Hypotension
Conditions
Keywords
Hypotension, Sevoflurane, Elderly
Brief summary
Two arms: elder group, young group. Dixon's up and down adaptive methodology for ED50. Executed after Anesthesia induction for 10min without touching the patient after starting mechanical ventilation.
Detailed description
This adaptive clinical trial will vary target end tidal sevoflurane by 0.4, then by 0.2 and by 0.1 thereafter in order to minimize sample size.
Interventions
DRUGSevoflurane
Inhaled sevoflurane until allocated dose (see adaptive protocol)
Sponsors
Brasilia University Hospital
Study design
Allocation
NON_RANDOMIZED
Intervention model
SEQUENTIAL
Primary purpose
BASIC_SCIENCE
Masking
SINGLE (Subject)
Masking description
Participant will not know allocation (sevoflurane concentration) and will be under general anesthesia
Intervention model description
Adaptive up and down methodology. Anesthesia will be induced using etomidate, rocuronium and remifentanil. After intubation and mechanical ventilation, a high fresh gas flow and variable vaporizer target concentration will be used to stabilize the patient's target end tidal sevoflurane in less than two minutes. Each patient's target end tidal sevoflurane is determined by the concentration used in the previous patient of the same group and by the incidence of hypotension. If the previous patient suffered hypotension, next patient's target concentration will drop. If there was no hypotension, next patient's target concentration will rise. The first patient on each group will be 2%. Target end tidal will vary 0.4% until the first crossover, then drop to 0.2% until the second crossover and will vary 0.1% thereafter.
Eligibility
Sex/Gender
ALL
Age
19 Years to 120 Years
Healthy volunteers
No
Inclusion criteria
* Understands experiment, is voluntary, signs informed consent; * Does not take medication that influences arterial pressure; * Normotensive.
Exclusion criteria
* Received any medication that influences arterial pressure before experiment;
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Hypotension incidence related to sevoflurane | During the first 10 minutes after end tidal sevoflurane concentration stabilizes | Any mean arterial pressure drop \> 10% compared to baseline |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Systolic hypotension | During the first 10 minutes after end tidal sevoflurane concentration stabilizes | Systolic arterial pressure drop \>10% |
| Diastolic hypotension | During the first 10 minutes after end tidal sevoflurane concentration stabilizes | Systolic arterial pressure drop \>10% |
Countries
Brazil
Contacts
Primary ContactGabriel MN Guimarães, MD, MSc
Outcome results
None listed