rSO2 Levels Research Articles

Usefulness of bilateral cerebral regional oxygen saturation measurements in determining selective cerebral perfusion flow rate in a pediatric patient with aortic arch stenosis: a case report

BackgroundWe report a pediatric case where bilateral regional oxygen saturation (rSO2) measurements were useful in determining the selective cerebral perfusion (SCP) flow rate.Case presentationA 9-year-old Japanese boy, 128 cm tall and weighing 25.6 kg, was scheduled for aortic arch reconstruction due to a 90–100 mmHg pressure gradient. Pediatric-sized oximetry sensors were attached to the bilateral forehead area. The rSO2 levels were 70–80% on the right and 80–90% on the left during cardiopulmonary bypass. Immediately following deep hypothermic circulatory arrest with the body temperature cooled to 25 °C, SCP was initiated from the right brachiocephalic artery at 10 mL/kg/min. As the rSO2 decreased steeply to 43–45% on the right and to 32–38% on the left, the SCP flow was increased to 15 mL/kg/min. The right rSO2 increased promptly to 50–60%, but the left rSO2 remained at 30–40%. After the SCP flow was increased to 20 mL/kg/min, bilateral rSO2 levels of 50–60% were obtained, and the SCP flow rate was maintained. The patient was transferred to the ICU postoperatively and extubated on the second postoperative day with no neurological abnormalities.ConclusionsBilateral rSO2 measurements are essential even for a pediatric patient undergoing SCP, despite the limited forehead area.

Early or delayed cord clamping during transition of term newborns: does it make any difference in cerebral tissue oxygenation?

BackgroundAccording to the World Health Organization’s recommendation, delayed cord clamping in term newborns can have various benefits. Cochrane metaanalyses reported no differences for mortality and early neonatal morbidity although a limited number of studies investigated long-term neurodevelopmental outcomes. The aim of our study is to compare the postnatal cerebral tissue oxygenation values in babies with early versus delayed cord clamping born after elective cesarean section.MethodsIn this study, a total of 80 term newborns delivered by elective cesarean section were included. Infants were randomly grouped as early (clamped within 15 s, n:40) and delayed cord clamping (at the 60th second, n:40) groups. Peripheral arterial oxygen saturation (SpO2) and heart rate were measured by pulse oximetry while regional oxygen saturation of the brain (rSO2) was measured with near-infrared spectrometer. Fractional tissue oxygen extraction (FTOE) was calculated for every minute between the 3rd and 15th minute after birth. (FTOE = pulse oximetry value-rSO2/pulse oximetry value). The measurements were compared for both groups.ResultsThe demographical characteristics, SpO2 levels (except postnatal 6th, 8th, and 14th minutes favoring DCC p < 0.05), heart rates and umbilical cord blood gas values were not significantly different between the groups (p > 0.05). rSO2 values were significantly higher while FTOE values were significantly lower for every minute between the 3rd and 15th minutes after birth in the delayed cord clamping group (p < 0.05).ConclusionOur study revealed a significant increase in cerebral rsO2 values and a decrease in FTOE values in the delayed cord clamping (DCC) group, indicating a positive impact on cerebral oxygenation and hemodynamics. Furthermore, the DCC group exhibited a higher proportion of infants with cerebral rSO2 levels above the 90th percentile. This higher proportion, along with a lower of those with such parameter below the 10th percentile, suggest that DCC may lead to the targeted/optimal cerebral oxygenetaion of these babies. As a result, we recommend measuring cerebral oxygenation, in addition to peripheral SpO2, for infants experiencing perinatal hypoxia and receiving supplemental oxygen.

Predictive value of TCCD and regional cerebral oxygen saturation for detecting early postoperative brain injury

