Clinical trial NCT06026033: The Effect of Anthropometrics on Desflurane Rise Time
Official title: Does Desflurane Take Longer to Reach Target Endtidal Concentration in Patients With Higher Body Muscle Content: a Pragmatic Study
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Desflurane
Anesthesia, General
Keywords: Anesthetics, Inhalation
Anesthesia, General
Desflurane
Lead sponsor: Recep Tayyip Erdogan University
Sponsor class: OTHER
First posted: 2023-09-06
Enrollment: 361
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Adult patients, who are scheduled for elective general anesthesia. Maintenance of anesthesia with desflurane should be included in the routine anesthesia plan.

Brief summary: Desflurane is increasingly used in general anesthesia. Its pharmacokinetic properties are known and its distribution is easily modeled. Yet these models fail in practice. In order to increase accuracy, any model should include cardiac output, alveolar ventilation and alveolar dead space, all of which are either hard to measure or impractical, at least.

A previous study performed by the same investigator showed that time to target endtidal concentration of sevoflurane is prolonged with increased cardiac output, but only if the patient has increased muscle mass. Although desflurane has lower muscle and fat solubility, our observations suggest a similar prolongation in case of increased muscle mass.

The investigators aim to investigate if patient characteristics such as gender, age, height, weight, body type prolongs time to reach target endtidal desflurane concentration in low flow anesthesia.

Detailed description: Low flow anesthesia is a frequently used application in anesthesiology practice. With the widespread use of modern anesthesia devices, the implementation of this application has become easier and its complications have been greatly reduced. It is routinely applied in our clinic, accompanied by both the protocols in the literature and the protocols the investigators have created.

Desflurane is the most recently developed inhaler anesthetic agent, and it has advantages such as faster recovery from anesthesia and less metabolism compared to sevoflurane. Although the physicochemical properties of desflurane are known, computer models for its use with low-flow anesthesia are based on desflurane's physicochemical properties, and not on the pharmacokinetic properties of patients. The inhaled induction times obtained with these models do not agree with our observations in practice.

In a study conducted in 2021, it was shown that parameters such as cardiac output and alveolar ventilation can increase the accuracy of these models. Among these models, the most frequently used one in the literature is included in the Gas Man simulator, which is also used in anesthesia specialty training. It allows one to perform studies that compare simulation-based and in vivo values are carried out.

A similar study was conducted by us with sevoflurane in 2018; A significant difference was found in the rate of increase in alveolar sevoflurane concentration according to cardiac output and muscle mass. Based on this study, the investigators aimed to investigate the effect of the patient's muscle mass evaluated by pragmatic measures such as height, body weight and body type on the rate of increase in the alveolar concentration of desflurane.

For this purpose, the investigators aimed to investigate the relationship between the time to reach the targeted alveolar desflurane gas concentration and patient characteristics. The investigators believe that the results of the study will be useful in explaining the factors affecting the induction of general anesthesia with desflurane.

Eligibility criteria: Inclusion Criteria:

* age \> 18 years
* planned elective surgery
* planned inhalational anesthesia
* planned use of desflurane

Exclusion Criteria:

* emergency surgery
* use of other inhalational anesthetic agent (sevoflurane, isoflurane, nitrous oxide)
* disclosed or recognized pregnancy

Primary outcomes:
measure: Rate of rise in expiratory desflurane concentration
timeFrame: intraoperative
measure: Rate of rise in inspiratory desflurane concentration
timeFrame: intraoperative
Secondary outcomes:
measure: Correlation between occurrence of hypertension and patient characteristics
timeFrame: intraoperative
measure: Correlation between occurrence of tachycardia and patient characteristics
timeFrame: intraoperative
Other outcomes:
Locations:
city: Rize
country: Turkey
facility: Recep Tayyip Erdogan University Medical Faculty, Department of Anesthesiology and Reanimation
Study officials:
affiliation: Recep Tayyip Erdogan University Medical Faculty, Department of Anesthesiology and Reanimation
name: Başar Erdivanlı, Assoc. Prof.
role: STUDY_DIRECTOR
affiliation: Recep Tayyip Erdogan University Medical Faculty, Department of Anesthesiology and Reanimation
name: Alihan Madran, M.D.
role: PRINCIPAL_INVESTIGATOR
References:
citation: Weber J, Missbach C, Schmidt J, Wenzel C, Schumann S, Philip JH, Wirth S. Prediction of expiratory desflurane and sevoflurane concentrations in lung-healthy patients utilizing cardiac output and alveolar ventilation matched pharmacokinetic models: A comparative observational study. Medicine (Baltimore). 2021 Feb 12;100(6):e23570. doi: 10.1097/MD.0000000000023570.
citation: Athiraman U, Ravishankar M, Jahagirdhar S. Performance of computer simulated inhalational anesthetic uptake model in comparison with real time isoflurane concentration. J Clin Monit Comput. 2016 Dec;30(6):791-796. doi: 10.1007/s10877-015-9776-6. Epub 2015 Sep 19.
citation: Philip JH. Using screen-based simulation of inhaled anaesthetic delivery to improve patient care. Br J Anaesth. 2015 Dec;115 Suppl 2:ii89-94. doi: 10.1093/bja/aev370.