Machine learning models of cerebral oxygenation (rcSO2) for brain injury detection in neonates with hypoxic-ischaemic encephalopathy.

The present study was designed to test the potential utility of regional cerebral oxygen saturation (rcSO2) in detecting term infants with brain injury. The study also examined whether quantitative rcSO2 features are associated with grade of hypoxic ischaemic encephalopathy (HIE). We analysed 58 term infants with HIE (>36 weeks of gestational age) enrolled in a prospective observational study. All newborn infants had a period of continuous rcSO2 monitoring and magnetic resonance imaging (MRI) assessment during the first week of life. rcSO2 Signals were pre-processed and quantitative features were extracted. Machine-learning and deep-learning models were developed to detect adverse outcome (brain injury on MRI or death in the first week) using the leave-one-out cross-validation approach and to assess the association between rcSO2 and HIE grade (modified Sarnat - at 1 h). The machine-learning model (rcSO2 excluding prolonged relative desaturations) significantly detected infant MRI outcome or death in the first week of life [area under the curve (AUC) = 0.73, confidence interval (CI) = 0.59-0.86, Matthew's correlation coefficient = 0.35]. In agreement, deep learning models detected adverse outcome with an AUC = 0.64, CI = 0.50-0.79. We also report a significant association between rcSO2 features and HIE grade using a machine learning approach (AUC = 0.81, CI = 0.73-0.90). We conclude that automated analysis of rcSO2 using machine learning methods in term infants with HIE was able to determine, with modest accuracy, infants with adverse outcome. De novo approaches to signal analysis of NIRS holds promise to aid clinical decision making in the future. KEY POINTS: Hypoxic-induced neonatal brain injury contributes to both short- and long-term functional deficits. Non-invasive continuous monitoring of brain oxygenation using near-infrared- spectroscopy offers a potential new insight to the development of serious injury. In this study, characteristics of the NIRS signal were summarised using either predefined features or data-driven feature extraction, both were combined with a machine learning approach to predict short-term brain injury. Using data from a cohort of term infants with hypoxic ischaemic encephalopathy, the present study illustrates that automated analysis of regional cerebral oxygen saturation rcSO2, using either machine learning or deep learning methods, was able to determine infants with adverse outcome.

Reference Ranges for Arterial Oxygen Saturation, Heart Rate, and Cerebral Oxygen Saturation during Immediate Postnatal Transition in Neonates Born Extremely or Very Preterm.

OBJECTIVE: To define percentile charts for arterial oxygen saturation (SpO2), heart rate (HR), and cerebral oxygen saturation (crSO2) during the first 15 minutes after birth in neonates born very or extremely preterm and with favorable outcome. STUDY DESIGN: We conducted a secondary-outcome analysis of neonates born preterm included in the Cerebral regional tissue Oxygen Saturation to Guide Oxygen Delivery in preterm neonates during immediate transition after birth III (COSGOD III) trial with visible cerebral oximetry measurements and with favorable outcome, defined as survival without cerebral injuries until term age. We excluded infants with inflammatory morbidities within the first week after birth. SpO2 was obtained by pulse oximetry, and electrocardiogram or pulse oximetry were used for measurement of HR. crSO2 was assessed with near-infrared spectroscopy. Measurements were performed during the first 15 minutes after birth. Percentile charts (10th to 90th centile) were defined for each minute. RESULTS: A total of 207 neonates born preterm with a gestational age of 29.7 (23.9-31.9) weeks and a birth weight of 1200 (378-2320) g were eligible for analyses. The 10th percentile of SpO2 at minute 2, 5, 10, and 15 was 32%, 52%, 83%, and 85%, respectively. The 10th percentile of HR at minute 2, 5, 10, and 15 was 70, 109, 126, and 134 beats/min, respectively. The 10th percentile of crSO2 at minute 2, 5, 20, and 15 was 15%, 27%, 59%, and 63%, respectively. CONCLUSIONS: This study provides new centile charts for SpO2, HR, and crSO2 for neonates born extremely or very preterm with favorable outcome. Implementing these centiles in guiding interventions during the stabilization process after birth might help to more accurately target oxygenation during postnatal transition period.