ObjectiveThis study aims to analyze the risk factors for early postoperative brain injury in patients undergoing cardiovascular surgery and explore the predictive value of transcranial color Doppler (TCCD) and regional cerebral oxygen saturation (rSO2) for detecting early postoperative brain injury in cardiovascular surgery patients.MethodsA total of 55 patients undergoing cardiovascular surgery with cardiopulmonary bypass in Changzhou No.2 The People’s Hospital of Nanjing Medical University were included in this study. Neuron-specific enolase (NSE) concentration was measured 24 h after operation. Patients were divided into brain injury (NSE ≥ 16.3 ng/mL) and normal (0 < NSE < 16.3 ng/mL) groups according to the measured NSE concentration. The clinical outcomes between the two groups were compared, including decreased rSO2 and cerebral blood flow (as measured by TCCD) levels. The risk factors of early postoperative brain injury were analyzed by multivariate logistic regression analysis, and the significant variables were analyzed by receiver operating characteristic (ROC) analysis.ResultsA total of 50 patients were included in this study, with 20 patients in the brain injury group and 30 patients in the normal group. Cardiopulmonary bypass time (min) (107 ± 29 vs. 90 ± 28, P = 0.047) and aortic occlusion time (min) (111 (IQR 81–127) vs. 87 (IQR 72–116), P = 0.010) were significantly longer in the brain injury group than in the normal group. Patients in the brain injury group had greater decreased rSO2 (%) (27.0 ± 7.3 vs. 17.5 ± 6.1, P < 0.001) and cerebral blood flow (%) (44.9 (IQR 37.8–69.2) vs. 29.1 (IQR 12.0–48.2), P = 0.004) levels. Multivariate logistic regression analysis suggested that decreased rSO2 and cerebral blood flow levels, aortic occlusion time, and history of atrial fibrillation were independent risk factors for early postoperative brain injury (P < 0.05). ROC analysis reported that the best cutoff values for predicting early postoperative brain injury were 21.4% and 37.4% for decreased rSO2 and cerebral blood flow levels, respectively (P < 0.05).ConclusionThe decreased rSO2 and cerebral blood flow levels, aorta occlusion time, and history of atrial fibrillation were independent risk factors for early postoperative brain injury. TCCD and rSO2 could effectively monitor brain metabolism and cerebral blood flow and predict early postoperative brain injury.

Association between pediatric postoperative delirium and regional cerebral oxygen saturation: a prospective observational study

BackgroundPostoperative delirium (POD) represents a prevalent and noteworthy complication in the context of pediatric surgical interventions. In recent times, a hypothesis has emerged positing that cerebral ischemia and regional cerebral oxygen desaturation might serve as potential catalysts in the pathogenesis of POD. The primary aim of this study was to methodically examine the potential relationship between POD and regional cerebral oxygen saturation (rSO2) and to assess the predictive and evaluative utility of rSO2 in the context of POD.MethodsThis prospective observational study was conducted at the Children’s Hospital, Zhejiang University School of Medicine, Zhejiang, China, spanning the period from November 2020 to March 2021. The research cohort comprised children undergoing surgical procedures within this clinical setting. To measure rSO2 dynamics, cerebral near-infrared spectroscopy (NIRS) was used to monitor rSO2 levels both before and after surgery. In addition, POD was assessed in the paediatric patients according to the Diagnostic and Statistical Manual of Mental Disorders Fifth Edition (DSM-5) criteria. The analysis of the association between the rSO2 index and the incidence of POD was carried out through the application of either the independent samples t-test or the nonparametric rank-sum test. To ascertain the threshold value of the adjusted rSO2 index for predictive and evaluative purposes regarding POD in the pediatric population, the Receiver Operating Characteristics (ROC) curve was employed.ResultsA total of 211 cases were included in this study, of which 61 (28.9%) developed POD. Participants suffering delirium had lower preoperative rSO2mean, lower preoperative rSO2min, and lower postoperative rSO2min, higher ∆rSO2mean, higher amount of ∆rSO2mean, lower ∆rSO2min (P < 0.05). Preoperative rSO2mean (AUC = 0.716, 95%CI 0.642–0.790), ∆rSO2mean (AUC = 0.694, 95%CI 0.614–0.774), amount of ∆rSO2mean (AUC = 0.649, 95%CI 0.564–0.734), preoperative rSO2min (AUC = 0.702, 96%CI 0.628–0.777), postoperative rSO2min (AUC = 0.717, 95%CI 0.647–0.787), and ∆rSO2min (AUC = 0.714, 95%CI 0.638–0.790) performed well in sensitivity and specificity, and the best threshold were 62.05%, 1.27%, 2.41%, 55.68%, 57.36%, 1.29%.ConclusionsThere is a close relationship between pediatric POD and rSO2. rSO2 could be used as an effective predictor of pediatric POD. It might be helpful to measure rSO2 with NIRS for early recognizing POD and making it possible for early intervention.

