Changes In Hemoglobin Concentration Research Articles

A wide field-of-view, modular, high-density diffuse optical tomography system for minimally constrained three-dimensional functional neuroimaging.

The ability to produce high-quality images of human brain function in any environment and during unconstrained movement of the subject has long been a goal of neuroimaging research. Diffuse optical tomography, which uses the intensity of back-scattered near-infrared light from multiple source-detector pairs to image changes in haemoglobin concentrations in the brain, is uniquely placed to achieve this goal. Here, we describe a new generation of modular, fibre-less, high-density diffuse optical tomography technology that provides exceptional sensitivity, a large dynamic range, a field-of-view sufficient to cover approximately one-third of the adult scalp, and also incorporates dedicated motion sensing into each module. Using in-vivo measures, we demonstrate a noise-equivalent power of 318 fW, and an effective dynamic range of 142 dB. We describe the application of this system to a novel somatomotor neuroimaging paradigm that involves subjects walking and texting on a smartphone. Our results demonstrate that wearable high-density diffuse optical tomography permits three-dimensional imaging of the human brain function during overt movement of the subject; images of somatomotor cortical activation can be obtained while subjects move in a relatively unconstrained manner, and these images are in good agreement with those obtained while the subjects remain stationary. The scalable nature of the technology we described here paves the way for the routine acquisition of high-quality, three-dimensional, whole-cortex diffuse optical tomography images of cerebral haemodynamics, both inside and outside of the laboratory environment, which has profound implications for neuroscience.

Prophylactic use of Tranexamic Acid during Caesarean Section in Preventing Postpartum haemorrhage– a Prospective Randomised Double Blind Placebo Controlled Study

Background: Postpartum haemorrhage (PPH) is a major cause of maternal mortality,accounting for one-quarter of all maternal deaths worldwide. Tranexamic acid (TXA), anantifibrinolytic agent, has therefore been investigated as a potentially useful complement toprevention and treatment of PPH. It has been proved to reduce blood loss in elective surgery,bleeding in trauma patients, and menstrual blood loss.
 Aims: To evaluate the effectiveness of TXA in reducing blood loss given just immediatelyafter delivery of baby in women undergoing cesarean section.
 Methods: This was a prospective, randomized, double blind, placebo controlled studyconducted in the Department of Gynaecology and Obstetrics unit of IBN SINA Medical CollegeDhaka, Bangladesh from June 2016 to May 2017. Participants were randomly assigned toTXA group or group A (n=60) and placebo group or group B (n=60). Randomization wasdone by residents using computer generated random numbers. Group A received 1 gram(10ml) of intravenous bolus dose of TXA just after delivery of the baby, Group B received 10ml of sterile distilled water for injection intravenously at the same time. Statistical analysishas been done by SPSS.
 Results: The subjective characteristics in the two groups were similar with respect to theirage, BMI, gestational age and gravidity. The duration of surgery was 40-50 minutes. Therewas no statistically significant difference in the heart rates (p>0.05) and blood pressuresbetween the two groups, after 2 hours of delivery. Blood losses from both placental deliveriesto the end of cesarean section and from end of CS to 2 hours postpartum were significantlylower in the study group (p<0.05). Change in hemoglobin concentration in study group wasalso significantly less than in the control group. Total amount of oxytocin required wassignificantly less in TXA group (p<0.05) also the number of women requiring other oxytocics(inj. Methyl ergometrine, inj carboprost and tab misoprostol per rectally) was significantlyless in TXA group (p< 0.05). The amount of intra-operative fluid required were significantlyless in TXA group (p<0.005); however post – operative fluid requirement and minor sideeffects in the form of nausea and vomiting were similar in both the groups.
 Conclusion: Tranexamic acid can effectively reduce blood loss in patients undergoing LSCSand its use was not associated with any side effects and or complications like thrombosis.The adoption of WHO guidelines for using uterotonic agents and prophylactically administeringTXA may significantly reduce the number of PPH incidents.
 Bangladesh J Obstet Gynaecol, 2018; Vol. 33(2) : 125-130

Venous occlusion during blood collection decreases plasma nitrite but not nitrate concentration in humans

