Neurotoxicity of Anesthesia in Middle Aged Patients

• Conditions: Anesthesia; Adverse Effect
• Interventions: Drug: Anesthesia Agent

• Registration Number: NCT04275531
• Lead Sponsor: Tanta University

Brief Summary

for the last 20 years, the increasing reports from non-human studies have raised suspicion that general anesthetics may cause neurotoxic changes in the developing brain that lead to adverse neurodevelopmental outcomes later in life.there are several case reports of reversible smell and taste dysfunction following exposure to general anesthesia suggesting a possible relationship between anesthetic agents and olfactory dysfunction.

this study is to assess the possible neurotoxicity of sevoflurane,isoflurane,and propofol based anesthesia guided by olfactory changes

Detailed Description

the primary inhibitory neurotransmitter GABA is found in neuronal synapses involving olfactory bulb. So, the involvement of common GABA pathway implies a possible interaction of general anesthetics with olfactory function.

olfactory identification is an associative memory which is found to be facilitated by action of melatonin. involvement of GABA receptor in the transfer of light information from suprachiasmatic nuclei to pineal gland suggests possible interaction of melatonin and anesthetic agents.

the aim of the study is to evaluate the possible neurotoxicity of sevoflurane,isoflurane,and propofol based anesthesia guided by olfactory changes

Study Timeline

• Study First Submitted: 2020-02-11
• Study First Submitted QC: 2020-02-15
• Study First Posted: 2020-02-19
• Study Start: 2021-03-01
• Status Verified: 2022-03
• Last Update Submitted: 2022-03-14
• Last Update Posted: 2022-03-15
• Primary Completion: 2022-08-01
• Study Completion: 2022-09-01

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 600

Inclusion Criteria

• patients aged 18-50 years
• both sex
• American society of Anesthesiologists' physical status I and II
• elective surgery of duration 90-120 minutes

Exclusion Criteria

• patients's refusal
• recent airway infection
• allergic rhinitis
• nasal polyps
• history of alcoholism
• smoking
• pregnancy
• menstruating female
• mental retardation
• psychiatric illness
• neurosurgical or oto-rhino-laryngeal surgery
• history of olfactory deficits or cognitive impairment
• CNS disease e.g. epilepsy
• history of first degree relative with alzheimer's disease,dementia, or cognitive dysfunction
• those who are unable to answer the tests themselves

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
regional anesthesia	Anesthesia Agent	surgical procedures which will be performed under intrathecal anesthesia without sedation
sevoflurane	Anesthesia Agent	surgical procedures which will be performed under general anesthesia and sevoflurane will be used for maintenance of anesthesia
isoflurane	Anesthesia Agent	surgical procedures which will be performed under general anesthesia and isoflurane will be used for maintenance of anesthesia
propofol	Anesthesia Agent	surgical procedures which will be performed under general anesthesia and propofol infusion will be used for maintenance of anesthesia

Primary Outcome Measures

Name	Time	Method
olfactory threshold	olfactory threshold will be measured at 12 hours preoperative then at 6, 24 and 48 hours postoperative	we will use (10 dilutions) of 4% n-butyl alcohol. The odorant and a blank will be presented to the participant. The test will be progressed from weaker-to-stronger concentrations of odorant. Two bottles will be presented to each participant, an odorant bottle and an identical bottle filled with distilled water. The participant will sniff each one for 9 seconds and then will chose which one smelled stronger. If the participant is incorrect at one concentration, the next higher concentration will be presented. When the correct choice is made, the same concentration of odorant will be presented to the participant until four consecutive correct responses are given.

Secondary Outcome Measures

Name	Time	Method
serum melatonin concentrations	serum melatonin will be measured at 12 hours preoperative then at 6, 24 and 48 hours postoperative	Melatonin levels will be measured in plasma by the enzyme-linked immunosorbent assay (ELISA)
olfactory identification	Smell identification will be measured at 12 hours preoperative then at 6, 24 and 48 hours postoperative	We will use UPSIT test.
cognitive dysfunction	Cognitive dysfunction will be evaluated at 12 hours preoperative then at 6, 24 and 48 hours postoperative	cognitive dysfunction will be evaluated by mini-mental state examination

Trial Locations

Locations (1)

Tanta University, Faculty of Medicine; 🇪🇬 Tanta, Egypt