rScO2 Values Research Articles

Impact of breast milk on cortical pain response in newborns during the heel prick procedure: a randomized controlled trial

ObjectiveTo investigate the effects of breast milk on cortical pain response and behavioral response in newborns during heel-prick procedure.Study designA prospective, randomized controlled trial was conducted on healty-term newborns, undergoing heel blood sampling. Infants were randomly assigned to study group with receive orally 2 ml breast milk (n = 45) or a control group with no intervention (n = 45). A near-infrared spectroscopy device was used to monitor regional cerebral oxygen saturation (rScO2), while neonatal pain expression was assessed by Neonatal Pain, Agitation, and Sedation Scale (N-PASS).ResultsThe N-PASS score (p = 0.001) and the crying time (p = 0.017) were significantly lower in the study group compared to the control group. Although the mean rScO2 values decreased in both groups during the procedure, the percent change in rScO2 was not significant difference between two groups.ConclusionBreast milk administration decreases behavioral responses to a noxious stimulus without reducing the cortical response to pain.Clinical trial registrationThis trial was registered under ClinicalTrials.gov identifier no. NCT05961904.

Is There a Risk of Stroke During Anterior Cervical Discectomy? A Randomized Controlled Trial.

To examine the effects of different retractor techniques for anterior cervical discectomy on cerebral oxygen saturation. In this study, a prospective comparative design was employed to examine the effects of different retractor techniques on a cohort of 48 adult patients with ASA I-II classification who underwent anterior cervical discectomy under general anesthesia. The study was conducted under assessor-blinded conditions, and the patients were divided equally into two groups: the self-retaining retractor group and the hand-held retractor group. In addition to standard anaesthesia monitoring, the utilization of cerebral oximetry monitoring was implemented for all patients. A total of 7 measurements were obtained at various stages, including preoperative, during anaesthesia induction, surgical positioning, surgical retraction, release of retractors, after correction of extension position, and prior to extubation. The main objective of this study was to evaluate the impact of neck position and surgical retraction on brain perfusion, as measured by regional cerebral oximetry. Sociodemographic data, duration of operation, hemodynamic parameters, bilateral regional cerebral oxygen saturation (rScO2), and Mini Mental State Examination (MMSE) scores did not differ significantly between the two groups. In both groups, the bilateral rScO2 decreased significantly with positioning and the left rScO2 decreased significantly following the installation of retractors. Only the left rScO2 increased significantly upon the release of both retractors. Following the correction of the neck position, bilateral rScO2 increased significantly in both groups (p < 0.001). The rScO2 of the left carotid artery was shown to significantly decrease due to the indirect impact of the retractors. After extending the head and neck, bilateral rScO2 values decreased significantly in both groups. However, despite this decline, there was no significant decrease in brain perfusion that would result in ischemia. The absence of a statistically significant distinction between the groups implies that it is unlikely to have an impact on brain perfusion.

The Impact of Various Anesthetic Techniques on Cerebral Oxygenation during Spinal Surgery Performed in a Prone Position with Controlled Hypotension

Background: While prone positioning during anesthesia is necessary for certain surgical procedures, it also increases the risk of postoperative neurological complications. This risk is exacerbated by controlled hypotension used to minimize blood loss during spinal surgeries. Monitoring regional cerebral oxygen saturation (rScO2 ) is essential for maintaining cerebral oxygenation and preventing adverse outcomes like cognitive dysfunction and organ failure. This study aimed to evaluate the effect of different anesthetic techniques on cerebral oxygenation in patients undergoing spinal surgery in the prone position with controlled hypotension. Methods: Fifty-four patients scheduled for spinal surgery in a prone position with controlled hypotension were randomly assigned into two equal groups, to receive sevoflurane or propofol anesthesia. Data were collected at various intervals: before and after anesthesia induction, post-induction in the prone position, during surgery, and before awakening in the supine position. Parameters recorded included rScO2 , peripheral oxygen saturation (SpO2), heart rate (HR), patient state index (PSI), end-tidal carbon dioxide tension (ETCO2 ), and mean arterial pressure (MAP). Results: rScO2 levels decreased in both patient groups once positioned in the prone position. However, the rScO2 values were significantly lower in the propofol group compared to the other group (p = 0.025, 0.032 respectively). Conclusion: The study suggests that propofol as the anesthetic agent may have exacerbated the decline in cerebral oxygenation associated with the transition to prone positioning. Sevoflurane might thus be preferable for patients at risk of compromised cerebral oxygenation.

