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Cognitive impairment is integral to the pathophysiology of psychosis. Recent findings implicate autonomic arousal-related activity in both momentary fluctuations and individual differences in cognitive performance. Although altered autonomic arousal is common in patients with first-episode psychosis (FEP), its contribution to cognitive performance is unknown.A total of 24 patients with FEP (46% male, age = 24.31 [SD 4.27] years) and 24 control subjects (42% male, age = 27.06 [3.44] years) performed the Multi-Source Interference Task in-scanner with simultaneous pulse oximetry. First-level models included the cardiac-blood oxygen level-dependent regressor, in addition to task (congruent, interference, and error) and nuisance (motion and CompCor physiology) regressors. The cardiac-blood oxygen level-dependent regressor reflected parasympathetic arousal-related activity and was created by convolving the interbeat interval at each heartbeat with the hemodynamic response function. Group models examined the effect of group or cognitive performance (reaction times × error rate) on arousal-related and task activity, while controlling for sex, age, and framewise displacement.Parasympathetic arousal-related activity was robust in both groups but localized to different regions for patients with FEP and healthy control subjects. Within both groups, arousal-related activity was significantly associated with cognitive performance across occipital and temporal cortical regions. Greater arousal-related activity in the bilateral prefrontal cortex (Brodmann area 9) was related to better performance in healthy control subjects but not patients with FEP.Autonomic arousal circuits contribute to cognitive performance and the pathophysiology of FEP. Arousal-related functional activity is a novel indicator of cognitive ability and should be incorporated into neurobiological models of cognition in psychosis.

Background: No periprocedural metric has demonstrated improved cardiac resynchronization therapy (CRT) outcomes in a multicenter setting. Objective: We sought to determine if left ventricular (LV) lead placement targeted to the coronary sinus (CS) branch generating the best acute hemodynamic response (AHR) results in improved outcomes at 6 months. Methods: In this multicenter randomized controlled trial, patients were randomized to guided CRT or conventional CRT. Patients in the guided arm had LV dP/dtmax measured during biventricular (BIV) pacing. Target CS branches were identified and the final LV lead position was the branch with the best AHR and acceptable threshold values. The primary endpoint was the proportion of patients with a reduction in LV end-systolic volume (LVESV) of ≥15% at 6 months. Results: A total of 281 patients were recruited across 12 centers. Mean age was 70.8 ± 10.9 years and 54% had ischemic etiology. Seventy-three percent of patients in the guided arm demonstrated a reduction in LVESV of ≥15% at 6 months vs 60% in the conventional arm (P = .02). Patients with AHR ≥ 10% were more likely to demonstrate a reduction of ESV ≥ 15% (84% of patients with an AHR ≥10% vs 28% with an AHR

Behavioral stability partially depends on the variability of net outcomes by means of the co-varied adjustment of individual elements such as multi-finger forces. The properties of cyclic actions affect stability and variability of the performance as well as the activation of the prefrontal cortex that is an origin of subcortical structure for the coordinative actions. Little research has been done on the issue of the relationship between stability and neuronal response. The purpose of the study was to investigate the changes in the neural response, particularly at the prefrontal cortex, to the frequencies of isometric cyclic finger force production. The main experimental task was to produce finger forces while matching the produced force to sine-wave templates as accurately as possible. Also, the hemodynamics responses of the prefrontal cortex, including oxy-hemoglobin concentration (ΔHbO) and the functional connectivity, were measured using functional near-infrared spectroscopy. The frequency conditions comprised 0.1, 1, and 2 Hz. The uncontrolled manifold (UCM) approach was applied to compute synergy indices in time-series. The relative phase (RP), the coefficient of variation (CV) of the peak and trough force values were computed as the indices of performance accuracy. The statistical parametric mapping (SPM) was implemented to compare the synergy indices of three frequency conditions in time-series. A less accurate performance in the high-frequency condition was caused not by the RP, but mainly by the inconsistent peak force values (CV; p < 0.01, ηp2 = 0.90). The SPM analysis revealed that the synergy indices were larger in the low-frequency than in high-frequency conditions. Further, the ΔHbO remained unchanged under all frequency conditions, while the functional connectivity decreased with an increase in the frequency of cyclic force production. The current results suggested that the concurrent activation of the prefrontal region mainly depends on the frequency of cyclic force production, which was associated with the strength of stability indices and performance errors. The current study is the first work to uncover the effect of frequency on the multi-finger synergies as to the hemodynamic response in the prefrontal cortex, which possibly provides a clue of the neural mechanism of synergy formation and its changes.