Study on cerebral oxygen saturation in children with sleep-disordered breathing.

To explore the association between the severity of sleep-disordered breathing, different types of respiratory events, peripheral oxygen saturation (SpO2), age and sleep stage on cerebral oxygen saturation (rSO2) in children. We enrolled children aged 4-14 years who were treated for snoring or mouth breathing at the Sleep Center of Beijing Children's Hospital, from February 2022 to July 2022. All children completed polysomnography, and SpO2, rSO2, and heart rate (HR) were recorded synchronously. A total of 70 children were included, including 16 (22.9%) with primary snoring, 38 (54.3%) with mild obstructive sleep apnea (OSA), and 16 (22.9%) with moderate-to-severe OSA. There were no significant differences in the mean rSO2 or minimum rSO2 among the primary snoring, mild OSA, and moderate-to-severe OSA groups (all p > 0.05). A total of 1119 respiratory events were included in the analysis. Regardless of the type of respiratory event, rSO2 and HR changes occur prior to fluctuations in SpO2. A mixed-effects model showed that ΔrSO2 was positively correlated with ΔSpO2, duration of respiratory event, mixed and obstructive apnea, central apnea, while negatively correlated with age and rapid eye movement (REM) sleep stage (all p < 0.05). Larger rSO2 fluctuations were impacted by a greater ΔSpO2, longer duration of respiratory events, younger age, apnea-related respiratory events and non-REM sleep stage. Thus, sleep disordered breathing in younger children warrants more attention. More research is needed to determine whether REM sleep has special protective effects on rSO2.

Utilization of NIRS Monitor to Compare the Regional Cerebral Oxygen Saturation Between Dexmedetomidine and Propofol Sedation in Mechanically Ventilated Critically ill Patients with Sepsis- A Prospective Randomized Control Trial.

AIM & BACKGROUND: Delirium frequently occurs in the acute phase of sepsis and is associated with increased ICU and hospital length of stay, duration of mechanical ventilation, and higher mortality rates. We utilized the Near-Infrared Spectroscopy monitor to measure and compare the regional cerebral oxygen saturation in mechanically ventilated patients of sepsis receiving either dexmedetomidine or propofol sedation and assessed the association between delirium and regional cerebral oxygen saturation. METHODS: A single center prospective randomized control trial conducted over a period of two years, 54 patients were included, equally divided between propofol and dexmedetomidine groups. Patients received a blinded study drug, propofol (10 mg/mL) or dexmedetomidine (5 mcg/mL) via infusion pump according to randomization. Infusion rates were adjusted every 10 min based on weight-based titration tables, aiming for target sedation (RASS -2 to 0). Management components included pain monitoring using the CPOT score and delirium assessment using CAM-ICU score. RESULTS: Dexmedetomidine group showed higher mean regional cerebral oxygen saturation as compared to propofol group (P = .036). No significant differences were found in mechanical ventilation or ICU stay durations, delirium-free days, or sedation cessation reasons. Delirium occurred in 36 patients, with lower mean regional cerebral oxygen saturation as compared to non-delirious patients. CONCLUSION: The dexmedetomidine group had higher regional cerebral oxygen saturation compared to the propofol group. Delirious patients showed lower cerebral oxygen saturation than non-delirious patients, suggesting a link between sedation type, cerebral oxygenation, and delirium.CTRI registration: REF/2021/11/048655 N.

Two-lung ventilation with artificial pneumothorax on cerebral desaturation and early postoperative cognitive outcome: a randomized controlled trial.

