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Amaç: Bu çalışmada, nazal cerrahi geçiren hastalarda uygulanan kontrollü hipotansiyonun serebral oksijen satürasyonu ve postoperatif kognitif disfonksiyon (POKD) üzerindeki etkisinin değerlendirmesi amaçlandı.Gereç ve Yöntem: Kırk hasta kapalı zarf yöntemi ile esmolol (Grup E, n=20) ve nitrogliserin (Grup N, n=20) olmak üzere iki gruba ayrıldı. Hastaların kognitif fonksiyonları operasyondan 1 gün önce ve 1 gün sonra Mini Mental Durum Testi ile değerlendirildi. Serebral desatürasyonu saptamak için rejyonel serebral oksijen satürasyonu yakın kızılötesi spektroskopi ile izlendi.Bulgular: Tüm gruplarda istenilen ortalama arteriyel kan basıncına (50-65 mmHg) ulaşıldı. Postoperatif 24. saatte 16 hastada (%40) kognitif fonksiyonlarda azalma meydana geldi. Postoperatif kognitif disfonksiyon açısından gruplar arasında istatistiksel olarak anlamlı fark yoktu. Postoperatif kognitif disfonksiyon ile serebral desatürasyon arasında anlamlı bir ilişki olduğu görüldü.Sonuç: Hipotansif anestezi sırasında görülen serebral desatürasyon erken POKD gelişimine neden olabilmektedir, bu nedenle hipotansif anestezi sırasında yakın serebral ve hemodinamik monitorizasyon ile kognitif fonksiyonların korunabileceğini düşünmekteyiz., Purpose: This study aimed to evaluate the effect of controlled hypotension on cerebral oxygen saturation and postoperative cognitive dysfunction (POCD) in patients undergoing nasal surgery.Materials and Methods: Forty patients were randomized by a sealed envelope method into two drug groups: esmolol (Group E, n=20) or nitroglycerin (Group N, n=20) administration prior to surgical incision. The cognitive functions of the patients were evaluated by the Mini-Mental State Examination Test 1 day before and 1 day after the operation. Regional oxygen saturation was monitored with near-infrared spectroscopy to detect cerebral desaturation.Results: The desired mean arterial blood pressure (50-65 mmHg) could be achieved in all groups. A decline in cognitive function occured in 16 patients (40%) at the 24th postoperative hour. There was no statistically significant difference between the groups in terms of POCD. There was a significant relationship between POCD and cerebral desaturation status. Conclusion: Cerebral desaturation seen during hypotensive anesthesia may cause early POCD development, therefore we think that close cerebral and hemodynamic monitoring during hypotensive anesthesia may preserve cognitive functions.

Purpose of review To give an overview of cerebral monitoring techniques for surgical ICU patients. Recent findings As the burden of postsurgical neurological and neurocognitive complications becomes increasingly recognized, cerebral monitoring in the surgical ICU might gain a relevant role in detecting and possibly preventing adverse outcomes. However, identifying neurological alterations in surgical ICU patients, who are often sedated and mechanically ventilated, can be challenging. Various noninvasive and invasive techniques are available for cerebral monitoring, providing an assessment of cortical electrical activity, cerebral oxygenation, blood flow autoregulation, intracranial pressure, and cerebral metabolism. These techniques can be used for the diagnosis of subclinical seizures, the assessment of sedation depth and delirium, the detection of an impaired cerebral blood flow, and the diagnosis of neurosurgical complications. Summary Cerebral monitoring can be a valuable tool in the early detection of adverse outcomes in surgical ICU patients, but the evidence is limited, and clear clinical indications are still lacking.

Background We performed a retrospective analysis of our earlier study on cerebral oxygenation monitoring by jugular venous oximetry (SjvO2) in patients of out-of-hospital cardiac arrest (OHCA). The study was focused on high SjvO2 values (≥ 75%) and their association with neurological outcomes and serum neuron-specific enolase (NSE) concentration. Method Forty OHCA patients were divided into (i) high (Group I), (ii) normal (Group II), and (iii) low (Group III) SjvO2, with the mean SjvO2 ≥75%, 55-74% and Results High mean SjvO2 occurred in 67% of patients, while no patients had low mean SjvO2. The unfavourable outcome was significantly more common in Group I than Group II (74% versus 23%, p Conclusion High mean SjvO2 are often associated with unfavourable outcomes and high NSE at 48 and 72 hours post-CA. Not only low but also high SjvO2 values may require therapeutic intervention.

Aim To measure the changes in cerebral oxygenation indices by near infrared time-resolved spectroscopy and the cerebral blood flow simultaneously after spinal anesthesia for cesarean section. Methods This prospective observational study was conducted for 25 pregnant women scheduled for elective cesarean section under spinal anesthesia. During a period of 15 min after spinal anesthesia, cerebral oxygenation (ScO2 ), and the total cerebral hemoglobin concentration (tHb) were measured using near infrared time-resolved spectroscopy and mean cerebral blood flow velocity (Vm) was measured using transcranial Doppler ultrasonography. Next, in the women who had nausea during the observed period, we compared these values when nausea was detected with those when it was not. Results Mean arterial pressure (MAP) decreased to around 60 mmHg (by 25% compared to the control) 6 min after spinal anesthesia. Compared to the control, ScO2 decreased by about 3% after 6 min and then gradually increased. The tHb, which reflects cerebral blood volume started to decrease just after spinal anesthesia and this continued until 12 min (the decrease was about 12%). Vm decreased by about 7%. In the 14 women who had nausea, MAP, Vm, and ScO2 values when nausea was detected were significantly lower than when it was not. Conclusion The changes in cerebral hemodynamics may be small after spinal anesthesia in ordinary cesarean section compared to the reduction of systemic arterial blood pressure. There might be greater decreases in cerebral blood flow and oxygenation when nausea occurred in the pregnant women who experienced it after spinal anesthesia.

