Effects of Low-Flow Anesthesia on Hemodynamic Parameters and Oxygenation in Morbidly Obese Patients (Oxygenation)

Effects of Low-Flow Anesthesia on Hemodynamic Parameters and Oxygenation in Morbidly Obese Patients Undergoing Bariatric Surgery: A Prospective, Randomized Clinical Trial

Low-flow anesthesia has been used for years with positive results, but its effects on hemodynamic parameters and oxygenation are not clearly known in high-risk morbidly obese patients who are prone to pulmonary dysfunction related to the obesity. Therefore, this prospective randomized study aimed to compare the effects of low-flow (0.75 L/min) and normal-flow (1.5 L/min) anesthesia on hemodynamic parameters and oxygenation in morbidly obese patients undergoing laparoscopic bariatric surgery.

Study Overview

• Status: Completed
• Conditions: Morbid Obesity; Bariatric Surgery Candidate; Hemodynamic Instability
• Intervention / Treatment: Diagnostic test: hemodynamic parameters; Diagnostic test: arterial blood gase

Detailed Description

Low-flow anesthesia has several potential benefits. It improves the flow dynamics of the inhaled air, increase mucociliary clearance, maintain body temperature, reduce fluid loss, result in savings of up to 75% and reduce greenhouse gas emissions and reduce treatment costs (10 - 13). However, it is necessary to examine whether the reduction of fresh gas flow affects the quality and safety of anesthesia management, especially during high-risk operations such as laparoscopic bariatric surgery.

Low-flow anesthesia has been used for years with positive results, but its effects on hemodynamic parameters and oxygenation are not clearly known in high-risk morbidly obese patients who are prone to pulmonary dysfunction related to the obesity. Therefore, this prospective randomized study aimed to compare the effects of low-flow (0.75 L/min) and normal-flow (1.5 L/min) anesthesia on hemodynamic parameters and oxygenation in morbidly obese patients undergoing laparoscopic bariatric surgery.

• Study Type: Interventional
• Enrollment (Actual): 48
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Turkey
  • Türkiye-Türkçe
    • Malatya, Türkiye-Türkçe, Turkey, 44090
      • Sedat Akbas

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 65 years (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Morbidly obese patients with American Society of Anesthesiology (ASA) scores of III-IV,
• Aged 18-65 years old,
• BMI>40

Exclusion Criteria:

• Pregnant
• Uncontrolled diabetes mellitus,
• Cardiovascular disease,
• Pulmonary disease,
• Cerebrovascular disease,
• Drug and alcohol addiction.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: SCREENING
• Allocation: RANDOMIZED
• Interventional Model: PARALLEL
• Masking: NONE

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
ACTIVE_COMPARATOR: low-flow anesthesia; Patients in low-flow anesthesia receive a fresh gas flow of 4 L/min for the first 10 minutes and were then maintain with a fresh gas flow of 0.75 L/min. Patients will be monitored for hemodynamic parameters during the perioperative period. Arterial blood gase will be analyzed for the oxygenation.	Diagnostic test: hemodynamic parameters; vital signs on the monitor including heart rate, mean arterial pressure, peripheral oxygen saturation and End-tidal Carbon Dioxide; Other Names: heart rate; mean arterial pressure; peripheral oxygen saturation; End-tidal Carbon Dioxide; Diagnostic test: arterial blood gase; Arterial blood gas including partial oxygen pressure and partial carbon dioxide pressure is an important routine investigation to monitor the acid-base balance of patients, effectiveness of gas exchange, and the state of their voluntary respiratory control.; Other Names: partial oxygen pressure; partial carbon dioxide pressure
ACTIVE_COMPARATOR: normal-flow anesthesia; Patients in normal-flow anesthesia received a fresh gas flow of 4 L/min for the first 10 minutes and were then maintained with a fresh gas flow of 1.5 L/min. Patients will be monitored for hemodynamic parameters during the perioperative period. Arterial blood gase will be analyzed for the oxygenation.	Diagnostic test: hemodynamic parameters; vital signs on the monitor including heart rate, mean arterial pressure, peripheral oxygen saturation and End-tidal Carbon Dioxide; Other Names: heart rate; mean arterial pressure; peripheral oxygen saturation; End-tidal Carbon Dioxide; Diagnostic test: arterial blood gase; Arterial blood gas including partial oxygen pressure and partial carbon dioxide pressure is an important routine investigation to monitor the acid-base balance of patients, effectiveness of gas exchange, and the state of their voluntary respiratory control.; Other Names: partial oxygen pressure; partial carbon dioxide pressure

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The level of partial oxygen pressure	The level of partial oxygen pressure is measured as mmHg in arterial blood gase analysis	From beginning of Anesthesia induction to the end of anesthesia (during perioperative period)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Heart rate	Heart rate is measured as beats/minute on the anesthesia monitor	From beginning of Anesthesia induction to the end of anesthesia (during perioperative period)
Mean arterial pressure	Mean arterial pressure is measured as mmHg on the anesthesia monitor	From beginning of Anesthesia induction to the end of anesthesia (during perioperative period)
Peripheral oxygen saturation	Peripheral oxygen saturation is measured as percentage (%) on the anesthesia monitor	From beginning of Anesthesia induction to the end of anesthesia (during perioperative period)

Collaborators and Investigators

• Sponsor: Inonu University
• Investigators: Study Director: Sedat Akbas, Asst Prof, Inonu University Medical Faculty

Publications and helpful links

General Publications

• Nunn Geoffrey BA. Low-flow anaesthesia. Continuing Education in Anaesthesia Critical Care & Pain Volume 8, Issue 1, February 2008, Pages 1-4

Helpful Links

• Low-flow anaesthesia

Study record dates

Study Major Dates

• Study Start (ACTUAL): October 18, 2018
• Primary Completion (ACTUAL): October 30, 2018
• Study Completion (ACTUAL): November 1, 2018

Study Registration Dates

• First Submitted: October 18, 2018
• First Submitted That Met QC Criteria: October 24, 2018
• First Posted (ACTUAL): October 26, 2018

Study Record Updates

• Last Update Posted (ACTUAL): January 7, 2019
• Last Update Submitted That Met QC Criteria: January 4, 2019
• Last Verified: January 1, 2019

More Information

Terms related to this study

• Keywords: Bariatric surgery; Morbidly obese patients; Arterial blood analysis
• Additional Relevant MeSH Terms: Overnutrition; Nutrition Disorders; Overweight; Body Weight; Obesity; Obesity, Morbid
• Other Study ID Numbers: sedatakbas4

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