Brain multimodality monitoring in patients suffering from acute aneurysmal subarachnoid hemorrhage: clinical value and complications.

Brain multimodality monitoring measuring brain tissue oxygen pressure, cerebral blood flow, and cerebral near-infrared spectroscopy may help optimize the neurocritical care of patients with aneurysmal subarachnoid hemorrhage and delayed cerebral ischemia. We retrospectively looked for complications associated with the placement of the probes and checked the reliability of the different tools used for multimodality monitoring. In addition, we screened for therapeutic measures derived in cases of pathological values in multimodality monitoring in 26 patients with acute aneurysmal subarachnoid hemorrhage. Computed tomography scans showed minor hemorrhage along with the probes in 12 patients (46.2%). Missing transmission of values was observed in 34.1% of the intended time of measurement for cerebral blood flow probes and 15.5% and 16.2%, respectively, for the two kinds of probes measuring brain tissue oxygen pressure. We identified 744 cumulative alarming values transmitted from multimodality monitoring. The most frequent intervention was modifying minute ventilation (29%). Less frequent interventions were escalating the norepinephrine dosage (19.9%), elevating cerebral perfusion pressure (14.9%) or inspiratory fraction of inspired oxygen (7.5%), transfusing red blood cell concentrates (1.2%), initiating further diagnostics (2.3%) and neurosurgical interventions (1.9%). As well, 355 cases of pathological values had no therapeutic consequence. The reliability of the measuring tools for multimodality monitoring regarding a continuous transmission of values must be improved, particularly for cerebral blood flow monitoring. The overall high rate of missing therapeutic responses to pathological values derived from multimodality monitoring in patients with aneurysmal subarachnoid hemorrhage underlines the need for structured tiered algorithms. In addition, such algorithms are the basic requirement for prospective multicenter studies, which are urgently needed to evaluate the role of multimodality monitoring in treating these patients.

No neurodevelopmental benefit of cerebral oximetry in the first randomised trial (SafeBoosC II) in preterm infants during the first days of life.

AIM: Cerebral hypoxia has been associated with neurodevelopmental impairment. We studied whether reducing cerebral hypoxia in extremely preterm infants during the first 72 hours of life affected neurological outcomes at two years of corrected age. METHODS: In 2012-2013, the phase II randomised Safeguarding the Brains of our smallest Children trial compared visible cerebral near-infrared spectroscopy (NIRS) monitoring in an intervention group and blinded NIRS monitoring in a control group. Cerebral hypoxia was significantly reduced in the intervention group. We followed up 115 survivors from eight European centres at two years of corrected age, by conducting a medical examination and assessing their neurodevelopment with the Bayley Scales of Infant and Toddler Development, Second or Third Edition, and the parental Ages and Stages Questionnaire (ASQ). RESULTS: There were no differences between the intervention (n = 65) and control (n = 50) groups with regard to the mean mental developmental index (89.6 ± 19.5 versus 88.4 ± 14.7, p = 0.77), ASQ score (215 ± 58 versus 213 ± 58, p = 0.88) and the number of children with moderate-to-severe neurodevelopmental impairment (10 versus six, p = 0.58). CONCLUSION: Cerebral NIRS monitoring was not associated with long-term benefits or harm with regard to neurodevelopmental outcome at two years of corrected age.

Artifact Management for Cerebral Near-Infrared Spectroscopy Signals: A Systematic Scoping Review.

Artifacts induced during patient monitoring are a main limitation for near-infrared spectroscopy (NIRS) as a non-invasive method of cerebral hemodynamic monitoring. There currently does not exist a robust "gold-standard" method for artifact management for these signals. The objective of this review is to comprehensively examine the literature on existing artifact management methods for cerebral NIRS signals recorded in animals and humans. A search of five databases was conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. The search yielded 806 unique results. There were 19 articles from these results that were included in this review based on the inclusion/exclusion criteria. There were an additional 36 articles identified in the references of select articles that were also included. The methods outlined in these articles were grouped under two major categories: (1) motion and other disconnection artifact removal methods; (2) data quality improvement and physiological/other noise artifact filtering methods. These were sub-categorized by method type. It proved difficult to quantitatively compare the methods due to the heterogeneity of the effectiveness metrics and definitions of artifacts. The limitations evident in the existing literature justify the need for more comprehensive comparisons of artifact management. This review provides insights into the available methods for artifact management in cerebral NIRS and justification for a homogenous method to quantify the effectiveness of artifact management methods. This builds upon the work of two existing reviews that have been conducted on this topic; however, the scope is extended to all artifact types and all NIRS recording types. Future work by our lab in cerebral NIRS artifact management will lie in a layered artifact management method that will employ different techniques covered in this review (including dynamic thresholding, autoregressive-based methods, and wavelet-based methods) amongst others to remove varying artifact types.