Background and Aims- Laryngoscopic and endotracheal intubation are noxious stimuli causes tachycardia, arrhythmias and hypertension. The aim of this study was to compare dexmedetomidine with placebo to attenuate stress response during laryngoscopy and endotracheal intubation.Methods-It was a randomised, double-blind placebo-controlled study. After Institutional Ethical Committee clearance, 60 patients of ASA 1& 2 were enrolled and divided into 30 each. Group NS received normal saline and Group D received injection dexmedetomidine 1μg/kgas infusion over 10 min. The general anaesthesia technique was standardised for both groups. The primary outcome measures were haemodynamic response at 1, 2, 5 and 10 min after intubation. The secondary outcome measures were to note down any adverse effects associated with drugs. The statistical package used was SPSS version 15.Results- There was a statistically significant difference (P

PURPOSE: To understand the hemodynamic effect of angiotensin II as a vasopressor in patients with shock secondary to COVID-19 infection. METHODS: A retrospective analysis was performed on all patients at a single center with COVID-19 infection and shock who were treated with angiotensin II. The hemodynamic response to angiotensin II was estimated by recording the mean arterial pressure, norepinephrine equivalent dose (NED) and urine output. RESULTS: Ten patients with COVID-19 related shock were treated with angiotensin II. Over the initial 6 hours, the average the norepinephrine equivalent dose decreased by 30.4% (from 64.6 mcg/min to 44 mcg/min) without a significant change in the mean arterial pressure (0.7% decrease). Six patients experienced at least a 25% reduction in norepinephrine equivalent dose by 6 hours, and two experienced at least a 50% reduction. CONCLUSIONS: On average, the hemodynamic response to angiotensin II in COVID-19 related shock was favorable. Two patients had a marked rapid improvement. Given the relationship of SARS-CoV-2 with the renin angiotensin aldosterone system, further evaluation of angiotensin II for the treatment of COVID-19 related shock is warranted.

Direct laryngoscopy and endotracheal intubation are associated with increase in sympathoadrenal activity results in hemodynamic instability. Many strategies were used to attenuate this response. Dexmedetomidine is one of the primary drug being used for this purpose. This study was designed to compare the effect of intravenous 0.5μg/kg, 0.75μg/kg, 1μg/kg dexmedetomidine to laryngoscopy and intubation. This study was conducted on 75 patients allotted into 3 groups 25 patients each. Group A -Inj. Dexmedetomidine 0.5 µg/kg. B - 0. 75µg/kg. C- 1µg/kg. vitals, sedation score were observed. After giving Inj. dexmedetomidine in a dose of 0.5,0.75 and 1 μg/kg change in HR at 10 minutes after laryngoscopy and intubation was 5.47%, 10.80% and 18.38% respectively, change in the SBP was 7.71%,14.69%,16.96% respectively, change in the DBP was 6.96%,13.40%,18.01%. We have found that effective dose to blunt the hemodynamic response to laryngoscopy &intubation is 0.5 μg/kg.

