Depth of Anesthesia on Implicit Memory

Anesthesia, General Clinical Trial

Official title:

The Effect of Depth of Anesthesia on Implicit Memory

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00584324
• Other study ID #: IRB No: 12634
• Status: Completed
• Phase: N/A
• First received: December 20, 2007
• Last updated: December 18, 2017
• Start date: March 2006
• Est. completion date: January 2012

Study information

• Verified date: December 2017
• Source: University of Oklahoma
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

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.

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 (Spielberger 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).

Recruitment information / eligibility

• Status: Completed
• Enrollment: 70
• Est. completion date: January 2012
• Est. primary completion date: January 2012
• Accepts healthy volunteers: No
• Gender: All
• Age group: 55 Years to 90 Years

Eligibility

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

Related Conditions & MeSH terms

• Anesthesia, General
• Memory

Intervention

Combination Product:
• BIS 40
Mini-mental state exam: For subjects > 60, this exam will be administered pre-operatively. Spielberger State-Trait anxiety test: Spielberger test just before being taken to the operating room. 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. Bispectral Index Monitor: The physiologic monitor is used intraoperatively to assess surgical anesthesia. Audio File: Playing an audio file (a list of spoken words) via headphones under general anesthesia during the surgical procedure.
• BIS 60
Mini-mental state exam: For subjects > 60, this exam will be administered pre-operatively. Spielberger State-Trait anxiety test: Spielberger test just before being taken to the operating room. 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. Bispectral Index Monitor: The physiologic monitor is used intraoperatively to assess surgical anesthesia. Audio File: Playing an audio file (a list of spoken words) via headphones under general anesthesia during the surgical procedure.

Locations

Country	Name	City	State
United States	University of Oklahoma Health Sciences Center	Oklahoma City	Oklahoma

Sponsors (1)

Lead Sponsor	Collaborator
University of Oklahoma

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	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		3 years
Secondary	To compare the pre and postoperative anxiety levels as a marker of clinical significance of operational implicit memory function.		3