Near-infrared Spectroscopy Cerebral Oximetry Research Articles

Noninvasive tracking of mixed venous oxygen saturation via near-infrared spectroscopy cerebral oximetry: a retrospective observational study

Although previous studies have shown correlation between regional cerebral oxygen saturation (rScO2) and mixed venous oxygen saturation (SvO2), there is a lack of pragmatic information on the clinical applicability of these findings, such as tracking ability. We retrospectively analyzed continuous intraoperative recordings of rScO2 and SvO2 obtained from a pulmonary artery catheter and either of two near-infrared spectroscopy (NIRS) devices (INVOS 5100C, Medtronic; O3, Masimo) during off-pump cardiopulmonary bypass (OPCAB) surgery in adult patients. The ability of rScO2 to track SvO2 was quantitatively evaluated with 5 min interval changes transformed into relative values. The analysis included 176 h of data acquired from 48 subjects (26 and 22 subjects for INVOS and O3 dataset, respectively). The area under ROC of the left-rScO2 for detecting change of SvO2 ≥ 10% in INVOS and O3 datasets were 0.919 (95% CI 0.903–0.936) and 0.852 (95% CI 0.818–0.885). The concordance rates between the interval changes of left-rScO2 and SvO2 in INVOS and O3 datasets were 90.6% and 91.9% with 10% exclusion zone. rScO2 can serve as a noninvasive tool for detecting changes in SvO2 levels, a critical hemodynamic measurement.

Out-of-hospital cardiac arrest treated with prehospital double sequential external defibrillation during eCPR in refractory VF — a case report

BackgroundDouble sequential external defibrillation (DSED) has demonstrated increased survival with good neurological outcome in a recent randomized controlled trial. DSED has not been studied in patients with extracorporeal cardiopulmonary resuscitation (eCPR).CaseWe present the first case of prehospital eCPR with ongoing refractory ventricular fibrillation (VF), terminated by DSED. After six shocks, return of spontaneous circulation was initially achieved; however, the patient went into recurrent VF. ECPR was performed prehospital, with VF still refractory after three more shocks. DSED successfully terminated VF and showed a further increase in etCO2 and near-infrared spectroscopy cerebral oximetry values.ConclusionDSED can be a sufficient strategy for patients in refractory VF while on eCPR and should be evaluated in further studies.

Correlation of Near-Infrared Spectroscopy Oximetry and Corresponding Venous Oxygen Saturations in Children with Congenital Heart Disease.

Invasive and non-invasive monitoring allow for early detection of hemodynamic compromise, facilitating timely intervention and avoidance of further decline. While venous oximetry is useful for assessing the adequacy of systemic oxygen delivery (DO2), it is most often intermittent, invasive, and costly. Near-infrared spectroscopy (NIRS) oximetry allows for the non-invasive estimation of the adequacy of DO2. We assessed the correlation between cerebral NIRS oximetry and superior vena cava (SVC) and jugular venous (JV) oxygen saturations and between renal NIRS oximetry and inferior vena cava (IVC) oxygen saturations. Systematic review of the literature was conducted to identify studies with data regarding near-infrared spectroscopy and venous saturation. The PubMed, EMBASE, Medline, and Cochrane databases were queried using the following terms in isolation and various combinations: "congenital heart disease," "near infrared spectroscopy," "venous saturation," and "pediatric." Pediatric studies in which simultaneous NIRS oximetry and corresponding venous oxygen saturations were simultaneously collected after cardiac surgery or catheterization were identified. Data were pooled from these studies to analyze the correlation between NIRS oximetry and the corresponding venous oxygen saturations. A total of 16 studies with 613 patients were included in the final analyses. Data were present to compare cerebral and renal NIRS oximetry with corresponding venous oxygen saturation. Cerebral NIRS and SVC and JV oxygen saturations and renal NIRS and IVC oxygen saturations demonstrated strong degrees of correlation (r-value 0.70 for each). However, cerebral NIRS and IVC oxygen saturation had a week degree of correlation (r-value of 0.38). Pooled analyses demonstrate that cerebral NIRS oximetry correlates strongly with SVC or JV oxygen saturation while renal NIRS oximetry correlates strongly with IVC oxygen saturations. A weak correlation was noted between cerebral NIRS oximetry and IVC oxygen saturations.

Efficacy of near-infrared spectroscopy cerebral oximetry on detection of critical cerebral perfusion during carotid endarterectomy under regional anesthesia.