Laryngoscopy and end tracheal intubation are stressful situation for the patients, as these procedures are capable of producing tachycardia, hypertension and arrhythmias. This study was conducted with the objective of arriving at an optimal dose of dexmedetomidine that can attenuate the hemodynamic response to laryngoscopy and intubation with minimal side effects. The current study was conducted in 60 patients, posted for elective surgery under general anesthesia withendotracheal intubation. The patients were divided into two groups: Group A and Group B. Group A received dexmedetomidine 0.5 μg/kg and group B received dexmedetomidine 1 μg/kg intravenously over 10 min prior to induction of anesthesia. The anesthesia technique was standardized in both the groups. Heart rate, systolic, diastolic and mean arterial pressure were monitored and recorded at 5min and 10 min of completion of infusion of study drug, after induction, and at 1 min, 2 min, 5 min after intubation. The baseline heart rate, systolic blood pressure, diastolic blood pressure and mean arterial pressure were statistically similar in both the groups. After the infusion of the study drug the mean heart rate, mean systolic blood pressure, mean diastolic blood pressure, mean arterial pressure at all times were comparable in both the groups. Episodes of hypotension and bradycardia were also statistically similar in both the groups. Attenuation of hemodynamic response to laryngoscopy and intubation by dexmedetomidine is similar with the two doses: 0.5 μg/kg and 1 μg/kg. Both the doses of dexmedetomidine were devoid of any significant adverse effects.

Background and objective: Remifentanil is used to attenuate maternal hemodynamic response to intubation and surgical stress during Induction–Delivery period of cesarean section. The goal was to compare the effects of two remifentanil dosing regimens on oxidative stress level, in correlation with its hemodynamic and neonatal effects. Methods: Fifty-one patients, 17 per group, enrolled for elective cesarean section were randomly divided by computer-generated codes into three parallel groups: (A) patients received a 1 μg.kg−1 remifentanil bolus immediately before induction, followed by 0.15 μg.kg−1.min−1 infusion, that was stopped after skin incision; (B) patients received a 1 μg.kg−1 remifentanil bolus immediately before induction; (C) (control), patients did not receive remifentanil until delivery. Maternal venous blood samples were taken at basal time, at extraction and 30 minutes after the end of operation for spectrophotometrical determination of malondialdehyde and advanced oxidation protein products concentration. The same was conducted for umbilical venous sample. Results: Systolic blood pressure and heart rate remained significantly lower in group A compared to B and C during entire Induction–Delivery period (p

Background: Laryngoscopy and intubation cause hypertension and tachycardia which can lead to myocardial ischemia or cerebrovascular hemorrhage in patients with raised intracranial pressure, hypertension. The objective of this study was to compare the efficacy of dexmedetomidine (1 mcg/kg) and fentanyl (2 mcg/kg) in attenuating hemodynamic response to laryngoscopy and intubation. Methods: Sixty patients scheduled for elective surgeries under general anaesthesia were randomly divided into two groups: Group D and Group F. Group D received dexmedetomidine 1 mcg/kg and group F received fentanyl 2 mcg/kg intravenously over 10 min prior to induction of anesthesia. All the drugs and techniques of anesthesia were standardized in patients in both the groups. Heart rate, systolic, diastolic and mean arterial pressure were recorded at following intervals: at baseline, after drug administration (at 2 and 5 min), after induction, and at 1, 2 and 5 min after intubation. Results: Heart rate and blood pressure was found to be significantly lower in dexmedetomidine group as compared to fentanyl group at 1, 2 and 5 min after intubation. Conclusions: Dexmedetomidine 1 mcg/kg is superior to fentanyl 2 mcg/kg for attenuation of hemodynamic response to laryngoscopy and intubation.

A kinetic model describing the impulse of increasing oxygen in the excited nervous tissue of the human brain in response to an external signal is presented. The model is based on biochemical data and describes experimental data on an impulsed hemodynamic response. The model predicts the dynamic behavior of the process participants, which preceding the oxygen impulse and determining the level of the BOLD-signal.

