Intraoperative Cerebral Desaturation Research Articles

The Effect of Intermittent Pneumatic Compression on Hemodynamics and Regional Cerebral Oxygen Saturation in Laparoscopic Bariatric Surgery with Mild Hypercapnia in the Steep Reverse Trendelenburg Position.

Obesity negatively affects hemodynamics and cerebral physiology. We investigated the effect of the utilization of an intermittent pneumatic compression (IPC) device on hemodynamics and cerebral physiology in patients undergoing laparoscopic bariatric surgery under general anesthesia with lung-protective ventilation. Sixty-four patients (body mass index > 30 kg/m2) were randomly assigned to groups that received an IPC device (IPC group, n = 32) and did not (control group, n = 32). The mean arterial pressure (MAP), heart rate (HR), need for vasopressors, cerebral oxygen saturation (rSO2), and cerebral desaturation events were recorded. The incidence of intraoperative hypotension was not significantly different between groups (p = 0.153). Changes in MAP and HR over time were similar between groups (p = 0.196 and p = 0.705, respectively). The incidence of intraoperative cerebral desaturation was not significantly different between groups (p = 0.488). Changes in rSO2 over time were similar between the two groups (p = 0.190) during pneumoperitoneum. Applying IPC to patients with obesity in the steep reverse Trendelenburg position may not improve hemodynamic parameters, vasopressor requirements, or rSO2 values during pneumoperitoneum under lung-protective ventilation. During laparoscopic bariatric surgery, IPC alone has limitations in improving hemodynamics and cerebral physiology.

Postoperative delayed neurocognitive recovery: Evaluation of its incidence and correlation with intraoperative cerebral desaturation − A prospective observational study

Delayed neurocognitive recovery (DNR) is commonly seen in patients in the postoperative period. Literature has shown that monitoring cerebral desaturation intraoperatively can predict the development of DNR in elderly patients undergoing surgery in prone position. This prospective observational study was conducted in patients of all ages, with the primary objective to determine the incidence of DNR and its correlation with cerebral oximetry. The secondary objectives were to determine if intraoperative cerebral desaturation influenced the neuropsychometric variables from preoperative to postoperative period. This study included 61 patients, aged >18 years undergoing spinal surgery in prone position. An evening before surgery and at 48h postoperatively, patients were subjected to neuropsychological examination; Hindi Mental State Examination, Colour Trail Test 1 (CTT 1), CTT 2, Auditory Verbal Learning (AVLT) tests conducted by principal investigator (PI). DNR was defined as a 20% change in any of the test scores from the baseline. rSO2 was recorded bilaterally every 10min throughout surgery by an independent person. Cerebral desaturation was defined as a 20% drop in rSO2 from the control value. The incidence of DNR was 24.6%. The duration of anesthesia and cerebral desaturation were found to be independently predictive of DNR, with each hour of anesthesia causing a two-fold increase in the chances of development DNR (P=0.019) and presence of cerebral desaturation causing a 6-fold increase (P=0.039). CTT 1 and CTT 2 tests had significantly larger increase in test scores in the postoperative period, in patients with cerebral desaturation. Duration of anesthesia and cerebral desaturation were factors predictive of the development of DNR in patients undergoing spine surgery in prone position.

Cerebral desaturation during neonatal congenital heart surgery is associated with perioperative brain structure alterations but not with neurodevelopmental outcome at 1 year.

The significance of intraoperative cerebral desaturation (CD) measured by near-infrared spectroscopy (NIRS) to predict neurological outcome after congenital heart surgery is uncertain. The goal of this study was to compare brain structure changes and neurodevelopmental outcome in patients with severe congenital heart disease with and without intraoperative CD. Neonates requiring congenital heart surgery were enrolled in a cohort study. NIRS data from their first cardiac operation were collected. Pre- and postoperative brain magnetic resonance imaging results and Bayley-III scores at 1 year were compared between patients with and without CD, defined by 2 NIRS thresholds: regional cerebral oxygen saturation (rSO2) of 45% (45%rSO2) and rSO2 below 20% of baseline value (20%BLrSO2). Thirty-two patients (72% male) with d-transposition of the great arteries (n = 24, 75%) and other complex types of congenital heart diseases (n = 8, 25%) were analysed. Perioperative relative lateral ventricle volume change was increased in patients with versus without intraoperative CD (P = 0.003 for 45%rSO2, P = 0.008 for 20%BLrSO2). For 45%rSO2, the effect of CD remained significant after adjusting for age at postoperative scan, time between scans and cardiac diagnosis (P = 0.019). New intracranial lesions occurred predominantly in CD groups (6/6 patients for 45%rSO2, 5/6 patients for 20%BLrSO2). Neurodevelopmental outcome at 1 year was not associated with intraoperative CD. This study demonstrates the clinical relevance of NIRS monitoring during congenital heart surgery. The occurrence of intraoperative CD is associated with perioperative lateral ventricle volume change and new intracranial lesions.

