Monitoring cerebral oxygen saturation in elderly patients undergoing general abdominal surgery

Exploratory Analysis of Cerebral Oxygen Reserves During Sleep Onset in Older and Younger Adults

“…Given the interest in examining age‐associated differences in cerebral oxygen reserves, the older adults in this study were screened to be in relatively good health and without any apparent functional decline. Although none of the subjects had rcSO 2 levels below 55%, a few of the older subjects experienced a fall of more than 15%, levels that previous studies report can also predict functional decline 22,23 . Such a finding suggests that these downward trends in cerebral oxygenation during sleep may reflect a preclinical state that marks individuals at risk for functional decline.…”

“…Given that these subjects had resting baseline levels of 60% to 61%, these changes represent a 15% to 18% decline from their baseline rcSO 2 values. Given that previous studies have reported that declines of 15% or more from resting baseline are associated with impaired cognition, 21–23 these modest declines may mark individuals who are at risk for cognitive decline. The fact that rcSO 2 —but not SaO 2 —returned to baseline levels upon wakening suggests that, although sleep may add to age‐associated decline in cerebral oxygen reserves, the ability to awaken from sleep is important for restoring vascular response to hypoxemia in older persons.…”

“…The validity of NIRS as a means of evaluating changes in rcSO 2 has been established under a number of experimental conditions, including measurement of jugular bulb venous oxygen saturation, which is considered an index of mixed cerebral oxygenation; 18 correlation of blood oxygen level with oxygen‐level dependent magnetic resonance imaging; 19 and cerebral blood flow as measured using transcranial Doppler sonography 20 . Recent studies using the INVOS 4100 in elderly subjects undergoing surgical procedures indicate that declines of greater than 15% or rcSO 2 values of 55% or less are associated with significant declines in cognition 21–23 . In the present study, the average of rcSO 2 values and the average change in rcSO 2 , from resting baseline to sleep, were used to characterize group differences in cerebral oxygen reserves.…”

The effect of pneumoperitoneum in the steep Trendelenburg position on cerebral oxygenation

“…With two infrared wavelengths, the HbO 2 fraction can be determined. An rSO 2 value <80% of baseline or rSO 2 <50% were associated with a higher incidence of cerebral ischemia, post‐operative cognitive decline and longer hospital stays 10,11,14 . Previous studies reported that a significant reduction in rSO 2 was common in elderly patients undergoing an abdominal surgery and in patients with increased ICP 8,10,11,15 …”

“…Near‐infrared spectroscopy (NIRS) was used in heart surgery, neurologic surgery and in patients with head injuries 6–8 . Recently, its use has been extended to assess cerebral damage during controlled hypotensive orthopedic surgery, liver transplantation and abdominal surgery in the elderly 9–12 . NIRS cerebral oximetry allows continuous and noninvasive monitoring of regional cerebral oxygen saturation (rSO 2 ), which reflects a balance between cerebral oxygen supply and demand using the different absorption characteristics of NIRS of oxygenated and deoxygenated hemoglobin (Hb) (HbO 2 and Hb, respectively) 13 .…”