Background Intradialytic blood pressure (BP) measurement is currently the main parameter used for monitoring hemodynamics during hemodialysis (HD). Since BP is dependent on cardiac output and total peripheral resistance, knowledge of these parameters throughout the HD treatment would potentially be valuable. Methods The use of a novel non-invasive monitoring system for profiling hemodynamic response patterns during HD was explored: a whole-body bio-impedance system was used to assess cardiac index (CI), total peripheral resistance index (TPRI), cardiac power index (CPI) among other parameters in chronic HD patients from 4 medical centers. Measurements were made pre, during and post dialysis. Patients were grouped into 5 hemodynamic profiles based on their main hemodynamic response during dialysis i.e. high TPRI; high CPI; low CPI; low TPRI and those with normal hemodynamics. Comparisons were made between the groups for baseline characteristics and 1-year mortality. Results In 144 patients with mean age of 67.3 ± 12.1 years pre-dialysis hemodynamic measurements were within normal limits in 35.4% but only 6.9% overall remained hemodynamically stable during dialysis. Intradialytic BP decreased in 65 (45.1%) in whom, low CPI (47 (72.3%)) and low TPRI (18 (27.7%) were recorded. At 1-year follow-up, mortality rates were highest in patients with low CPI (23.4%) and low TPRI (22.2%). Conclusions Non-invasive assessment of patients’ response to HD provides relevant hemodynamic information that exceeds that provided by currently used BP measurements. Use of these online analyses could potentially improve the safety and performance standards of dialysis by guiding appropriate interventions, particularly in responding to hypertension and hypotension. Electronic supplementary material The online version of this article (10.1186/s12882-019-1542-4) contains supplementary material, which is available to authorized users.

Stroke is characterized by delays in the resting-state hemodynamic response, resulting in synchronization lag in neural activity between brain regions. However, the structural basis of this lag remains unclear. In this study, we used resting-state functional MRI (rs-fMRI) to characterize synchronization lag profiles between homotopic regions in 15 individuals (14 males, 1 female) with brain lesions consequent to stroke as well as a group of healthy comparison individuals. We tested whether the network communication efficiency of each individual’s structural brain network (connectome) could explain interindividual and interregional variation in synchronization lag profiles. To this end, connectomes were mapped using diffusion MRI data, and communication measures were evaluated under two schemes: shortest paths and navigation. We found that interindividual variation in synchronization lags was inversely associated with communication efficiency under both schemes. Interregional variation in lag was related to navigation efficiency and navigation distance, reflecting its dependence on both distance and structural constraints. Moreover, severity of motor deficits significantly correlated with average synchronization lag in stroke. Our results provide a structural basis for the delay of information transfer between homotopic regions inferred from rs-fMRI and provide insight into the clinical significance of structural-functional relationships in stroke individuals.

We sought to assess acute hemodynamic changes after implementation of negative extrathoracic pressure (NEP) in spontaneously breathing ambulatory Fontan patients with symptomatic heart failure. We hypothesized that application of NEP would result in an acute decrease in pulmonary artery pressure. Ten patients with clinical evidence of Fontan failure underwent baseline hemodynamic catheterization while breathing spontaneously. Hemodynamic measurements were then repeated after 30 min of continuous NEP. After 30 min of continuous NEP, 4/10 patients had a decrease in their Fontan pressure by 2 mmHg and one patient had a decrease by 1 mmHg. There were three patients that had an increase in Fontan pressure by 2 mmHg. In 7/10 patients, indexed pulmonary vascular resistance decreased by an average of 31%. In symptomatic Fontan patients with a favorable hemodynamic response to NEP during catheterization, potential benefit of longer-term NEP to improve clinical status should be explored.

Due to movement automatization, the engagement of high-order cognitive processing during the motor execution of a task is expected to decrease over repetitions and practice. In this study, we assessed single session changes in the prefrontal hemodynamic signals in response to training a piano chord progression in an ecological experimental setting. We acquired functional near-infrared spectroscopy signals from 15 subjects without any previous experience on playing keyboard instruments. Our findings were that oxygenated hemoglobin changes at orbitofrontal cortex followed an inverted U-shaped curve over task execution, while the subjects' performance presented a steady slope. These results suggest an initial executive function engagement followed by facilitation of motor execution over time.