The cerebrovascular effects of supine hypertension (SH) are still poorly understood. With aging and atherosclerosis of the vascular system, it is not uncommon for SH and non-neurogenic orthostatic hypotension to co-occur. Given evidence for end organ damage and more extreme cerebral dysfunction in those with SH-orthostatic hypotension, we hypothesized that SH would be associated with impaired cerebral autoregulation. The aim of this study was to characterize the cerebrovascular response to orthostasis. Near-infrared spectroscopy was used to quantify the cerebrovascular response. We analyzed data from Wave 3 of TILDA (The Irish Longitudinal Study on Ageing; n=2750). Cerebral oxygenation and blood pressure (BP) were monitored continuously during an active stand. Responses were modeled using multilevel mixed-effects models and adjusted for important covariates such as age, sex, education, antihypertensive medications, and comorbidities. Forty-nine percent of the sample had SH. Those with SH demonstrated an impaired BP response and a slower recovery of BP after standing, graded by severity of SH. The cerebral oxygenation response was similar for both groups, but when standardized to mean arterial BP, the response was impaired in those with SH. A deficit of −0.83% (95% CI, −0.93 to −0.74) remained after 3 minutes of standing. Our study determined that cerebral oxygenation and cerebral autoregulation are impaired in those with SH. In older patients, consideration should be given to measuring SH and screening for orthostatic hypotension. Therapeutic studies are needed to better understand the relationship between cerebral oxygenation, medications, supine BP, and orthostatic hypotension.

Objective The study aimed to investigate the effects of kangaroo mother care (KMC) on repeated procedural pain and cerebral oxygenation in preterm infants. Study Design Preterm infants of 31 to 33 weeks of gestational age were randomly divided into an intervention group (n = 36) and a control group (n = 37). Premature infant pain profile (PIPP) scores, heart rate, oxygen saturation, regional cerebral tissue oxygenation saturation (rcSO2), and cerebral fractional tissue oxygen extraction (cFTOE) were evaluated during repeated heel stick procedures. Each heel stick procedure included three phases: baseline, blood collection, and recovery. KMC was given to the intervention group 30 minutes before baseline until the end of the recovery phase. Results Compared with the control group, the intervention group showed lower PIPP scores and heart rates, higher oxygen saturation, and rcSO2 from the blood collection to recovery phases during repeated heel sticks. Moreover, there were significant changes in cFTOE for the control group, but not the intervention group associated with repeated heel stick procedures. Conclusion The analgesic effect of KMC is sustained over repeated painful procedures in preterm infants, and it is conducive to stabilizing cerebral oxygenation, which may protect the development of brain function. Key Points

Objective Pneumoperitoneum can cause disruption in splanchnic perfusion. This study aims to investigate effects of pneumoperitoneum on splanchnic oxygenation during abdominal laparoscopic surgery in paediatric patients with NIRS (Near-Infrared Spectroscopy). Material and methods A total of 45 patients between 1 and 4 years of age with ASA physical status I–II and scheduled to undergo abdominal laparoscopic surgery under general anaesthesia were enrolled in this prospective, observational surgery. No premedication was used. Standard monitoring and regional splanchnic saturation (rSPcO2), regional cerebral oxygen saturation (rScO2) with NIRS were established before anaesthesia. Anaesthesia was induced with an inhalational agent and maintained with an oxygen/air mixture and sevoflurane. Peripheral oxygen saturation (SPO2), rSPcO2, rScO2, heart rate (HR), mean arterial pressure (MAP), end tidal CO2 (Et-CO2), and insufflation pressure (IP) were continuously monitored during administration of anaesthesia and recorded. After intubation (baseline T0); before CO2 insufflation induced pneumoperitoneum (PP) (T1); CO2 PP insufflation (T2); 5 minutes after PP insufflation (T3); 10 minutes after PP insufflation (T4); 15 minutes after PP insufflation (T5); 20 minutes after PP insufflation (T6); 30 minutes after PP insufflation (T7), 60 minutes after PP insufflation (T8), and after desufflation (T9). Bradycardia and hypotension were recorded. Paracetamol IV 10 mg kg−1 was applied for post-operative analgesia. p

Music therapy is a novel intervention that may minimize neonatal stress. The mechanism of action is still largely unknown. We hypothesized that one mechanism of action regards altered brain oxygenation (either due to altered cerebral perfusion or altered cerebral oxygen consumption). We measured cerebral oxygenation before, during and after music therapy sessions using Near-Infrared Spectroscopy (NIRS). We extracted data on cerebral oxygen saturation (rcSO2) and calculated cerebral fractional tissue oxygen extraction (cFTOE). In addition, we measured heart rate. We included 20 infants, receiving 44 music therapy sessions. Median gestational age was 27 weeks, the majority were males. We identified two distinct reactions: in one group rcSO2 increased and cFTOE decreased during therapy compared with before therapy, whereas in the other group rcSO2 decreased and cFTOE increased during therapy compared with before therapy. The first may indicate a sedative effect, whereas the second may reflect a hyperalert state. The observed changes in heart rate may contribute to these observations through altered cerebral perfusion. The clinical significance of these two distinct reactions for music processing and (future) neurological functioning in these infants warrants further investigation.

