Assessing Cerebral Blood Flow Autoregulation During Surgery in the Head-up Position

This study is currently recruiting participants. (see Contacts and Locations)
Verified July 2010 by Johns Hopkins University
Sponsor:
Collaborators:
Anesthesia Patient Safety Foundation
Information provided by (Responsible Party):
Charles W. Hogue, Johns Hopkins University
ClinicalTrials.gov Identifier:
NCT01225185
First received: October 18, 2010
Last updated: March 7, 2013
Last verified: July 2010
  Purpose

Neurological injury after elective shoulder surgery in the beach chair position is thought to result from cerebral hypoperfusion and should therefore be preventable by appropriate hemodynamic monitoring and management. This proposal will use a system to continuously monitor cerebral blood flow autoregulation to identify safe arterial blood pressure targets in patients in the beach chair position, compared with a control cohort having orthopedic surgery in the lateral decubitus supine position. Autoregulation data will be compared against a new, highly specific and sensitive serum biomarker of neurologic injury, glial fibrillary acid protein, and postoperative neurocognitive testing results.


Condition
Shouldersurgery

Study Type: Observational
Study Design: Observational Model: Case Control
Time Perspective: Prospective
Official Title: Assessing Cerebral Blood Flow Autoregulation in the Head-up Versus Supine Position During General Anesthesia and Its Relationship With Postoperative Neurocognitive Changes and Serum Biomarkers of Brain Injury

Further study details as provided by Johns Hopkins University:

Primary Outcome Measures:
  • cerebral oximetry index between subjects in the head up or supine position during surgery under general anesthesia [ Time Frame: During surgery ] [ Designated as safety issue: Yes ]

Secondary Outcome Measures:
  • To compare the range of arterial blood pressure required for a normal cerebral oximetry index between subjects anesthetized in the head up or supine position. [ Time Frame: During surgery ] [ Designated as safety issue: Yes ]
  • To assess the association between impaired cerebral blood flow autoregulation and postoperative neurocognitive decline and elevation of serum glial fibrillary acid protein. [ Time Frame: 1 month after surgery for neurocognitive decline; perioperatively for serum GFAP levels. ] [ Designated as safety issue: Yes ]

Estimated Enrollment: 240
Study Start Date: July 2010
Estimated Study Completion Date: September 2016
Estimated Primary Completion Date: July 2016 (Final data collection date for primary outcome measure)
Groups/Cohorts
Patients undergoing shoulder surgery
This observational study will compare cerebral blood flow autoregulation in patients undergoing surgery in either the supine lateral position or the semi-recumbent or "beach chair" position. The choice of patient positioning is not randomized but based on usual surgical considerations.

Detailed Description:

Neurologic injury under general anesthesia in the beach chair position is believed to result from cerebral hypoperfusion.1 We hypothesize that brain hypoperfusion in this circumstance is caused by blood pressure monitoring that does not reflect of cerebral perfusion pressure. Maintenance of arterial blood pressure above an individual's lower limit of cerebral blood flow autoregulation would prevent this devastating complication. Near infrared spectroscopy can be used to continuously monitor autoregulation with the cerebral oximetry index (COx), a moving linear correlation coefficient between cortical tissue oxygen saturation and arterial pressure. We hypothesize that subjects in the beach chair position have impaired cerebral blood flow autoregulation compared with subjects undergoing surgery in the lateral decubitus supine position. We will test this hypothesis by comparing CBF autoregulation data, including the percentage of time patients undergoing elective surgery have abnormal autoregulation, in the beach chair position versus supine position. We will establish the range of arterial pressure required to maintain autoregulation in the two groups. Cerebral autoregulation results will be assessed for a relationship with postoperative neurocognitive dysfunction and with serum glial fibrillary acid protein levels, a biomarker of brain injury.

The specific aims of this study are:

  1. To compare the average cerebral oximetry index and the percentage of time with abnormal COx between subjects in the head up or supine position during surgery under general anesthesia.
  2. To compare the range of arterial blood pressure required for a normal cerebral oximetry index between subjects anesthetized in the head up or supine position.
  3. To assess the association between impaired cerebral blood flow autoregulation and postoperative neurocognitive decline 1 month after surgery and perioperative elevation of serum glial fibrillary acid protein.

Monitoring autoregulation non-invasively with COx has the potential to improve patient safety by delineating individualized limits of safe ABP for patients at risk of neurologic injury.

  Eligibility

Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population

120 patients undergoing shoulder surgery in the supine lateral position and 120 subjects undergoing surgery in the beach chair position.

Criteria

Inclusion Criteria:

  • Patients 18 years old or older undergoing shoulder arthroscopy in the beach chair position or lateral decubitus position without elevation of the head.

Exclusion Criteria:

  • Women of child bearing potential require a negative urine HCG test to be enrolled. Patients unable to attend postoperative cognitive testing sessions will be excluded from the study as will those with known allergy to adhesive tape.
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01225185

Contacts
Contact: Charles W Hogue, Md 410-614-1516 chogue2@jhmi.edu
Contact: Michelle Parish, RN 410-614-0891 mparish@jhmi.edu

Locations
United States, Maryland
The Johns Hopkins Hospital Recruiting
Baltimore, Maryland, United States, 21287
Contact: Michelle Parish, RN    410-614-0891    mparish@jhmi.edu   
Sponsors and Collaborators
Johns Hopkins University
Anesthesia Patient Safety Foundation
Investigators
Principal Investigator: Charles W Hogue, MD The Johns Hopkins Medical Institutions
  More Information

No publications provided

Responsible Party: Charles W. Hogue, Professor, Johns Hopkins University
ClinicalTrials.gov Identifier: NCT01225185     History of Changes
Other Study ID Numbers: APSF, 1R01HL092259
Study First Received: October 18, 2010
Last Updated: March 7, 2013
Health Authority: United States: Federal Government

Keywords provided by Johns Hopkins University:
neurological complications
brain blood flow autoregulation

ClinicalTrials.gov processed this record on July 20, 2014