BACKGROUND: The effect of two lung ventilation (TLV) with carbon dioxide artificial pneumothorax on cerebral desaturation and postoperative neurocognitive changes in elderly patients undergoing elective minimally invasive esophagectomy (MIE) is unclear. OBJECTIVES: The first aim of this study was to compare the effect of TLV and one lung ventilation (OLV) on cerebral desaturation. The second aim was to assess changes in early postoperative cognitive outcomes of two ventilation methods. METHODS: This prospective, randomized, controlled trial enrolled patients 65 and older scheduled for MIE. Patients were randomly assigned (1:1) to TLV group or OLV group. The primary outcome was the incidence of cerebral desaturation events (CDE). Secondary outcomes were the cumulative area under the curve of desaturation for decreases in regional cerebral oxygen saturation (rSO2) values below 20% relative to the baseline value (AUC.20) and the incidence of delayed neurocognitive recovery. RESULTS: Fifty-six patients were recruited between November 2019 and August 2020. TLV group had a lower incidence of CDE than OLV group [3 (10.71%) vs. 13 (48.14%), P = 0.002]. TLV group had a lower AUC.20 [0 (0-35.86) % min vs. 0 (0-0) % min, P = 0.007], and the incidence of delayed neurocognitive recovery [2 (7.4%) vs. 11 (40.7%), P = 0.009] than OLV group. Predictors of delayed neurocognitive recovery on postoperative day 7 were age (OR 1.676, 95% CI 1.122 to 2.505, P = 0.006) and AUC.20 (OR 1.059, 95% CI 1.025 to 1.094, P < 0.001). CONCLUSION: Compared to OLV, TLV had a lower incidence of CDE and delayed neurocognitive recovery in elderly patients undergoing MIE. The method of TLV combined with carbon dioxide artificial pneumothorax may be an option for these elderly patients. Chinese Clinical Trial Registry (identifier: ChiCTR1900027454).

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

BACKGROUND: Postoperative 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. METHODS: This 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. RESULTS: A 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%. CONCLUSIONS: There 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.

Cerebral oxygenation during immediate fetal-to-neonatal transition and fidgety movements between six to 20 weeks of corrected age: An ancillary study to the COSGOD III trial.

Fidgety movements provide early information about a potential development of cerebral palsy in preterm neonates. The aim was to assess differences in the combined outcome of mortality and fidgety movements defined as normal or pathological in very preterm neonates according to the group allocation in the randomised-controlled multicentre COSGOD III trial. Preterm neonates of two centres participating in the COSGOD III trial, whose fidgety movements were assessed as normal or pathological at six to 20 weeks of corrected age, were analysed. In the COSGOD III trial cerebral oxygen saturation (crSO2) was measured by near-infrared spectroscopy (NIRS) during postnatal transition and guided resuscitation in preterm neonates randomised to the NIRS-group, whereby medical support was according routine, as it was also in the control group. Fidgety movements were classified in normal or abnormal/absent at six to 20 weeks of corrected age. Mortality and fidgety movements of preterm neonates allocated to the NIRS-group were compared to the control-group. Normal outcome was defined as survival with normal fidgety movements. One-hundred-seventy-one preterm neonates were included (NIRS-group n = 82; control-group n = 89) with a median gestational age of 29.4 (27.4-30.4) and 28.7 (26.7-31.0) weeks in the NIRS-group and the control-group, respectively. There were no differences in the combined outcome between the two groups: 90.2% of the neonates in the NIRS-group and 89.9% in the control-group survived with normal outcome (relative risk [95% CI]; 0.96 [0.31-2.62]).Conclusions: In the present cohort of preterm neonates, monitoring of crSO2 and dedicated interventions in addition to routine care during transition period after birth did not show an impact on mortality and fidgety movements defined as normal or pathological at six to 20 weeks corrected age. What is Known • Fidgety movements display early spontaneous motoric pattern and may provide early information about a potential development of cerebral palsy in preterm neonates.  What is New  â€¢ This retrospective observational study of the randomised-controlled multicentre COSGOD III trial is the first study investigating the potential influence of cerebral oxygenation guided resuscitation during postnatal transition period on combined outcome of mortality and fidgety movements up to 20 weeks of corrected age in very preterm neonates. • This study adds to the growing interest of assessing cerebral oxygenation, that monitoring of cerebral oxygen saturation and dedicated interventions during postnatal transition period according to the COSGOD III trial has no significant influence on mortality and fidgety movements defined as normal or pathological in very preterm neonates.

Near-infrared spectroscopy to measure brain oxygenation: A comparison of measurements on the skin, skull and dura mater.