BackgroundTo maintain vascular tone and blood flow when tissue oxygenation is reduced, nitrite anions are reduced to nitric oxide (NO). From a practical perspective, it is unclear how the application of a tourniquet during blood collection might influence measurement of NO metabolites. Accordingly, this study evaluated the effect of venous occlusion on plasma nitrite and nitrate during venous blood collection. MethodsFifteen healthy participants completed two trials that were preceded by the ingestion of nitrate-rich beetroot juice (BRJ; total of ~8.4 mmol nitrate) or no supplementation (control). In both trials, blood was collected using a venepuncture needle while a tourniquet was applied to the upper arm and using an indwelling intravenous cannula, from the opposing arm. The venepuncture samples were collected at 35 s post occlusion. Changes in the oxygenation of forearm flexor muscles were assessed using near-infrared spectroscopy. Plasma nitrite and nitrate were analysed using gas-phase chemiluminescence. ResultsIn the control trial, plasma nitrite was significantly elevated when collected via the cannula (179 ± 67 nM) compared to venepuncture (112 ± 51 nM, P = 0.03). The ingestion of BRJ increased plasma nitrite and values remained higher when sampled from the cannula (473 ± 164 nM) compared to venepuncture (387 ± 136 nM, P < 0.001). Plasma nitrate did not differ between collection methods in either trial (all P > 0.05). The delta changes in total-, deoxy-, and oxy-haemoglobin were all significantly greater during venepuncture sample compared to the cannula sample at the point of blood collection (all P < 0.05). ConclusionsVenous occlusion during venepuncture blood collection lowers plasma nitrite concentration, potentially due to localised changes in haemoglobin concentration and/or a suppression of endogenous NO synthesis. Accordingly, the method of blood collection to enable measurements of NO metabolites should be carefully considered and consistently reported by researchers.

Изменения показателей крови у животных при введении в зону перелома бедренной кости компонентов на основе ионов лантаноидов и кальция в эксперименте

Introduction Reduction of time to restore bone integrity remains one of the main problems in traumatology and orthopedics. To solve this problem, various kinds of components have been used, one of which are bisphosphonates. This article presents an experiment, the purpose of which was to study the effect of components based on etidronates of lanthanide or calcium on blood indicators by different ways of their introduction into the femoral fracture site in experimental animals. Materials and methods Studies were conducted on 75 male rats aged 5–6 months, weighing 300–350 g. A femoral fracture was modeled in all animals, and retrograde intramedullary osteosynthesis was performed. Animals were divided into 5 groups. Group 1 received no components; a component based on etidronates of lanthanide and calcium was introduced in group 2 through a catheter; group 3 had paraossal administration of etidronates of lanthanide and calcium; group 4 had paraossal introduction of a component based on etidronate calcium through a catheter; and group 5 had introduction of components based on etidronates and calcium. Animals received the investigated components twice in the fracture zone on days 3 and 5 after the operation, except the comparison group. Results In groups with a catheter, the most pronounced local inflammatory response was observed. Changes in hemoglobin concentration were observed in all groups, in the early (7 days) period. It was found that in rats which were injected with components containing lanthanides, the average content of hemoglobin, erythrocytes and leukocytes were identical to those of group 1. Conclusion The study revealed that the components, which include lanthanide ions do not cause negative changes in the rat blood according to hematological tests.

The Mechanical Properties of Mimic Skin

This paper focuses on the characterized of the mechanical properties and hyper elastic behavior of lab made skin. Bovine Serum Albumin (BSA) combined with gelatin as a base. BSA is a plasma lead concentrations or heparin plasma which is separated from blood sample and it is not associated with significant changes in iron or hemoglobin concentrations. In general, the gelatin is widely used as the best material for skin substitution since it exhibits the characteristic of human skin. However, the lab made skin layer was made of non-halal type gelatin (Type B). The methodology process started by adding the BSA and using the type A gelatin to carry out the mechanical properties and hy-per elastic behavior of halal lab made skin layer. A uniaxial tensile test standard that being used in this study is ASTM D412. The raw data (Load-Extension) from computational was plotted on graph stress-strain. The numerical approach such as Mooney-Rivlin model and Yeoh’s model were selected to analyze a stress-stretch of composition gelatin and BSA. From the results Mooney-Rivlin model, the con-stant, C1 is in the range of (0.0187-0.0658) MPa and C2 is in the range of (0.0628-0.0737) MPa. Meanwhile the constant, CP for Yeoh model is in the range of (0.0748-0.0861) MPa. As a conclusion, the composition of gelatin and Bovine Serum Albumin is a best combina-tion as it increases the strength of the lab made skin layer. Therefore, the most suitable composition is 10 wt.% of gelatin and Bovine Serum Albumin.