Patients undergoing coronary artery bypass grafting (CABG) are at risk of developing postoperative renal impairment, amongst others caused by renal ischemia and hypoxia. Intra-operative monitoring of renal region tissue oxygenation (SrtO2) might be a useful tool to detect renal hypoxia and predict postoperative renal impairment. Therefore, the aim of this study was to assess the ability of intra-operative SrtO2 to predict postoperative renal impairment, defined as an increase of serum creatinine concentrations of > 10% from individual baseline, and compare this with the predictive abilities of peripheral and cerebral tissue oxygenation (SptO2 and SctO2, respectively) and renal specific tissue deoxygenation. Forty-one patients undergoing elective CABG were included. Near-infrared spectroscopy (NIRS) was used to measure renal region, peripheral (thenar muscle) and cerebral tissue oxygenation during surgery. Renal region specific tissue deoxygenation was defined as a proportionally larger decrease in SrtO2 than SptO2. ROC analyses were used to compare predictive abilities. We did not observe an association between tissue oxygenation measured in the renal region and cerebral oxygenation and postoperative renal impairment in this small retrospective study. In contrast, SptO2 decrease > 10% from baseline was a reasonable predictor with an AUROC of 0.767 (95%CI 0.619 to 0.14; p = 0.010). Tissue oxygenation of the renal region, although non-invasively and continuously available, cannot be used in adults to predict postoperative renal impairment after CABG. Instead, peripheral tissue deoxygenation was able to predict postoperative renal impairment, suggesting that SptO2 provides a better indication of ‘general’ tissue oxygenation status.Registered at ClinicalTrials.gov: NCT01347827, first submitted April 27, 2011.

Cerebral and somatic near-infrared spectroscopy monitors are commonly used to detect tissue oxygenation in various circumstances. This form of monitoring is based on tissue infrared absorption and can be influenced by several physiological and non-physiological factors that can induce error in the interpretation. This narrative review explores those clinical and technical limitations and proposes solutions and alternatives in order to avoid some of those pitfalls.

AIM To assess cerebral oxygenation in premature infants who are transitioning from nasal continuous positive airway pressure (nCPAP) to heated humidified high-flow nasal cannula therapy (HFNC). METHODS A prospective observational study done in a single-centre neonatal intensive care unit (NICU). Regional cerebral oxygen saturations (RcSO2 ) were measured using frequency-domain near-infrared spectroscopy (FD-NIRS) in very low birthweight (VLBW) premature infants born at

Objective To assess the relationship between cerebral oxygenation in the first 72 h of life and neurodevelopmental impairment (NDI) at 2 years corrected age in former premature infants. Study design Prospective observational cohort study of 127 infants

Brain injury is one of the most consequential problems facing neonates, with many preterm and term infants at risk for cerebral hypoxia and ischemia. To develop effective neuroprotective strategies, the mechanistic basis for brain injury must be understood. The fragile state of neonates presents unique research challenges; invasive measures of cerebral blood flow and oxygenation assessment exceed tolerable risk profiles. Near-infrared spectroscopy (NIRS) can safely and non-invasively estimate cerebral oxygenation, a correlate of cerebral perfusion, offering insight into brain injury-related mechanisms. Unfortunately, lack of standardization in device application, recording methods, and error/artifact correction have left the field fractured. In this article, we provide a framework for neonatal NIRS research. Our goal is to provide a rational basis for NIRS data capture and processing that may result in better comparability between studies. It is also intended to serve as a primer for new NIRS researchers and assist with investigation initiation.

Rationale: Studies suggest that reduced cerebral perfusion may contribute to delirium development in the intensive care unit (ICU). However, evidence is limited because of factors including small s...

Aim:To compare the effect of bupivacaine and bupivacaine/fentanyl combination on cerebral oxygenation values with the Near-infrared spectroscopy (NIRS) technique in elective cesarean sections performed under spinal anesthesia.Methods:Fifty patients who underwent cesarean section under spinal anesthesia were randomly divided into two groups. 7.5-10 mg 0.5% hyperbaric bupivacaine was administered to the bupivacaine group (n=25) and 7.5-10 mg 0.5% hyperbaric bupivacaine+20-25 mcg fentanyl was given to the combination group (n=25). Heart rate, mean arterial pressure, peripheral oxygen saturation, mean values of regional cerebral oxygen saturation after spinal anesthesia were recorded preoperatively and the 1st, 5th, 10th, 15th and 20th minutes after anesthesia. The presence of perioperative nausea and vomiting was assessed with the Verbal Descriptive Scale.Results:Significant difference was observed in mean arterial pressure values between groups (p=0.001). There was a statistically significant change in cerebral oxygenation values during surgery in both groups (p=0.001). The frequency of nausea and vomiting was lower in the combination group (p=0.009).Conclusion:The non-invasive NIRS technique can be safely applied in the monitoring of cerebral oxygenation and hemodynamics in elective cesarean section procedures undergoing spinal anesthesia.

Background: Sevoflurane unfortunately increases the cranial blood flow, blood volume, and pressure changes cope with cerebral aneurysmal neuroanesthesia goals. Propofol decreases the brain metaboli...