The Effect of Different Anesthesia Depths on Postoperative Cognitive Function of Tumor Patients Monitored by Narcotrend

Abstract Objectives The study aimed to examine the influence of different anesthesia depths monitored by Narcotrend on postoperative cognitive dysfunction (POCD) in elderly patients undergoing radical resection of gastrointestinal malignancies. Methods Individuals in the control group (n = 40) maintained the Narcotrend index (NTI) at 50 to 59 monitored by Narcotrend, whereas the experimental group at 30 to 39. The mini-mental state examination (MMSE) scale and serum S100β concentration were used to evaluate the cognitive function. Cerebral oxygen metabolism and inflammation were evaluated, presenting as regional oxygen saturations of brain (rSO2) and cerebral oxygen uptake rate (CERO2), serum tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6). Results Experimental group presented prominently high levels of rSO2 and low levels of CERO2 relative to controls, meanwhile with reduced serum TNF-α and IL-6. Individuals receiving deep anesthesia owned low levels of S100β and enhanced MMSE score, which showed negative correlation. Low incidence rate of POCD was detected in the experimental group. Both age (hazard ratio = 5.219, 95% confidence interval = 1.813–15.025) and NTI score (hazard ratio = 3.707, 95% confidence interval = 1.292–10.633) were independent influence factors for the onset of POCD. Conclusion NTI maintained at 30 to 39 can reduce the incidence of POCD in the early postoperative period for elderly patients receiving gastrointestinal tumors surgery, the contribution might be attributed to the improvement of perioperative cerebral oxygen metabolism and inflammatory stress response.

Effects of positive end-expiratory pressure on regional cerebral oxygen saturation in elderly patients undergoing thoracic surgery during one-lung ventilation: a randomized crossover-controlled trial

BackgroundA significant reduction in regional cerebral oxygen saturation (rSO2) is commonly observed during one-lung ventilation (OLV), while positive end-expiratory pressure (PEEP) can improve oxygenation. We compared the effects of three different PEEP levels on rSO2, pulmonary oxygenation, and hemodynamics during OLV.MethodsForty-three elderly patients who underwent thoracoscopic lobectomy were randomly assigned to one of six PEEP combinations which used a crossover design of 3 levels of PEEP—0 cmH2O, 5 cmH2O, and 10 cmH2O. The primary endpoint was rSO2 in patients receiving OLV 20 min after adjusting the PEEP. The secondary outcomes included hemodynamic and respiratory variables.ResultsAfter exclusion, thirty-six patients (36.11% female; age range: 60–76 year) were assigned to six groups (n = 6 in each group). The rSO2 was highest at OLV(0) than at OLV(10) (difference, 2.889%; [95% CI, 0.573 to 5.204%]; p = 0.008). Arterial oxygen partial pressure (PaO2) was lowest at OLV(0) compared with OLV(5) (difference, -62.639 mmHg; [95% CI, -106.170 to -19.108 mmHg]; p = 0.005) or OLV(10) (difference, -73.389 mmHg; [95% CI, -117.852 to -28.925 mmHg]; p = 0.001), while peak airway pressure (Ppeak) was lower at OLV(0) (difference, -4.222 mmHg; [95% CI, -5.140 to -3.304 mmHg]; p < 0.001) and OLV(5) (difference, -3.139 mmHg; [95% CI, -4.110 to -2.167 mmHg]; p < 0.001) than at OLV(10).ConclusionsPEEP with 10 cmH2O makes rSO2 decrease compared with 0 cmH2O. Applying PEEP with 5 cmH2O during OLV in elderly patients can improve oxygenation and maintain high rSO2 levels, without significantly increasing peak airway pressure compared to not using PEEP.Trial registrationChinese Clinical Trial Registry ChiCTR2200060112 on 19 May 2022.

Cerebral oxygenation saturation in childhood: difference by age and comparison of two cerebral oximetry algorithms.

Few reports are available on the monitoring of regional cerebral oxygen saturation (rSO2) in pediatric patients undergoing non-cardiac surgical procedures. In addition, no study has examined the rSO2 levels in children of a broad age range. In this study, we aimed to assess and compare rSO2 levels in pediatric patients of different age groups undergoing non-cardiac surgery. We used two oximeters, tNIRS-1, which uses time-resolved spectroscopy, and conventional INVOS 5100C. Seventy-eight children-26 infants, 26 toddlers, and 26 schoolchildren-undergoing non-cardiac surgery were included. We investigated the differences in the rSO2 levels among the age groups and the correlation between the models and physiological factors influencing the rSO2 values. rSO2 measured by INVOS 5100C was significantly lower in infants than those in other patients. rSO2 measured by tNIRS-1 was higher in the toddler group than those in the other groups. The rSO2 values of tNIRS-1 and INVOS 5100C were moderately correlated (r = 0.41); however, those of INVOS 5100C were approximately 20% higher, and a ceiling effect was observed. The values in INVOS 5100C and tNIRS-1 were affected by blood pressure and the minimum alveolar concentration of sevoflurane, respectively. In pediatric patients undergoing non-cardiac surgery, rSO2 values differed across the three age groups, and the pattern of these differences varied between the two oximeters employing different algorithms. Further research must be conducted to clarify cerebral oxygenation in children.