Protective effects of extracts of lichen Dirinaria consimilis (Stirton) D.D. Awasthi in bifenthrin- and diazinon-induced oxidative stress in rat erythrocytes in vitro

The intoxication of insecticides such as bifenthrin and diazinon has been reported to generate free radicals, and thereby alter the antioxidant defense system in erythrocytes. The present study is aimed to investigate the protective effects of acetone (DA) and methanolic (DM) extracts of lichen Dirinaria consimilis against bifenthrin and diazinon toxicity in rats’ erythrocytes in vitro. Rats’ erythrocytes were exposed to bifenthrin and diazinon, individually and also in combination with DA or DM at 1 ppm for 3 h at 37 ˚C. By using spectrophotometric methods, all the samples were estimated for changes in hemoglobin (Hb) concentration, malondialdehyde (MDA) levels, and enzyme [Superoxide dismutase (SOD), catalase (CAT), and glutathione S-transferases (GST)] activities. The outcomes showed that both the insecticides were highly toxic to rats’ erythrocytes. Among all groups, both the insecticides and DA exposed groups showed very low levels of MDA content, and GST activity in rats’ erythrocytes, when compared to the control. Besides, DA groups pretreated with both insecticides showed significant improvement of total Hb concentration, SOD, and CAT activities, with respect to the control. Hence, the present results indicate that the extracts of D. consimilis act as an antioxidant agent that reduces oxidative stress burden in insecticides toxicity.

Study protocol and pilot results of an observational cohort study evaluating effect of red blood cell transfusion on oxygenation and mitochondrial oxygen tension in critically ill patients with anaemia: the INsufficient Oxygenation in the Intensive Care Unit (INOX ICU-2) study

IntroductionThe recently developed protoporphyrin IX-triple state lifetime technique measures mitochondrial oxygenation tension (mitoPO2) in vivo at the bedside. MitoPO2might be an early indicator of oxygen disbalance in cells of critically...

Single-cell O2 exchange imaging shows that cytoplasmic diffusion is a dominant barrier to efficient gas transport in red blood cells

Disorders of oxygen transport are commonly attributed to inadequate carrying capacity (anemia) but may also relate to inefficient gas exchange by red blood cells (RBCs), a process that is poorly characterized yet assumed to be rapid. Without direct measurements of gas exchange at the single-cell level, the barriers to O2 transport and their relationship with hematological disorders remain ill defined. We developed a method to track the flow of O2 in individual RBCs by combining ultrarapid solution switching (to manipulate gas tension) with single-cell O2 saturation fluorescence microscopy. O2 unloading from RBCs was considerably slower than previously estimated in acellular hemoglobin solutions, indicating the presence of diffusional barriers in intact cells. Rate-limiting diffusion across cytoplasm was demonstrated by osmotically induced changes to hemoglobin concentration (i.e., diffusive tortuosity) and cell size (i.e., diffusion pathlength) and by comparing wild-type cells with hemoglobin H (HbH) thalassemia (shorter pathlength and reduced tortuosity) and hereditary spherocytosis (HS; expanded pathlength). Analysis of the distribution of O2 unloading rates in HS RBCs identified a subpopulation of spherocytes with greatly impaired gas exchange. Tortuosity imposed by hemoglobin was verified by demonstrating restricted diffusivity of CO2, an acidic gas, from the dissipative spread of photolytically uncaged H+ ions across cytoplasm. Our findings indicate that cytoplasmic diffusion, determined by pathlength and tortuosity, is a major barrier to efficient gas handling by RBCs. Consequently, changes in RBC shape and hemoglobin concentration, which are common manifestations of hematological disorders, can have hitherto unrecognized and clinically significant implications on gas exchange.

Low hemoglobin increases risk for cerebrovascular disease, kidney disease, pulmonary vasculopathy, and mortality in sickle cell disease: A systematic literature review and meta-analysis.

