Depth of Anesthesia on Implicit Memory

This study has been completed.
Sponsor:
Information provided by (Responsible Party):
University of Oklahoma
ClinicalTrials.gov Identifier:
NCT00584324
First received: December 20, 2007
Last updated: February 1, 2012
Last verified: February 2012
  Purpose

Purpose of this study is to see if different levels of anesthesia have an effect on hearing spoken words without awareness of having heard them or anxiety after surgery.


Condition Intervention
Anesthesia, General
Memory
Behavioral: Mini-mental state exam
Behavioral: Spielberg's State-Trait anxiety test
Behavioral: Spoken word-stem completion test
Device: Bispectral Index Monitor
Other: Audio File

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Investigator)
Primary Purpose: Supportive Care
Official Title: The Effect of Depth of Anesthesia on Implicit Memory

Resource links provided by NLM:


Further study details as provided by University of Oklahoma:

Primary Outcome Measures:
  • To test the presence of implicit memory under two different planes of surgical general anesthesia in patients undergoing urologic (transurethral) or orthopedic (internal and external fixation) procedures [ Time Frame: 3 years ] [ Designated as safety issue: Yes ]

Secondary Outcome Measures:
  • To compare the pre and postoperative anxiety levels as a marker of clinical significance of operational implicit memory function. [ Time Frame: 3 ] [ Designated as safety issue: No ]

Enrollment: 70
Study Start Date: March 2006
Study Completion Date: January 2012
Primary Completion Date: January 2012 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: 1
Target BIS 40
Behavioral: Mini-mental state exam
For subjects > 60, this exam will be administered pre-operatively.
Behavioral: Spielberg's State-Trait anxiety test
Operative phase of study: Spielberg test just before being taken to the operating room.
Other Name: SPS test
Behavioral: Spoken word-stem completion test
After discharge from recovery but within 24 hrs. post surgery, this test along with the anxiety test will be administered.
Device: Bispectral Index Monitor
The physiologic monitor is used intraoperatively to assess surgical anesthesia
Other Name: BIS Monitor
Other: Audio File
Playing an audio file (a list of spoken words) via headphones under general anesthesia during the surgical procedure.
Experimental: 2
Target BIS 60
Behavioral: Mini-mental state exam
For subjects > 60, this exam will be administered pre-operatively.
Behavioral: Spielberg's State-Trait anxiety test
Operative phase of study: Spielberg test just before being taken to the operating room.
Other Name: SPS test
Behavioral: Spoken word-stem completion test
After discharge from recovery but within 24 hrs. post surgery, this test along with the anxiety test will be administered.
Device: Bispectral Index Monitor
The physiologic monitor is used intraoperatively to assess surgical anesthesia
Other Name: BIS Monitor
Other: Audio File
Playing an audio file (a list of spoken words) via headphones under general anesthesia during the surgical procedure.

Detailed Description:

Amnesia (lack of recall) is one of the most important goals of general anesthesia. Inadvertent free recall during a major surgical procedure is not only inhumane, but also predisposes the patient to morbidity such as post-traumatic stress disorder. Therefore, it is standard practice among anesthesiologists to inquire about free (explicit) recall during a post-anesthetic visit.

Free recall requires a functional long term memory. Historically, lack of free recall during general anesthesia has been regarded as complete absence of long term memory activity. However, recent evidence suggests that the relationship between general anesthesia and memory is more complex than previously thought.

Objectives of the proposed are twofold: (1) to test the presence of implicit memory under two different planes of surgical general anesthesia in elderly males (55-90 years old) during a uniform surgical procedure (urologic procedures via transurethral approach) (2) to compare the pre and postoperative anxiety levels as a marker of clinical significance of operational implicit memory function.

The study is divided into three phases: pre-operative, operative, and post-operative.

Pre-operative phase will consist of a cognitive function test (mini-mental state exam). This will be administered at the urology or pre-operative anesthesia clinic visit, after obtaining the informed consent of the patient.

Operative phase will start with a baseline anxiety test (Spielberg's state-trait anxiety test) just before being taken to the operating room. This will be followed by playing an audio file (a list of spoken words) via headphones under general anesthesia during the surgical procedure.

Post-operative phase will have of a spoken word-stem completion test (just before discharge from the hospital) and a repeat of the anxiety test mentioned above (2 to 3 weeks post-operatively).

  Eligibility

Ages Eligible for Study:   55 Years to 90 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • Persons signing informed consent
  • Elective general surgery for orthopedics (external or internal fixation) or urologic (transurethral)
  • Literate
  • Native English speaking

Exclusion Criteria:

  • Hearing impaired
  • History of cognitive dysfunction
  • Subjects requiring post-operative sedation for any indication
  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: NCT00584324

Locations
United States, Oklahoma
University of Oklahoma Health Sciences Center
Oklahoma City, Oklahoma, United States, 73104
Sponsors and Collaborators
University of Oklahoma
Investigators
Principal Investigator: Mehmet S. Ozcan, MD University of Oklahoma
  More Information

No publications provided

Responsible Party: University of Oklahoma
ClinicalTrials.gov Identifier: NCT00584324     History of Changes
Other Study ID Numbers: IRB No: 12634
Study First Received: December 20, 2007
Last Updated: February 1, 2012
Health Authority: United States: Institutional Review Board

Keywords provided by University of Oklahoma:
elective surgery
general anesthesia
implicit memory

Additional relevant MeSH terms:
Anesthetics
Central Nervous System Depressants
Physiological Effects of Drugs
Pharmacologic Actions
Central Nervous System Agents
Therapeutic Uses

ClinicalTrials.gov processed this record on October 19, 2014