Effects of N95 Masks on Cerebral Oxygen Saturation and End-Tidal Carbon Dioxide Partial Pressure in Healthcare Workers

Background: Healthcare workers must wear masks throughout their shifts, especially those in operating rooms for long periods. Objectives: This study evaluated the effects of wearing N95 masks on blood and cerebral oxygen saturation levels for three hours. Methods: The present case-control study enrolled 20 operating room workers wearing N95 masks. Their blood oxygen saturation (SaO2), end-tidal carbon dioxide partial pressure (PETCO2), and right- and left-sided cerebral regional oxygen saturation (rSO2) were measured in the beginning (0 h) and after wearing N95 masks for one and three hours. Results: Wearing a mask affected PETCO2, rSO2, and pulse rate and caused fatigue and lightheadedness in some cases. The participants' mean PETCO2 increased significantly, from 32 mmHg before putting on a mask to 38 mmHg after wearing it for three hours (P &lt; 0.05). No significant change was observed in the participants' mean rSO2, though changes in their rSO2 levels were recorded (P &gt; 0.05). Conclusions: We showed evidence of changes in different physiology parameters due to using masks for 1 to 3 h. Notably, wearing an N95 mask increased end-tidal carbon dioxide partial pressure and decreased cerebral oxygen saturation in individual cases, not all cases.

Effect of cerebral oxygen saturation monitoring in patients undergoing superficial temporal anterior-middle cerebral artery anastomosis for ischemic Moyamoya disease: a prospective cohort study.

Regional cerebral oxygen saturation (rSO2) is linked with blood pressure. This study evaluated the influence of perioperative rSO2 monitoring on the prognosis of ischemic Moyamoya disease (MMD) patients undergoing anastomosis surgery. In this prospective cohort, patients with unilateral ischemic MMD of Suzuki stage ≥3 were included. The decision of rSO2 was made by the clinician and the patient. The rSO2 group maintained intraoperative rSO2 levels through the modulation of blood pressure, inhaled oxygen concentration, carbon dioxide in arterial blood, and red blood cell transfusion. The non-rSO2 group used conventional anesthesia practices. Perioperative mean arterial pressure (MAP), rSO2 values, neurological complications, and postoperative results were assessed. A total of 75 eligible patients were categorized into a rSO2 monitoring group (n = 30) and a non-rSO2 monitoring group (n = 45). For the rSO2 group, the preoperative rSO2 was significantly lower on the affected side (P < 0.05). After anastomosis, this value notably increased (P = 0.01). A moderate relationship was observed between perioperative rSO2 and MAP before, during, and after surgery, with correlation coefficients (r) of 0.536, 0.502, and 0.592 (P < 0.05). Post-surgery MAP levels differed between the groups, with the rSO2 group showing decreased levels compared to pre-surgery and the non-rOS2 group displaying elevated levels. Notably, the rSO2 group reported shorter hospitalizations and decreased neurological complications. Patients with a hypertension history found postoperative MAP influencing hospital stay duration. Perioperative rSO2 surveillance enhanced cerebral perfusion and minimized postoperative complications in ischemic MMD patients. Thus, rSO2 monitoring is advocated for MMD patients undergoing vascular anastomosis.