Sickle cell disease (SCD) is characterized by deoxygenation–induced polymerization of hemoglobin in red blood cells, leading to hemolytic anemia, vaso–occlusion, and the development of multiple clinical complications. To characterize the clinical burden associated with differences in hemoglobin concentration and hemolysis measures, a systematic literature review of MEDLINE, EMBASE, and related meta–analyses was undertaken. For quantitative analyses related to hemoglobin concentration, pooled results were analyzed using random effects models to control for within–and between–study variability. To derive risk ratios associated with hemoglobin concentration change, we combined ratios of means from select studies, which reported hazard and odds ratios in meta–analyses for hemoglobin concentration–related outcomes and changes between groups. Forty-one studies were identified for inclusion based on relating hemoglobin concentration to clinical outcomes. Meta–analyses demonstrated that mean hemoglobin concentration was significantly lower in patients with cerebrovascular disease (0.4 g/dL), increased transcranial Doppler velocity in cerebral arteries (0.6 g/dL), albuminuria (0.6 g/dL), elevated estimated pulmonary artery systolic pressure (0.9 g/dL), and in patients that subsequently died (0.6 g/dL). In a risk reduction meta–analysis, modeled increased hemoglobin concentrations of 1 g/dL or greater resulted in decreased risk of negative clinical outcomes of 41% to 64%. In conclusion, chronic anemia is associated with worse clinical outcomes in individuals with SCD and even modest increases in hemoglobin concentration may be beneficial in this patient population. This systematic review has been registered on Prospero (Registration number CRD42018096860; https://www.crd.york.ac.uk/prospero/).

Extendable, large-field multi-modal optical imaging system for measuring tissue hemodynamics.

Simultaneous imaging of multiple hemodynamic parameters helps to evaluate the physiological and pathological status of biological tissue. To achieve multimodal hemodynamics imaging with a large field of view, an infinite conjugate relay lens system compatible with the standard C-Mount camera lens is designed to adapt one camera lens with multiple CCD/CMOS cameras for simultaneously multi-wavelength imaging. Using this relay lens system, dual wavelength reflectance imaging and laser speckle contrast imaging were combined to simultaneously detect the changes in blood flow, oxygenation, and hemoglobin concentrations. To improve the accuracy of hemoglobin concentration measurement with an LED illumination source, an integral algorithm is proposed that accounts for the dependence of differential pathlength factors (DPF) on hemoglobin concentrations and the integral effect of both the emission spectrum of the light source and the spectrum response of the detector. The imaging system is validated by both phantom and in vivo experiments, including the arterial occlusion, and the detection of blood volume pulse (BVP) and blood flow pulse (BFP) signal in human subjects. The system helps in the exploration of macroscopic tissue hemodynamics.

Using Near Infrared Spectroscopy, Diffuse Correlation Spectroscopy, and Intravital Video Microscopy to Monitor the Skeletomuscular and Cerebral Microcirculation

IntroductionThe microcirculation is the primary facilitator of oxygen delivery in tissue, and dysfunction in the microvasculature is often the first indication of a disease state. The microcirculation can be studied using a variety of methods, both invasive and non‐invasive. Two non‐invasive optical methods are near infrared spectroscopy (NIRS) and diffuse correlation spectroscopy (DCS). NIRS is sensitive to changes in tissue hemoglobin concentration and oxygen, while DCS is sensitive to changes in blood flow. However, neither method can directly visualize changes on a capillary by capillary basis. Intravital Video Microscopy (IVVM) allows us to do so, but is an invasive technique that requires surgery to expose the microcirculation. By using IVVM we can compare a direct visualization of the microvasculature to the signal received by NIRS/DCS in an equivalent microvascular bed. In addition, we can compare the NIRS/DCS signal from the skeletal muscle to the signal from the brain, allowing us to simultaneously monitor change in these two organs in response to disease progression or in response to stimulus.MethodsData is collected from Sprague Dawley rats (n=4) using both a dual wavelength Olympus inverted microscope (with 2 Rolera XR cameras and a beam splitter) and an in‐house NIRS/DCS device. Rats are anaesthetized and have their right extensor digitorum longus (EDL) muscle, found in the hind limb, exposed and reflected over the objective. Probes for the NIRS/DCS device are located on the left hind limb and the top of the skull. IVVM is used to collect microvascular velocity, hematocrit, and oxygen saturation from the right EDL, and NIRS/DCS will be used to collect microvascular hematocrit, oxygen saturation, and blood flow data from the left hind limb and the brain. Microvascular blood flow and oxygen saturation data from the left and right hind limbs will be compared, then the NIRS/DCS‐gathered data from the left hind limb will be compared to NIRS/DCS‐gathered data from the brain.DiscussionThis study will be the first to make a direct comparison between NIRS/DCS and IVVM measurements of the microcirculation, and will provide insight into the sensitivity of NIRS/DCS and its ability to accurately monitor the microvasculature. In addition, this study will be the first to make a direct comparison between skeletomuscular and cerebral NIRS/DCS measurements. Future work includes using this approach to determine the differences in effect of a phenylephrine bolus or an inspired oxygen challenge on these two microvascular beds. Further studies will determine whether disease progression occurs on the same timeline in the brain as it does in skeletal muscle.Support or Funding InformationNSERC Discovery Grant to C.G. Ellis.

