Cerebral Near-infrared Spectroscopy Values Research Articles

Is near-infrared spectroscopy a promising predictor for early intracranial hemorrhage diagnosis in the Emergency Department?

Intracranial hemorrhage (ICH) is a serious medical condition that can lead to significant morbidity and mortality if not diagnosed and treated promptly. Early detection and treatment are essential for improving the outcome in patients with ICH. Near-infrared spectroscopy (NIRS) is a non-invasive imaging technique that has been used to detect changes in brain tissue oxygenation and blood flow in various conditions. The aim of this study was to investigate the predictive potential of NIRS for early diagnosis of ICH in patients presenting to the Emergency Department (ED) triage with headache. A total of 378 patients were included in the study. According to the final diagnosis of the patients, 4 groups were formed: migraine, tension-cluster headache, intracranial hemorrhage and intracranial mass, and control group. Cerebral NIRS values "rSO2" were measured at the first professional medical contact with the patient. The right and left rSO2 (RrSO2, LrSO2) were significantly lower and the rSO2 difference was significantly higher in the intracranial hemorrhage group compared to all other patient groups (P<0.001). The cut-off values determined in the receiver operating characteristics (ROC) analysis were RrSO2 ≤67, LrSO2 ≤67, and ΔrSO2 ≥9. This study found that a difference of more than 9 in cerebral right-left NIRS values can be a non-invasive, easy-to-administer, rapid, and reliable diagnostic test for early detection of intracranial bleeding. NIRS holds promise as an objective method in ED triage for patients with intracranial hemorrhage. However, further research is needed to fully understand the potential benefits and limitations of this method.

Combined cerebral and somatic near-infrared spectroscopy oximetry monitoring during liver surgery: an observational and non-interventional study.

BackgroundCerebral oximetry using near-infrared spectroscopy (NIRS) is used for monitoring cerebral oxygen saturation during cardiac surgery and is correlated with clinical outcomes. Our goal was to explore cerebral and somatic NIRS in liver resections as a predictor of post-operative complications.MethodsProspective observational and non-interventional study from a tertiary care university hospital including adult patients undergoing liver resection monitored using NIRS at four sites before and during surgery. Those sites were: frontotemporal left and right zones, right thigh, and right arm. Anesthesiologists and surgeons were blinded to oximetry values. Correlations were assessed between baseline oximetry values and cerebro-somatic desaturation load (threshold of 80% from baseline) values with peri-operative events and complications.ResultsNinety patients were distributed equally among gender with a mean age of 59.7 ± 13.1 years. Lower baseline cerebral and/or somatic values were associated with increased risk of delirium, respiratory failure, surgical and renal complications, blood transfusions, and length of stay in the intensive care unit and in the hospital (P < 0.05). The severity of somatic desaturation below 80% was the only parameter associated with blood losses (P = 0.030) and length of hospital stay (P = 0.047).ConclusionsCerebral and somatic desaturation does occur in liver resection and can be used simultaneously during liver surgery. Both baseline cerebral and somatic NIRS values are correlated with complications and outcomes. However, thigh desaturation appears more sensitive than cerebral NIRS values in predicting some of these complications.

Comparison of bilateral cerebral and somatic tissue oxygenation with near-infrared spectroscopy in cyanotic and acyanotic pediatric patients receiving cardiac surgery.

IntroductionCompromise of tissue oxygenation during surgery is associated with increased mortality and morbidity in the postoperative period in patients with congenital cardiac disorders. It may be monitored with near-infrared spectroscopy (NIRS). We aimed to evaluate the tissue oxygenation and factors which may affect it by bilateral cerebral and somatic NIRS levels during cardiopulmonary bypass and to compare the NIRS values of cyanotic and acyanotic patient groups.Material and methodsTwo groups of patients with cyanotic and acyanotic congenital heart diseases were included in the study. Each group consisted of 15 patients between 0 and 5 years of age. All data were collected following anesthesia induction (T1), the 10th (T2) and 30th min (T3) of cardiopulmonary bypass (CPB), every 30 min during CPB (T4, T5, T6) and 1 h after (TS). Bilateral and somatic NIRS, blood gases, mean arterial pressure, and temperatures were recorded.ResultsLeft and right somatic NIRS values in groups at all measurements did not differ significantly. Left and right cerebral NIRS values at T2 and T3 in cyanotic patients were significantly higher than in acyanotic patients. Mean arterial pressure and lactate levels at T1 and T3 measurements were responsible for left cerebral NIRS changes and mean arterial pressure on right cerebral NIRS values.ConclusionsMonitorization of tissue perfusion has critical importance during CPB of patients with congenital heart defects. Oxygenation may easily and reliably be measured with NIRS. Cerebral and somatic NIRS are more pronounced in cyanotic patients and cerebral NIRS is strongly associated with mean arterial pressure and circulating lactate levels.