Factors affecting intradialytic hepatic oxygenation: Associations between ultrafiltration rate and changes in systemic blood pressure

Hepato-splanchnic circulation influences the oxygenation of abdominal organs and is important in preventing a reduction in intradialytic blood volume. However, the association between changes in intradialytic hepato-splanchnic circulation and clinical factors remain unknown. We enrolled 91 hemodialysis (HD) patients (20 with intradialytic hypotension (IDH) and 71 without IDH). During HD, hepatic regional oxygen saturation (rSO2), a marker of hepatic oxygenation reflecting hepato-splanchnic circulation and oxygenation, was monitored. Changes in hepatic rSO2 at the lowest systolic blood pressure (BP) during HD were analyzed to identify associations with clinical factors. Hepatic rSO2 levels were 55.8 ± 15.3% before HD and 53.8 ± 14.9% at the lowest systolic BP; therefore, % changes in hepatic rSO2 were -2.7 ± 11.3%. These values were significantly lower in patients with IDH than in those without IDH (-13.8 ± 9.3% vs 0.4 ± 9.8%, p < 0.001). Multivariable regression analysis showed that % changes in hepatic rSO2 were independently associated with % changes in systolic BP (standardized coefficient: 0.416) and ultrafiltration rate (-0.206). Furthermore, % changes in mean BP (0.304) were identified as affecting % changes in hepatic rSO2 instead of those in systolic BP. Changes in intradialytic hepatic oxygenation is associated with ultrafiltration rate and changes in systemic BP. Further studies are required to clarify the directionality of the association between changes in hepatic oxygenation and changes in systemic BP during HD.

Does Cerebral Oxygenation Change during Peripherally Inserted Central Catheterization in Preterm Infants?

This study aimed to evaluate the effect of peripherally inserted central venous catheterization on cerebral oxygenation by near-infrared spectroscopy in very low birth weight preterm infants. Forty-one preterm infants (gestational age ≤32 weeks and birth weight ≤1,500 g) requiring peripherally inserted central venous catheter were included. Hemodynamic data and cerebral regional oxygen saturation values measured by near-infrared spectroscopy were prospectively collected before (T0) and every 5 minutes for 30 minutes following catheterization. When compared with baseline (T0) values, those values having relative maximum changes in the first 15 minutes and between 15 and 30 minutes were defined as T15 max and T30 max, respectively. Any change of more than a 10% decrease in baseline cerebral rSO2 was considered clinically significant. Additionally, any changes exceeding 20% in heart rate and mean arterial blood pressure values were considered significant. Following catheterization, the time interval to reach the baseline for cerebral regional oxygen saturation was noted. Cerebral regional oxygen saturation values at T15 max and T30 max were found to have decreased significantly in 46 and 22% of patients, respectively. A statistically significant difference was observed between these two time periods (p = 0.002); no significant differences in heart rate, mean arterial blood pressure, or cerebral fractional oxygen extraction values at T15 max and T30 max were observed. All patients reached their baseline cerebral regional oxygen saturation in a median of 25 (15-60) minutes. In very low birth weight preterm infants, monitoring cerebral regional oxygen saturation by near-infrared spectroscopy before and after peripherally inserted central venous catheterization may be useful in clinical practice. The assessment of factors affecting cerebral oxygenation and, in the case of low cerebral oxygenation, implementation of corrective actions before peripherally inserted central catheterization may offer a neuroprotective strategy. · Monitoring cerebral rSO2 by NIRS during PICC line procedure might be useful in preterm infants.. · In this study, a significant decrease in cerebral rSO2 level following catheterization was observed.. · Implementation of corrective actions before PICC line procedure may offer a neuroprotective strategy..

Association between intraoperative plantar regional oxygen saturation and acute kidney injury after cardiac surgery.

Acute kidney injury (AKI) is one of the most common complications after cardiac surgery, associated with increased mortality and morbidity. Near-infrared spectroscopy (NIRS) continuously measures regional oxygen saturation(rSO2) in real-time. This exploratory retrospective study aimed to investigate the association between intraoperative plantar rSO2 and postoperative AKI in cardiac surgery patients. Between August 2019 and March 2021, 394 patients were included. Plantar and cerebral rSO2 were monitored using NIRS intraoperatively. The primary outcome was AKI within 7 postoperative days. The nonlinear association between plantar rSO2, cerebral rSO2, and mean arterial blood pressure (MBP) and AKI was assessed, and plantar rSO2<45% was related to an increased risk of AKI. Multivariable logistic regression analyses revealed that longer duration and higher area under the curve below plantar rSO2<45% and MBP<65 mmHg were more likely to be associated with increased odds of AKI. In additional multivariable regression analyses, association between plantar rSO2<45% and AKI was still maintained after adjusting the duration or AUC of MBP<65 mmHg as a covariate. Cerebral rSO2 levels were not associated with AKI. Independent of MAP, intraoperative plantar rSO2 was associated with AKI after cardiac surgery. However, intraoperative cerebral rSO2 was not associated with AKI. Intraoperative plantar rSO2 monitoring may be helpful in preventing AKI.