The Relation Between Oxygen Saturation Measured by Pulse Oximetry vs Near-infrared Spectroscopy Following Surfactant Therapy in Very Low-birth-weight Neonates

Background: Monitoring regional cerebral oxygen saturation (rScO2) and hemodynamic stability (eg, mean arterial blood pressure [MABP]) in high-risk premature infants is crucial to enhance daily clinical practices in neonatal intensive care units (NICUs). Objectives: This study aimed to investigate potential differences between oxygen saturation measurements obtained via near-infrared spectroscopy (NIRS) and pulse oximetry (PO). Methods: This pilot study enrolled 20 very low-birth-weight (VLBW) premature neonates through a non-random, available sampling approach. We gathered maternal and fetal demographic data along with clinical characteristics of the neonates. The study focused on assessing tissue and cerebral oxygenation using PO and NIRS. We specifically monitored changes in mean rScO2 and MABP at various time points: before, during, and 5 and 10 min after the administration of surfactant injection (SI) via the endotracheal tube. Results: The mean gestational age, neonatal birth weight, and Apgar scores at 1 and 5 min after birth were 28.44 ± 2.57 weeks, 1063 ± 246 g, 6.05 ± 2.57, and 7.94 ± 1.79, respectively. No significant differences were observed between mean rScO2 values measured by NIRS and PO before (P = 0.631), during (P = 0.722), and 5 min after (P = 0.783) SI. However, a significant difference between PO and NIRS-based rScO2 values was found 10 min after SI (96.95% vs 75.0%; P = 0.04). Additionally, there was no significant correlation between mean rScO2 and MABP recorded before, during, and after SI. Conclusions: There were no differences in oxygen saturation measurements (recorded by PO) and rScO2 values (recorded by NIRS) before, during, and immediately after SI. Therefore, using PO in NICUs to assess cerebral oxygenation, autoregulation, and hypoxia appears both reasonable and cost-effective. Further multicenter studies are needed to validate the practical advantages and cost-effectiveness of NIRS as an emerging monitoring system.

Comparison of Tritube™ tube and Evone® ventilator use with traditional narrow-lumen tube use in microlaryngeal surgery cases

Aim: To evaluate the feasibility and safety of the Tritube™ tube and Evone® ventilator and compare patients intubated using Tritube™ and ventilated with flow-controlled ventilation (FCV) using Evone® (TT–FCV group) to those intubated using a traditional microlaryngeal intubation tube and ventilated with volume-controlled ventilation (MLT-VCV group) in terms of perioperative parameters and outcomes during microlaryngeal surgery (MLS). &#x0D; Material and Method: A prospective observational design was conducted. This study was carried out in 6 (six) months between February 2022 and September 2022. After receiving their informed consent, 18 patients were randomly assigned to two groups. Patients older than 18 years, who were scheduled for elective MLS were included in the study. The closed opaque envelope method was used for randomization. The same standard anesthesia protocol was applied to all patients. The patients’ demographic parameters, American Society of Anesthesiology physical status (ASA), Mallampati and Cormack-Lehane scores, duration of ventilation, duration of surgery, hemodynamic parameters, ventilation parameters, and complications were recorded. &#x0D; Results: Twenty-one patients recruited for the study. Three of them regretted to participate to study. At the end 18 patients were analyzed. The mean age of population was 53(43-62). When the intraoperative respiratory and hemodynamic parameters of the patients were compared between the two groups, the regional cerebral oxygen saturation (rScO2) (p=0.020), tidal volume (p=0.005), compliance of the respiratory system (p=0.001), and post-extubation rScO2 (p=0.001) values were statistically significantly higher in the TT-FVC group compared to the MLT-VCV group. Right rScO2 (p=0.038), left rScO2 (p=0.047), and time to extubation (p=0.021) were statistically significantly lower in the TT-FVC group compared to the MLT-VCV group.&#x0D; Conclusion: According to the findings we obtained, utilizing Tritube™ and Evone® during MLS surgeries appears to be effective in terms of achieving safe airway management.

