infraclavicular Brachial Plexus Block Phase 4
Recruiting NCT06014749 - Serratus Intercostal Block Versus Epidural Analgesia in Eventration: Prospective Observational Study
Completed NCT04438369 - Evaluation of Ultrasound-guided Erector Spinae Block for Postoperative Analgesia in Laprascopic Ventral Hernia Repair. N/A
Terminated NCT03500744 - Erector Spinae Plane Block for Major Gynecologic and Urologic Surgery N/A
Completed NCT05160298 - Analgesic Effect of Bilateral Erector Spinae Plane Block With Ropivacaine After Sternotomy for Cardiac Surgery Phase 2
Recruiting NCT06121726 - Predictive Factors for the Effectiveness of the Ilioinguinal Iliohypogastric Nerve Block for Hernia Surgery
Completed NCT04549090 - Ultrasound Guided Posterior Quadratus Lumborum Block for Postoperative Analgesia in Gynecologic Surgery
Completed NCT05286190 - Caudal Block and Transversus Abdominis Plane Block in Pediatric Inguinal Hernia Repair N/A
Completed NCT02200016 - Displacement of Popliteal Sciatic Nerve Catheters After Major Foot and Ankle Surgery Phase 4
Recruiting NCT06089798 - Analgesic Efficacy of Ultrasound-guided Bilateral Pecto-intercostal Plane Block in Pediatric Cardiac Surgery
Not yet recruiting NCT06115720 - Consent in Anaesthesia N/A
Completed NCT04668183 - Ultrasound-guided PNB and DPNB for Pediatric Distal Hypospadias Surgery
Completed NCT05344105 - Comparison of Postoperative Analgesic Efficacy of Transversalis Fascia Plan Block and Erector Spina Plan Block N/A
Not yet recruiting NCT06313294 - Postoperative Follow-up Via Text Messages Automated Versus Telephone in Patients With Continuous Regional Anesthesia N/A
Completed NCT02950558 - Anesthesia for Pain After Ankle Fracture Surgery Phase 4
Completed NCT05351151 - Pain Reduction in Maxillomandibular Surgery Using Maxillary and Mandibular Nerve Blocks N/A