Near-infrared spectroscopy in the medical management of infants

Near-infrared spectroscopy (NIRS) is a technology that is easy to use and can provide helpful information about organ oxygenation and perfusion by measuring regional tissue oxygen saturation (rSO2) with near-infrared light. The sensors can be placed in different anatomical locations to monitor rSO2 levels in several organs. While NIRS is not without limitations, this equipment is now becoming increasingly integrated into modern healthcare practice with the goal of achieving better outcomes for patients. It can be particularly applicable in the monitoring of pediatric patients because of their size, and especially so in infant patients. Infants are ideal for NIRS monitoring as nearly all of their vital organs lie near the skin surface which near-infrared light penetrates through. In addition, infants are a difficult population to evaluate with traditional invasive monitoring techniques that normally rely on the use of larger catheters and maintaining vascular access. Pediatric clinicians can observe rSO2 values in order to gain insight about tissue perfusion, oxygenation, and the metabolic status of their patients. In this way, NIRS can be used in a non-invasive manner to either continuously or periodically check rSO2. Because of these attributes and capabilities, NIRS can be used in various pediatric inpatient settings and on a variety of patients who require monitoring. The primary objective of this review is to provide pediatric clinicians with a general understanding of how NIRS works, to discuss how it currently is being studied and employed, and how NIRS could be increasingly used in the near future, all with a focus on infant management.

Modeling, Simulation and Validation of Alteration in Blood Flow and Regional Oxygenation Under Arterial Occlusion.

The paper presents the mathematical modeling along with an experimental approach for the identification of arterial occlusion condition. Arterial occlusion occurs due to development of constriction and/or thrombus in the lumen of the artery. A geometry of the thrombus has been modeled for the analysis of the arterial occlusion condition in modeling part. The proposed model of the thrombus has been simulated using Comsol® multiphysics considering different hemodynamic parameters. Variation in regional oxygen saturation (rSO2) of the arterial occlusion condition has been validated with experimental process, where occlusion of the artery has been done by applying external pressure. The experimental study has been conducted to monitor alteration in rSO2 level profile for occlusion using near infrared spectroscopy (NIRS) methodology. NIRS signal data has been collected from twenty-three subjects with no reported musculoskeletal, psychiatric, or any other neurological deficits using Mespere NeurOs® oxymeter. Experimental data reveal that the oxygenation level decreases considerably due to arterial occlusion as compared to the healthy condition at 95% of confidence interval (p < .05). Dynamic time warping algorithm reveals that variation in rSO2 due to proposed thrombus geometry has more similarity with experimental study.

Acute Kidney Injury after High-Flow Regional Cerebral Perfusion in Neonatal and Infant Aortic Arch Repair.

We applied high-flow regional cerebral perfusion (HFRCP) for aortic arch reconstruction in neonates and infants by monitoring regional oxygen saturation of the thigh (rSO2T) using near-infrared spectroscopy to maintain peripheral perfusion. This study was designed to investigate the optimal perfusion flow of HFRCP for renal protection. From 2009 to 2021, 28 consecutive neonates and infants who underwent aortic arch reconstruction with HFRCP were enrolled. The median age of the patients was 27 days; the median body weight was 3.0 kg. In HFRCP, perfusion flow was targeted at approximately 80-100 mL/kg/min and then lowered corresponding to brain rSO2 levels and blood gas data. Isosorbide dinitrate and chlorpromazine were administered to enhance peripheral perfusion flow. Regional oxygen saturation of the forehead and thighs were monitored. The stage of acute kidney injury (AKI) was classified based on the Kidney Disease Improving Global Outcomes criteria. No patients had neurological events and peritoneal dialysis after surgery. The incidence of AKI was 39.3% with only three patients having greater than stage 2 AKI. The maximum postoperative serum creatinine concentration was negatively associated with the lowest rSO2T during HFRCP. The rSO2T during HFRCP was a predictive factor for postoperative creatinine increase of ≧0.3 mg/dL. The area under receiver operating characteristic curve was 0.78 with the cutoff value of 48% for rSO2T. The rSO2T during HFRCP is a potential predictor of postoperative renal function. To prevent AKI, the rSO2T should be preserved more than 48% by increasing HFRCP flow.

The Effect of Electroacupuncture Preconditioning on Regional Cerebral Oxygen Saturation Levels in Elderly Patients with Diabetes.

