Memory During Inhalation Anesthesia Performed With or Without Bispectral Index (BIS) in Patients Undergoing Thyroidectomy

The purpose of this study is 1) to investigate whether the use of BIS as a guide to the administration of inhaled anesthetic (sevoflurane or desflurane) compared with the use of hemodynamic parameters (blood pressure and heart rate) would affect the occurrence of implicit memory and /or dreams recall and 2) to check whether the occurrence of implicit memory and/or dreams recall is related with MAC (Minimal Alveolar Concentration) of inhalational anesthetics and/or preoperative anxiety levels.

Study Overview

• Status: Unknown
• Conditions: Thyroidectomy
• Intervention / Treatment: Drug: Inhaled anesthetics; Drug: Inhaled anesthetics

• Study Type: Observational
• Enrollment (Anticipated): 130

Contacts and Locations

Study Locations

• Italy
  • Rome, Italy, 00168
    • Recruiting
    • Catholic University Of Sacred Heart
    • Principal Investigator: Liliana Sollazzi, MD, Associate Professor

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 70 years (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Probability Sample

Study Population

Patients undergoing general anesthesia for thyroidectomy

Description

Inclusion Criteria:

• Age between 18 and 70 years
• Class-ASA Physical Status I-II

Exclusion Criteria:

• Psychiatric or neurological disorders and/or hearing disorders
• Obesity (Body Mass Index > 30)
• Drug addiction, alcoholism
• Patient with difficulty in understanding italian language and/or education level below middle school

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Hemodynamic parameters; Hemodynamic parameters will be used as a guide for anesthesia.	Drug: Inhaled anesthetics; Inhaled anaesthetic drugs (sevoflurane or desflurane) concentration will be changed on the basis of hemodynamic parameters (mean arterial pressure and heart rate greater or less than 20% compared to preoperative values).; Drug: Inhaled anesthetics; Inhaled anaesthetic drugs (sevoflurane or desflurane) concentration will be changed on the basis of Bispectral Index (BIS) value which will be maintained between 40 and 50.
BIS; Bispectral Index (BIS) will be used as a guide for anesthesia.	Drug: Inhaled anesthetics; Inhaled anaesthetic drugs (sevoflurane or desflurane) concentration will be changed on the basis of hemodynamic parameters (mean arterial pressure and heart rate greater or less than 20% compared to preoperative values).; Drug: Inhaled anesthetics; Inhaled anaesthetic drugs (sevoflurane or desflurane) concentration will be changed on the basis of Bispectral Index (BIS) value which will be maintained between 40 and 50.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Implicit memory	Implicit memory will be investigated using free association test: patients, during maintenance of anesthesia, will listen a piece of one of two stories, "Puss in Boots" or "Pinocchio", each followed by four keywords. Approximately 24 hours after surgery, patients will be asked to associate the first thing that comes to mind with these keywords in order to highlight the presence of implicit memory. The test will be repeated twice and will be positive if the patient will reply with the title of the story or a word of it.	Approximately 24 hours after surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Dreams recall	A first interview about dreams recall will be carried out 5 minutes after awakening from anesthesia. Patients will be asked about dream content.	Approximately 5 minutes after awakening from anesthesia
Explicit memory	Patients will be asked about the last thing they remembered before going to sleep; the first thing they remember when they woke up; and anything which happen in between, including sounds, dreams and imagination.	Approximately 24 hours after surgery
Dreams recall	Patients will be asked again about dreams recall. The content of dreams will be analyzed using the 5-point Likert scales which contains the following dreams characteristics: memory content, emotional content, emotional intensity, vivid description, amount of sounds, meaning, how much movement, strange, episodic content, references to episodes of life.	Approximately 24 hours after anaesthesia

Collaborators and Investigators

• Sponsor: Catholic University of the Sacred Heart

Study record dates

Study Major Dates

• Study Start: June 1, 2010

Study Registration Dates

• First Submitted: June 9, 2010
• First Submitted That Met QC Criteria: June 16, 2010
• First Posted (ESTIMATE): June 17, 2010

Study Record Updates

• Last Update Posted (ESTIMATE): February 9, 2011
• Last Update Submitted That Met QC Criteria: February 8, 2011
• Last Verified: January 1, 2010

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Central Nervous System Depressants; Anesthetics
• Other Study ID Numbers: A/1051/2009