Ventilatory Effect on Speed of Anesthesia Under Various Inhaled Anesthetics

Sponsor

DongGuk University (Other)

Overall Status

Completed

CT.gov ID

NCT01171833

Collaborator

(none)

Enrollment

Arms

Duration (Months)

Study Details

Study Description

Brief Summary

Three groups of patients are going to have minor surgery under general anesthesia with inhaled anesthetics and different ventilatory setting (Tidal volume: 8, 10, 12 ml/kg, respiratory rate: 10/min each). Group A (Sevoflurane) will use sevoflurane, group B (Desflurane) will use desflurane, and group C (Isoflurane) will use isoflurane. It will be observed differences among the groups for ventilatory effects on speed of induction.

Duration of this randomised controlled trial will be about 3 months. Estimated sample size will be 36 patients(12 in each group).

Condition or Disease	Intervention/Treatment	Phase
Pharmacokinetics of Inhaled Anesthetics	Drug: Sevoflurane Drug: Desflurane Drug: Isoflurane	N/A

Detailed Description

No premedicant will be given. The anesthetic workstation and a circulatory circuit will be prefilled with 1.0 MAC of inhaled anesthetic that will be selected randomly.

Group A (n=12): Sevoflurane 2.0 vol%
Group B (n=12): Desflurane 6.0 vol%
Group C (n=12): Isoflurane 1.2 vol%

Each group has 3 subgroups according to the ventilatory setting that will also be randomly determined.

Hypoventilation: tidal volume 8 ml/kg, respiratory rate 10 /min
Normoventilation: tidal volume 10 ml/kg, respiratory rate 10 /min
Hyperventilation: tidal volume 12 ml/kg, respiratory rate 10 /min

Patients will be preoxygenated with 100% oxygen (5 L/min) for 5 minutes under pulse oximeter, EKG, and noninvasive blood pressure monitoring. Bispectral index (BIS) monitor will be applied.

The induction of general anesthesia will start with propofol (2 mg/kg), rocuronium (0.8 mg/kg) and remifentanil infusion (0.1 mcg/kg/min). The size of a tracheal tube will be 7.5 mm (ID) for male, 7.0 mm (ID) for female. After intubation, anesthesia workstation will be connected to the tracheal tube. Ventilation will start, and that point will be time 0. During 720 seconds, inspiratory (PIgas) and end-tidal concentration of inhaled anesthetics (ETgas), end-tidal partial pressure of carbon dioxide, and BIS will be measured at time 0, 30, 60, 90, 120 ,150, 180, 240, 300, 360, 480, 600, and 720 seconds. Mean blood pressure and heart rate will also be recorded every 2 minutes. Fresh gas flow will be kept at 6 L/min with 100% oxygen.

The fraction of ETgas/PIgas will be analyzed with nonlinear mixed effects modeling.

Estimated sample size will be 36 patients (12 in each group, 4 in each ventilatory settings).

Study Design

Study Type:

Interventional

Actual Enrollment :

36 participants

Allocation:

Randomized

Intervention Model:

Parallel Assignment

Masking:

Single (Participant)

Primary Purpose:

Basic Science

Official Title:

Effect of Ventilation on Speed of Induction of Anesthesia in Desflurane, Sevoflurane, and Isoflurane

Study Start Date :

Jun 1, 2010

Actual Primary Completion Date :

Oct 1, 2010

Actual Study Completion Date :

Oct 1, 2010

Arms and Interventions

Arm	Intervention/Treatment
Experimental: Group A(Sevoflurane) Twelve patients will be enrolled in this group. They will be divided into subgroups with ventilatory settings. Each subgroup has 4 patients. A8: tidal volume(8 ml/kg) and respiratory rate(10 /min) A10: tidal volume(10 ml/kg) and respiratory rate(10 /min) A12: tidal volume(12 ml/kg) and respiratory rate(10 /min)	Drug: Sevoflurane 2.0 vol% prefilled in a corrugated circuit. Other Names: Sevorane
Experimental: Group B(Desflurane) Twelve patients will be enrolled in this group. They will be divided into subgroups with ventilatory settings. Each subgroup has 4 patients. A8: tidal volume(8 ml/kg) and respiratory rate(10 /min) A10: tidal volume(10 ml/kg) and respiratory rate(10 /min) A12: tidal volume(12 ml/kg) and respiratory rate(10 /min)	Drug: Desflurane 6.0 vol% prefilled in a corrugated circuit. Other Names: Suprane
Experimental: Group C(Isoflurane) Twelve patients will be enrolled in this group. They will be divided into subgroups with ventilatory settings. Each subgroup has 4 patients. A8: tidal volume(8 ml/kg) and respiratory rate(10 /min) A10: tidal volume(10 ml/kg) and respiratory rate(10 /min) A12: tidal volume(12 ml/kg) and respiratory rate(10 /min)	Drug: Isoflurane 1.2 vol% prefilled in a corrugated circuit. Other Names: Aerane

Arm

Intervention/Treatment

Experimental: Group A(Sevoflurane)

Twelve patients will be enrolled in this group. They will be divided into subgroups with ventilatory settings. Each subgroup has 4 patients. A8: tidal volume(8 ml/kg) and respiratory rate(10 /min) A10: tidal volume(10 ml/kg) and respiratory rate(10 /min) A12: tidal volume(12 ml/kg) and respiratory rate(10 /min)

Drug: Sevoflurane

2.0 vol% prefilled in a corrugated circuit.

Other Names:

Sevorane

Experimental: Group B(Desflurane)

Drug: Desflurane

6.0 vol% prefilled in a corrugated circuit.

Other Names:

Suprane

Experimental: Group C(Isoflurane)

Drug: Isoflurane

1.2 vol% prefilled in a corrugated circuit.

Other Names:

Aerane

Outcome Measures

Primary Outcome Measures

End-tidal concentrations of isoflurane, sevoflurane and desflurane, and BIS values with hypo-, normo-, hyperventilation [at 0, 30, 60, 90, 120, 180, 240, 300, 360, 480, 600, 720 sec after volatile gas starts]
The inspiratory, and end-tidal concentrations of volatile anesthetics, partial pressure of end-tidal carbon dioxide will be recorded from an S/5 Avance anesthetic workstation (Datex-Ohmeda) and an embedded monitor. BIS values are measured with a BIS monitor.

Eligibility Criteria

Criteria

Ages Eligible for Study:

20 Years to 60 Years

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Inclusion Criteria:

ASA PS I, II
Age: 20-60 years male and female
Elective schedule with minor surgery
BMI < 30

Exclusion Criteria:

Patients with pulmonary, cardiac, endocrinal, neuromuscular and neurological diseases or past history
Upper airway anomaly or deformity
ASA PS III or higher
Pregnant women
BMI >= 30