Background In this study we compared intraoperative bleeding and regional cerebral oxygenation in patients with different degrees of the reverse Trendelenburg position (RTP) during endoscopic sinus surgery (ESS). Methods In total, 120 patients with chronic rhinosinusitis treated by ESS were randomly assigned to the following 4 groups: a horizontal position (HP) group, and 5°, 10°, and 15° RTP (5-RTP, 10-RTP, and 15-RTP, respectively) groups. The primary outcome was the Boezaart grading scale (BS). The cerebral oxygen saturation (ScO2 ), total blood loss, numerical rating scale (NRS) scores, and complications were also recorded. Results The median BS values in the HP, 5-RTP, 10-RTP, and 15-RTP groups were 2.0, 2.0, 2.1, and 1.7, respectively. Multiple pairwise comparisons of the BS showed significant differences between the 15-RTP group and the other 3 groups (HP, 5-RTP, and 10-RTP). Regarding the NRS and bleeding rate, significant differences were found between the HP and 15-RTP groups. No difference was found in ScO2 among the 4 groups, and no cerebral desaturation events occurred in any group. No complications, including vital organ (heart, brain, and kidney) dysfunction problems, were reported in this study during hospitalization. Conclusion Compared with HP, 5-RTP, and 10-RTP, 15-RTP can improve visual clarity during ESS, and ScO2 is not affected by the degree of RTP. No cerebral deoxygenation or vital organ dysfunction was observed in this study. Therefore, we recommend 15-RTP with moderate deliberate hypotension for ESS.

Background: Decreased cerebral perfusion and oxygenation are common in hemodialysis patients. Magnitude of the arteriovenous fistula involvement in this phenomenon is not known. The aim of this study was to investigate the effect that a short-term arteriovenous fistula flow interruption has on cerebral oxygenation and to review and suggest possible explanations. Methods: In 19 patients, basic laboratory and clinical data were obtained and arteriovenous fistula flow volume was measured by ultrasonography. Baseline regional cerebral oxygen saturation (rSO2) was measured by near-infrared spectroscopy. Manual pressure was then applied on the fistula, resulting in total blood flow interruption. After 1 min of manual compression, rSO2 and blood pressure values were noted again. The compression-related change in rSO2 was assessed, as well as its association with arteriovenous fistula flow volume, blood pressure, and other parameters. Results: Mean cerebral rSO2 increased after arteriovenous fistula compression (from 53.6% ± 11.4% to 55.6% ± 10.8%; p = 0.000001; 95% confidence interval = 1.39–2.56). The rSO2 increase was higher in patients with lower rSO2 at baseline (r = −0.46; p = 0.045). Conclusion: A significant rise in cerebral oxygenation was observed following the manual compression of arteriovenous fistula. Therefore, the arteriovenous fistula could have a role in impaired cerebral oxygenation in hemodialysis patients.

Neurocritical monitoring is important in caring for patients in the neurological intensive care unit. Although clinical neurologic examination is standard for neurocritical monitoring, changes found during the examination are often late signs and insufficient to detect and prevent secondary brain injury. Therefore, various neuromonitoring tools have been developed to monitor different physiologic parameters, such as cerebral oxygenation, cerebral blood flow, cerebral pressure, cerebral autoregulation, cerebral electric activity, and cerebral metabolism. In this review, we have discussed current commonly used neurocritical monitoring tools. No single monitor is sufficient and perfect for neurocritical monitoring. Multimodal neurocritical monitoring is the current trend. However, the lack of common formatting standards and uncertainty of improvement in patients' outcomes warrant further studies of multimodal neurocritical monitoring. Nevertheless, multimodal neurocritical monitoring considers individual pathophysiological variations in patients or their injuries and allows clinicians to tailor individualized management decisions.

Objective Previous studies have reported that hyperventilation prolongs seizure length. However, there is no clear consensus in clinical guidelines on how to perform hyperventilation during Electroconvulsive Therapy (ECT). The present study aims to investigate the effects of hyperventilation on seizure length and cerebral oxygenation. Methods Forty patients aged 18-65 and classified as ASA I-II, who would have their first ECT course were included in the study. Ethics committee approval was obtained and all patients' consent was taken. The consecutive patients were randomized into two groups as follows: group H (20 patients; target etCO2: 25-30 mmHg) and group N (20 patients; target etCO2 35-40 mmHg). All patients were ventilated with a facial mask for two minutes and later were ventilated by a laryngeal mask (LMA) for one minute. Vital signs, peripheric oxygen saturation (SpO2), and regional oxygen saturation (rSO2) were measured before general anesthesia induction, on the 3rd minute of ventilation with an LMA (LMA3), on the 1st minute postictal (PI1), on the 5th (PI5), and 10th (PI10) minutes. The motor seizure duration, Richmond sedation-agitation scale, and the time needed to reach Aldrete Score 9 were also recorded. Results There was a significant difference between the groups when they were compared concerning seizure length and recovery time. However, when we compared the rSO2 values that were measured at different times in group H, the difference between the measurements was statistically significant. When rSO2 values in group H were compared in doubles, there were significant differences between measurements between the basal and LMA3, basal and PI1, and the basal and PI5. When Richmond agitation scores in both groups are compared, there were no significant differences between the groups. Conclusion This study found that seizure length was longer, and the recovery time was shorter in group H. There was a contribution of hyperventilation on cerebral oxygenation that was measured on the same person at different times, but cerebral oxygenation was not statistically different from patients that were normoventilated. More studies are required to form a consensus regarding how hyperventilation applies to ECT.