Multisite Near Infrared Spectroscopy During Cardiopulmonary Bypass in Pediatric Patients

Multisite near infrared spectroscopy (NIRS) monitoring during pediatric cardiopulmonary bypass (CPB) has not been extensively validated. Although it might be rational to explore regional tissue saturation at different body sites (namely brain, kidney, upper body, lower body), conflicting results are currently provided by experience in children. The aim of our study was to evaluate absolute values of multisite NIRS saturation during CPB in a cohort of infants undergoing pediatric cardiac surgery to describe average differences between cerebral, renal, upper body (arm), and lower body (thigh) regional saturation. Furthermore, the correlation between cerebral NIRS and cardiac index (CI) at CPB weaning was evaluated. Twenty-five infants were enrolled: their median weight, age, and body surface area were 3.9 (3.3-6) kg, 111 (47-203) days, and 0.24 (0.22-0.33) m(2) , respectively. Median Aristotle score was 8 (6-10), and vasoactive inotropic score at CPB weaning was 16 (14-25). A total of 17 430 data points were recorded by each sensor: two-way ANOVA showed that time (P < 0.0001) and site (P = 0.0001) significantly affected variations of NIRS values: however, if cerebral NIRS values are excluded, sensor site is no more significant (P = 0.184 in the no circulatory arrest [noCA] group and P = 0.42 in the circulatory arrest [CA] group). Analysis of NIRS saturation changes over time showed that, at all sites, average NIRS values increased after CPB start, even if the increase of cerebral saturation was less intense than other sites (P < 0.0001). Detailed analysis of interaction between site of NIRS measurement and time point showed that cerebral NIRS (ranging from 65 to 75%) was always significantly lower than that of other channels (P < 0.0001) that tended to be in the range of oversaturation (80-90%), especially during the CPB phase. Average cerebral NIRS values of patients who did not undergo circulatory arrest (CA) during CPB, 10 min after CPB weaning, were associated with average CI values with a significant correlation (r = 0.7, P = 0.003). In conclusion, during CPB, cerebral NIRS values are expected to remain constantly lower than somatic sensors, which instead tend to show similar elevated saturations, regardless of their position. Based on these results, positioning of noncerebral NIRS sensors during CPB without CA may be questioned.

Initial Single-Center Experience With Levosimendan Infusion for Perioperative Management of Univentricular Heart With Ductal-Dependent Systemic Circulation

The aim of this study was to evaluate the safety and the efficacy of levosimendan, a novel calcium sensitizer agent, on postoperative hemodynamic and metabolic parameters of neonates affected by single ventricle anatomy. Twenty consecutive neonates scheduled for the Norwood procedure with Blalock Taussig shunt were prospectively enrolled. All patients received an infusion of levosimendan at 0.1 μg/kg/min commencing 24 hours before surgery, and the infusion was continued for 48 hours after surgery. No side effects (intolerance to the drug, hypotension, arrhythmias) were shown. A median inotropic score (IS) of 37 was necessary to maintain a mean arterial pressure between 45 and 50 mm Hg at intensive care unit (ICU) admission: IS was significantly reduced after 72 hours (P < .05). Brain natriuretic peptide values decreased significantly from 1210 to 459 pg/mL in 72 hours (P < .05). Median SvO2 increased significantly from 38% to 59% during the evaluated period (P < .05). Cerebral near-infrared spectroscopy values were close to 40% at ICU admission with a significant stable increase to 50% after 12 hours (P < .05). Median lactate level was 13 mmol/L at ICU admission but showed a trend to a rapid and significant decrease after 12 hours (P < .05). Median urine output was surprisingly elevated, always remaining between 5.2 and 6.2 mL/kg/h throughout the postoperative period. Survival rate was 85% at 30 days (17/20 patients) and 75% (15/20) at hospital discharge. Levosimendan infusion in a cohort of neonates with univentricular anatomy was safe and potentially beneficial on postoperative hemodynamic and metabolic parameters.

Measurements of Optical Pathlength Using Phase-Resolved Spectroscopy in Patients Undergoing Cardiopulmonary Bypass

Near infrared spectroscopy (NIRS) has been used during cardiac surgery to monitor cerebral oxygenation although the validity of this technique has yet to be established. Although optical pathlength included in the algorithm for calculating NIRS values is supposed to be constant, recent evidence has suggested that optical pathlength could be affected by acute hemodilution in animals. We conducted the present study to investigate whether optical pathlength changes during cardiopulmonary bypass (CPB), and whether these changes affect NIRS values in adult patients. Nine patients undergoing elective cardiac surgery with CPB were enrolled in this study. Optical pathlength and cerebral NIRS values (oxyhemoglobin [DeltaO(2)Hb] and tissue oxygen index) were measured by phase-resolved spectroscopy and NIRO 100, respectively. Optical pathlength, hemoglobin concentration, and NIRS values were measured at the following points: 1) after the induction of anesthesia, 2) 10 min after the start of CPB, 3) 60 min after the start of CPB, and 4) 1 h after CPB. The associations between optical pathlength and other variables were analyzed by Pearson correlation coefficients and multiple regression analysis. Optical pathlength significantly increased starting at 27.7-30.8 cm at 10 min, and 31.3 cm at 60 min after the start of CPB (P < 0.0001). Hemoglobin concentrations significantly decreased (from 11.2 to 7.1 g/dL at 10 min and 7.7 g/dL at 60 min P < 0.0001). There was a significant correlation (r = 0.55, P < 0.001) between percentage changes in pathlength and hemoglobin concentration. Multiple regression analysis showed that optical pathlength was a significant determinant of DeltaO2Hb. The results indicate that optical pathlength can change during CPB and its changes may affect DeltaO2Hb.