Awareness During Blended Anaesthesia
- Conditions
- Intraoperative AwarenessConsciousness, Level Depressed
- Interventions
- Device: monitor for depth of hypnosis
- Registration Number
- NCT01800578
- Lead Sponsor
- Germano De Cosmo
- Brief Summary
the aim of this study was to estimate the relations between Bispectral Index values and explicit or implicit memory or dreams during two different minimal alveolar concentration (MAC) of sevoflurane in patients undergoing blended anaesthesia for major abdominal surgery and ,in this way, estimate the possibility to reduce, in presence of a deep analgesia, like epidural analgesia, the requirement of halogenated volatile anesthetics.
- Detailed Description
The decreased responsiveness to stimulation defines depth of anaesthesia which is a balance between effects of anaesthetic drugs and surgical stimulations.
Awareness is a rare occurrence with an incidence of 0,1-0,2 % , defined as postoperative recall of events occurring during general anaesthesia.
Different stages of awareness should be defined: conscious awareness with explicit recalls with pain; conscious awareness with explicit recalls without pain; conscious awareness without explicit recall and possible implicit recall; subconscious awareness without explicit recall and possible implicit recall; no awareness .
This memory can be traumatic and may result in developing a chronic posttraumatic stress disorder (PTSD) in more than half of subjects .
Some cases of awareness are caused by inadequate anesthesia and are potentially avoidable through the assessment of depth of hypnosis by an intraoperative monitoring , especially when muscle relaxants are used.
The Bispectral Index ( BIS ), one of the devices designed to monitor brain activity, through a proprietary algorithm , elaborates EEG and provides an index of hypnotic level.
Thus, several variables, derived from EEG time and frequency domain, are combined into a single index indicating the patient's level of consciousness.
A range between 40 and 60, during surgery, permits both to prevent awareness and to reduce the dose of anesthetic agent administered .
In this study, during major abdominal surgery, an epidural analgesia was performed to suppress afferent noxious stimuli and combined with a general anaesthesia based on halogenates.
Thereby the aim of this study was to estimate the relations between Bispectral Index values and explicit or implicit memory or dreams during two different minimal alveolar concentration (MAC) of sevoflurane in patients undergoing blended anaesthesia for major abdominal surgery and ,in this way, estimate the possibility to reduce, in presence of a deep analgesia, like epidural analgesia, the requirement of halogenated volatile anesthetics.
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- All
- Target Recruitment
- 36
native Italian speakers American society of anaesthesiologist physical status I-II -
refusal of placement of epidural catheter neurological or psychiatric diseases hearing impairment use of drugs know to affect central nervous system coagulopathy heart conditions infections allergy to local anaesthetics liver or renal disease
Study & Design
- Study Type
- OBSERVATIONAL
- Study Design
- Not specified
- Arm && Interventions
Group Intervention Description Bispectral Index Group monitor for depth of hypnosis -
- Primary Outcome Measures
Name Time Method correlation between BIS and free association test score every 15 min during anaesthesia and 24 h after emergency from anaesthesia
- Secondary Outcome Measures
Name Time Method MAC of sevoflurane necessary to avoid awareness 24 h after emergency from anaesthesia
Trial Locations
- Locations (1)
Catholic University of Sacred Heart
🇮🇹Rome, Rm, Italy