Preoperative cerebral oxygenation in high-risk noncardiac surgical patients: an observational study on postoperative mortality and complications

Near Infrared Spectroscopy (NIRS) has become widely accepted to evaluate regional cerebral oxygen saturation (rScO2), potentially acting as a surrogate parameter of reduced cerebral oxygen delivery or increased consumption. Low preoperative rScO2 is associated with increased postoperative complications after cardiac surgery. However, its universal potential in pre-anesthesia risk assessment remains unclear. Therefore, we investigated whether low preoperative rScO2 is indicative of postoperative complications and associated with poor outcomes in noncardiac surgical patients. We prospectively enrolled 130 patients undergoing high-risk noncardiac surgery. During pre-anesthesia evaluation, baseline rScO2 was recorded with and without oxygen supplementation. The primary endpoint was 30-day mortality, while secondary endpoints were postoperative myocardial injury, respiratory complications, and renal failure. We further evaluated the impact of body position and preoperative hemoglobin (Hb) concentration on rScO2. Of the initially enrolled 130 patients, 126 remained for final analysis. Six (4.76%) patients died within 30 postoperative days. 95 (75.4%) patients were admitted to the ICU. 32 (25.4%) patients suffered from major postoperative complications. There was no significant association between rScO2 and 30-day mortality or secondary endpoints. Oxygen supplementation induced a significant increase of rScO2. Furthermore, Hb concentration correlated with rScO2 values and body position affected rScO2. No significant association between rScO2 values and NYHA, LVEF, or MET classes were observed. Preoperative rScO2 is not associated with postoperative complications in patients undergoing high-risk noncardiac surgery. We speculate that the discriminatory power of NIRS is insufficient due to individual variability of rScO2 values and confounding factors.

Low Intraoperative Cerebral Oxygen Saturation Is Associated with Acute Kidney Injury after Off-Pump Coronary Artery Bypass.

By monitoring the brain as the index organ of global oxygen supply-demand balance including major organs, regional cerebral oxygen saturation (rScO2) may indicate adequacy of renal perfusion. The aim of this study was to investigate the relationship between perioperative rScO2 and acute kidney injury (AKI) after off-pump coronary artery bypass (OPCAB). AKI was diagnosed according to the Kidney Disease: Improving Global Outcomes criteria. Collected rScO2 variables were baseline, mean, and lowest value during surgery, maximal percentage decrease from baseline, and areas under the threshold below an absolute value of 50% (AUT50) and of 80% of baseline (AUT80%base). Among 580 patients, AKI developed in 143 (24.7%) patients. Patients with AKI had lower baseline, mean, and lowest rScO2 and higher AUT50 and AUT80%base than those without AKI despite routine efforts to restore the rScO2 values within 20% of the baseline. Among the rScO2 variables, the area under the receiver operating characteristic curve of mean rScO2 was the highest (0.636), which was used for the multivariable logistic regression. Multivariable logistic regression revealed mean rScO2 as an independent predictor of AKI (odds ratio, 0.964; 95% confidence interval, 0.937-0.990; p = 0.008), along with chronic kidney disease and emergency surgery. Low intraoperative mean rScO2 was independently associated with AKI after OPCAB, which may serve as an early marker of renal injury.

Can near infrared spectroscopy predict stroke in coronary artery by-pass graft?

Aim: Central nervous system may be affected after coronary artery by-pass graft (CABG) and carotid artery stenosis is an important risk factor. Near infrared spectroscopy (NIRS) is used to measure the regional cerebral oxygen concentration (rScO2). The aim of this study is to determine the relationship of rScO2 in patients with carotid artery lesion and to determine the relation of stroke with rScO2 changes.&#x0D; Material and Method: The patients who had cardiac bypass surgery were involved in the study. Demographic characteristics and presence of carotid artery stenosis, were collected from the files. Bilateral rSO2 measurements performed by 2 sensors. RScO2 values are detected in 5 minutes of cross-clamp (XCL5), XCL30, XCL60, XCL90, XCL120 and after the by-pass.&#x0D; Results: 57 patients were involved in the study (40 male and mean age 62.54±13.08). 17 (29%) patients had carotid stenosis. rScO2 levels are statistically significantly decreased in the patients with stenosis after post-clamp 30 minutes. Three patients had stroke after surgery (5.2%). Two of the patients had carotid stenosis while one patient did not have. &#x0D; Conclusion: RScO2 decreased in carotid artery stenosis irrespective of the degree of the stenosis after 30 minutes of cross-clamp. Cerebral perfusion follow-up is important during the CPB and NIRS is a method that can be used for this purpose.

Correlation and agreement of regional cerebral oxygen saturation measured from sensor sites at frontal and temporal areas in adult patients undergoing cardiovascular anesthesia.