Development of a Pediatric Rodent Model to Characterize the Toxic Mechanisms of Inhaled Phosphine

Phosphine (PH3) is a toxic, heavier‐than‐air gas produced from metal phosphide pesticides. Metal phosphides are commercially available and commonly used in agriculture and residential settings as fumigants. PH3 is a suspected metabolic poison and mitochondrial toxicant, although its precise mechanism of toxicity is unknown. Phosphine’s misuse in residential areas has resulted in numerous human exposures and fatalities. Documented cases of PH3 exposure indicate that children may have more severe toxicity and increased lethality following PH3 inhalation. To address this finding we have developed a pediatric rodent inhalation model of PH3 exposure. Development of this pediatric model will allow characterization of the toxic responses and toxic mechanisms induced by PH3 exposure. Male and female Sprague Dawley rats at post‐natal day (PND) 21, 28, and 42 were exposed to PH3 via nose‐only inhalation. Female rats at PND 28 were found to have the lowest median lethal concentration x time (LCt50) and were used to characterize PH3‐induced toxicity. Rats (n=4–9) were exposed to either ambient air or the LCt50 of PH3 (14,119ppm x min) for 20 minutes and removed from the inhalation system after an additional 5‐minute “off gas” period. To identify the target organ of toxicity, the heart, lung, liver, and kidney were collected at 0.5, 3, 6, and 24 hours post‐exposure and processed for histopathology. Cardiac tissue at 24 hours after phosphine exposure showed tissue degeneration and focal necrosis. Significant pathology was not observed in the other tissues evaluated, suggesting that the heart is the major target organ of toxicity following PH3 inhalation. PH3‐induced toxicity was additionally characterized using pulse oximetry, a blood gas panel, lung resistance and compliance, and complete blood counts (CBC). Pulse oximetry revealed no significant changes in tissue oxygenation; however, rats exposed to PH3 had significantly reduced heart rates at 0.5 and 3 hours post‐exposure. Assessment of blood gases found significantly reduced pH, bicarbonate, total CO2, and base excess levels in PH3‐exposed rats at 0.5 hours post‐exposure. These findings are indicative of PH3‐induced metabolic acidosis. Impairment of pulmonary function was assessed post‐exposure using resistance and compliance. There were no significant changes in resistance, compliance, elastance, inspiratory capacity, or measurements of forced expiratory volume after PH3 inhalation. This suggests that PH3‐induced symptoms of respiratory distress may be related to impaired cardiac function. CBC revealed no significant changes in red blood cell number, hemoglobin concentration, or hematocrit following PH3 exposure. These data indicate that our pediatric rat model aligns with human findings of increased lethality, cardiotoxicity, and metabolic acidosis induced by inhalation phosphine. This pediatric model will be used for the development of medical countermeasures for phosphine exposure.Support or Funding InformationThis research was supported by interagency agreement (AOD18014‐001‐00000) between the NIH Office of the Director and USAMRICD under the oversight of the Chemical Countermeasures Research Program at the National Institute of Allergy and Infectious Diseases.

The Effect of Tranexamic Acid Administration on Perioperative Bleeding in Patients Undergoing Knee or Hip Arthroplasty: A Single-Centre Retrospective Study.

