The Effect of Anthropometrics on Desflurane Rise Time

Does Desflurane Take Longer to Reach Target Endtidal Concentration in Patients With Higher Body Muscle Content: a Pragmatic Study

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.

Study Overview

• Status: Completed
• Conditions: Anesthesia, General; Desflurane
• Intervention / Treatment: Drug: Desflurane induction

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.

• Study Type: Observational
• Enrollment (Actual): 361

Contacts and Locations

Study Locations

• Turkey
  • Rize, Turkey, 53100
    • Recep Tayyip Erdogan University Medical Faculty, Department of Anesthesiology and Reanimation

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• 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.

Description

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

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

Patients scheduled for general anesthesia; Patients scheduled for elective general anesthesia will be included, if accepts and signs the informed consent. The inhalational anesthetic should be desflurane. No other inhalational agent should be used during the induction of anesthesia. The inspiratory and expiratory concentration of any inhalational agent should be zero before the induction of anesthesia.

Drug: Desflurane induction; Following tracheal intubation, the fresh gas flow will be set to 1 liters/minute, desflurane vaporizer will be set to maximum.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Rate of rise in expiratory desflurane concentration	Correlation between the time required for the endtidal expiratory desflurane concentration to reach 8% and patient characteristics	intraoperative
Rate of rise in inspiratory desflurane concentration	Correlation between the time required for the endtidal inspiratory desflurane concentration to reach 6% and patient characteristics	intraoperative

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Correlation between occurrence of hypertension and patient characteristics	Correlation between occurrence of hypertension defined as any measurement of systolic arterial blood pressure > 160 mmHg and patient characteristics	intraoperative
Correlation between occurrence of tachycardia and patient characteristics	Correlation between occurrence of tachycardia defined as any measurement of heart rate > 100/minute and patient characteristics	intraoperative

Collaborators and Investigators

• Sponsor: Recep Tayyip Erdogan University
• Collaborators: Recep Tayyip Erdogan University
• Investigators: Study Director: Başar Erdivanlı, Assoc. Prof., Recep Tayyip Erdogan University Medical Faculty, Department of Anesthesiology and Reanimation; Principal Investigator: Alihan Madran, M.D., Recep Tayyip Erdogan University Medical Faculty, Department of Anesthesiology and Reanimation

Publications and helpful links

General Publications

• 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.
• 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.
• 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.

Study record dates

Study Major Dates

• Study Start (Actual): February 1, 2022
• Primary Completion (Actual): August 30, 2023
• Study Completion (Actual): September 1, 2023

Study Registration Dates

• First Submitted: March 31, 2023
• First Submitted That Met QC Criteria: September 3, 2023
• First Posted (Actual): September 6, 2023

Study Record Updates

• Last Update Posted (Actual): December 22, 2023
• Last Update Submitted That Met QC Criteria: December 18, 2023
• Last Verified: December 1, 2023

More Information

Terms related to this study

• Keywords: Desflurane; Anesthesia, General; Anesthetics, Inhalation
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Central Nervous System Depressants; Anesthetics, General; Anesthetics; Anesthetics, Inhalation; Desflurane
• Other Study ID Numbers: 2022/11

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No