Comparison of Low Versus Normal Flow Anesthesia on Cerebral Oxygenation and Bispectral Index in Morbidly Obese Patients

NCT ID: NCT03438734

Last Updated: 2018-04-17

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 52 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2017-11-08
• Study Completion Date: 2018-02-17

Brief Summary

Obesity is a chronic disease that affects quality and duration of life negatively. It's not clearly known the effects of low flow anesthesia on cerebral oxygenation with high-risk morbidly obese patients. In this study, it was aimed to compare the effects of general anesthesia with low flow (0,75 L/min) and normal flow (1,5 L/min) on cerebral oxygenation and depth of anesthesia in morbidly obese patients in bariatric surgery.

Detailed Description

Obesity is a chronic disease that affects quality and duration of life negatively. It is one of the most important health problem in the world along with very common in Turkey. Initially, obesity was considered the problem of developed countries but it has become inevitable with increase income levels, changes in lifestyles, reduction of energy consumption and increase of energy intake in developing countries. Today, the second important cause of preventable deaths after smoking is obesity. The World Health Organization (WHO) has stated that it will be the most important health problem of the 21st century. According to WHO determinations; as of 2008, the prevalence of overweight in the world is 35% and the prevalence of obesity is around 11%. The definition of body mass index (BMI) is used in defining and classifying obesity. WHO is making the definition of overweight and obesity based on body mass index [BMI = Weight (kg) / Height (m2)]. It is called as obesity when the calculated value is over 30 kg/m2, morbid obesity over 40 kg/m2 and super obesity over 50 kg/m2.

Morbid obesity operations, with effective results on achieving weight loss continuity once it has been widely applied in Europe and the United States, have been frequently implemented in Turkey as well. With the rising obesity in Turkey, laparoscopic bariatric surgery which has low complication rates is preferred.

Low flow general anesthesia is applied to reduce pollution rates and treatment costs in operation rooms. However, the reduction of fresh gas flow should not affect the quality and safety of anesthesia management, especially in high risk operations such as morbid obesity surgery. Insufflation of abdominal cavity with carbon dioxide during laparoscopic surgery is resulted in increased intraabdominal pressure, decreased functional residual capacity and pulmonary compliance, increased hypercapnia and systemic vascular resistance. Especially in the trendelenburg position it may be difficult to detect cerebral hypoxia as a consequence of increased intracranial pressure and decreased cerebral blood flow .

During general anesthesia, there are several options for monitoring the cerebral condition. One of them is cerebral oximetry method which estimates regional tissue oxygenation by transcutaneous measurement on the frontal cortex. Near-infrared spectroscopy (NIRS) is a monitor used following the adequacy of cerebral perfusion with noninvasive and continuous measurement and reflects regional saturation.

With the development of technology, the safety of anesthesia devices and the advancement of monitoring techniques are positively affecting the anesthesia management. The effects of low flow anesthesia, which has been used for years and whose positive aspects are well practiced, are not clearly known on cerebral oxygenation with high-risk morbidly obese patients. In this prospective randomized study, it was aimed to compare the effects of general anesthesia with low flow (0,75 L/min) and normal flow (1,5 L/min) on cerebral oxygenation and depth of anesthesia in morbidly obese patients in bariatric surgery.

Conditions

Morbid Obesity; Anesthesia Awareness; Anesthesia Complication

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: SCREENING
• Blinding Strategy: SINGLE

Study Groups

Low flow

Anesthesia was maintained with desflurane inhalation with a flow of 2 L/min in 0.5 O2 oxygen-air mixture in both groups. While target minimum alveolar concentration (MAC) was 1-1.5 and the flow rate was adjusted to 0.75 L/min. Regional cerebral oxygen saturation is a useful clinical research tool for noninvasive and continuous monitoring of hemodynamic and brain oxygenation. Regional cerebral oxygen saturation (Near-infrared spectroscopy system, NIRS, Cerebral Oximeter) monitoring was performed to all patients.

The most effective method for depth of anesthesia and assessment of sedation is bispectral analysis of mean frequency of electroencephalography. The values of Bispectral Index (BIS, Bispectral Index, Monitoring System) decreases with the deepening of anesthesia.

Group Type: ACTIVE_COMPARATOR

Regional cerebral oxygen saturation

Intervention Type: DEVICE

Regional cerebral oxygen saturation is a useful clinical research tool for noninvasive and continuous monitoring of hemodynamic and brain oxygenation. Regional cerebral oxygen saturation (Near-infrared spectroscopy system, NIRS, Cerebral Oximeter) monitoring was performed to all patients.