BackgroundThe function and viability of the brain depend on adequate oxygen supply. A decrease in cerebral blood supply causing cerebral desaturation may lead to many neurological complications. Direct measurement of regional cerebral oxygen saturation (rScO2) assists in early detection and management. Near-infrared spectroscopy (NIRS) has been introduced for measuring rScO2. A pair of sensors are attached to the right and left forehead. However, there are some situations where the forehead of the patient is not accessible for sensor attachment (e.g., neurosurgery involving the frontal area; a bispectral index (BIS) sensor already attached, or a wound to the forehead); therefore, alternate sites for sensor attachment are required. The temporal area was proposed as an alternate site. The objective of this study was to assess the correlation and agreement of rScO2 measured at the forehead vs. the temporal area.MethodsAdult patients undergoing cardiothoracic or vascular surgery were monitored for rScO2 using two pairs of ForeSight sensors. The first pair (A1 and A2) were attached to the right and left forehead, while the second pair (B1 and B2) were attached to the right and left temporal area. The rScO2 values measured from A1 vs. B1 and A2 vs. B2 were assessed for correlation and agreement using the Bland-Altman analysis.ResultsData from 19 patients with 14,364 sets of data were analyzed. The data from A1 vs. B1 and A2 vs. B2 showed moderate positive correlation (r = 0.627; P < 0.0001 and r = 0.548; P < 0.0001). The biases of A1 vs. B1 and A2 vs. B2 were −2.3% (95% CI [−2.5 to −2.2]; P < 0.0001) and 0.7% (95% CI [0.6–0.8]; P < 0.0001). The lower and upper limits of agreement of A1 vs. B1 were −17.5% (95% CI [−17.7 to −17.3]) and 12.8% (95% CI [12.6–13.0]). The lower and upper limits of agreement of A2 vs. B2 were −14.6% (95% CI [−14.8 to −14.4]) and 16.0% (95% [CI 15.8–16.3]).ConclusionsThe rScO2 values measured from sensors at the frontal and temporal areas show a moderate correlation with sufficiently good agreement. The temporal area may be an alternative to the frontal area for cerebral oximetry monitoring.

Cerebral Oxygenation and Activity During Surgical Repair of Neonates With Congenital Diaphragmatic Hernia: A Center Comparison Analysis.

Background and aim: Neonatal brain monitoring is increasingly used due to reports of brain injury perioperatively. Little is known about the effect of sedatives (midazolam) and anesthetics (sevoflurane) on cerebral oxygenation (rScO2) and cerebral activity. This study aims to determine these effects in the perioperative period.Methods: This is an observational, prospective study in two tertiary pediatric surgical centers. All neonates with a congenital diaphragmatic hernia received perioperative cerebral oxygenation and activity measurements. Patients were stratified based on intraoperatively administrated medication: the sevoflurane group (continuous sevoflurane, bolus fentanyl, bolus rocuronium) and the midazolam group (continuous midazolam, continuous fentanyl, and continuous vecuronium).Results: Intraoperatively, rScO2 was higher in the sevoflurane compared to the midazolam group (84%, IQR 77–95 vs. 65%, IQR 59–76, p = < 0.001), fractional tissue oxygen extraction was lower (14%, IQR 5–21 vs. 31%, IQR 29–40, p = < 0.001), the duration of hypoxia was shorter (2%, IQR 0.4–9.6 vs. 38.6%, IQR 4.9–70, p = 0.023), and cerebral activity decreased more: slow delta: 2.16 vs. 4.35 μV2 (p = 0.0049), fast delta: 0.73 vs. 1.37 μV2 (p = < 0.001). In the first 30 min of the surgical procedure, a 3-fold increase in fast delta (10.48–31.22 μV2) and a 5-fold increase in gamma (1.42–7.58 μV2) were observed in the midazolam group.Conclusion: Sevoflurane-based anesthesia resulted in increased cerebral oxygenation and decreased cerebral activity, suggesting adequate anesthesia. Midazolam-based anesthesia in neonates with a more severe CDH led to alarmingly low rScO2 values, below hypoxia threshold, and increased values of EEG power during the first 30 min of surgery. This might indicate conscious experience of pain. Integrating population-pharmacokinetic models and multimodal neuromonitoring are needed for personalized pharmacotherapy in these vulnerable patients.Trial Registration: https://www.trialregister.nl/trial/6972, identifier: NL6972.