Significant neonatal intraoperative cerebral and renal oxygen desaturation identified with near-infrared spectroscopy.

Near-infrared spectroscopy (NIRS) was used to monitor intraoperative regional oxygen saturation (rSO2) during open (Op) and minimally invasive (MI) surgery performed in neonates (N) and children. NIRS sensors were applied to the forehead and flanks for cerebral rSO2 (C-rSO2) and renal rSO2 (R-rSO2), respectively. MI included laparoscopy (La), retroperitoneoscopy (Re) and thoracoscopy (Th). In children, Op and MI were major operations taking at least 3h (MOp; MMI). Pathological desaturation (PD) was defined as > 20% deterioration in rSO2. Mean ages at surgery were N: 5.2 ± 8.2days, MOp: 2.4 ± 2.9years, and MMI: 3.8 ± 4.3years. Despite significantly shorter operative times in N (169 ± 94min; p < 0.0001), PD was significantly worse; PD(C-rSO2): N = 14/35 (40.0%) versus MOp = 3/36 (8.3%) and MMI = 7/58 (12.1%); p = 0.0006, and PD(R-rSO2): N = 27/35 (77.1%) versus MOp = 6/36 (16.7%) and MMI = 7/58 (12.1%); p < 0.0001, respectively. PD(R-rSO2) occurred immediately with visceral reduction in NOp (Fig.1) and PD was frequent during NMI(Th) (Fig.2). rSO2 was stable throughout MOp and MMI (Fig.3). Fig. 1 Pathological desaturation in renal rSO2 after visceral reduction for gastroschisis. Renal rSO2 deteriorated immediately after viscera were returned to the abdominal cavity rSO2 regional oxygen saturation Fig. 2 Fragility of tissue perfusion during thoracoscopic lung lobectomy in a neonate. Pathological desaturation occurred frequently during neonatal thoracoscopic surgery rSO2 regional oxygen saturation Fig. 3 Changes in cerebral and renal rSO2 according to operative time. Cerebral and renal rSO2 did not appear to change according to operative time during major open and major minimally invasive surgery in children. rSO2 regional oxygen saturation CONCLUSIONS: NIRS is a non-invasive technique for monitoring rSO2 as an indicator of intraoperative stress and vascular perfusion. PD was so significant in neonates that intraoperative NIRS is highly recommended during thoracoscopy and procedures requiring visceral manipulation.

CORR Insights®: What Is the Risk of Intraoperative Cerebral Oxygen Desaturation in Patients Undergoing Shoulder Surgery in the Beach Chair Position?

CORR Insights®: What Is the Risk of Intraoperative Cerebral Oxygen Desaturation in Patients Undergoing Shoulder Surgery in the Beach Chair Position?

What Is the Risk of Intraoperative Cerebral Oxygen Desaturation in Patients Undergoing Shoulder Surgery in the Beach Chair Position?