BACKGROUND: The reliability of near-infrared spectroscopy (NIRS) for measuring cerebral oxygenation (ScO2 ) is controversial due to the possible contamination from extracranial tissues. We compared ScO2 measured with the NIRS optode on the forehead, the skull and the dura mater in anaesthetised patients undergoing craniotomy. We hypothesised that ScO2 measured directly on the skull and the dura mater would differ from ScO2 measured on the skin. METHODS: This prospective observational study included 17 adult patients scheduled for elective craniotomy. After induction of general anaesthesia, ScO2 was measured on the forehead skin, as well as on the skull and on the dura mater in the surgical field. The primary comparison was the difference in ScO2 measured on the dura mater and on ScO2 measured on the skin; secondary comparisons were the differences in ScO2 on the skull and ScO2 on the skin and the dura mater, respectively. Data were described with median (5%-95% range) and analysed with the Wilcoxon signed-rank test. RESULTS: ScO2 values on the dura mater were obtained in 11 patients, and median ScO2 (48%, 29%-95%) did not differ significantly from ScO2 on the skin (73%, 49%-92%; p = .052), median difference -25% (-35.6% to -1.2%). ScO2 on the skull (N = 16) was lower than that on the skin (63% [43%-79%] vs. 75% [61%-94%]; p = .0002), median difference -10% (-20.8 to -3.0). CONCLUSION: In adults undergoing craniotomy, NIRS-based ScO2 measured on the dura mater did not reach statistically significantly lower values than ScO2 measured on the skin, whereas values on the skull were lower than on the skin, indicating a contribution from scalp tissue to the signal.

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.

BACKGROUND: A 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. METHODS: Forty-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. RESULTS: After 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). CONCLUSIONS: PEEP 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 REGISTRATION: Chinese Clinical Trial Registry ChiCTR2200060112 on 19 May 2022.

Prospective Randomized Pilot Trial on the Effects of Mild Hypercapnia on Cerebral Oxygen Saturation in Patients Undergoing Off-Pump Coronary Artery Bypass Grafting.

OBJECTIVE AND DESIGN: A single-center prospective randomized controlled study was conducted to assess the effect of targeted mild hypercapnia (TMH) on cerebral oxygen saturation (rSO2) in patients undergoing off-pump coronary artery bypass grafting (CABG). SETTING AND PARTICIPANTS: A prospective randomized controlled study involving 100 patients undergoing off-pump CABG at U. N. Mehta Hospital, Ahmedabad, Gujarat, India. INTERVENTION: Patients were randomized to either the TMH (PaCO2 45-55 mmHg) or the targeted normocapnia (TN; PaCO2 35-45 mmHg) group, containing 50 patients in each group. MEASUREMENTS: Monitoring of rSO2, heart rate, mean arterial pressure (MAP), PaCO2, and peripheral oxygen saturation was done at baseline, after induction, after left internal mammary artery harvesting, at each grafting (distal and proximal), after protamine, and after shifting to the intensive care unit. The standardized minimental-state examination (SMMSE) was performed preoperatively and at 8, 12, and 24 hours postextubation. Data were analyzed using an independent sample t test. RESULTS: The TMH group had higher MAP during grafting (p < 0.001) and higher rSO2 on both sides during distal and proximal grafting (p < 0.001) and after protamine (p < 0.05), as compared to the TN group. Compared to preoperative values, SMMSE scores in the TN group were significantly lower at 12 and 24 hours postextubation (p < 0.001). CONCLUSION: TMH during grafting increased the cerebral blood flow and rSO2 when hemodynamic instability was very common. It has a protective role on the brain and helps maintain cognition postoperatively.

First Characterization of Tissue Oxygen Saturation Recovery Patterns in Pediatric Cardiac Surgery Patients Undergoing Remote Ischemic Preconditioning and the Association With Clinical Outcomes.