Intratracheal cobinamide (vitamin B12 analog) administration increases survivability in rabbits exposed to a lethal dose of inhaled hydrogen sulfide.

BACKGROUND: Hydrogen sulfide is a highly toxic, flammable, and colorless gas. Hydrogen sulfide has been identified as a potential terrorist chemical threat agent in mass-casualty events. Our previous studies showed that cobinamide, a vitamin B12 analog, effectively reverses the toxicity from hydrogen sulfide poisoning. In this study, we investigate the effectiveness of intratracheally administered cobinamide in treating a lethal dose hydrogen sulfide gas inhalation and compare its performance to saline control administration. METHODS: A total of 53 pathogen-free New Zealand White rabbits were used for this study. Four groups were compared: (i) received no saline solution or drug intratracheally (n = 15), (ii) slow drip saline intratracheally (n = 15), (iii) fast drip saline intratracheally (n = 15), and (iv) slow drip cobinamide intratracheally (n = 8). Blood pressure was continuously monitored, and deoxy- and oxyhemoglobin concentration changes were monitored in real-time in vivo using continuous wave near-infrared spectroscopy. RESULTS: The mean (± standard deviation) weight for all animals (n = 53) was 3.87 ± 0.10 kg. The survival rates of the slow cobinamide and the fast saline groups were 75 percent and 60 percent, respectively, while the survival rates in the slow saline and control groups were 26.7 percent and 20 percent, respectively. A log-rank (Mantel-Cox) test showed that survival in fast saline and slow cobinamide groups were significantly greater than those of no saline control and slow saline groups (P < 0.05). The slow and no saline control groups were not significantly different (P = 0.59). The slow cobinamide group did significantly better than the slow saline group (P = 0.021). DISCUSSION: The ability to use intratracheal cobinamide as an antidote to hydrogen sulfide poisoning is a novel approach to mass-casualty care. The major limitations of this study are that it was conducted in a single species at a single inhaled hydrogen sulfide concentration. Repeated investigations in other species and at varying levels of hydrogen sulfide exposure will be needed before any definitive recommendations can be made. CONCLUSIONS: We demonstrated that intratracheal cobinamide and fast saline drip improved survival for hydrogen sulfide gas inhalation in rabbit models. Although further study is required, our results suggest that intratracheal administration of cobinamide and fast saline may be useful in hydrogen sulfide mass-casualty events.

Hybrid Repair with Reversed Sequence Supra-aortic Debranching in Ruptured Arch Aneurysm.

Aortic arch pathology in a high-risk patient in whom the resternotomy approach is unfeasible due to treated mediastinitis after ascending aortic replacement presents a unique challenge for hybrid arch repair (HAR) because of the need for supra-aortic debranching from unusual inflow sites other than the ascending aorta. This report describes a "reversed sequence" extra-anatomical supra-aortic debranching procedure as a salvage technique performed to enable HAR. An 83-year-old woman with a history of ascending aortic replacement for type A aortic dissection, mediastinitis complicated by sternal osteomyelitis, and a chest wall reconstructed with a rectus abdominis myocutaneous flap presented with chest pain because of a contained dissecting arch aneurysm rupture. The patient underwent supra-aortic debranching from the bilateral common femoral arteries and thoracic endovascular aortic repair to the ascending aorta under cerebral near-infrared spectroscopy (NIRS) monitoring. Completion imaging by angiography demonstrated successful exclusion of the ruptured aneurysm. The regional cerebral oxygen saturation level, monitored by NIRS, did not change markedly during surgery. The patient was neurologically intact with adequate cerebral blood flow assessed postoperatively by 123 I-IMP single photon emission computed tomography. Total debranching of the supra-aortic vessels from the common femoral artery for inflow is feasible and provides adequate cerebral perfusion. This procedure may offer an alternative treatment option in patients with complex conditions involving aortic arch pathology.