Previous studies have shown that intraoperative cerebral desaturation in patients undergoing shoulder surgery in the beach chair position varies widely, from 0% to 80%. To our knowledge, the risk of intraoperative cerebral desaturation is not known after all identified intraoperative modifiable physiologic parameters that influence cerebral blood flow have been controlled for. (1) What is the risk of intraoperative cerebral desaturation during shoulder surgery with the patient in the beach chair position when patients received combined general anesthesia and an interscalene block, and what other factors associated with intraoperative cerebral desaturation can be identified? (2) Is intraoperative cerebral desaturation associated with 24-hour cognitive decline? (3) What factors are associated with intraoperative hypotension? Between April and December 2020, 51 patients underwent elective shoulder surgery in the beach chair position at one center. Nine patients were excluded: four patients refused to participate, two patients were unable to receive an interscalene brachial plexus block, and three patients were operated on in less than 70° upright position. A total of 42 patients (aged 63 ± 10 years, of whom 52% [22 of 42] were female) were prospectively recruited into this study. Each patient was diagnosed with a rotator cuff tear and underwent arthroscopic repair in the beach chair position, which was performed in an upright position of 70° to 80°. Near-infrared spectroscopy was used to monitor regional cerebral oxygen saturation. The mean arterial pressure was monitored and controlled so that it was more than 70 mmHg in patients without hypertension and within 20% from the baseline mean arterial pressure in patients with hypertension. All patients received the standardized anesthesia protocol, which consisted of an interscalene brachial plexus block and general anesthesia. Intraoperative cerebral desaturation was defined as a decrease in the regional cerebral oxygen saturation level of more than 20% from the baseline value that lasted longer than 15 seconds after induction of anesthesia. Patients' clinical characteristics such as age, sex, BMI, preoperative hemoglobin level, preexisting medical conditions, and continuing antihypertensive medications on the morning of surgery were analyzed to identify the association with intraoperative cerebral desaturation. We used the Montreal Cognitive Assessment to assess cognitive function at preoperative and 24 hours postoperative. Episodes of hypotension and its treatment after maximum head elevation were recorded. The patients' clinical characteristics were analyzed to determine their association with hypotensive events. In this study, intraoperative cerebral desaturation occurred in 43% (18 of 42) of patients, and female sex was identified as an associated risk (odds ratio 4.3 [95% confidence interval 1.2 to 16.2]; p = 0.03). The median (interquartile range) duration of intraoperative cerebral desaturation was 19 minutes (5 to 38). There was no association between intraoperative cerebral desaturation and 24-hour postoperative cognitive decline (OR 0.6 [95% CI 0.1 to 2.4]; p = 0.44). Risk factors for intraoperative hypotension were a history of hypertension, regardless of whether or not the patient took antihypertensive drugs on the morning of surgery (OR 4.9 [95% CI 1.3 to 18.1]; p = 0.02), and dyslipidemia (OR 4.3 [95% CI 1.2 to 16.3]; p = 0.03). The intraoperative cerebral desaturation risk in the beach chair position was high. Female sex was an intraoperative cerebral desaturation risk factor. However, there was no association between intraoperative cerebral desaturation and postoperative cognitive decline. Patients with hypertension and dyslipidemia are at risk of intraoperative hypotension after positioning. Further large-scale studies are required to identify intraoperative cerebral desaturation-associated adverse neurologic outcome. Level II, therapeutic study.

Konjenital Kalp Cerrahisi Geçiren Pediatrik Hastalarda Serebral Desatürasyon İle Komplikasyonlar Arasındaki İlişki: Prospektif Kohort Çalışması

Objective: In this study, we aimed to investigate the incidence of cerebral desaturation and the possible relationship between intraoperative cerebral desaturation and postoperative complications. Methods: A prospective, observational study was performed 115 patients under 18 years of age who required open heart surgery in a university hospital. Cerebral desaturation was defined as a 25% decrease in cerebral saturation (low alarm limit) when compared with the basal value. Duration (second) was referred to the amount of time the patient stays below low alarm limit. Depth (%) was referred to gap between the patient’s cerebral regional oxygen saturation (rSO2) level and the rSO2 low alarm limit. The cerebral desaturation score was calculated using the %*seconds. The patients were divided into two groups: group 1 (desaturation score &gt;3000 %sec) and group 2 (desaturation score ≤ 3000 %sec). The groups were compared in terms of demographic data, intraoperative and postoperative variables, postoperative complications, and duration of intensive care and hospital stays. Results: In the study, 59 patients (51.3%) were male and 28 patients (24.3%) had cyanotic heart disease. A total of 55 patients (47.8%) experienced over 3000 %sec desaturation. Postoperative complications were found to be increased in group 1 (71% vs 3.3%; χ²=57.119, p&lt;0.001). In the multiple logistic regression analysis, desaturation score&gt;3000 %sec (p&lt;0.001), low body surface area (p=0.001) and prolonged cardiopulmonary bypass (p=0.006) were found to be associated with postoperative complications. Conclusion: In patients undergoing congenital heart surgery, cerebral desaturation score &gt;3000 %sec is associated with a negative effect on patient prognosis.