Objective The purpose of this study is to examine the effect of the workstation type on the severity of mental stress by means of measuring prefrontal cortex (PFC) activation using functional near-infrared spectroscopy. Background Workstation type is known to influence worker’s health and performance. Despite the practical implications of ergonomic workstations, limited information is available regarding their impact on brain activity and executive functions. Method Ten healthy participants performed a Montreal imaging stress task (MIST) in ergonomic and nonergonomic workstations to investigate their effects on the severity of the induced mental stress. Results Cortical hemodynamic changes in the PFC were observed during the MIST in both the ergonomic and nonergonomic workstations. However, the ergonomic workstation exhibited improved MIST performance, which was positively correlated with the cortical activation on the right ventrolateral and the left dorsolateral PFC, as well as a marked decrease in salivary alpha‐amylase activity compared with that of the nonergonomic workstation. Further analysis using the NASA Task Load Index revealed a higher weighted workload score in the nonergonomic workstation than that in the ergonomic workstation. Conclusion The findings suggest that ergonomic workstations could significantly improve cognitive functioning and human capabilities at work compared to a nonergonomic workstation. Application Such a study could provide critical information on workstation design and development of mental stress that can be overlooked during traditional workstation design and mental stress assessments.

Introduction: Near-infrared spectroscopy has been used to measure the regional oxygen saturation (rSO2) of the brain, and decreases in cerebral rSO2 have been reported to lead to cognitive impairment in patients undergoing hemodialysis. However, reports about the association between changes in cerebral oxygenation and clinical parameters at hemodialysis initiation, including hemoglobin level, are lacking. Methods: This study included 33 patients at the hemodialysis initiation phase. Cerebral rSO2 was monitored using an INVOS 5100C. Included patients were assessed twice (at hemodialysis initiation and 42.7 ± 20.8 days after the first measurement), and changes in cerebral rSO2 were compared with changes in clinical parameters. Results: Cerebral rSO2 at the second measurement significantly increased compared with that at hemodialysis initiation (57.2 ± 6.8% vs 54.4 ± 8.8%, p Conclusion: Cerebral rSO2 was low in the presence of low hemoglobin levels at hemodialysis initiation and improved in response to hemoglobin increase in addition to changes in serum albumin levels. Attention should be paid to changes in hemoglobin levels even at hemodialysis initiation to prevent the deterioration of cerebral oxygenation, and this might contribute to the maintenance of cognitive function in patients undergoing hemodialysis.

Regional cerebral oxygenation index (rSO2) based on near-infrared spectroscopy (NIRS) is frequently used to detect low venous oxyhemoglobin saturation (ScvO2). We compared the performance of 2 generations of NIRS devices. Clinically obtained, time-matched cerebral rSO2 and ScvO2 values were compared in infants monitored with the FORE-SIGHT (n = 73) or FORE-SIGHT ELITE (n = 47) by linear regression and Bland-Altman analyses. In both devices, cerebral rSO2 correlated poorly with measured ScvO2 (FORE-SIGHT partial correlation 0.50 [95% confidence interval {CI}, 0.40-0.58]; FORE-SIGHT ELITE partial correlation 0.47 [0.39-0.55]) and mean bias was +8 (standard deviation [SD] 13.2) for FORE-SIGHT and +14 (SD 12.5) for FORE-SIGHT ELITE. When ScvO2 was

Introduction: Magnesium sulfate (MgSO4) is frequently administered for maternal and fetal neuroprotection in preeclampsia (PE) and imminent preterm birth, respectively. Objective: To assess whether MgSO4 affects neonatal cerebral oxygenation, blood flow, and cerebral autoregulation (CAR) during the first postnatal days independently from PE. Methods: 148 neonates 0.5) was determined. Linear mixed models were applied. Results: MgSO4 exposure was recorded in 77 neonates. Twenty-nine neonates were born following PE. MgSO4 independently lowered cFTOE (B: –0.026, 95% CI: –0.050 to 0.002, p < 0.05) but did not affect PSV and RI. PE was associated with a lower cFTOE (B: –0.041, 95% CI: –0.067 to –0.015, p < 0.05) and a tendency towards both lower PSV (B: –4.285, 95% CI: –9.067 to 0.497, p < 0.1) and more impaired CAR (B: 4.042, 95% CI: –0.028 to 8.112, p < 0.1), which seemed to be strongly mediated by fetal brain sparing. MgSO4 did not alter CAR. Conclusions: In contrast to fetal brain sparing in PE, MgSO4 seems to lower cFTOE by lowering cerebral oxygen demands in preterm neonates without affecting the cerebrovasculature.

Continuous monitoring of cerebral oxygenation and its application to the management of the severe neurological patient is a challenge for the management of patients with acute critical brain damage. Although several techniques have been described for monitoring brain, brain tissue oxygen monitoring provides relevant information about oxygen levels of brain tissue. However, the development of this technique has been associated with the need to answer not only some technical aspects of it as well as the meaning of the changes of the cerebral oxygenation in the neurocritical patient. The consensus document responds to various questions related to the monitoring of cerebral oxygenation by means of a cerebral oxygen tissue pressure sensor. For this purpose, a list of questions was prepared and a reviewed of the medical literature was made. The quality of the evidence and the degree of recommendation was evaluated using the GRADE methodology.