Cerebral desaturation and delirium in patients having non-cardiac surgery - a pilot study

BackgroundPostoperative delirium (POD) is associated with increased short- and long-term mortality and several risk factors have been described. Decreased regional cerebral oxygen saturations (rScO2) may be a modifiable risk factor for POD yet its measurement is not used in routine clinical practice. AimsThe primary aim of this study was to assess the feasibility of measuring rScO2 and screening for POD in patients over 60 years of age having non-cardiac surgery. Our secondary aim was to perform exploratory analyses of the relationship between boluses of intra-operative vasopressor and rScO2 values. MethodsrScO2 were recorded in 60 patients over the age of 60 years having non-cardiac surgery in a single centre. Patients were screened daily for delirium for up to 7 days of the inpatient stay or until discharge, which ever occurred sooner. ResultsOf the 60 patients recruited, 58 underwent complete daily assessment for POD. Of those, 2 developed POD (3.4%). Patients that developed POD tended to be older, but no other statistically significant differences were observed. Analysis of the effect of phenylephrine boluses on rScO2 observed a ‘rise, drop, return’ pattern in an 8-minute window post-bolus administration. ConclusionThe study protocol was found to be feasible to deliver. The study was unable to find any associations between rScO2 and POD, however, the study identified a relationship between intraoperative vasopressor boluses and subsequent rScO2.

Effects of Spinal and Epidural Anaesthesia on Brain Oxygenation in Lumbar Disc Surgery

Aim: Due to the sympathetic blockage in spinal and epidural anesthesia applied in lumbar disc surgery, hemodynamic effects are different from each other and these effects may cause changes in cerebral oxygenation. In our study, we aimed to compare the effects of spinal and epidural anesthesia on brain oxygenation in patients undergoing elective LDS. Material and Methods: ASA I-II, 50 patients were included in our study. Group S: (n = 25) 15mg(3ml) 5% isobaric bupivacaine intrathecal and Group E: (n = 25) 40mg(8ml) isobaric bupivacaine (5%), 70mg(3.5ml) lidocaine hydrochloride (2%), 75 µg(1.5ml) fentanyl and 3 ml saline were applied to lomber epidural gap. The hemodynamic variables and bilateral regional cerebral oxygen saturation (rScO2) of the patients were recorded with the Near-Infrared Spectroscopy (NIRS) method in the basal, supine position in the 5th, 10th minutes after the central block, 10th minute in the prone position and the patient was placed in the supine position again. Results: In demographic data, hemodynamic parameters and periodic measurements in Group S and Group E, brain right and left hemisphere rScO2 values (Group S: right hemisphere rScO2 (basal) 69.7 ± 5.5, (60 minutes) 64 ± 7; left hemisphere rScO2 (basal) 70.2 ± 5.1, (60 minutes) 64 ± 8, Group E: right hemisphere rScO2 (basal) 71.6 ± 7.2, (60 minutes) 66.6 ± 5; left hemisphere rScO2 (basal) 71.7 ± 7.3, (60 minutes) 66.8 ± 5), no statistically significant difference was found (p&gt; 0.05). Conclusion: Spinal and Epidural anesthesia affect rScO2 in a similar way. Since epidural anesthesia causes a more balanced anesthesia, it can balance cerebral blood volume and oxygenation. This study may be a guide for studies evaluating the effects of spinal and epidural anesthesia on brain oxygenation, especially in geriatric patient groups. Keywords: Lumbar disc surgery, Spinal anaesthesia, Epidural anaesthesia, Near-Infrared Spectroscopy (NIRS), Regional Brain Oxygenation Saturation(rScO2) DOI: 10.7176/JHMN/79-09 Publication date: August 31 st 2020

Regional Cerebral Oxygen Saturation Monitoring during Spinal Surgery in Order to Identify Patients at Risk for Cerebral Desaturation

Background: Near infrared spectroscopy (NIRS) devices are non-invasive and monitor cerebral oxygen saturation (rScO2) continuously. NIRS interventional protocol is available in order to avoid hypoxic brain injury. Methods: We recruited patients scheduled for spinal surgery (n = 44). rScO2 was monitored throughout the surgery using INVOS 4100 cerebral oximeter. If the rScO2 values dropped more than 20% below baseline, or there was an absolute drop to below 50%, NIRS interventional protocol was followed. Results: In two patients rScO2 decreased by more than 20% from baseline values. In one patient rScO2 decreased to below 50%. NIRS protocol was initiated. As the first step, correct head position was verified–in one patient rScO2 increased above the threshold value. In the two remaining patients, mean arterial pressure was raised by injecting Ephedrin boluses as the next step. rScO2 raised above threshold. Patients with desaturation episodes had longer medium time of the operation (114 ± 35 versus 200 ± 98 min, p = 0.01). Pearson’s correlation showed a negative correlation between rScO2 and duration of operation (r = −0.9, p = 0.2). Receiver operating characteristic curve analysis showed blood loss to be a strong predictor for possible cerebral desaturation (Area under the curve (AUC): 0.947, 95%CI: 0.836–1.000, p = 0.04). Conclusion: Patients with higher blood loss might experience cerebral desaturation more often than spinal surgery patients without significant blood loss.