ObjectiveTranexamic acid (TXA) has been used to reduce perioperative bleeding in various surgeries because of its antifibrinolytic effect. Recently, patients undergoing orthopaedic surgery in our institution received a loading dose of TXA (10 00 mg) before surgery, followed by 100 mg h−1 until the end of surgery. The purpose of the present study was to evaluate the efficacy of TXA administration on the perioperative blood loss in patients undergoing knee arthroplasty or hip arthroplasty.MethodsA retrospective cross-sectional study was conducted for the records in patients who underwent surgery without TXA administration (control group) and patients who underwent surgery with TXA administration (TXA group). Amount of intraoperative blood loss, intraoperative infusion volume, intraoperative blood transfusion volume, postoperative blood transfusion volume, changes in haemoglobin concentrations (ΔHb) and estimated blood loss were collected. Data were adjusted by propensity score method.ResultsA total of 126 (63 in the control group and 63 in the TXA group) patients were included during the study period. Intraoperative infusion, postoperative transfusion, ΔHb and estimated blood loss were significantly reduced in the TXA group, although there were no significant differences in the volumes of intraoperative transfusion and blood loss.ConclusionThe administration of TXA (loading dose of 1000 mg and continuous infusion of 100 mg h−1) reduced postoperative transfusion and perioperative blood loss. These results indicated that TXA administration is useful for reducing perioperative blood loss in patients undergoing knee or hip arthroplasty.

Monitoring Differences in Vaginal Hemodynamic and Temperature Response for Sexual A rousal by Different Anesthetic Agents Using an Optical Probe

The selection of anesthetic agent is important in preclinical studies, since each agent affects the systemic hemodynamics in different ways. For that reason, we hypothesized that different anesthetic agents will result in different vaginal hemodynamic response and temperature during sexual arousal, in an animal model. To validate the hypothesis, animal experiments were performed using female rats with two anesthetic agents widely used in preclinical studies: ketamine and isoflurane. Our previously developed near-infrared-spectroscopy-based probe was used to measure the changes of oxyhemoglobin (OHb), deoxyhemoglobin (RHb), and total hemoglobin (THb) concentrations along with temperature from the animal vaginal wall. As a control, saline was administered to both isoflurane- and ketamine-anesthetized animals, and did not show any significant changes in OHb, RHb, THb, or temperature. However, an administration of apomorphine (APO, 80 μg/kg) induced increases of OHb (63 ± 28 μM/DPF), RHb (35 ± 20 μM/DPF), and THb (98 ± 49 μM/DPF) in ketamine-anesthetized animals, while decreases of OHb (52 ± 76 μM/DPF) and THb (38 ± 30 μM/DPF) and an increase of RHb (28 ± 51 μM/DPF) were found in isoflurane-anesthetized animals. The vaginal temperature decreased from the baseline in both ketamine-(0.42°C) and isoflurane-(1.22°C)anesthetized animals. These results confirmed our hypothesis, and suggest that a preclinical study monitoring hemodynamic responses under anesthesia should employ an appropriate anesthetic agent for the study.

Working Memory of Patients with Mild Cognitive Impairment due to Brain Trauma Based on fNIRS.

Objective To discuss the activation characteristics of the prefrontal cortex of people with mild cognitive impairment （MCI） due to brain trauma during working memory tasks. Methods The psychological experiment design software E-prime was used and N-back paradigm was adopted as working memory task. Functional near-infrared spectroscopy （fNIRS） was used to detect changes in cortical oxygenated hemoglobin concentrations of 22 channels within the prefrontal lobe of 24 people with MCI due to brain trauma （study group） and 27 healthy volunteers （control group） with matching gender and age. Behavioral data, such as the number of keystroke errors and reaction time, were recorded simultaneously. Independent samples t test and non-parametric test were used to compare the mean value of oxygenated hemoglobin concentration change, the number of key errors and the mean value of reaction time of the two groups in each task. Results （1） The differences in the number of errors and reaction time between the two groups in 1-back and 2-back tasks had statistical significance （P<0.05）.The main effects of task load and group were both significant （task F=14.11, P=0.001 1; group F=10.39, P=0.001 5）. （2） During the 1-back task, the differences in oxygenated hemoglobin concentration changes of the 22 channels between the two groups had no statistical significance （P>0.05）. During the 2-back task, the differences in oxygenated hemoglobin concentration changes of the two groups in channel 2, 3, 7, 9, 10, 11, 14, 15, 18, 19, 21 and 22 had statistical significance （P<0.05）. （3） In the 1-back task, the left frontal pole and dorsolateral prefrontal area in both groups were activated. In the 2-back task, the activation areas of the control group were the left frontal pole area and the left dorsolateral prefrontal area, while that of the study group almost covered most of the left and right frontal pole areas, which were scattered and the right area was activated, too. Conclusion Patients with MCI due to brain trauma have obvious working memory impairment, and during the 2-back working memory task, the activation of the prefrontal lobe decreased, but the activation range was wider.