To date, the clinical use of functional near-infrared spectroscopy (NIRS) to detect cerebral ischemia has been largely limited to surgical settings, where motion artifacts are minimal. In this study, we present novel techniques to address the challenges of using NIRS to monitor ambulatory patients with kidney disease during approximately eight hours of hemodialysis (HD) treatment. People with end-stage kidney disease who require HD are at higher risk for cognitive impairment and dementia than age-matched controls. Recent studies have suggested that HD-related declines in cerebral blood flow might explain some of the adverse outcomes of HD treatment. However, there are currently no established paradigms for monitoring cerebral perfusion in real-time during HD treatment. In this study, we used NIRS to assess cerebral hemodynamic responses among 95 prevalent HD patients during two consecutive HD treatments. We observed substantial signal attenuation in our predominantly Black patient cohort that required probe modifications. We also observed consistent motion artifacts that we addressed by developing a novel NIRS methodology, called the HD cerebral oxygen demand algorithm (HD-CODA), to identify episodes when cerebral oxygen demand might be outpacing supply during HD treatment. We then examined the association between a summary measure of time spent in cerebral deoxygenation, derived using the HD-CODA, and hemodynamic and treatment-related variables. We found that this summary measure was associated with intradialytic mean arterial pressure, heart rate, and volume removal. Future studies should use the HD-CODA to implement studies of real-time NIRS monitoring for incident dialysis patients, over longer time frames, and in other dialysis modalities.

Objective/Introduction: Near-infrared spectroscopy (NIRS) is a non-invasive technique to detect cerebral ischemia by monitoring changes in regional cerebral oxygenation (rSO2) in the frontal lobes. However, there are no studies showing the changes in NIRS values in response to hemodynamic variations during stages of carotid endarterectomy (CEA) procedure and clinical implications of these changes. The aim of this study was to determine if hemodynamic changes affect NIRS values during carotid endarterectomy and if our results may help to provide strategies for hemodynamic management in these patients. Methods: A total of 50 consecutive patients undergoing CEA were prospectively included in the study. NIRS was measured at first minute after clamping of carotid artery, and then systolic blood pressure was increased above 150 mmHg. NIRS values from both hemispheres were recorded simultaneously at certain time points and were analyzed to evaluate the changes at different stages of operation and to assess correlations with hemodynamic parameters. Results: NIRS values on the right and left sides were correlated with systolic (right P

A 71-year-old man undergoing hemodialysis (HD) was admitted to our hospital with congestive heart failure (CHF) and pneumonia. After admission, ultrafiltration with HD was urgently performed because of a lack of respiratory improvement despite the use of noninvasive positive pressure ventilation. During HD, cerebral regional saturation of oxygen (rSO2) was monitored by INVOS 5100c oxygen saturation monitor (Covidien Japan, Japan) to evaluate changes in tissue oxygenation. At HD initiation, cerebral rSO2 was very low at 34% under the fraction of inspiratory oxygen (FiO2) of 0.4. Ultrafiltration was performed at the rate of 0.5 L/h thereafter, cerebral rSO2 gradually improved even as inhaling oxygen concentration decreased. At the end of HD, cerebral rSO2 improved at 40% under a FiO2 of 0.28 as excess body fluid was removed. After pneumonia and CHF improved, he was discharged. Reports of the association between cerebral oxygenation and acute CHF status in patients undergoing HD are limited; therefore, in our experience with this case, cerebral oxygenation deteriorated with the CHF status but was improved by adequate body-fluid management during HD.

In the brain, increased neural activity is correlated with increases of cerebral blood flow and tissue oxygenation. However, how cerebral oxygen dynamics are controlled in the behaving animal remains unclear. We investigated to what extent cerebral oxygenation varies during locomotion. We measured oxygen levels in the cortex of awake, head-fixed mice during locomotion using polarography, spectroscopy, and two-photon phosphorescence lifetime measurements of oxygen sensors. We find that locomotion significantly and globally increases cerebral oxygenation, specifically in areas involved in locomotion, as well as in the frontal cortex and the olfactory bulb. The oxygenation increase persists when neural activity and functional hyperemia are blocked, occurred both in the tissue and in arteries feeding the brain, and is tightly correlated with respiration rate and the phase of respiration cycle. Thus, breathing rate is a key modulator of cerebral oxygenation and should be monitored during hemodynamic imaging, such as in BOLD fMRI., Understanding mechanisms of cerebral oxygen regulation is critical for healthy brain function. Here the authors show that respiration is a key modulator of cerebral oxygenation, which will be helpful in better resolving neurally-generated functional brain imaging signals, such as BOLD fMRI.

Background: The effects of ketofol (a combination of ketamine and propofol) on systemic hemodynamics and requirement of opioids/Propofol have already been studied and published. However, there is paucity in the literature on the effects of ketofol on cerebral oxygenation. This study aims to compare the effects of ketofol (ketamine + propofol [1:5]) with propofol on cerebral oxygenation using jugular venous oxygen saturation (SjVO2), in patients undergoing surgical clipping of intracranial aneurysms. Materials and Methods: A total of 40 World Federation of Neurosurgeons I and II patients were randomized into ketofol (n = 20) and propofol (n = 20) groups. Postinduction, SjVO2 catheter was inserted, and anesthesia was maintained with propofol and fentanyl in the propofol group and ketofol and fentanyl in the ketofol group. Jugular venous oxygen saturation (SjVO2) was obtained at baseline, 1 h and 2 h intraoperatively, and at 6 h after the surgery. Intraoperative hemodynamics and brain relaxation scores were also noted. Results: Entire SjVO2 values in both groups were within the normal limits. Higher SjVO2 values were observed in ketofol group compared to propofol at 1 and 2 h after starting of the drug and at 6 h after surgery (P < 0.05). In propofol group, a significant fall in SjVO2 was recorded at 2 h after beginning the drug as compared to the baseline (P = 0.001). More than 20% fall in mean arterial pressure (MAP) compared to baseline MAP was noted in 75% of patients in propofol group and 15% of patients in ketofol group (P = 0.002). In propofol group, 55% of patients required rescue drug phenylephrine to treat hypotension, whereas only 15% of patients required it in ketofol group (P = 0.02). Fentanyl requirement in ketofol group was less as compared to the propofol group (P = 0.022). Brain relaxation scores were comparable in both the study groups (P = 0.887). Conclusion: Maintenance of anesthesia with ketofol provides better cerebral oxygenation and hemodynamic stability compared to propofol in neurosurgical patients.

