Anesthesia; Adverse Effect
Conditions
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
Interventions
DRUGAnesthesia Agent
various anesthetic agents used in both general and regional anesthesia
Sponsors
Tanta University
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to 50 Years
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 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
| Measure | Time frame | Description |
|---|---|---|
| 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 |
| 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) |
Countries
Egypt
Outcome results
None listed