Background: Patients undergoing carotid endarterectomy (CEA) may suffer from cerebral hypoperfusion during the carotid cross-clamping. Near-infrared spectroscopy cerebral oximetry (NIRS) is a non-invasive method of regional cerebral oxygen saturation measurement reflecting changes in cerebral blood flow during CEA. The main goal of the study was to evaluate the accuracy of the NIRS in detecting cerebral hypoperfusion during CEA under regional anesthesia (RA) and compare it with awake neurological testing. Patients and methods: A prospective observational study of 28 patients that underwent CEA in RA and manifested neurologic deficits, and 28 consecutive controls from a tertiary and referral center, was performed. All patients were monitored with NIRS cerebral oximetry and awake testing as the control technique. Subsequently, operating characteristic curve and Cohen's kappa coefficient were determined to evaluate the reliability of the monitoring test. Results: NIRS presented a sensitivity of 27.3% and a specificity of 89.3% in comparison to awake testing. Receiver operating characteristic (ROC) curve analysis demonstrated that a decrease of at least 20% in cerebral oxygen saturation is the best threshold to infer cerebral hypoperfusion. However, the respective area under the curve (AUROC) was 0.606 (95% CI: 0.456-0.756, P=0.178) with a calculated Cohen's kappa of 0.179, P=0.093. Regarding 30-days outcomes, only awake testing has shown significant associations with stroke and postoperative complications (P=0.043 and P=0.05), which were higher in patients with post-clamping neurologic deficits. Conclusions: NIRS demonstrated a reduced discriminative capacity for critical cerebral hypoperfusion, and does not seem to add substantial clinical benefits to the awake test.

Regional Cerebral Oximetry as an Indicator of Acute Brain Injury in Adults Undergoing Veno-Arterial Extracorporeal Membrane Oxygenation-A Prospective Pilot Study.

Background: Regional cerebral oxygen saturation (rScO2) measured by near-infrared spectroscopy (NIRS) can be used to monitor brain oxygenation in extracorporeal membrane oxygenation (ECMO). ECMO patients that develop acute brain injuries (ABIs) are observed to have worse outcomes. We evaluated the association between rScO2 and ABI in venoarterial (VA) ECMO patients.Methods: We retrospectively reviewed prospectively-collected NIRS data from patients undergoing VA ECMO from April 2016 to October 2016. Baseline demographics, ECMO and clinical characteristics, cerebral oximetry data, neuroradiographic images, and functional outcomes were reviewed for each patient. rScO2 desaturations were defined as a >25% decline from baseline or an absolute value < 40% and quantified by frequency, duration, and area under the curve per hour of NIRS monitoring (AUC rate, rScO2*min/h). The primary outcome was ABI, defined as abnormalities noted on brain computerized tomography (CT) or magnetic resonance imaging (MRI) obtained during or after ECMO therapy.Results: Eighteen of Twenty patients who underwent NIRS monitoring while on VA ECMO were included in analysis. Eleven patients (61%) experienced rScO2 desaturations. Patients with desaturations were more frequently female (73 vs. 14%, p = 0.05), had acute liver dysfunction (64 vs. 14%, p = 0.05), and higher peak total bilirubin (5.2 mg/dL vs. 1.4 mg/dL, p = 0.02). Six (33%) patients exhibited ABI, and had lower pre-ECMO Glasgow Coma Scale (GCS) scores (5 vs. 10, p = 0.03) and higher peak total bilirubin levels (7.3 vs. 1.4, p = 0.009). All ABI patients experienced rScO2 desaturation while 42% of patients without ABI experienced desaturation (p = 0.04). ABI patients had higher AUC rates than non-ABI patients (right hemisphere: 5.7 vs. 0, p = 0.01, left hemisphere: 119 vs. 0, p = 0.06), more desaturation events (13 vs. 0, p = 0.05), longer desaturation duration (2:33 vs. 0, p = 0.002), and more severe desaturation events with rScO2 < 40 (9 vs. 0, p = 0.05). Patients with ABI had lower GCS scores (post-ECMO initiation) before care withdrawal or discharge than those without ABI (10 vs. 15, p = 0.02).Conclusions: The presence and burden of cerebral desaturations noted on NIRS cerebral oximetry are associated with secondary neurologic injury in adults undergoing VA ECMO.