Factors associated with delirium after cardiac surgery: A prospective cohort study.

Background: Delirium is a frequent complication after cardiac surgery and is associated with a higher incidence of morbidity and mortality and a prolonged hospital stay. However, knowledge of the variables involved in its occurrence is still limited; therefore, in this study, we evaluated the perioperative risk factors independently associated with this complication. Methods: This study was conducted in a referral tertiary care university hospital with a cardiovascular focus. A total of 311 consecutive adult patients undergoing any type of cardiac surgery were evaluated. The subjects were examined at regular intervals in the postoperative period using the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) tool. Results: The incidence of postoperative delirium (PD) was 10%. Among the 18 pre-, intra- and postoperative variables evaluated, the logistic regression analysis showed that low education level, history of diabetes or stroke, type of surgery, prolonged extracorporeal circulation, or red blood cell transfusion in the intra- or postoperative period were independently associated with delirium after cardiac surgery. An increased body mass index was identified as a protective factor. Conclusions: The aforementioned risk factors are significantly and independently associated with the presentation of PD. Because some of these factors can be treated or avoided, the results of this study are highly relevant to reduce the risk of this complication and improve the care of patients undergoing cardiac surgery.

Monitoring of near-infrared spectrum values during packed red blood cell transfusion in pediatric intensive care unit.

OBJECTIVES: Packed red blood cell (PRBC) transfusion is one of the most common treatment options in pediatric intensive care unit (PICU) which targets a better cerebral oxygenation. This study aimed to show the cerebral near-infrared spectroscopy (cNIRS) changes during PRBC transfusions in PICU. MATERIAL AND METHODS: In this prospective observational study, changes in regional cerebral tissue oxygen saturation (rSO2) in pediatric patients, who required PRBC transfusion were monitored. All the cNIRS and related values were classified as baseline values. The same values were measured and calculated at the end of transfusion and named as 4th-hour values. Further measurements and calculations were made three hours later and named as 7th-hour values. Changes in cNIRS, cerebral tissue fractional oxygen extraction (CTFOE), cNIRS variability index (cNIRS-VI) were compared using Friedman test. RESULTS: A total of 53 PRBC transfusions were monitored. Baseline haemoglobin increased from 6.3 (5.9, 6.7) gr/dL to 8.6 (8.4, 9) gr/dL at the 7th-hour. cNIRS values improved during transfusion (P=0.012), with a concomitant decrease in cNIRS-VI and CTFOE values (P<0.001 and P=0.017 consecutively) CONCLUSION: Our study revealed that there is an increase in cNIRS and related values after transfusion compared to baseline values in critically ill children admitted to a PICU. Age of PRBC did not have an effect on delta-cNIRS or post-transfusion hemoglobin values. There is a moderate correlation between the baseline cNIRS values and delta-cNIRS value after the transfusion.

Potential Relationship between Cerebral Fractional Tissue Oxygen Extraction (FTOE) and the Use of Sedative Agents during the Perioperative Period in Neonates and Infants.

Fractional tissue oxygen extraction (FTOE) by means of cerebral near-infrared spectroscopy (NIRS) provides information about oxygen uptake in the brain. Experimental animal data suggest that sedative agents decrease cerebral oxygen demand. The aim of the present study was to investigate the association between the cerebral FTOE and the use of pre and intraoperative sedative agents in infants aged 1-90 days. Cerebral NIRS was continuously applied during open major non-cardiac surgery in 46 infants. The main outcomes were the mean intraoperative FTOE and the percentage (%) of time of intraoperative hyperoxiaFTOE relative to the total duration of anesthesia. HyperoxiaFTOE was defined as FTOE ≤ 0.1. Cumulative doses of sedative agents (benzodiazepines and morphine), given up to 24 h preoperatively, correlated with the mean intraoperative FTOE (Spearman's rho = -0.298, p = 0.0440) and were predictive for the % of time of intraoperative hyperoxiaFTOE (ß (95% CI) 47.12 (7.32; 86.92)) when adjusted for the patients' age, type of surgery, preoperative hemoglobin, intraoperative sevoflurane and fentanyl dose, mean intraoperative arterial blood pressure, and end-tidal CO2 by multivariate 0.75 quantile regression. There was no association with 0.5 quantile regression. We observed the suggestive positive association of decreased fractional cerebral tissue oxygen extraction and the use of sedative agents in neonates and infants undergoing surgery.