Does Repeated Painful Stimuli Change Cerebral Near-Infrared Spectroscopy Response in Healthy, Term, Large for Gestational Age Newborns?

The objective of this study was to evaluate the effect of repeated painful stimuli on short-term pain response in healthy, term, large for gestational age newborns by measuring the regional cerebral oxygen saturation (rScO2), and behavioral and physiological responses. We compared term large for gestational age infants who received repeated painful stimuli (study group) with term, appropriate for gestational age infants (control group). A pulse oximeter and a near-infrared spectroscopy probe were connected to babies during the study period, and the responses of the babies were recorded by video, from which the crying time and the Neonatal Infant Pain Scale were obtained. The heart rate, peripheral oxygen saturation (SpO2), and rScO2 data were sampled every 1 second and exported to a personal computer via digital output during the study period. The maximum heart rate, the minimum SpO2, and peak, baseline, and mean rScO2 measurements following skin puncture were recorded. Data were compared within 1 group and between the 2 groups. After the heel prick, crying time (P<0.001) and Neonatal Infant Pain Scale scores (P=0.024) increased, and SpO2 levels decreased significantly (P=0.012) in the study group versus the control group. Although mean rScO2 increased significantly within 1 group (P<0.001), it was not significant between the 2 groups. The percent change in rScO2 was greater in the study group (5.2 [2.5 to 9.3]) compared with the control group (2.8 [1.1 to 8.2], P=0.037). We showed that rScO2 values changed significantly within the first few days of life in babies who received more painful stimuli compared with the control group, similar to behavioral and physiological responses.

P3720Cerebral near-infrared spectroscopy monitoring during transcatheter aortic valve implantation

Abstract Introduction Stroke and transient ischemic attack (TIA) are important periprocedural cerebrovascular complications of transcatheter aortic valve implantation (TAVI). Regional cerebral O2 saturation is an indicator for cerebral perfusion and can be measured in real-time and noninvasively by near-infrared spectroscopy (NIRS). In this pilot study we evaluated the feasibility and utility of NIRS during TAVI. Methods Regional cerebral O2 saturation (rScO2, bihemispheric) was measured by near-infrared spectroscopy during 32 transfemoral TAVI procedures (female 56.3%, mean age 81.8 years). All patients received conscious sedation and O2-supplement if peripheral oxygen saturation (SpO2) was below 95%. Baseline rScO2 was measured at the beginning of the procedure, as well as before, during and 5min after rapid pacing for valve deployment. Results Mean preoperative mini mental state examination score was 26.5 points (theoretically max. 30 points, &gt;24 points no severe cognitive impairment). Two-third of the patients (n=21) required oxygen supply (mean 4.0 l/min) during the TAVI procedure. Mean baseline rScO2 was 59.3% with no differences between both cerebral hemispheres (left 60.3% vs. right 58.7% p=0.23). Compared to baseline rScO2 and rScO2 assessed immediately before rapid passing, rScO2 dropped significantly during rapid pacing (59.3% vs. 51.8%, p&lt;0.01 and 60.9% vs. 51.8%, p&lt;0.01 respectively). Five minutes after rapid pacing rScO2 values had normalized again (post rapid pacing 60.9% vs. 51.8% during rapid pacing, p&lt;0.01; baseline 59.3% vs. post rapid pacing 60.9%, p=0.51). Intraprocedural cerebrovascular events were observed in two cases. One patient developed a left-sided hemiplegia (stroke, later verified by cerebral CT scan) and one patient a transient tremor of the left upper extremity (TIA, new hemorrhagic or ischemic event ruled out by cerebral CT scan). In both cases we observed an abnormal sudden rScO2 decrement by the corresponding right hemispheric NIRS sensor (left-right hemisphere sensor: 60% vs. 44% and 63% vs. 48% respectively). Conclusion Regional cerebral O2 saturation, an indicator for cerebral perfusion, decreases significantly during rapid pacing of TAVI procedure. Furthermore, rScO2 measurement by NIRS may be helpful to detect cerebrovascular complications early during TAVI procedure.

Impact of 2 Distinct Levels of Mean Arterial Pressure on Near-Infrared Spectroscopy During Cardiac Surgery: Secondary Outcome From a Randomized Clinical Trial.