Near-infrared spectroscopy cerebral oximetry as a predictor of neurological intolerance during carotid artery stenting with proximal protection

Carotid artery stenting (CAS) with proximal protection can expose occlusion intolerance (OI) due to ipsilateral cerebral hemisphere hypoperfusion. Near-infrared spectroscopy (NIRS) cerebral oximetry can monitor regional cerebral oxygenation (rSO2) in the frontal lobes, and is used during CAS to predict cerebral blood flow insufficiency. The aim of this study was to evaluate rSO2 as a predictor of OI during CAS. We retrospectively examined 146 patients who underwent CAS with proximal protection. An INVOS® NIRS oximeter was used for rSO2 measurement, which was compared with stump pressure (SP) measured by a guiding catheter during occlusion of the common carotid artery (CCA) and external carotid artery. For the lesion with OI, distal filter protection was combined with proximal protection if possible, and CCA was intermittently occluded during the procedure. Twenty-seven patients (18%) developed OI. The relative decrease in NIRS oximeter saturation (ΔrSO2) on the ipsilateral side was significantly lower in the OI group than in the tolerance group (14 ± 5.1% vs. 3.4 ± 3.5, p < 0.001). Using ΔrSO2 of 8% as the cutoff value for predicting OI, sensitivity was 92% and specificity was 89%. SP was significantly lower in the OI group than in the tolerance group (22 ± 13 mmHg vs. 40 ± 22 mmHg, p < 0.001). Using SP ≤25 mmHg as the cutoff value for predicting OI, sensitivity was 78% and specificity was 77%. ΔrSO2 was more reliable than SP for predicting OI. Distal filter protection should be combined with proximal protection to prevent prolonged neurological symptoms due to OI.

O-221 Safeboosc – A Phase Ii Randomised Clinical Trial On Cerebral Near-infrared Spectroscopy Oximetry In Extremely Preterm Infants: Abstract O-221 Table 1

Background and aims Extremely preterm infants have a high risk of moderate to severe long-term neurodevelopmental impairment. Hypoxic or hyperoxic brain injury may be a contributing factor. The SafeBoosC trial investigated if it is possible to stabilise the cerebral oxygenation of extremely preterm infants. Methods This was a phase II randomised, single blinded, clinical trial. Infants born before 28 weeks of gestation were eligible. Within 3 h of birth, infants were randomly assigned to either cerebral near infrared spectroscopy (NIRS) oxygenation monitoring in combination with a treatment guideline (experimental) or blinded NIRS monitoring with standard care (control). The primary outcome was the area under the curve of the time series of absolute deviation from the cerebral oxygenation target range of 55% to 85%, expressed in % hours (the burden of hypoxia and hyperoxia). We hypothesised that there would be more than 50% reduction in this burden in the experimental group. Results 166 infants with a median postmenstrual age of 26.4 weeks were enrolled (Table 1). Two infants were withdrawn. 86 infants randomised to the NIRS group had a median burden of hypoxia and hyperoxia of 36.1% hours (IQR 9.2 to 79.5) compared with 81.3% hours (IQR 38.5 to 181.3) in the control group (Figure 1), a reduction of 58% (95% CI 35% to 73%) (p= Conclusions Cerebral oxygenation was stabilised using a treatment guideline in combination with cerebral NIRS monitoring in extremely preterm infants.

The management of extremely preterm infants

Extreme prematurity is associated with an increased risk of mortality, morbidities and long-term neurodevelopmental impairment. Optimizing prenatal, perinatal and postnatal care is essential to improve long-term outcome of extremely preterm babies. Intrauterine growth restriction (IUGR) has been associated with a poorer neurological outcome and prenatal care should aim to an optimal balance between minimizing fetal injury or death versus the risks of iatrogenic preterm delivery. In the clinical phase of IUGR, hemodynamic adaptation occurs with blood flow redistribution preferentially to the brain, the so-called “brain sparing effect”. However, controversy remains as to whether “brain-sparing” indicates a higher risk of brain injury or is a protective mechanism [1]. The mechanisms underlying fetal growth restriction, also determine a limitation of lung growth and maturation, thus making the lung more vulnerable to postnatal damage and increasing the risk of bronchopulmonary dysplasia (BPD), the most significant respiratory complication of prematurity [2]. Current evidence suggests that the risk of BPD may be partially related to other antenatal factors as choriamniositis (CA), which is a leading cause of very preterm delivery. Whereas CA promotes lung maturation, mediated by prenatal inflammation mechanisms, and thereby decreases the severity of respiratory distress syndrome, it also seems to increase the risk of BPD, making the lung more susceptible to subsequent postnatal insults [3]. Neonatal resuscitation and postnatal management during the first minutes of life also play an important role in determining early and long-term outcome of VLBW. A multifaced intervention in respiratory care in the delivery room immediately after birth, including a sustained lung inflation procedure and a non invasive starting ventilation, seems to be effective in improving respiratory outcome [4]. Delayed umbilical cord clamping has received increasing attention in the management at birth of preterm infants as it seems to be beneficial and safe, being associated with less delivery room resuscitation interventions, improved haemodynamic stability and decreased rates of intraventricular hemorrhage [5]. Different pathophysiological mechanisms are involved in injuring the premature brain, in particular infection-inflammation, pre- and/or postnatal malnutrition, and abnormalities in systemic and cerebral haemodynamics and oxygen supply. Preventative measures are key to reduce neurological morbidities in an extremely preterm population and research projects are focusing on the possibility to stabilize cerebral oxygenation in the first days of life through the application of cerebral near-infrared spectroscopy oximetry and implementation of clinical treatment guidelines in order to reduce the risk of brain damage [6].