Aim: The aim of the current study was to assess whether executive function and prefrontal oxygenation are dependent on fitness level and age in older adults. Methods: Twenty-four healthy males aged between 55 and 69 years old were recruited for this study. They were stratified by age, leading to the creation of two groups: 55–60 years old and 61–69 years old. A median split based on CRF created higher- and lower-fit categories of participants. Cerebral oxygenation was assessed using functional near-infrared spectroscopy (fNIRS) during a computerized Stroop task. Accuracy (% of correct responses) and reaction times (ms) were used as behavioural indicators of cognitive performances. Changes in oxygenated (∆[HbO2]) and deoxygenated (∆[HHb]) hemoglobin were measured to capture neural changes. Repeated measures ANOVAs (CRF × Age × Stroop conditions) were performed to test the null hypothesis of an absence of interaction between CRF, Age and executive performance. Results: We also found an interaction between CRF and age on reaction times (p = .001), in which higher fitness levels were related to faster reaction times in the 61–69 year olds but not in the 55–60 year olds. Regarding ΔHHb, the ANOVA revealed a main effect of CRF in the right PFC (p = .04), in which higher-fit participants had a greater Δ[HHb] than the lower-fit (d = 1.5). We also found fitness by age interaction for Δ[HHb] in the right PFC (p = .04). Conclusion: Our results support the positive association of CRF on cerebral oxygenation and Stroop performance in healthy older males. They indicated that high-fit individuals performed better in the 61–69 year olds group, but not in the 55–60 years old group. We also observed a greater PFC oxygenation change (as measured by Δ[HHb]) in the high-fit individuals.

The neonatal transition involves physiological modifications as a consequence of the complexity of the perinatal period. Various strategies can be used to attain the same level of postnatal cerebral oxygenation, depending on the status of the infant at birth. We evaluated such strategies by recording 20 full-term newborns by near-infrared spectroscopy during the first 10 min of life. The acid–base status at birth revealed two clustered profiles of cerebral oxygenation dynamics. Lower pH and base excess and higher lactate levels were associated with more rapid attainment of the 95% maximal tissue oxygenation index value. These results suggest that metabolic mechanisms drive initial cerebral oxygenation dynamics during this critical period. These results confirm the capacity of newborns to develop multiple strategies to protect the brain.

Background To evaluate the impact of positive end-expiratory pressure (PEEP) on intracranial pressure (ICP) in animals with different respiratory mechanics, baseline ICP and volume status. Methods A total of 50 male adult Bama miniature pigs were involved in four different protocols (n = 20, 12, 12, and 6, respectively). Under the monitoring of ICP, brain tissue oxygen tension and hemodynamical parameters, PEEP was applied in increments of 5 cm H2O from 5 to 25 cm H2O. Measurements were taken in pigs with normal ICP and normovolemia (Series I), or with intracranial hypertension (via inflating intracranial balloon catheter) and normovolemia (Series II), or with intracranial hypertension and hypovolemia (via exsanguination) (Series III). Pigs randomized to the control group received only hydrochloride instillation while the intervention group received additional chest wall strapping. Common carotid arterial blood flow before and after exsanguination at each PEEP level was measured in pigs with intracranial hypertension and chest wall strapping (Series IV). Results ICP was elevated by increased PEEP in both normal ICP and intracranial hypertension conditions in animals with normal blood volume, while resulted in decreased ICP with PEEP increments in animals with hypovolemia. Increasing PEEP resulted in a decrease in brain tissue oxygen tension in both normovolemic and hypovolemic conditions. The impacts of PEEP on hemodynamical parameters, ICP and brain tissue oxygen tension became more evident with increased chest wall elastance. Compare to normovolemic condition, common carotid arterial blood flow was further lowered when PEEP was raised in the condition of hypovolemia. Conclusions The impacts of PEEP on ICP and cerebral oxygenation are determined by both volume status and respiratory mechanics. Potential conditions that may increase chest wall elastance should also be ruled out to avoid the deleterious effects of PEEP.