Cerebral oxygenation during pediatric congenital cardiac surgery and its association with outcome: a retrospective observational study

PurposeNon-invasive cerebral oxygen saturation (ScO2) monitoring is an established tool in the intraoperative phase of pediatric congenital cardiac surgery (CCS). This study investigated the association between ScO2 and postoperative outcome by investigating both baseline ScO2 values and intraoperative desaturations from baseline.MethodsAll CCS procedures performed in the period 2010-2017 in our institution in which ScO2 was monitored were included in this historical cohort study. Baseline ScO2 was determined after tracheal intubation, before surgical incision. Subgroups were based on cardiac pathology and degree of intracardiac shunting. Poor outcome was defined based on length of stay (LOS) in the intensive care unit (ICU)/hospital, duration of mechanical ventilation (MV), and 30-day mortality. Intraoperatively, ScO2 total time below baseline (TBBL) and ScO2 time-weighted average (TWA) were calculated.ResultsData from 565 patients were analyzed. Baseline ScO2 was significantly associated with LOS in ICU (odds ratio [OR] per percentage decrease in baseline ScO2, 0.95; 95% confidence interval [CI], 0.93 to 0.97; P < 0.001), with LOS in hospital (OR, 0.93; 95% CI, 0.91 to 0.96; P < 0.001), with MV duration (OR, 0.92; 95% CI, 0.90 to 0.95; P < 0.001) and with 30-day mortality (OR, 0.94; 95% CI, 0.91 to 0.98; P = 0.007). Cerebral oxygen saturation TWA had no associations, while ScO2 TBBL had only a small association with LOS in ICU (OR, 1.02; 95% CI, 1.01 to 1.03; P < 0.001), MV duration (OR,1.02; 95% CI, 1.01 to 1.03; P = 0.002), and LOS in hospital (OR, 1.02; 95% CI, 1.01 to 1.04; P < 0.001).ConclusionIn pediatric patients undergoing cardiac surgery, low baseline ScO2 values measured after tracheal intubation were associated with several adverse postoperative outcomes. In contrast, the severity of actual intraoperative cerebral desaturation was not associated with postoperative outcomes. Baseline ScO2 measured after tracheal intubation may help identify patients at increased perioperative risk.

Cerebral Desaturation Events During Shoulder Arthroscopy in the Beach Chair Position.

The beach chair position (BCP) is commonly used position in upper extremity surgery. Although there are many advantages to surgery in this position, there are also potential drawbacks and described complications including devastating neurologic outcomes. The etiology of these complications is postulated to be due to the gravitational effects of the seated position leading to cerebral hypoperfusion. We review the current literature on intraoperative cerebral monitoring and neurocognitive complications with shoulder surgery performed in the BCP. A previous systematic review estimated the incidence of neurocognitive complications after surgery in the BCP to be 0.004%. However, the true incidence is unknown and is likely much more common. Reports of neurologic complications have revealed a need for heightened vigilance, alternative anesthesia techniques, and improved monitoring. Methods for monitoring have included near-infrared spectroscopy, a measurement of cerebral oximetry shown to reliably detect cerebral hypoperfusion. In this literature review, we sought to update the incidence of intraoperative cerebral desaturation events (CDEs) to investigate the relationship of CDEs to neurocognitive complications and to review recent reported cases of neurocognitive complications. Existing literature suggest that accurate intraoperative monitoring of cerebral perfusion may improve patient safety.

The effect of high-dose nitroglycerin on the cerebral saturation and renal function in cardiac surgery: A propensity score analysis.