Noninvasive assessment of hemodynamic variables using near-infrared spectroscopy in patients experiencing cardiogenic shock and individuals undergoing venoarterial extracorporeal membrane oxygenation

PurposeThe relationship between near-infrared spectroscopy cerebral oximetry (CrSO2), peripheral oximetry (PrSO2) and hemodynamic variables is not fully understood. MethodsThe relationship between CrSO2/PrSO2 and cardiac index (CI), systemic vascular resistance index (SVRI) and mean arterial pressure (MAP) in patients experiencing cardiogenic shock and those undergoing venoarterial extracorporeal membrane oxygenation (ECMO) was retrospectively analyzed; in patients on ECMO, total circulatory index (TCI) was calculated from the sum of CI and extracorporeal blood flow index. ResultsIn patients experiencing cardiogenic shock (n = 10), significant correlations between PrSO2 values and CI (Spearman r = 0.81; P < .0001), SVRI (r = −0.45; P < .0001), and MAP (r = 0.58; P < .0001) were found. Significant correlations between CrSO2 and CI (r = 0.55; P < .0001) and SVRI (r = −0.47; P < .0001), but not MAP, were observed. Linear regression analysis revealed that CI could be calculated using the following equation: CI = PrSO2/24.0.In patients on VA ECMO (n = 12), significant correlations were found between PrSO2 and TCI (r = 0.68; P < .0001), SVRI (r = −0.47; P < .0001), and MAP (r = 0.27; P = .025). Significant correlations were also found between CrSO2 and TCI (r = 0.68; P < .0001) and SVRI (r = −0.51; P < .0001), but not MAP. ConclusionsResults of the present study suggest that CrSO2 and PrSO2 in particular can be used for noninvasive estimation and monitoring of global circulatory status in patients experiencing cardiogenic shock and individuals undergoing ECMO.

Impact of Extracranial Contamination on Regional Cerebral Oxygen Saturation

Cerebral oximetry is a noninvasive technology using near-infrared spectroscopy (NIRS) to estimate regional cerebral oxygen saturation. Although NIRS cerebral oximetry is being increasingly used in many clinical settings, interdevice technologic differences suggest potential variation in the ability to accurately acquire brain oxygenation signals. The primary objective of this study was to determine if NIRS-derived regional cerebral oxygen saturation measurements accurately account for oxygen saturation contamination from extracranial tissue. Twelve healthy volunteers had each of three NIRS devices (FORE-SIGHT [CAS Medical Systems Inc; Brandford, CT], INVOS 5100C-PB [Covidien; Boulder, CO], and EQUANOX Classic 7600 [Nonin Medical Inc; Plymouth, MN]) randomly applied to the forehead. After this, a circumferential pneumatic head cuff was positioned such that when inflated, hypoxia-ischemia would be produced in the extracranial scalp tissue beneath the NIRS cerebral oximeters. Comparisons among the three devices were made of the NIRS measurements before and following hypoxia-ischemia produced in the scalp tissue with inflation of the head cuff. The induction of extracranial hypoxia-ischemia resulted in a significant reduction in regional cerebral oxygen saturation measurements in all three NIRS devices studied. At 5 min postinflation of the pneumatic head cuff, the INVOS demonstrated a 16.6 ± 9.6% (mean ± SD) decrease from its baseline (P = 0.0001), the FORE-SIGHT an 11.8 ± 5.3% decrease from its baseline (P < 0.0001), and the EQUANOX a 6.8 ± 6.0% reduction from baseline (P = 0.0025). Extracranial contamination appears to significantly affect NIRS measurements of cerebral oxygen saturation. Although the clinical implications of these apparent inaccuracies require further study, they suggest that the oxygen saturation measurements provided by cerebral oximetry do not solely reflect that of the brain alone.