ObjectiveThis study aimed to evaluate the effect of electroacupuncture preconditioning on regional cerebral oxygen saturation (rSO2) levels in elderly patients with diabetes.MethodsForty patients undergoing elective diabetic foot surgery were enrolled in this study. All patients were aged 65 years and above and weighed 45–75 kg. All were characterized as class II or III according to the American Society of Anesthesiologists’ physical status classification system. Patients were divided randomly into an electroacupuncture group (group E) and a control group (group C); both groups comprised 20 patients. In group E, the DU20 (Baihui), DU24 (Shenting), and EX-HN1 (Sishencong) acupoints were selected for electroacupuncture 30 min prior to administering anesthesia, while in group C, patients underwent routine anesthesia without electroacupuncture. The patients in both groups were anesthetized using a sciatic nerve block. The number of cases with increased or decreased regional oxygen saturation (rSO2) compared with the baseline as well as rSO2 variability in the two groups were recorded and compared.ResultsThere was no significant difference in the preoperative rSO2 values between the two groups (54.4 ± 4.8 (L), 53.9 ± 5.2 (R) [group C] vs 54.1 ± 5.2 (L), 54.5 ± 4.6 (R)[group E]). Compared with group C, the rSO2 in group E increased (50.3 ± 3.9 [group C] vs 58.4 ± 3.2[group E]), and this difference was statistically significant (P < 0.001).ConclusionElectroacupuncture stimulation can increase rSO2 levels in patients with diabetes.Clinical Registration NumberChiCTR2100048783 (http://www.chictr.org.cn).

Cerebral oxygenation and body mass index association with cognitive function in chronic kidney disease patients without dialysis: a longitudinal study

In chronic kidney disease (CKD) patients, the prevalence of cognitive impairment increases with CKD progression; however, longitudinal changes in cognitive performance remain controversial. Few reports have examined the association of cerebral oxygenation with cognitive function in longitudinal studies. In this study, 68 CKD patients were included. Cerebral regional oxygen saturation (rSO2) was monitored. Cognitive function was evaluated using mini-mental state examination (MMSE) score. Clinical assessments were performed at study initiation and 1 year later. MMSE score was higher at second measurement than at study initiation (p = 0.022). Multivariable linear regression analysis showed that changes in MMSE were independently associated with changes in body mass index (BMI, standardized coefficient: 0.260) and cerebral rSO2 (standardized coefficient: 0.345). This was based on clinical factors with p < 0.05 (changes in BMI, cerebral rSO2, and serum albumin level) and the following confounding factors: changes in estimated glomerular filtration rate, hemoglobin level, proteinuria, salt and energy intake, age, presence of diabetes mellitus, history of comorbid cerebrovascular disease, and use of renin–angiotensin system blocker. Further studies with a larger sample size and longer observational period are needed to clarify whether maintaining BMI and cerebral oxygenation improve or prevent the deterioration of cognitive function.

Ultrasound-guided erector spinae plane block in patients undergoing pediatric abdominal surgery: a randomized study

BackgroundErector spinae plane block (ESPB) can provide effective analgesia in pediatric abdominal surgery. Additionally, when used as an analgesic method in abdominal surgery, ESPB may increase regional intra-abdominal tissue oxygen saturation (rSO2) throughout the operation. However, the number of related studies conducted on pediatric patients is insufficient.ResultsFifty-two patients undergoing lower abdominal surgery were allocated into two groups, the ESPB (E) and the control (C). Group E received general anesthesia plus unilateral ultrasound-guided ESPB, and group C received general anesthesia alone. Intraoperative fentanyl consumption, Face, Legs, Activity, Cry, Consolability (FLACC) score, time to first rescue analgesia and adverse events were recorded over the first 24 h postoperatively. The rSO2 level was evaluated in both groups throughout the operation. The FLACC score was significantly lower in group E than in group C (p<0.05). Four patients in group E required intraoperative fentanyl compared to 12 patients in group C (p<0.05). The first rescue analgesic administration time was significantly longer in group E than in group C (p<0.05). No significant difference in rSO2 values was detected between the groups (p>0.05). However, in group E, rSO2 values were significantly increased after the block compared to the postinduction values.ConclusionsESPB provides effective perioperative analgesia in children undergoing low abdominal surgery. Although there was no significant difference in rSO2 values between the groups, ESPB administration consistently increases rSO2 over time.Trial registrationThe trial was registered at ClinicalTrials.gov before patient enrolment (NCT03808129-13.12.2018).