OBJECTIVE: This study aimed to delineate the recovery patterns of regional oxygen saturation (SrO2) in pediatric cardiac surgery patients subjected to remote ischemic preconditioning (RIPC), utilizing near-infrared spectroscopy (NIRS) for quantification. It also sought to establish the correlation between these perfusion patterns and postoperative clinical outcomes. DESIGN: A prospective longitudinal observational study. SETTING: The study was conducted at Fundación Valle Del Lili, a high-complexity service provider institution in Fundación Valle Del Lili. PARTICIPANTS: Pediatric patients (younger than 18 years of age) scheduled for elective cardiac surgery requiring cardiopulmonary bypass between August 2022 and July 2023. INTERVENTIONS: RIPC was performed after anesthetic induction, involving cycles of ischemia and reperfusion on a lower limb. Monitoring included SrO2 using NIRS. MEASUREMENTS AND MAIN RESULTS: The study identified 4 distinct patterns of SrO2 during RIPC. Findings demonstrated a significant association between the negative SrO2 pattern and increased postoperative adverse events, including extended hospital stays and higher mortality, while a positive pattern was associated with better outcomes. CONCLUSIONS: Specific patterns of SrO2 response to RIPC may serve as important indicators for risk stratification in congenital heart surgery. This study illustrated the potential of NIRS in detecting hypoxic states and predicting postoperative outcomes, emphasizing the need for standardized clinical interpretation of RIPC patterns.

Relationship Between Regional Cerebral Oxygen Saturation and Percutaneous Oxygen Saturation at Initial Mobilisation in Patients with Acute Heart Failure.

In patients with acute heart failure, early mobilisation is performed according to physical condition, biometric information, and haemodynamic stability. Regional cerebral oxygen saturation (rSO2) is useful in monitoring patients during assisted circulation and cardiac arrest, but the measurement of rSO2 during early mobilisation is not standardised, and its relationship with percutaneous oxygen saturation (SpO2) has not been investigated. This study aimed to investigate the relationship between rSO2 and SpO2 during initial mobilisation in patients with acute heart failure. Patients with acute heart failure who presented to our emergency centre and were referred for physical therapy were included in this study. Data from 21 of the 24 patients who decided to start mobilisation based on the criteria of the Japanese Society of Intensive Care Medicine were analysed. The resting rSO2 was 58.6%, and it significantly changed (p < 0.001), with a decrease in the first half of sitting on the edge of the bed (SEB) and an increase from the second half to the end of the SEB. The resting SpO2 was 96.0%, with a trend towards an increase in the latter half of the SEB (p = 0.05608). Changes in rSO2 during initial mobilisation in patients with acute heart failure differed from those in SpO2.

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

OBJECTIVE: This 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. METHODS: A 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. RESULTS: A 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). CONCLUSION: The 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.

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.

Cerebral and intestinal oxygen saturation of different volumes of red blood cell transfusion in preterm infants.

OBJECTIVES: The purpose of this study was to investigate and compare the effects of 20 ml/kg and 15 ml/kg red blood cell transfusion (RBCT) on cerebral and intestinal tissue oxygenation, the number of administered transfusions, and neonatal complications in premature infants with anemia. METHODS: This prospective, randomized, partially blinded observational study investigated anemic neonates of gestational age < 32 weeks (Registration ID: ChiCTR 1,900,026,672). The infants were randomly assigned to receive 15 or 20 ml/kg red blood cell transfusion. Cerebral and intestinal tissue oxygen saturation (cer rSO2 and int rSO2) were collected 2 h before transfusion, 2, 4, 6, 12, 24, and 48 h after the beginning of transfusion by Near-infrared spectroscopy (NIRS). We also collected vital signs including heart rate (HR), peripheral oxygen saturation (SpO2), and mean arterial blood pressure (MABP) 2 h before infusion, 2 h, and 6 h after the beginning of transfusion. Then we analyzed and compared regional oxygen saturation(rSO2), fractional tissue oxygen extraction (FTOE), and other outcome readouts (blood transfusion numbers, changes in hematocrit and hemoglobin, hospitalization days, HR, SpO2, MABP, and complications) between the two groups. The intraindividual comparisons of the above readouts before transfusion and those after transfusion were also evaluated within each group. RESULT: 73 newborns received 20 ml/kg (large volume group) and 78 newborns received 15 ml/kg transfusion (small volume group). There was no significant difference in cer rSO2, int rSO2, Cerebral fractional tissue oxygen extraction (cFTOE), and intestinal fractional tissue oxygen extraction (iFTOE) between the two groups. rSO2, MABP, and SpO2 increased; HR, cFTOE, and iFTOE decreased following transfusion in both groups. The transfusion number of the large volume group is significantly less than that of the small volume group (1.9 ± 0.3 vs. 2.6 ± 0.9, p < 0.01) and hospitalization days were also less than those in the low volume group (44.3 ± 8.2 vs. 47.6 ± 9.8, p < 0.05). The increases in hematocrit and hemoglobin were higher in the large volume group than those in small volume (hematocrit increment (%),10.7 ± 4.2 vs. 10.1 ± 5.9, p = 0.015; Hb concentration after blood transfusion (g/L) 132.3 ± 11.1 vs. 127.4 ± 15.4, p = 0.028). CONCLUSION: After the transfusion, cer rSO2 and int rSO2 increased significantly, FTOE decreased and vital signs improved in both the 15 ml/kg and 20 ml/kg groups, and these changes were not significantly different between the two groups. However, the larger group showed a more pronounced increase in hematocrit and hemoglobin, a reduction in the total number of transfusions, and a shorter duration of hospitalization after transfusion in preterm infants without increasing complications.