The aim of the study was to evaluate the effects of high-dose nitroglycerine administered during cardiopulmonary bypass on the intraoperative cerebral saturation and postoperative serum creatinine concentration in cardiac surgery. In a retrospective cohort study, a total of 239 patients undergoing cardiac surgery with cardiopulmonary bypass at a tertiary medical center were included. General anesthesia consisted of volatile anesthetic and either intravenous loading of high-dose nitroglycerin (infusion rate 10 to 20 mg·h with a total dose of ≥0.5 mg·kg) starting from rewarming of cardiopulmonary bypass throughout the end of the surgery (NTG group; N = 96) or without high-dose nitroglycerin (control group; N = 143). Data for intraoperative cerebral saturation and serum creatinine concentrations before and after cardiac surgery were collected. Propensity score method was used to adjust for potential confounders. Patients receiving high-dose nitroglycerin had significantly lower mean arterial pressure and hematocrit levels during and after cardiopulmonary bypass. The risk of intraoperative cerebral desaturation was left-sided 23.9% versus 38.5% (p = 0.023), right-sided 28.1% versus 35.7% in the NTG and control groups, respectively. The risk of new-onset stroke and postoperative dialysis was 2.1% versus 6.3% and 1.0% versus 3.5% in the NTG and control groups, respectively. An infusion of high-dose nitroglycerin initiating at rewarming of cardiopulmonary bypass and throughout the postbypass interval may induce hypotension and hemodilution in cardiac surgical patients. Cerebral saturation and renal function were well maintained without increasing the risk of stroke and renal replacement therapy after cardiac surgery with cardiopulmonary bypass.

Cerebral oxygen desaturation occurs frequently in patients with hypertension undergoing major abdominal surgery.

Hypertensive patients are more likely to experience latent cerebral ischemia causing regional cerebral oxygen saturation (rSO2) decrease during general anesthesia. The aim of this prospective observational study was to assess the incidence of decreased rSO2 in hypertensive patients undergoing major abdominal surgery and the perioperative factors affecting this change in rSO2. A total of 41 hypertensive patients were enrolled and stratified according to their hypertension as controlled and uncontrolled. The intraoperative rSO2 and physiological data were routinely collected. The Mini-Mental State Exam (MMSE) was used to test cognitive function before surgery and after 4 days. Cerebral desaturation was defined as a decrease in rSO2 of more than 20% of the baseline value. There were 20 patients (49%) suffering intraoperative cerebral desaturation classified into cerebral desaturation group (group D) and those 21 without intraoperative desaturation classified into normal group (group N). The area under the curve below 90 and 80% of baseline (AUCrSO2 <90% of baseline and AUCrSO2 <80% of baseline) was lower in patients of group N (2752.4 ± 1453.3 min% and 0.0 min%) than in patients of group D (6264.9 ± 1832.3 min% and 4486.5 ± 1664.9 min%, P < 0.001). Comparing the two groups, the number of uncontrolled hypertensive individuals in group D (12/20) was significantly more than group N (4/21) (P = 0.007). A significant correlation was observed between relative decrease in MAP and relative decrease in rSO2 (r2 = 0.495, P < 0.001). Moreover, nine patients (45%) in group D occurred early postoperative cognitive function decline were more than three patients (14.3%) in group N (P = 0.031). This pilot study showed a large proportion of hypertensive patient experienced cerebral desaturation during major abdominal surgery and uncontrolled hypertension predisposed to this desaturation. NCT02147275 (registered at http://www.clinicaltrials.gov ).

Effects of anesthetics on early postoperative cognitive outcome and intraoperative cerebral oxygen balance in patients undergoing lung surgery: a randomized clinical trial.