Cerebral Oximetry after Low Pressure versus Standard Pressure Pneumoperitoneum in Laparoscopic Nephrectomy.

To evaluate whether pneumoperitoneum pressure lower than the standard pressure would allow higher cerebral oxygen saturation (rSO2) during laparoscopic nephrectomy (LN). Randomised controlled trial. Ondokuz Mayis University Hospital, Samsun, Turkey, from January to November 2020. Sixty-two patients (aged 18-65 years; ASA I-III) scheduled for LN were equally divided into a low-pressure (LP; 8 mmHg) and standard-pressure (SP; 14 mmHg) group. Mechanical ventilator settings were adjusted to maintain 32-37 mmHg ETCO2 and >96% SpO2 throughout the surgery. The rSO2 was evaluated by near-infrared spectroscopy before and one minute after induction and then every five minutes until patient transfer to the recovery unit. Oxygen and carbon dioxide partial pressures, pH, and haemoglobin, recorded at five minutes after induction, five and 30 minutes after insufflation, and 10 minutes after desufflation, were examined for correlations with rSO2. Both groups had similar rSo2, arterial blood gas, and haemoglobin values at all measurement times. The LP group showed no differences between the preoperative values and the values obtained at the different time points. In contrast, the SP group showed significant differences between the preoperative and the measured values (except at 25, 30, and 35 minutes) (p = 0.001). Four patients (12.9%) in both groups showed cerebral desaturation. The rSO2 values were moderately correlated with the CO2 and haemoglobin values. Low insufflation pressure offered no advantages over standard pressure in terms of haemodynamics, arterial blood gases, cerebral oxygen saturation during LN, and CO2 insufflation did not change rSO2 levels. Key Words: Pneumoperitoneum, Spectroscopy, Oximetry, Nephrectomy, Surgery, Laparoscopic nephrectomy.

Abstract 10029: Near-Infrared Spectroscopy Assessments for the Prediction of Neurological Outcome in the Rat Model of Cardiac Arrest

Introduction: Clinical studies have demonstrated that the initial rapid decrement in regional cerebral oxygen saturation (rSO 2 ) level by near-infrared spectroscopy shortly after ROSC was associated with good neurological outcomes. Aim: To evaluate whether the timing of rSO 2 decline shortly after ROSC reflects the severity of brain injury in a well-established rat model of CA/CPR. Methods: We used a total of 85 Wister SD rats (male, 435.2±3.1 g).To produce variable severities of brain injury, CA was induced by different asphyxial times and resuscitated by finger chest compressions and mechanical ventilation. Survival time was recorded for 72 hours after ROSC. Daily neurofunctional scores (NFS) were evaluated by an investigator blinded to the experiments. Electroencephalography (EEG), immunohistochemistry, plasma IL-6, and the gene expressions of cytokines (IL-1, IL-6, TNF-α, HMGB-1) and mitochondrial fission-related proteins (Dnm1L, Fis1, Mief1) in the brain were also evaluated. Result: Animals in the 12-min CA group exhibited a longer time to EEG recovery after CA/CPR compared with the 6-min group (P&lt;.0001), suggesting the longer CA duration induces a delayed brain electrical recovery. Time from ROSC to achieving the initial minimum rSO 2 value (defined as T nadir ) was significantly prolonged as CA time increased; 15.3 ± 2.3, 32.1 ± 22.1, and 44.0 ± 2.8 min in 6, 9, and 12min CA, respectively (ANOVA: P&lt;.0001). T nadir cut-off of 24-min provided the optimal sensitivity and specificity for predicting good neurologic outcomes (NFS≥60%) at 72 hours after ROSC (AUC, 0.88; sensitivity, 89%; specificity, 86%; P&lt;.01). T nadir showed a better predictive power for the good neurological outcome compared with plasma IL-6. Immunohistochemistry at 24 hours post-CA revealed that FJB-positive degenerating neurons in cortex, caudoputamen, and hippocampus were conspicuous in animals with T nadir &gt;24-min, but not in animals with T nadir ≤24-min. Animals with T nadir &gt;24 tended to have a higher gene expression level of IL-6 in the brain at 2 hours post-ROSC compared to those with T nadir ≤24. T nadir did not show associations with other inflammatory or mitochondrial fission markers. Conclusion: T nadir can be a novel predictor for a good neurological outcome after CA/CPR.