Effects of regional cerebral oxygen saturation monitoring on postoperative cognitive dysfunction in older patients: a systematic review and meta-analysis.

BACKGROUND: Postoperative cognitive dysfunction (POCD) is common after surgery and anesthesia, particularly in older patients. It has been reported that regional cerebral oxygen saturation (rSO2) monitoring potentially influences the occurrence of POCD. However, its role in the prevention of POCD remains controversial in older patients. Additionally, the quality of evidence on this topic is still relatively poor. METHODS: The electronic databases PubMed, EMBASE, Web of Science, and Cochrane Library were systematically searched using the indicated keywords from their inception to June 10, 2022. We limited our meta-analysis to randomized controlled trials (RCTs) that assessed the effects of rSO2 monitoring on POCD in older patients. Methodological quality and risk of bias were assessed. The primary outcome was the incidence of POCD during hospitalization. The secondary outcomes were postoperative complications and the length of hospital stay (LOS). Odds ratios (OR) and 95% confidence intervals (CI) were calculated to determine the incidence of POCD and postoperative complications. The standardized mean difference (SMD) instead of the raw mean difference and 95% CI were calculated for LOS. RESULTS: Six RCTs, involving 377 older patients, were included in this meta-analysis. The incidence of POCD ranges from 17 to 89%, with an overall prevalence of 47% in our pooled analysis. Our results demonstrated that rSO2-guided intervention could reduce the incidence of POCD in older patients undergoing non-cardiac surgery (OR, 0.44; 95% CI, 0.25 to 0.79; P = 0.006) rather than cardiac surgery (OR, 0.69; 95% CI, 0.32 to 1.52; P = 0.36). Intraoperative rSO2 monitoring was also associated with a significantly shorter LOS in older patients undergoing non-cardiac surgery (SMD, -0.93; 95% CI, -1.75 to -0.11; P = 0.03). Neither the incidence of postoperative cardiovascular (OR, 1.12; 95% CI, 0.40 to 3.17; P = 0.83) nor surgical (OR, 0.78; 95% CI, 0.35 to 1.75; P = 0.54) complications were affected by the use of rSO2 monitoring. CONCLUSION: The use of rSO2 monitoring is associated with a lower risk of POCD and a shorter LOS in older patients undergoing non-cardiac surgery. This may have the potential to prevent POCD in high-risk populations. Further large RCTs are still warranted to support these preliminary findings.

Effects of permissive hypercapnia on intraoperative cerebral oxygenation and early postoperative cognitive function in older patients with non-acute fragile brain function undergoing laparoscopic colorectal surgery: protocol study.