BACKGROUND In endotracheal anaesthesia, tracheal intubation can have undesirable cardiovascular events. With no effect in normal healthy persons, these deleterious effects in patients with hypertension, raised intracranial pressure, raised intraocular pressure and coronary arterial disease. This procedure requires a safe drug which negates all these undesirable effects, which are transient in nature. METHODS A prospective study was carried out from June 2008 to August 2010 in S.V. Medical College and SVRRGG Hospital, among patients posted for surgery under general anaesthesia, after satisfying the inclusion and exclusion criteria. Patients were randomized into two groups Clonidine and Nifedipine groups. Patients were evaluated for blood pressure, SpO2, pulse, ECG during the study. RESULTS We observed a sharp but mild decrease in pulse rate in Clonidine group, but in all, pulse rate in the patients remains the same all over the duration of surgery. There was elevation in pulse rate in Nifedipine group, in all measured time intervals. Mean arterial blood pressure, systolic blood pressure and diastolic blood pressure in Clonidine group remain the same through all the time intervals measured, but in Nifedipine group it decreases slightly. The fall in mean arterial blood pressure, systolic blood pressure and diastolic blood pressure in the Nifedipine group made it necessary for constant vigil of hemodynamic monitoring during the general anaesthesia. We did not encounter any observed complications in the study. CONCLUSIONS Nifedipine group shows rise in Mean Arterial Pressure during intubation but a sustained fall later. Clonidine group shows decrease in Mean Arterial Pressure, Blood Pressure after laryngoscopy and continues throughout procedure.

ObjectivesThis study aimed to clarify haemodynamic responses of different age groups to simulated long working hours.MethodsMen of three age groups participated in this study (16 in their 30s (mean 33.9±2.7 years old), 15 in their 40s (45.5±2.9) and 16 in their 50s (54.1±2.7)). All participants conducted 12 45-min personal computer-based tasks from 09:00 to 22:00. Nine 10-min to 15-min breaks between task periods, a 1-hour break at noon, and a 50-min break in the evening were provided. Haemodynamic responses were measured during task periods. All participants had normal resting systolic blood pressure (SBP ResultsNo haemodynamic indices were significantly different among groups at baseline. Compared with baseline, SBP was almost unchanged for the 30s group but increased for the 40s and 50s groups during task periods. The 50s group showed higher SBP compared with the 30s group especially in the latter half of the working hours (pConclusionThe 50s group showed higher SBP and TPR responses than the 30s group, especially in the latter half of working hours. These results suggest that older workers might suffer more cardiovascular damage related to long working hours.

Affective touch activates a brain network responsible for processing social-emotional stimuli in infants, children, and adults, with a core node in the superior temporal sulcus (STS). STS is known to be a region highly susceptible to individual variability, including for tactile stimuli processing. However, little is known about how this region is recruited to process affective touch in infancy. The aim of this study was to examine brain activity to affective touch in the temporal region (STS) and understand if it relates to behavioral patterns of sensory-over responsivity (SOR) to touch. Twelve-month-old infants (n = 24) were given affective and discriminative stimuli to the forearm while they were watching a silent movie. Brain activation was recorded in the STS for measures of oxy-hemoglobin (HbO(2)) and deoxy-hemoglobin (Hbb) using functional near infra-red spectroscopy (fNIRS). Aversive responses to tactile stimuli were measured using the Infant-Toddler Sensory Profile. A significant hemodynamic response increase in HbO(2) to affective touch was observed in the STS for infants with less aversive behavioral responses to tactile stimuli. The findings suggest that brain activity in the STS for affective touch might be related to individual differences in the affective reaction toward touch., This study was supported by the Portuguese Science Foundation through an individual doctoral grant to Helga Miguel (SFRH/BD/86694/2012). The work was conducted at Psychology Research Center (UID/PSI/01662/2013), University of Minho, and supported by the Portuguese Science Foundation and the Portuguese Ministry of Science, Technology and Higher Education through national funds (PSI/01662) and co-financed by FEDER through COMPETE2020 under the PT2020 Partnership Agreement (POCI-01-0145-FEDER-007653).

The haemodynamic response to the beach-chair position may be affected by the presence of left ventricular hypertrophy where remodelling of cardiac chambers can potentially lead to left ventricular outflow tract obstruction. We present a case report of severe hypotension in the beach-chair position, where focused cardiac ultrasound identified left ventricular hypertrophy and geometric features that contributed to the hypotensive response. This case illustrates that focused cardiac ultrasound has the potential to alert the clinician preoperatively to left ventricular outflow tract obstruction susceptibility during surgery in the beach-chair position, and intraoperatively to direct management should sudden decreases in blood pressure occur.