Correlation between Regional Cerebral Saturation and Invasive Cardiac Index Monitoring after Heart Transplantation Surgery.

The present study assessed the correlations between cerebral regional saturation detected by near infrared spectroscopy (NIRS) and cardiac index (CI) measured by pulmonary artery catheter. This was a retrospective cohort study conducted in the cardiac intensive care unit in a tertiary care children's hospital. Patients younger than 18 years of age who underwent heart transplantation and had a pulmonary artery catheter on admission to the pediatric cardiac intensive care unit between January, 2010, and August, 2013, were included. There were no interventions. A total of 10 patients were included with median age of 14 years (range, 7-17). Indications for transplantation were dilated cardiomyopathy ( n = 9) and restrictive cardiomyopathy ( n = 1). Mixed venous oxygen saturation (SvO 2 ), cerebral regional tissue saturation (rSO 2 ), and CI were recorded hourly for 8 to 92 hours post-transplantation. Spearman's rank correlation coefficient was used to assess correlations between SvO 2 and cerebral rSO 2 and between CI and cerebral rSO 2 . A total of 410 data points were collected. Median, 25th and 75th percentiles of cerebral rSO 2 , CI, and SvO 2 were 65% (54-69), 2.9 L/min/m 2 (2.2-4.0), and 75% (69-79), respectively. The correlation coefficient between cerebral rSO 2 and CI was 0.104 ( p = 0.034) and that for cerebral rSO 2 and SvO 2 was 0.11 ( p = 0.029). The correlations between cerebral rSO 2 and CI and between cerebral rSO 2 and SvO 2 were weak. Cerebral rSO 2 as detected by NIRS may not be an accurate indicator of CI in critically ill patients.

A retrospective study about cerebral near-infrared spectroscopy monitoring during paediatric cardiac surgery and intra-operative patient blood management.

OBJECTIVES: Cerebral non-invasive monitoring of oxygen saturation by near-infrared spectroscopy (rSO2) during paediatric cardiac surgery is supposed to decrease the risk of neurological complications. Since haemoglobin level is one of the factors changing rSO2, we aimed to explore if rSO2 monitoring influences intra-operative RBC (red blood cell) transfusion threshold and volumes, as well as the duration of ICU stay. METHODS: The design was a retrospective analysis involving 91 children less than 2 years of age (including 16 neonates) with a congenital heart disease requiring surgical treatment with or without cardiopulmonary bypass from January 2006 to August 2009. Systematic rSO2 monitoring was introduced after September 2007 (n=56). The independent factors associated with the intra-operative transfusion threshold haemoglobin (Hb) level>9.5g/dL, total volume of intra-operative RBC transfusion<30mL/kg and ICU stay<6 days were identified by multivariate analysis logistic regression. Data were expressed as medians (25-75%). RESULTS: Cardiac malformations and demographic characteristics were similar in both periods. Two independent factors, weight and rSO2 monitoring, were identified as independent factors associated with the three end-points. The transfusion threshold, total transfusion volume and ICU stay with and without rSO2 were 9.8 (8.9 to 10.3) versus 8.7 (8.2 to 9.6) g/dL (P<0.0001), 20 (14-49) versus 36 (22.5-51.5) mL/kg (P=0.0165) and 5 (3-8) versus 7 (5-10.7) days (P=0.0084), respectively. CONCLUSION: rSO2 monitoring changed our transfusion strategy with an earlier transfusion but a reduced total RBC volume and decreased the length of ICU stay.