BACKGROUND: Perioperative brain protection in older patients has been the focus of research recently; meanwhile, exploring the relationship between regional cerebral oxygen saturation (rSO2) and brain function in the perioperative period has been an emerging and challenging area-the difficulties related to the real-time monitoring of rSO2 and the choice of feasible interventions. As an advanced instrument for intraoperative rSO2 monitoring, the clinical application of near-infrared spectrum (NIRS) cerebral oxygen monitoring has gradually increased in popularity and is being recognized for its beneficial clinical outcomes in patients undergoing cardiac and noncardiac surgery. In addition, although sufficient evidence to support this hypothesis is still lacking, the effect of permissive hypercapnia (PHC) on rSO2 has expanded from basic research to clinical exploration. Therefore, monitoring intraoperative rSO2 in older patients with NIRS technology and exploring possible interventions that may change rSO2 and even improve postoperative cognitive performance is significant and clinically valuable. METHODS: This study is a single-center randomized controlled trial (RCT). 76 older patients are enrolled as subjects. Patients who meet the screening criteria will be randomly assigned 1:1 to the control and intervention groups. PHC-based mechanical ventilation will be regarded as an intervention. The primary outcome is the absolute change in the percent change in rSO2 from baseline to the completion of surgery in the intervention and control groups. Secondary outcomes mainly include observations of intraoperative cerebral oxygenation and metabolism, markers of brain injury, and assessments of patients' cognitive function using scale through postoperative follow-up. DISCUSSION: The findings of this RCT will reveal the effect of PHC on intraoperative rSO2 in older patients with nonacute fragile brain function (NFBF) and the approximate trends over time, and differences in postoperative cognitive function outcomes. We anticipate that the trial results will inform clinical policy decision-makers in clinical practice, enhance the management of intraoperative cerebral oxygen monitoring in older patients with comorbid NFBF, and provide guidance for clinical brain protection and improved postoperative cognitive function outcomes. TRIAL REGISTRATION: ChiCTR, ChiCTR2200062093, Registered 9/15/2022.

Effects of targeted mild hypercapnia versus normocapnia on cerebral oxygen saturation in patients undergoing laparoscopic hepatectomy under low central venous pressure: a prospective, randomized controlled study.

BACKGROUND: Laparoscopic hepatectomy under low central venous pressure (LCVP) is associated with intraoperative organ hypoperfusion, including cerebral hypoperfusion. We hypothesized that a ventilation strategy designed to achieve targeted mild hypercapnia (TMH) (end-tidal carbon dioxide partial pressure [PetCO2] of 45 ± 5 mmHg) rather than targeted normocapnia (TN) (PetCO2 of 30 ± 5 mmHg) would increase regional cerebral oxygen saturation (rSO2) during laparoscopic hepatectomy under LCVP. METHODS: Eighty patients undergoing laparoscopic hepatectomy under LCVP were randomly divided into the TMH group (n = 40) and the TN group (n = 40). Mechanical ventilation was adjusted to maintain the PetCO2 within the relevant range. Cerebral oxygenation was monitored continuously using the FORE-SIGHT system before anesthetic induction until the patient left the operating room. Patient and surgical characteristics, rSO2, intraoperative hemodynamic parameters (CVP, mean artery blood pressure [MAP], and heart rate), PetCO2, intraoperative blood gas analysis results, and postoperative complications were recorded. RESULTS: No significant differences were observed in CVP, MAP, and heart rate between the two groups during surgery. The rSO2 was significantly lower in the TN group on both the left and right sides during the intraoperative period (P < 0.05), while the TMH group had a stable rSO2. In the TN group, the mean rSO2 decreased most during liver parenchymal transection when compared with the baseline value (P < 0.05). The mean (standard deviation) percentage change in rSO2 from baseline to parenchymal transection was - 7.5% (4.8%) on the left and - 7.1% (4.6%) on the right. The two groups had a similar incidence of postoperative complications (P > 0.05). CONCLUSION: Our findings demonstrate that rSO2 is better maintained during laparoscopic hepatectomy under LCVP when patients are ventilated to a PetCO2 of 45 ± 5 mmHg (TMH) than a PetCO2 of 30 ± 5 mmHg (TN). TRIAL REGISTRATION: ChiCTR2100051130(14/9/2021).

Development of a nomogram to predict negative postoperative behavioral changes based on a prospective cohort.

