Context-sensitive decrement times for inhaled anesthetics in obese patients explored with Gas Man®

Anesthesia care providers and anesthesia decision support tools use mathematical pharmacokinetic models to control delivery and especially removal of anesthetics from the patient's body. However, these models are not able to reflect alterations in pharmacokinetics of volatile anesthetics caused by obesity. The primary aim of this study was to refine those models for obese patients. To investigate the effects of obesity on the elimination of desflurane, isoflurane and sevoflurane for various anesthesia durations, the Gas Man® computer simulation software was used. Four different models simulating patients with weights of 70 kg, 100 kg, 125 kg and 150 kg were constructed by increasing fat weight to the standard 70 kg model. For each modelled patient condition, the vaporizer was set to reach quickly and then maintain an alveolar concentration of 1.0 minimum alveolar concentration (MAC). Subsequently, the circuit was switched to an open (non-rebreathing) circuit model, the inspiratory anesthetic concentration was set to 0 and the time to the anesthetic decrements by 67% (awakening times), 90% (recovery times) and 95% (resolution times) in the vessel-rich tissue compartment including highly perfused tissue of the central nervous system were determined. Awakening times did not differ greatly between the simulation models. After volatile anesthesia with sevoflurane and isoflurane, awakening times were lower in the more obese simulation models. With increasing obesity, recovery and resolution times were higher. The additional adipose tissue in obese simulation models did not prolong awakening times and thus may act more like a sink for volatile anesthetics. The results of these simulations should be validated by comparing the elimination of volatile anesthetics in obese patients with data from our simulation models.

Medienart:

E-Artikel

Erscheinungsjahr:

2021

Erschienen:

2021

Enthalten in:

Zur Gesamtaufnahme - volume:35

Enthalten in:

Journal of clinical monitoring and computing - 35(2021), 2 vom: 17. Apr., Seite 343-354

Sprache:

Englisch

Beteiligte Personen:

Weber, Jonas [VerfasserIn]
Schmidt, Johannes [VerfasserIn]
Wirth, Steffen [VerfasserIn]
Schumann, Stefan [VerfasserIn]
Philip, James H [VerfasserIn]
Eberhart, Leopold H J [VerfasserIn]

Links:

Volltext

Themen:

Anesthesia decision support tools
Anesthesia uptake and distribution
Anesthetics
Anesthetics, Inhalation
CRS35BZ94Q
CYS9AKD70P
Computer simulation
Desflurane
End-tidal control delivery machines
Inhalation anesthesia
Isoflurane
Journal Article
Methyl Ethers
Pharmacokinetics
Physiology based model

Anmerkungen:

Date Completed 28.10.2021

Date Revised 28.10.2021

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1007/s10877-020-00477-z

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM306612100