Effect of Low Flow Anesthetics on Neurocognitive Decline in the Elderly

Effect of Low Fresh Gas Flow Volatile Anesthetics on Postoperative Neurocognitive Function in Elderly Patients

This study aims to investigate the effect of inhaled anesthetics with a low fresh gas flow on cognitive function of elderly patients undergoing elective surgery

Geriatric patients scheduled to undergo surgery were tested with Mini Mental State Examination (MMSE) in the preoperative visit. MMSE was repeated postoperatively at the 6th hour, the 1st, 3rd, and 7th day. Visual analogue scale (VAS) test was performed simultaneously on the postoperative 6th hour, the 1st, 3rd, and 7th day. Two cohorts were created according to the amount of fresh gas flow (low flow vs high flow) in the maintenance phase of the inhalational anesthetic. MMSE scores were compared between cohorts and baseline. VAS scores were compared between cohorts.

Inclusion Criteria:

• Age>65
• Consenting to participate
• Scheduled for surgery longer than 2 hours under GA
• Able to read and write

Exclusion Criteria:

• Age<65
• Refusing to participate
• Existing visual impairment preventing the patient from reading or writing
• Unable to read and write
• Existing major neurocognitive disorder
• Use of TIVA or regional techniques
• Allergies to the volatile agents
• Uncontrolled DM, acute alcohol intoxication
• Conditions increasing tissue oxygen consumption (sepsis, thyrotoxicosis, etc.)
• Anticipation/existence of major hemorrhage
• Haemodynamic instability > 10 min or more than 5 times intraoperatively