Effects of anaesthesia-induced hypotension and phenylephrine on plasma volume expansion by hydroxyethyl starch: A randomised controlled study.

Changes in blood haemoglobin concentration indicate plasma volume expansion following hydroxyethyl starch (HES) infusion, but may be affected by vascular tone and HES-induced shedding of the endothelial surface layer (ESL). We hypothesised that anaesthesia-induced hypotension enhances changes in plasma volume as assessed by blood haemoglobin concentration (ΔPVHb , %) following HES infusion. Fifty-two patients undergoing abdominal surgery were randomised to receive a continuous infusion of saline (S group) or phenylephrine to restore vascular tone (P group) (n=26 each). Both groups received an infusion of 8mL/kg 6% HES solution after induction of general anaesthesia. We compared ΔPVHb at the end of fluid infusion (15minutes) and 15minutes later (30minutes) between the two groups. We assessed changes in ESL structure by measuring plasma concentrations of hyaluronate and syndecan-1. P<.05 was considered statistically significant. Mean arterial blood pressure was lower in the S group approximately by 30-40% compared to the P group (P<.001). ΔPVHb was larger in the S group compared to the P group at 15minutes (24.9 [5.2] % vs 19.0 [5.2] %; P<.001) and 30minutes (26.5 [5.9] % vs 16.9 [6.6] %; P<.001). There were no clinically significant differences in plasma concentrations of hyaluronate and syndecan-1 with time and between the groups. Increased volume expansion of circulating plasma following HES infusion in anaesthesia-induced hypotension compared to when blood pressure is restored by phenylephrine may result from an attenuation of transcapillary fluid filtration, rather than ESL shedding. UMIN Clinical Trial Registration Number: UMIN000017394 (http://www.umin.ac.jp/ctr/index.htm).

Dihydroartemisinin-piperaquine for the routine treatment of uncomplicated malaria in Northern Ghana

&lt;p class="abstract"&gt;&lt;strong&gt;Background:&lt;/strong&gt; Dihydroartemisinin-piperaquine is a first line treatment for uncomplicated malaria in Ghana. A facility-based study was undertaken to examine the effectiveness of the treatment in the routine health care system.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods:&lt;/strong&gt; The study was undertaken at the Navrongo demographic surveillance area. Patients presenting with acute febrile illness were enrolled after informed consented and confirmation by microscopy. Patients were randomized into supervised group who received treatment under direct observation and unsupervised group which had only the first treatment given under supervision. Treatment was according to bodyweight and 42 days follow-up was undertaken.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Results:&lt;/strong&gt; A total of 194 patients were enrolled; 54.1% were females and 51% had supervised treatment. The median age and weight were 6.7 years and 20.0 kg respectively. Mean baseline temperature, haemoglobin concentration and parasite density were, 37.6 &lt;sup&gt;o&lt;/sup&gt;C, 11.1 g/dl and 11,098 parasites per microliter of blood respectively. Study completion rate was 93.3%, day 42 polymerase chain reaction-unadjusted adequate clinical and parasitological responses rate (ACPR) was 93.4% by evaluable and 87.1 % by intention-to-treat (ITT). The day 42 ACPR by evaluable was 92.3% in the supervised arm compared to 94.4% in the unsupervised arm. The day 42 ACPR by ITT was 85.7% in the supervised and 88.5% in the unsupervised arms. The fever resolution and haemoglobin concentration changes for the two arms were similar.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Conclusions: &lt;/strong&gt;The results show that dihydroartemisinin-piperaquine is effective and good first-line antimalarial in the routine health delivery system.&lt;/p&gt;

Assessment of the brain ischemia during orthostatic stress and lower body negative pressure in air force pilots by near-infrared spectroscopy.