Bispectral Index (BIS)

Intervention Type: DEVICE

The most effective method for depth of anesthesia and assessment of sedation is bispectral analysis of mean frequency of electroencephalography. The values of BIS decreases with the deepening of anesthesia.

Normal flow

Anesthesia was maintained with desflurane inhalation with a flow of 2 L/min in 0.5 O2 oxygen-air mixture in both groups. While target minimum alveolar concentration (MAC) was 1-1.5 and the flow rate was adjusted to 1.5 L/min.Regional cerebral oxygen saturation is a useful clinical research tool for noninvasive and continuous monitoring of hemodynamic and brain oxygenation. Regional cerebral oxygen saturation (Near-infrared spectroscopy system, NIRS, Cerebral Oximeter) monitoring was performed to all patients.

The most effective method for depth of anesthesia and assessment of sedation is bispectral analysis of mean frequency of electroencephalography. The values of Bispectral Index (BIS, Bispectral Index, Monitoring System) decreases with the deepening of anesthesia.

Group Type: SHAM_COMPARATOR

Regional cerebral oxygen saturation

Intervention Type: DEVICE

Regional cerebral oxygen saturation is a useful clinical research tool for noninvasive and continuous monitoring of hemodynamic and brain oxygenation. Regional cerebral oxygen saturation (Near-infrared spectroscopy system, NIRS, Cerebral Oximeter) monitoring was performed to all patients.

Bispectral Index (BIS)

Intervention Type: DEVICE

The most effective method for depth of anesthesia and assessment of sedation is bispectral analysis of mean frequency of electroencephalography. The values of BIS decreases with the deepening of anesthesia.

Interventions

Regional cerebral oxygen saturation

Regional cerebral oxygen saturation is a useful clinical research tool for noninvasive and continuous monitoring of hemodynamic and brain oxygenation. Regional cerebral oxygen saturation (Near-infrared spectroscopy system, NIRS, Cerebral Oximeter) monitoring was performed to all patients.

Intervention Type: DEVICE

Bispectral Index (BIS)

The most effective method for depth of anesthesia and assessment of sedation is bispectral analysis of mean frequency of electroencephalography. The values of BIS decreases with the deepening of anesthesia.

Intervention Type: DEVICE

Other Intervention Names

NIRS (Near-infrared spectroscopy system); BIS

Eligibility Criteria

Inclusion Criteria

• American Society of Anesthesiology score I-III,
• 18-65 years,
• BMI> 35

Exclusion Criteria

• American Society of Anesthesiology IV,
• Under 18 years,
• Over 65 years,
• Obstetric patients,
• Uncontrolled diabetes mellitus, cardiovascular and pulmonary disease,
• Cerebrovascular disease,
• Patients who refused informed consent forms

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 65 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Inonu University

OTHER

Sponsor Role: lead

Responsible Party

Sedat AKBAS

Asst. Prof.

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Sedat AKBAS

Role: STUDY_DIRECTOR

Inonu University Medical Faculty

Locations

Sedat AKBAS

Malatya, Türkiye-Türkçe, Turkey (Türkiye)

Countries

Turkey (Türkiye)

References

Jones KB Jr. Experience with the Roux-en-Y gastric bypass, and commentary on current trends. Obes Surg. 2000 Apr;10(2):183-5. doi: 10.1381/096089200321668659. No abstract available.

Reference Type: BACKGROUND

PMID: 10782184 (View on PubMed)

Vegh T. Cerebral Oximetry in General Anaesthesia. Turk J Anaesthesiol Reanim. 2016 Oct;44(5):247-249. doi: 10.5152/TJAR.2016.26092016. Epub 2016 Oct 1. No abstract available.

Reference Type: BACKGROUND

PMID: 27909605 (View on PubMed)

Kupisiak J, Goch R, Polenceusz W, Szyca R, Leksowski K. Bispectral index and cerebral oximetry in low-flow and high-flow rate anaesthesia during laparoscopic cholecystectomy - a randomized controlled trial. Wideochir Inne Tech Maloinwazyjne. 2011 Dec;6(4):226-30. doi: 10.5114/wiitm.2011.26256. Epub 2011 Dec 20.

Reference Type: RESULT

PMID: 23255984 (View on PubMed)

Provided Documents

Document Type: Study Protocol and Statistical Analysis Plan

View Document

Other Identifiers

sedatakbas1

Identifier Type: -

Identifier Source: org_study_id