BACKGROUND: It is believed that negative postoperative behavioral changes (NPOBC) is associated with negative perioperative outcomes in children. The importance of development of a predictive model of NPOBC was noted. This study aims to identify potential risk factors develop a nomogram to predict NPOBC on postoperative day 3 based on a prospective cohort. METHODS: A prospective observational study was conducted on children(American Society of Anesthesiologists I ~ III) aged 2 ~ 12 years who underwent selective surgery under general anesthesia between September 2022 and February 2023. The patient's clinical data were analyzed. The method of measuring NPOBC is with the The Posthospital Behaviour Questionnaire (PHBQ), and all of children remained hospitalized at the time of assessment. The enrolled patients were categorized into the NPOBC group and the non-NPOBC group according to if children developed NPOBC on postoperative day 3. Univariate and multivariate logistic regression analyses were performed to identify independent risk factors and develop the nomogram to predict NPOBC. Internal validation was performed using the parametric bootstrapping method. RESULTS: One hundred ninety-two patients were enrolled in the study, 44.8% (86/192 patients) of children developed NPOBC on postoperative day 3. Univariate and multivariate logistic regression analysis demonstrated that the Pediatric Anesthesia Behavior (PAB) score (OR: 1.23, 95%CI: 1.14-1.33), cerebral desaturation (OR: 1.16, 95%CI: 1.02-1.32), and postoperative pain score (OR: 1.07, 95%CI: 1.02-1.13) were independent predictors for NPOBC on postoperative day 3 (P < 0.05). They were used to develop the prediction model. The calibration curve demonstrated satisfied discrimination and calibration of the prediction model. The model presented with good discriminative ability (area under the receiver operating characteristic curve: 0.762 [95%CI: 0.691-0.833]). The decision curve analysis also revealed the great clinical utility of the nomogram. CONCLUSION: Based on our prospective observational study, pre-anesthesia patients with higher PAB scores, presence of cerebral desaturation, and higher postoperative pain score were more likely to develop NPOBC on postoperative day 3. We established and validated a nomogram for predicting NPOBC, which could help assess patients individually, identify high-risk groups of NPOBC and improve patient prognosis. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR-2,200,059,776. Registered 11 May 2022.

Effect of remimazolam versus propofol for the induction of general anesthesia on cerebral blood flow and oxygen saturation in elderly patients undergoing carotid endarterectomy.

BACKGROUND: This study was conducted to investigate the effects and safety of remimazolam versus propofol on cerebral oxygen saturation and cerebral hemodynamics during the induction of general anesthesia in patients receiving carotid endarterectomy (CEA), so as to provide theoretical basis for better clinical application of remimazolam. METHODS: Forty-three patients (60-75 years old) with carotid artery stenosis (carotid artery stenosis greater than 70%) were randomly divided into the remimazolam group (R group) and the propofol group (P group). Anesthesia was induced with remimazolam (0.3 mg/kg) or propofol (1.5-2 mg/kg) individually. At time of admission (T0), post-anesthesia induction (T1), consciousness disappears (T2), 1 min after loss of consciousness (T3), 2 min after loss of consciousness (T4) and pre-endotracheal intubation (T5), measurement in patients with regional cerebral oxygen saturation (SrO2), average blood flow velocity (Vm), resistance index (RI), mean arterial pressure (MAP), heart rate (HR) and cardiac index (CI) were recorded. RESULTS: SrO2 increased significantly in both groups after induction of anesthesia compared with baseline (P < 0.05) and decreased after loss of consciousness (P < 0.05). There was no difference in the mean value of the relative changes in SrO2 between the groups. Meanwhile, the Vm, RI, HR and CI of each time point between two groups showed no statistically significant difference (P > 0.05) while MAP in group P at T5 was lower than that in group R individually(P < 0.05). In each group, Vm, HR, CI and MAP at T2-T5 were all significantly reduced compared with T1, with statistically differences(P < 0.05). Specifically, there was no difference of RI at each time between or within groups(P > 0.05). CONCLUSIONS: Our study revealed that remimazolam can be administered safely and effectively during the induction of general anesthesia for carotid endarterectomy in elder population and it demonstrated superiority in hemodynamic changes compared with propofol. CLINICAL TRIAL REGISTRATION: This trial was retrospectively registered with the Chinese Clinical Trial Registry. REGISTRATION NUMBER: ChiCTR2300070370. Date of registration: April 11, 2023.