Dyspnea due to mitral stenosis (MS) and/or pulmonary hypertension (PHT) in patients who may have both conditions presents a challenging diagnostic dilemma. The hemodynamic response to exercise is probably the most helpful method to arrive at the correct diagnosis and treatment algorithm. In this hemodynamic rounds discussion, we evaluated a patient with MS and PHT prior to the decision for mitral valvuloplasty. KEY POINTS: Symptoms in patients with mitral stenosis and pulmonary hypertension cannot always be attributed to one pathology. Catheter-based hemodynamics are often needed to differentiate valve from lung disease. Exercise hemodynamics can clarify the predominant pathology in complex clinical scenarios.

Background It is still unknown whether newborn infant parasympathetic evaluation (NIPE), based on heart rate variability (HRV) as a reflection of parasympathetic nerve tone, can predict the hemodynamic response to a nociception stimulus in children less than 2 years old. Methods Fifty-five children undergoing elective surgery were analyzed in this prospective observational study. Noninvasive mean blood pressure (MBP), heart rate (HR) and NIPE values were recorded just before and 1 min after general anesthesia with endotracheal intubation as well as skin incision. The predictive performance of NIPE was evaluated by receiver-operating characteristic (ROC) curve analysis. A significant hemodynamic response was defined by a > 20% increase in HR and/or MBP. Results Endotracheal intubation and skin incision caused HR increases of 22.2% (95% confidence interval [CI] 17.5–26.9%) and 3.8% (2.1–5.5%), MBP increases of 18.2% (12.0–24.4%) and 10.6% (7.7–13.4%), and conversely, NIPE decreases of 9.9% (5.3–14.4%) and 5.6% (2.1–9.1%), respectively (all P

Background Functional magnetic resonance imaging (fMRI) in awake behaving mice is well positioned to bridge the detailed cellular-level view of brain activity, which has become available owing to recent advances in microscopic optical imaging and genetics, to the macroscopic scale of human noninvasive observables. However, though microscopic (e.g., two-photon imaging) studies in behaving mice have become a reality in many laboratories, awake mouse fMRI remains a challenge. Owing to variability in behavior among animals, performing all types of measurements within the same subject is highly desirable and can lead to higher scientific rigor. Methods We demonstrated blood oxygenation level–dependent fMRI in awake mice implanted with long-term cranial windows that allowed optical access for microscopic imaging modalities and optogenetic stimulation. We started with two-photon imaging of single-vessel diameter changes (n = 1). Next, we implemented intrinsic optical imaging of blood oxygenation and flow combined with laser speckle imaging of blood flow obtaining a mesoscopic picture of the hemodynamic response (n = 16). Then we obtained corresponding blood oxygenation level–dependent fMRI data (n = 5). All measurements could be performed in the same mice in response to identical sensory and optogenetic stimuli. Results The cranial window did not deteriorate the quality of fMRI and allowed alternation between imaging modalities in each subject. Conclusions This report provides a proof of feasibility for multiscale imaging approaches in awake mice. In the future, this protocol could be extended to include complex cognitive behaviors translatable to humans, such as sensory discrimination or attention.

Approximately 10% of sudden cardiac deaths among patients under 35 years of age is owing to hypertrophic cardiomyopathy (HCM)-related cardiac arrest (CA). CA is often associated with pre-arrest or peri-arrest hypotension and is treated by a set of interventions, including the administration of epinephrine. It is debated whether epinephrine increases or decreases survival to discharge following CA. HCM is associated with septal hypertrophy with a dynamic left ventricular outflow tract obstruction and impaired peripheral vasoconstriction in response to α1-adrenergic stimulation, both of which could cause epinephrine to have a different effect than in the general population. This systematic review of the literature aimed to investigate if patients with HCM in CA have a detrimental hemodynamic response to epinephrine. A literature search was performed in October 2016 using Medline (OVID), Embase (Elsevier), and Cochrane Library (Wiley). The initial search generated 2429 articles, of which 22 articles were found to meet inclusion criteria: four physiology studies, 13 case reports of hypotensive HCM patients, and five case reports of HCM patients in CA. The reviewed studies demonstrate that epinephrine effect varies in patients with HCM: in some cases, the expected hypertensive effect was obtained, but in others, a paradoxical hypotensive effect, or no effect, was observed. The probable mechanism of this effect is an increased left ventricular outflow tract obstruction. Other drugs were considered in several of these cases. In summary, the retrieved studies jointly suggest that patients with HCM may respond differently to epinephrine than patients without HCM. The suitability of epinephrine in HCM-associated CA is questionable.