Near-infrared spectroscopy (NIRS) is used worldwide to monitor regional cerebral oxygenation (rScO2) during cardiopulmonary bypass (CPB). Intervention protocols meant to mitigate cerebral desaturation advocate to increase mean arterial pressure (MAP) when cerebral desaturation occurs. However, the isolated effect of MAP on rScO2 is uncertain. The aim of the present study was in a randomized, blinded design to elucidate the effect of 2 distinct levels of MAP on rScO2 values during CPB.We hypothesized that a higher MAP would be reflected in higher rScO2 values, lower frequency of patients with desaturation, and a less pronounced cerebral desaturation load. This is a substudy of the Perfusion Pressure Cerebral Infarct trial, in which we investigated the impact of MAP levels during CPB on ischemic brain injury after cardiac surgery. Deviation in rScO2 was a predefined outcome in the Perfusion Pressure Cerebral Infarct trial. Patients were randomized to low MAP (LMAP; 40-50 mm Hg) or high MAP (HMAP; 70-80 mm Hg) during CPB. CPB pump flow was fixed at 2.4 L/min/m, and MAP levels were targeted using norepinephrine. Intraoperatively, NIRS monitoring was performed in a blinded fashion, with sensors placed on the left and right side of the patient's forehead. NIRS recordings were extracted for offline analysis as the mean value of left and right signal during prespecified periods. Mean rScO2 during CPB was defined as the primary outcome in the present study. The average MAP level during CPB was 67 mm Hg ± SD 5.0 in the HMAP group (n = 88) and 45 mm Hg ± SD 4.4 in the LMAP group (n = 88). Mean rScO2 was significantly lower in the HMAP group during CPB (mean difference, 3.5; 95% confidence interval, 0.9-6.1; P = .010). There was no difference in rScO2 values at specified time points during the intraoperative period between the 2 groups. Significantly more patients experienced desaturation below 10% and 20% relative to rScO2 baseline in the HMAP group (P = .013 and P = .009, respectively), and the cerebral desaturation load below 10% relative to rScO2 baseline was more pronounced in the HMAP group (P = .042). In a randomized blinded study, we observed that a higher MAP induced by vasopressors, with a fixed CPB pump flow, leads to lower mean rScO2 and more frequent and pronounced cerebral desaturation during CPB. The mechanism behind these observations is not clear. We cannot exclude extracranial contamination of the NIRS signal as a possible explanation. However, we cannot recommend increasing MAP by vasoconstrictors during cerebral desaturation because this is not supported by the findings of the present study.

The association between postoperative cognitive dysfunction and cerebral oximetry during cardiac surgery: a secondary analysis of a randomised trial

BackgroundPostoperative cognitive dysfunction (POCD) occurs commonly after cardiac surgery. Near-infrared spectroscopy (NIRS) has been used to monitor regional cerebral oxygen saturation (rScO2) in order to minimise the occurrence of POCD by applying dedicated interventions when rScO2 decreases. However, the association between rScO2 intraoperatively and POCD has not been clarified. MethodsThis is a secondary analysis of a randomised trial with physician-blinded NIRS monitoring and cognitive testing at discharge from hospital and at 3 months after surgery. The association between intraoperative rScO2 values and POCD at discharge from hospital and at 3 months after surgery was investigated. The prespecified candidate predictive variable of interest was cumulative time during surgery with rScO2 ≥10% below its preoperative value. ResultsOne hundred and fifty-three patients had complete NIRS data and neurocognitive assessments at discharge, and 44 of these patients (29%) had POCD. At 3 months, 148 patients had complete data, and 12 (8%) of these patients had POCD. The median time with rScO2 >10% below preoperative values did not differ for patients with and without POCD at discharge (difference=0.0 min; Hodges-Lehmann 95% confidence interval, −3.11–1.47, P=0.88). Other rScO2 time thresholds that were assessed were also not significantly different between those with and without POCD at discharge. This applied both to absolute rScO2 values and relative changes from preoperative values. Similar results were found in relation to POCD at 3 months. ConclusionsNo significant association was found between intraoperative rScO2 values and POCD. These findings bring into question the rationale for attempting to avoid decreases in rScO2 if the goal is to prevent POCD. Clinical trial registrationNCT 02185885.

Cerebral Oxygenation as a Monitoring Parameter for Mortality During Venoarterial Extracorporeal Membrane Oxygenation.