One-lung ventilation (OLV) may impair cerebral oxygen balance and induce postoperative cognitive dysfunction (POCD). It is unclear whether the type of anesthetic influences the incidence of POCD in patients undergoing OLV. This prospective study compared the incidence of POCD and intraoperative cerebral oxygen desaturation in OLV patients anesthetized with propofol vs sevoflurane during lung surgery. There were 148 participants enrolled in this study and randomized equally to either the propofol or the sevoflurane group. Anesthesia was maintained with either propofol or sevoflurane combined in both groups with fentanyl and epidural anesthesia. Regional cerebral oxygen saturation (rSO2), jugular bulb venous oxygen saturation (SjO2), and the incidence of cerebral oxygen desaturation (rSO2 or SjO2 < 50% or rSO2 < 80% of baseline) were measured during anesthesia. Cognitive function was assessed using seven neurocognitive tests two days preoperatively, five days postoperatively (primary outcome), and three months postoperatively. Bivariable and multivariable regression analyses were conducted to identify factors associated with POCD. Rates of POCD did not differ statistically between groups five days postoperatively (propofol, 16/72 patients; sevoflurane, 24/72 patients; RR, 0.67; 95% CI, 0.39 to 1.15; P = 0.14) or three months postoperatively (propofol, 9/60 patients; sevoflurane, 12/58 patients; RR, 0.73; 95% CI, 0.33 to 1.59; P = 0.42). Only three subjects per group showed intraoperative cerebral oxygen desaturation. Multivariable regression analysis revealed older age as an independent predictor of POCD. No statistically significant difference in the incidence of POCD could be detected between the sevoflurane and propofol anesthesia groups. Postoperative cognitive dysfunction was relatively frequent following OLV in both groups. ( UMIN 000002826).

Association between frailty, cerebral oxygenation and adverse post-operative outcomes in elderly patients undergoing non-cardiac surgery: An observational pilot study.

Background and Aims:Although both frailty and low cerebral oxygen saturation increase the risk of post-operative complications, their relationship is yet to be investigated. The purpose of this observational study was to investigate the association between frailty, intraoperative cerebral oxygen saturation and post-operative complications in elderly patients undergoing non-cardiac surgery.Methods:After approval from the Institutional Review Board, 25 elderly patients (>65 years) undergoing non-cardiac major surgery were included in this study. Pre-operatively, all included patients were assessed for frailty and classified into frail and non-frail groups. All patients had routine intraoperative monitors, and a cerebral oximeter applied during anaesthesia. The ‘intraoperative’ anaesthesiologist and the post-operative study investigator were blinded to cerebral oximeter readings throughout the study. The incidence of significant intraoperative cerebral oxygen desaturation, adverse post-operative outcomes and length of hospital stay were compared. Statistical significance was defined as a value of P < 0.05.Results:We found that the frail group had more intraoperative cerebral desaturation (odds ratio [OR] [95% confidence interval [CI]]: 1.75 [1.11–2.75]) and longer median (interquartile range) length of hospital stay compared to the non-frail group (13.5 days [8.75–27.5] and 8 days [6–11], respectively). Furthermore, in patients with a low-baseline cerebral oxygen saturation (<55%), intraoperative cerebral desaturation (OR [95% CI]: 2.10 [1.00–4.42]), adverse post-operative outcomes (OR [95% CI]: 1.80 [1.00–3.23]) and median (interquartile range) length of hospital stay (15 days [9–31.5] vs. 9 days [6.25–13.75], P = 0.04) were significantly higher compared to subjects with higher baseline (≥55%) cerebral oxygen saturation.Conclusions:Frail patients have more intraoperative cerebral desaturation and longer lengths of hospital stay compared to non-frail patients.

Effect of controlled hypotension on regional cerebral oxygen saturation during rhinoplasty: a prospective study.

The aim of this study was to investigate the effect of controlled hypotension on cerebral oxygen saturation (rSO2) using near infrared spectroscopy (NIRS) and evaluation of postoperative cognitive function in patients undergoing rhinoplasty. Fifty adult patients who were scheduled for elective rhinoplasty surgery and required controlled hypotension were enrolled in this prospective study. Controlled hypotension was provided using a combination of propofol and remifentanil infusion supplemented with nitroglycerin infusion as necessary. rSO2 was evaluated during controlled hypotension by NIRS. Cerebral desaturation was observed in 5 out of 50 patients (10%) during hypotensive anesthesia. The greatest decrease from baseline was 28% when MAP was 57mmHg. In both non-desaturated and desaturated patients, postoperative MMSE scores were significantly lower than preoperative scores. There was a 4% decrease in the non-desaturated patients and a 7% decrease in the desaturated patients when preoperative and postoperative MMSE scores were compared. A decline in cognitive function 1day after surgery was observed in 23 patients (46%) and in all patients with intraoperative cerebral desaturation. The current study showed that even if SpO2 is in the normal range, there might be a decrease of more than 20% in cerebral oxygen saturation during controlled hypotension.