Background and Aim: The purpose of this study was to compare the effect of thiopental sodium-midazolam combination on the stress response and hemodynamic changes between tracheal intubation and laryngeal mask airway insertion during airway management. Materials and Methods: In this clinical trial study, 70 patients ASA 1, 2 candidates for elective surgery were randomly divided into two groups of tracheal intubation and laryngeal airway mask insertion. Hemodynamic variables including mean arterial pressure, heart rate, and arterial oxygen saturation were measured and compared between the two groups before and after intubation. Results: There was no significant difference between the two groups in regard to demographic data (age, sex, height, and weight), heart rate, mean arterial pressure and arterial oxygen saturation at 1 and 3 minutes after induction of anesthesia and 1, 3, 5 and 10 minutes after intubation. (P> 0.05). But there were significant differences between the two groups in relation to heart rate at 1 and 3 minutes after intubation, so that heart rate at these times was significantly higher in the intubation group than in the laryngeal airway mask group (P

Background Motor impairments are frequently associated with preterm birth and interfere in acquisition of essential skills to global development. Using Near Infrared Spectroscopy (NIRS), the study of neural correlates of motor development in early stages of life are feasible in an ecological assessment. Aims To evaluate changes in cortical activity in response to a sensorimotor stimulation in preterm and full-term infants at 6 and 12 months of age. Study design A longitudinal study was conducted with 22 infants (12 preterm and 10 full-term). Hemodynamic activity during sensorimotor task (8 blocks of 8 s of vibration applied to infant's right hand) was measured by Functional Near Infrared Spectroscopy (fNIRS). The optical probe consisted of 84 channels positioned according to the international 10–20 system coordinates, covering the frontal (38 channels), parietal (16 channels), temporal (22 channels) and occipital (8 channels) lobes of both hemispheres. Results Preterm and full-term infants exhibited differences of location of the activation as well on the hemodynamic response in both the evaluated age groups. Conclusions Group differences in activation of sensorimotor cortex observed in this study demonstrate the potential of fNIRS application for preterm evaluation of motor development in children. Overall, the present work contributes to our understanding of cortical activation of cerebral motor skills spanning early ages in preterm-born children.

Introduction: Failure to secure the airway can lead to adverse cardiopulmonary events, brain damage or even anaesthetic death. The advent of various optical or video laryngoscopes have brought about a revolution in airway management. Truview PCDTM laryngoscope is a recently introduced device with a unique blade and prismatic lens which without external manipulation makes visualization of laryngeal inlet much easier. We have therefore compared glottic visualization haemodynamic response and ease of intubation between Truview PCDTM, McCoy and Macintosh laryngoscope blades. Material and Methods: Patients were randomly allocated into three groups of 40 each. Group I-Truview PCD TM laryngoscope, group II- McCoy laryngoscope and group III- Macintosh laryngoscope group. After induction patients were intubated with appropriate blade according to the group allocated. Visualization of laryngeal inlet was graded using Modified Cormack and lehane. Ease of intubation was also graded and hemodynamic parameters were noted on following occasions. Baseline (T1), before induction (T2), after induction (T3), immediately after intubation (T4), 1 min, 3 min and 5 min after intubation (T5,T6 and T7 respectively). Result: Quantitative variables were co-related using ANOVA/Kruskal Wallis test between the three groups and post hoc comparison was performed by independent T test/ Mann-Whitney test (when the data sets were not normally distributed) between the two groups. Qualitative variables were correlated using Chi-square test/Fisher’s exact test. The data was entered in MS EXCEL spreadsheet and analysis was done using Statistical Package for Social Sciences (SPSS) version 21.0 (Chicago, USA). A P-value of There was a difference in visualization of glottis which was statistically significant between the three groups (P Conclusion: Truview PCD TM laryngoscope blade can be used in difficult airway situation to visualize glottis. The time taken to intubate is longer and failure rate i

