The Effect of Intraoperative Hyperoxemia on Postoperative Delirium in Geriatric Patients and the Preventive Role of Oxygen Reserve Index"

The definition of elderly by the World Health Organization is individuals aged 65 and older. As the average life expectancy continues to increase, the number of surgical procedures performed in the geriatric population is also increasing.

Postoperative delirium is a complication that occurs after surgery and is characterized by sudden-onset confusion, fluctuating mental status, and attention deficits. Its incidence increases in elderly patients and is higher in those with pre-existing mild cognitive impairment. The etiology encompasses multiple factors such as age, presence of additional comorbidities, metabolic disorders, hypoxia, polypharmacy, pain, hypothermia, and may be associated with the depth of anesthesia during surgery.

Early recognition and prevention of delirium will become more prominent in the future due to reduced hospitalization durations, postoperative complications, and mortality rates.

Various methods are available to detect hyperoxemia during surgery. Hyperoxemia can be detected using noninvasive finger pulse oximetry with the oxygen reserve index parameter. Oxygen levels can be noninvasively assessed during operations using routine oxygen saturation and oxygen reserve index measurements.

Delirium can be evaluated in both intensive care and ward patients. The gold standard for diagnosis is the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria. DSM-5 criteria require psychiatric evaluation and are conducted by someone with psychiatric training. Additionally, the Confusion Assessment Method (CAM) is used for diagnosis and can be evaluated as CAM-ICU for intubated patients in intensive care units.