Background Cerebral and myocardial hypoperfusion occur during hemodialysis in adults. Pediatric patients receiving chronic hemodialysis have fewer cardiovascular risk factors, yet cardiovascular morbidity remains prominent. Methods We conducted a prospective observational study of pediatric patients receiving chronic hemodialysis to investigate whether intermittent hemodialysis is associated with adverse end organ effects in the heart or with cerebral oxygenation (regional O2 saturation [rSO2]). We assessed intradialytic cardiovascular function and rSO2, using noninvasive echocardiography to determine myocardial strain and continuous noninvasive nearinfrared spectroscopy for rSO2. We measured changes in blood volume and central venous oxygen saturation (mCVO2) were pre-, mid-, and post-hemodialysis. Results The study included 15 patients (median age, 12 years; median hemodialysis vintage 13.2 [9, 24] months were included. Patients were asymptomatic. The rSO2 did not change during hemodialysis, whereas mCVO2 decreased significantly, from 73% to 64.8 %. Global longitudinal strain of the myocardium worsened significantly by mid-hemodialysis and persisted post-hemodialysis. The ejection fraction remained normal. Lower systolic blood pressure and faster blood volume change were associated with worsening myocardial strain; only blood volume change was significant in multivariate analysis (β coefficient, -0.3; 95% confidence interval [95% CI], -0.38 to -0.21; P=0.0001). Blood volume change was also associated with a significant decrease in mCVO2 (β coefficient 0.42; 95% CI, 0.07 to 0.76; P=0.001). Access, age, hemodialysis vintage, and ultrafiltration volume were not associated with worsening strain. Conclusion s Unchanged rSO2 suggested that cerebral oxygenation was maintained during hemodialysis. However, despite maintained ejection fraction, intradialytic myocardial strain worsened in pediatric hemodialysis and was associated with blood volume change. The effect of hemodialysis on individual organ perfusion in pediatric versus adult patients receiving hemodialysis might differ.

Introduction: Maternal tobacco smoking during pregnancy is a global health problem leading to an increased risk for fetal and neonatal morbidities. So far, there are no data of the potential impact of maternal smoking during pregnancy on the most vulnerable period after birth – the immediate postnatal transition. The aim of the present study was therefore, to compare cerebral oxygenation during immediate postnatal transition in term neonates with and without prenatal tobacco exposure.Methods: Included in this post-hoc analysis were healthy term neonates, with measurements of cerebral oxygenation (INVOS 5100C) during the first 15 min after birth, and for whom information on maternal smoking behavior during pregnancy was available. Neonates with prenatal tobacco exposure (smoking group) were matched 1:1 according to gestational age (±1 week), birth weight (±100 grams) and hematocrit (±5 %) to neonates without (non-smoking group). Cerebral regional tissue oxygen saturation (crSO2), cerebral fractional tissue oxygen extraction (cFTOE), arterial oxygen saturation (SpO2) and heart rate (HR) within the first 15 min after birth were compared between the two groups.Results: Twelve neonates in the smoking group with a median (IQR) gestational age of 39.1 (38.8–39.3) weeks and a birth weight of 3,155 (2,970–3,472) grams were compared to 12 neonates in the non-smoking group with 39.1 (38.7–39.2) weeks and 3,134 (2,963–3,465) grams. In the smoking group, crSO2 was significantly lower and cFTOE significantly higher until min 5 after birth. HR was significantly higher in the smoking group in min 3 after birth. Beyond this period, there were no significant differences between the two groups.Conclusion: Cerebral oxygenation within the first 5 min after birth was compromised in neonates with prenatal tobacco exposure. This observation suggests a higher risk for cerebral hypoxia immediately after birth due to fetal tobacco exposure.

Significance: Time-resolved near-infrared spectroscopy (t-NIRS) is a new technology; at the moment, data on its precision in preterm infants are rare. Aim: Therefore, the aim of this study was to analyze the precision of t-NIRS-based measurements of the cerebral oxygenation in preterm infants. Approach: In 70 neonates [age: 4.7 ± 2.0 days, sex (f/m): 33/37], cerebral oxygenation ( t - rSO 2 ) was measured with an optode placed over the left frontotemporal lobe on the head, measurement duration was 1 min, and a reapplication was done for four further times (five applications). Results: Overall mean for t - rSO 2 values was 62.2 % ± 4.1 % . We found a within-patient variation for t - rSO 2 of 2.6%. Furthermore, 95% of all observed values were within a range of ± 5 % from the mean when looking on several reapplications and ± 2 % when looking within one application. Most of the variation in t - rSO 2 (60.4%) contributed to differences between patients. The remaining 39.6% of the variation was due to measurement errors and real changes of the measured signal within the neonates. Conclusions: Since within-patient variation of t - rSO 2 measures were below a clinical meaningful threshold of 5%, the measurement can be denoted as precise.

The aim was to investigate the potential differences in muscle (vastus lateralis) and cerebral (prefrontal cortex) oxygenation levels as well as in the number of repetitions and total work output between isokinetic eccentric and concentric exercise at a moderate relative intensity until exhaustion. Ten recreationally active young men underwent two isokinetic exercise sessions either concentric or eccentric, one on each randomly selected leg. The protocols were performed at 60°/s and an intensity corresponding to 60% of the maximal voluntary contraction (MVC) of each contraction type. Concentric torque was significantly lower compared to eccentric torque in both peak values and at values corresponding to 60% of MVC [230 ± 18 Nm vs. 276 ± 19 Nm (P = .014) and 137 ± 12 Nm vs. 168 ± 11 Nm, respectively (P = .010)]. The participants performed 40% more contractions during eccentric compared to concentric exercise [122 ± 15 vs. 78 ± 7, respectively]. No differences were found in the levels of oxyhaemoglobin, deoxyhemoglobin, total haemoglobin and tissue saturation index when eccentric and eccentric exercise regimes were compared (all P > .05). Our results demonstrate that eccentric exercise of moderate intensity leads to greater resistance to fatigue and more work output compared to concentric exercise, despite the comparable muscle and cerebral oxygenation levels.