Regional cerebral oxygen saturation monitoring for predicting postoperative cognitive dysfunction

Background Postoperative cognitive dysfunction (POCD) commonly develops after major surgery in elderly patients which may affect patients' outcome.Regional cerebral oxygen saturation (rSO2) serves as a tool to evaluate cerebral oxygen supply-demand balance.It has been reported that intraoperative cerebral desaturation closely associated with POCD.Objective The aim of this review is to evaluate the correlation between rSO2 values and postoperative cognitive dysfunction.Content Near infrared spectroscopy (NIRS) allows continuous,noninvasive monitoring.of rSO2.It is regarded as a promising,but not widely accepted technique to reduce POCD.This article reviewed the correlation between rSO2 values and postoperative cognitive dysfunction.Trend NIRS appears to be a new tool to predict central nervous system complications,however,futher study need to be conducted to evaluate the overall efficacy. Key words: Regional cerebral oxygen saturation; Near infrared spectroscopy; Postoperative cognitive dysfunction

Systematic review of near-infrared spectroscopy determined cerebral oxygenation during non-cardiac surgery

Near-infrared spectroscopy (NIRS) is used to monitor regional cerebral oxygenation (rScO2) during cardiac surgery but is less established during non-cardiac surgery. This systematic review aimed (i) to determine the non-cardiac surgical procedures that provoke a reduction in rScO2 and (ii) to evaluate whether an intraoperative reduction in rScO2 influences postoperative outcome. The PubMed and Embase database were searched from inception until April 30, 2013 and inclusion criteria were intraoperative NIRS determined rScO2 in adult patients undergoing non-cardiac surgery. The type of surgery and number of patients included were recorded. There was included 113 articles and evidence suggests that rScO2 is reduced during thoracic surgery involving single lung ventilation, major abdominal surgery, hip surgery, and laparoscopic surgery with the patient placed in anti-Tredelenburg's position. Shoulder arthroscopy in the beach chair and carotid endarterectomy with clamped internal carotid artery (ICA) also cause pronounced cerebral desaturation. A >20% reduction in rScO2 coincides with indices of regional and global cerebral ischemia during carotid endarterectomy. Following thoracic surgery, major orthopedic, and abdominal surgery the occurrence of postoperative cognitive dysfunction (POCD) might be related to intraoperative cerebral desaturation. In conclusion, certain non-cardiac surgical procedures is associated with an increased risk for the occurrence of rScO2. Evidence for an association between cerebral desaturation and postoperative outcome parameters other than cognitive dysfunction needs to be established.

Cerebral Desaturation in Cardiac Surgery: the Importance of Monitoring in the Icu

Intraoperative cerebral oxygen desaturation measured using near infrared spectroscopy (NIRS) derived cerebral oximetry has been associated with significant postoperative morbidity in cardiac surgery patients. There is little information on postoperative cerebral oximetry from cardiac surgery patients while in the intensive care unit (ICU); a period of potential significant bleeding, hemodynamic, and respiratory compromise. We examined the relative incidence and clinical significance of cerebral desaturation experienced by cardiac surgery patients in both the intraoperative period (OR) and for the first 24 hours in the postoperative ICU.

Fixing Hearts and Protecting Minds

Ischemic heart disease is a significant cause of mortality and morbidity in Western populations. Consistent with this, coronary artery bypass graft (CABG) surgery remains one of the most frequently performed major surgeries. Improved survival rates mean that our research focus now extends beyond surgical technique to include quality of postoperative outcome. Postoperative cognitive dysfunction (POCD) has emerged as one of the most challenging and hotly debated issues, with increasing impetus to answer the unresolved question: does fixing the heart come at a cost to the brain? CABG surgery is associated with neurological events including stroke in 1.6%1 and delirium in 5.8%2 of patients. Beyond these severe and marked alterations to neurological function, there has been a widely held belief that CABG surgery is associated with POCD, which may presage a decline toward dementia. Research has been influenced by the 1995 Consensus Statement3 into the study of POCD in patients undergoing CABG surgery. Although the methods of investigation set forth by the Consensus Statement achieved widespread acknowledgment, its specific recommendations have not always been followed.4 Despite significant methodological issues, it seems that the balance of interpretation has historically been in favor of CABG surgery as a cause of significant POCD. More recently, however, a review of a series of publications from a well-controlled longitudinal cohort study conducted at Johns Hopkins5 and a meta-analysis6 suggested that cognition is in fact stable or may even show some improvement after CABG surgery in the majority of patients, at least within the first year (Figures 1 and 2). There is little doubt that POCD affects some patients in the short term, but the pathophysiological mechanisms underlying this and the influence on longer-term cognitive function remain uncertain. For research to progress, we require a paradigmatic shift in our focus from …