There are no recommended guidelines for monitoring parameters during venoarterial extracorporeal membrane oxygenation (V-A ECMO). We evaluated whether regional cerebral oxygen saturation (rScO2) could be a monitoring parameter for mortality during V-A ECMO. We retrospectively searched our database for adult patients who underwent V-A ECMO between April 2015 and October 2016 and identified 21 patients with rScO2 data. Their baseline and clinical characteristics during the first 7 days (vital signs, arterial blood gas results, ECMO variables, rScO2, Swan-Ganz catheter parameters, transthoracic echocardiography parameters, and outcomes) were collected and evaluated for associations with 28 day mortality. The survivor group (12 patients, 57.1%) had higher rScO2 values and lower lactate levels, compared with the nonsurvivor group (nine cases, 42.9%) during the first 7 days. The areas under the receiver operating characteristics curves were 0.87 for right rScO2 (p < 0.001) and 0.86 for left rScO2 (p < 0.001). The optimal cutoff values for right and left rScO2 were 58% (sensitivity: 78.7%, specificity: 83.3%) and 57% (sensitivity: 80.0%, specificity: 70.8%), respectively. Kaplan-Meier analysis revealed that the risks of 28 day mortality were higher among patients with a right rScO2 of <58% and a left rScO2 of <57%, compared with patients with a right rScO2 of ≥58% and a left rScO2 of ≥57% (both, p < 0.001). We suggest that rScO2 may be used as a monitoring parameter for 28 day mortality among patients undergoing V-A ECMO.

Effects of Carbon Dioxide Insufflation and Trendelenburg Position on Brain Oxygenation During Laparoscopy in Children.

Laparoscopic appendectomy has become more popular compared with the open appendectomy in children, but there are limited data on the effects of pneumoperitoneum and Trendelenburg position on cerebral oxygenation. This study was designed to evaluate the changes in cerebral saturation using near-infrared spectroscope during laparoscopic surgery in children. The children underwent laparoscopic (LAP Group, n=22) or open appendectomy (OPEN Group, n=22). Right and left cerebral oxygenation (RScO2-LScO2), heart rate (HR), mean arterial pressure (MAP), end-tidal CO2pressure (PETCO2), and peripheral oxygen saturations (SpO2) were recorded between anesthesia induction (T0, baseline), after induction (T1), after intubation (T2), 5 minutes after intubation (T3), 5 minutes after pneumoperitoneum-15th minute at OPEN (T4), 5 minutes after Trendelenburg-20th minute at OPEN (T5), 30 minutes after pneumoperitoneum-45th minute at OPEN (T6), 5 minutes after supine position-skin suturing at OPEN (T7), 5 minutes postextubation (T8). Groups were similar with respect to their demographic data. In LAP group, a significant increase in HR was recorded at T5. No significant difference was observed in the MAP, PETCO2, SpO2, RScO2, and LScO2 values between the groups. There was a significant increase in the perioperative T1 to T8 values compared with the T0 values in LScO2 of the LAP group. Our results suggest that pneumoperitoneum and Trendelenburg position does not alter the hemodynamic values and can be safely performed in children without altering regional brain oxygenation levels.

Changes of rScO2 and ScvO2 in children with sepsis-related encephalopathy with different prognoses and clinical features.

Clinical features of sepsis-associated encephalopathy in children with different prognoses were analyzed and the changes of regional cerebral oxygen saturation (rScO2) and central venous oxygen saturation (ScvO2) were measured. Eighty children with sepsis-related encephalopathy, admitted to the Pediatric Intensive Care Unit (PICU) of the Children's Hospital Affiliated to Zhengzhou University, were enrolled in this study and post-intensive care syndrome (PICS) scoring was performed within 24 h after admission. Patients were separated into groups according to the score results and treatment outcomes. Clinical features, functional tests, imaging examinations, PICS scores, and modified Glasgow Coma Scale (GCS) scores were compared among children with varying severities and prognoses. The changes of rScO2 and ScvO2 at different time-points among children with different prognoses were measured and compared. According to PICS scores, there were 8 non-critically ill children, 42 critically ill children, and 30 extremely critically ill children. Fifty-two children survived, and the survival rate was 65%. Comparison of the clinical characteristics of children with different conditions showed that deep coma, generalized seizure, severe electroencephalogram (EEG) abnormalities, and the survival of children were significantly associated with the severity of disease (P<0.05). At the same time, compared to the survivors group, the rates of generalized seizures and severe EEG abnormalities were significantly increased in the deceased children group, while the PICS and GCS scores were significantly decreased (P<0.05). rScO2 values in the deceased group were lower than those in the survival group at different time-points, but the differences were not significant (P>0.05). On the contrary, ScvO2 values were significantly higher in the deceased group than those in the survivors group (P<0.05). The lower the PICS and GCS scores in children with sepsis-related encephalopathy, the more serious the condition, and the more likely to develop disturbance of consciousness, epileptic seizures, and abnormal EEG changes. Whereas, changes of ScvO2 are closely related to prognosis.