A methodology for the assessment of the cerebral hemodynamic reaction to normotensive hypovolemia, reduction in cerebral perfusion and orthostatic stress leading to ischemic hypoxia and reduced muscular tension is presented. Most frequently, the pilots of highly maneuverable aircraft are exposed to these phenomena. Studies were carried out using the system consisting of a chamber that generates low pressure around the lower part of the body - LBNP (lower body negative pressure) placed on the tilt table. An in-house developed 6-channel NIRS system operating at 735 and 850 nm was used in order to assess the oxygenation of the cerebral cortex, based on measurements of diffusely reflected light in reflectance geometry. The measurements were carried out on a group of 12 active pilots and cadets of the Polish Air Force Academy and 12 healthy volunteers. The dynamics of changes in cerebral oxygenation was evaluated as a response to LBNP stimuli with a simultaneous rapid change of the tilt table angle. Parameters based on calculated changes of total hemoglobin concentration were proposed allowing to evaluate differences in reactions observed in control subjects and pilots/cadets. The results of orthogonal partial least squares-discriminant analysis based on these parameters show that the subjects can be classified into their groups with 100% accuracy.

Is TKA with computer-assisted navigation associated with less blood loss? A comparative study between computer-navigated and conventional method

The aim of this study is to evaluate whether computer-assisted navigated TKA reduces perioperative blood loss. Patients were randomly divided into 2 groups and underwent either a conventional TKA (n = 40) or a TKA with computer-assisted navigation (n = 40). Perioperative blood loss was evaluated by laboratory parameters, postoperative drain output and number of required transfusions. Change in hemoglobin concentration and in hematocrit levels was similar. Also, there was no statistically significant difference in drain output and in the number of transfused units. The results of this study showed that TKA with computer-assisted navigation is similar to the conventional TKA regarding perioperative hemorrhage.

Preoperative intravenous iron before cardiac surgery: a prospective multicentre feasibility study

BackgroundPreoperative anaemia affects one third of patients undergoing cardiac surgery and is associated with increased mortality and morbidity. Although it is recommended that perioperative teams should identify and treat patients with preoperative anaemia before surgery, introducing new treatment protocols can be challenging in surgical pathways. The aim of this study was to assess the feasibility and effectiveness of introducing a preoperative intravenous iron service as a national initiative in cardiac surgery. MethodsWe performed a multicentre, stepped, observational study using the UK Association of Cardiothoracic Anaesthesia and Critical Care Research Network. The primary feasibility outcome was the ability to set up an anaemia and intravenous iron clinic at each site. The primary efficacy outcome was change in haemoglobin (Hb) concentration between intervention and operation. Secondary outcomes included blood transfusion and hospital stay. Patients with anaemia were compared with non-anaemic patients and with those who received intravenous iron as part of their routine treatment protocol. ResultsSeven out of 11 NHS hospitals successfully set up iron clinics over 2 yr, and 228 patients were recruited into this study. Patients with anaemia who received intravenous iron were at higher surgical risk, were more likely to have a known previous history of iron deficiency or anaemia, had a higher rate of chronic kidney disease, and were slightly more anaemic than the non-treated group. Intravenous iron was administered a median (inter-quartile range, IQR [range]) of 33 (15–53 [4–303]) days before surgery. Preoperative intravenous iron increased [Hb] from baseline to pre-surgery; mean (95% confidence interval) change was +8.4 (5.0–11.8) g L−1 (P<0.001). Overall, anaemic compared with non-anaemic patients were more likely to be transfused (49% [59/136] vs 27% (22/92), P=0.001) and stayed longer in hospital (median days [IQR], 9 [7–15] vs 8 [6–11]; P=0.014). The number of days alive and at home was lower in the anaemic group (median days [IQR], 20 [14–22] vs 21 [17–23]; P=0.033). ConclusionThe development of an intravenous iron pathway is feasible but appears limited to selected high-risk cardiac patients in routine NHS practise. Although intravenous iron increased [Hb], there is a need for an appropriately powered clinical trial to assess the clinical effect of intravenous iron on patient-centred outcomes.