The Role of Intraoperative Regional Oxygen Saturation Using Near Infrared Spectroscopy in the Prediction of Low Output Syndrome After Pediatric Heart Surgery

We report on the applicability of intraoperative regional oxygen saturation (rSO2) desaturation score by near-infrared spectroscopy in the early detection of postoperative low output state (LOS) in infants with congenital heart disease who underwent cardiac surgery. Between July and October 2011 the intra- and immediate postoperative courses of 22 patients undergoing elective cardiac surgery for congenital heart disease were analyzed. The intraoperative cerebral and somatic rSO2 were measured and a rSO2 desaturation score calculated (by multiplying the rSO2 below 50% of the threshold by seconds). The aim of the study was to evaluate the applicability of intraoperative rSO2 de-saturation score in the early detection of postoperative LOS. Thirteen of 22 patients (62%) had an intraoperative cerebral rSO2 desaturation score >3000% per second. Patients with a rSO2 de-saturation score >3000% per second had a significantly lower intraoperative central venous saturation (SvO2, p = 0.002), cardiac index (CI, p = 0.004), oxygen availability indexed (DO2I, p = 0.0004), and a significantly higher extraction of oxygen (ERO2, p = 0.0005) when compared to patients with a rSO2 desaturation score <3000% per second. Nine patients had postoperative LOS; all of them had an intraoperative rSO2 de-saturation score >3000% per second (9/13 patients, 69%; p = 0.001) requiring prompt treatment with major inotropic support, surface hypothermia, and extracorporeal membrane oxygenation (ECMO) support (n = 4). Twenty-one patients survived. One patient died from ventricular failure and inability to wean from ECMO support. The intraoperative use of NIRS provided an early warning sign of hemodynamic or metabolic compromise, enabling early and rapid intervention to prevent or reduce the severity of potentially life-threatening complications.

Cerebral Desaturation During Shoulder Arthroscopy: A Prospective Observational Study

Patients undergoing arthroscopic shoulder surgery in the beach chair position may be at increased risk for serious neurocognitive complications as a result of cerebral ischemia. We sought to define the (1) incidence; (2) timing; and (3) magnitude of intraoperative cerebral desaturation events (CDEs) in subjects undergoing arthroscopic shoulder surgery in the beach chair position, as well as whether (4) the length of surgery was an independent risk factor for intraoperative CDEs. Regional cerebral tissue oxygen saturation (rSO2) was monitored intraoperatively using near-infrared spectroscopy on 51 consecutive patients undergoing arthroscopic shoulder surgery in the beach chair position. Intraoperative decreases in rSO2 of 20% or greater were defined as CDEs. The incidence of intraoperative CDEs in our series was 18% (nine of 51). Among the patients demonstrating CDE (n = 9), the mean time to onset of initial CDE was 18 minutes 38 seconds postinduction. Of those experiencing CDEs, the mean maximal decrease in rSO2 was 32% from preoperative baseline per patient. Additionally, the mean number of separate CDE instances was 1.89 in this patient population with an average duration of 3 minutes 3 seconds per instance. There was no statistically significant difference (p = 0.202) between patients demonstrating CDEs and those without in regard to length of surgery (95 versus 88 minutes). The degree and duration of cerebral ischemia required to produce neurocognitive dysfunction in this patient population remains undefined; however, cerebral oximetry with near-infrared spectroscopy allows prompt identification and treatment of decreased cerebral perfusion. We believe protocols aimed at detecting and reversing CDE may improve patient safety.