The Effect of Minimal Flow Anesthesia on Oxidative and Neuroendocrine Stress Response
Trial Snapshot
- Phase
- Not Applicable
- Status
- Active, not recruiting
- Sponsor
- Bezmialem Vakif University
- Enrollment
- 2
- Locations
- 2
- Primary Endpoint
- Interleukin 6 (IL-6) level
Study Overview
Brief Summary
Patients under general anesthesia who are unconscious and have stopped spontaneous breathing are actively ventilated with anesthesia machines, ensuring the anesthesia gas reaches the lungs and then the bloodstream. Not all the gas reaching the lungs during respiration is used; a small portion is absorbed by the body, and most of it is expelled during exhalation. After eliminating the carbon dioxide in the expired gas, it is more suitable to re-breathe the remaining gas. The portion taken by the patient needs to be provided for the next breath, and this added gas is called "fresh gas flow." Today, low flow anesthesia is defined when the fresh gas flow rate is 0.5-1 L/min, minimal flow anesthesia when it is 0.25-0.5 L/min, and metabolic flow anesthesia when it is 0.25 L/min. Our study will evaluate the effects of minimal flow anesthesia, which is widely used today due to its advantages, on oxidative stress and neuroendocrine stress response
Detailed Description
General anesthesia is characterized by anesthesia, analgesia, amnesia, and muscle relaxation. The most common practice today for maintaining anesthesia after induction is to add a low-density effective inhalation anesthetic to an oxygen/air mixture. Patients who are unconscious and have stopped spontaneous breathing are actively ventilated with anesthesia machines, ensuring the anesthesia gas reaches the lungs and then the bloodstream. Minute ventilation refers to the total amount of gas (oxygen, air, and anesthetic agent mixture) a patient breathes in one minute, which is approximately 5-6 L in a normal adult weighing 70 kg.
During respiration, not all the gas reaching the lungs is used; a small portion is absorbed by the body, and most of it is expelled during exhalation. After eliminating the carbon dioxide in the expired gas, it is more suitable to re-breathe the remaining gas for lung physiology, environmental protection, and cost-effectiveness. The portion taken by the patient needs to be provided for the next breath, and this added gas is called "fresh gas flow."
Today, in adults, low flow anesthesia is defined when the fresh gas flow rate is 0.5-1 L/min, minimal flow anesthesia when it is 0.25-0.5 L/min, and metabolic flow anesthesia when it is 0.25 L/min. Reducing the fresh gas flow has positive effects on the patient's health under anesthesia, environmental protection, and cost-effectiveness, as well as reducing pathologies in the operating room staff due to air pollution. Low flow anesthesia has been shown to have no adverse effects on oxygenation, ventilation, organ functions, or hemodynamic parameters. It does not affect any surgical procedure.
The acute stress response associated with surgery and anesthesia is connected to the neuroendocrine-metabolic system and the inflammatory-immune system. In response to surgical stress, adrenocorticotropic hormone(ACTH) is released from the pituitary gland via corticotropin-releasing hormone(CRH). ACTH stimulates the adrenal cortex to release glucocorticoid (cortisol). Both innate and adaptive immune cells play a role in the stress response to surgery. Cytokines mediate the local inflammatory response seen with tissue damage. Pro-inflammatory cytokines, such as interleukin-6 (IL-6), are released, peaking in the first 24 hours post-surgery.
Previous studies have shown an increase in cortisol, ACTH, and IL-6 values on the first postoperative day; their changes were recorded by measuring them at induction, the end of surgery, and at postoperative 12 and 24 hours. The body contains unstable molecules defined as free oxygen radicals. These molecules are balanced by antioxidant molecules. The imbalance in favor of oxidants leads to oxidative stress, causing a series of tissue damage. The biochemical markers indicating this balance are total antioxidant status (TAS) and total oxidative status (TOS).
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Parallel
- Primary Purpose
- Screening
- Masking
- Triple (Participant, Care Provider, Outcomes Assessor)
Eligibility Criteria
- Ages
- 18 Years to 65 Years (Adult, Older Adult)
- Sex
- All
- Accepts Healthy Volunteers
- No
Inclusion Criteria
- •• Ages 18-65
- •Scheduled for elective septorhinoplasty
- •ASA (physical status) 1-2
Exclusion Criteria
- •• ASA (physical status) III-IV
- •Under 18 or over 65
- •Pregnant individuals
- •Serious cardiovascular disease or arrhythmia
- •Chronic obstructive pulmonary disease
- •Severe respiratory failure
- •Uncontrolled cerebrovascular disease
- •Hepatic or renal dysfunction
- •Allergy to propofol, fentanyl, rocuronium, sevoflurane
- •Pituitary gland disease (e.g., pituitary adenoma)
- •Adrenal gland disease (e.g., pheochromocytoma, Cushing's disease)
- •Immune deficiency
- •Neuroendocrine system disease
- •BMI > 40
- •Patients who refuse to provide written informed consent.
Outcomes
Primary Outcomes
Interleukin 6 (IL-6) level
Time Frame: Just before surgery begins, postoperative 6th hour and postoperative 18th hour
Proinflammatory cytokines (Biochemical marker)
Adrenocorticotropic hormone (ACTH) level
Time Frame: Just before surgery begins, postoperative 6th hour and postoperative 18th hour
Adrenocorticotropic hormone(Biochemical marker)
Cortisol level
Time Frame: Just before surgery begins, postoperative 6th hour and postoperative 18th hour
Biochemical marker
Total oxidative status (TOS) Level
Time Frame: Just before surgery begins, end of surgery, postoperative 6th hour and postoperative 18th hour
Total oxidative status; blood biochemical tests are used to calculate oxidative indicators.
Total antioxidative status( TAS) Level
Time Frame: Just before surgery begins, end of surgery, postoperative 6th hour and postoperative 18th hour
Total antioxidative status; blood biochemical tests are used to calculate oxidative indicators.
Secondary Outcomes
- amount of bleeding(end of surgery)
- Amount of volatile anesthetic use(End of anesthesia)
- Body temperature change(From the beginning of anesthesia to the 18th postoperative hour)
- The presence of nausea and vomiting(From the recovery of anesthesia to the 18th postoperative hour)
- Assessment of pain(From the recovery of anesthesia to the 18th postoperative hour)
- Adverse events(From the recovery of anesthesia to the 18th postoperative hour)
Investigators
Hilal Deniz, Dr
Resident Doctor
Bezmialem Vakif University