Introduction: Endotracheal extubation can be associated with hypertension, tachycardia, arrhythmias, myocardial ischemia and raised intracranial pressures due to sympathetic stimulation. Aim: To compare the efficacy of dexmedetomidine, fentanyl and placebo in decreasing stress response to tracheal extubation in elective general surgery patients. Materials and Methods: 180 patients of either sex, ASA grade I -II normotensive, aged 18-65 years undergoing elective general surgeries of 60-180 minutes duration under general anaesthesia were randomized into 3 groups. Anaesthetic technique was standardized. Patients in Group N, F and D received an IV infusion of 100 ml of 0.9% normal saline, fentanyl 1?g/kg and dexmedetomidine 0.5?g/kg respectively 10 minutes before extubation for a period of 10 minutes. HR, SBP, DBP, MAP and SPO2 were recorded before, during and after extubation. Results: Statistically significant lesser increase in HR, SBP, DBP, MAP were noted after extubation in the dexmedetomidine group than the fentanyl group. Dexmedetomidine group had better extubation quality than the fentanyl group. Ramsay sedation and Aldrete scores were similar in all 3 groups. Hypotension and bradycardia were more with dexmedetomidine group than the fentanyl group but none required intervention. Conclusion: Dexmedetomidine 0.5?g/kg infusion administered 10 minutes before tracheal extubation was better compared to fentanyl 1?g/kg infusion in attenuating the hemodynamic stress response with comparable adverse effects. Hence, dexmedetomidine infusion can be a safer alternative to fentanyl infusion for attenuating extubation stress response. Keywords: Dexmedetomidine, Fentanyl, Extubation, Hemodynamic response.

Background Spatial and temporal resolution of brain network activity can be improved by combining different modalities. Functional Magnetic Resonance Imaging (fMRI) provides full brain coverage with limited temporal resolution, while electroencephalography (EEG), estimates cortical activity with high temporal resolution. Combining them may provide improved network characterization. New Method We examined relationships between EEG spatiospectral pattern timecourses and concurrent fMRI BOLD signals using canonical hemodynamic response function (HRF) with its 1st and 2nd temporal derivatives in voxel-wise general linear models (GLM). HRF shapes were derived from EEG-fMRI time courses during “resting-state”, visual oddball and semantic decision paradigms. Results The resulting GLM F-maps self-organized into several different large-scale brain networks (LSBNs) often with different timing between EEG and fMRI revealed through differences in GLM-derived HRF shapes (e.g., with a lower time to peak than the canonical HRF). We demonstrate that some EEG spatiospectral patterns (related to concurrent fMRI) are weakly task-modulated. Comparison with existing method(s) Previously, we demonstrated 14 independent EEG spatiospectral patterns within this EEG dataset, stable across the resting-state, visual oddball and semantic decision paradigms. Here, we demonstrate that their time courses are significantly correlated with fMRI dynamics organized into LSBN structures. EEG-fMRI derived HRF peak appears earlier than the canonical HRF peak, which suggests limitations when assuming a canonical HRF shape in EEG-fMRI. Conclusions This is the first study examining EEG-fMRI relationships among independent EEG spatiospectral patterns over different paradigms. The findings highlight the importance of considering different HRF shapes when spatiotemporally characterizing brain networks using EEG and fMRI.

The hemodynamic response function (HRF), a model of brain blood-flow changes in response to neural activity, reflects communication between neurons and the vasculature that supplies these neurons in part by means of glial cell intermediaries (e.g., astrocytes). Intact neural-vascular communication might play a central role in optimal cognitive performance. This hypothesis can be tested by comparing healthy individuals to those with known white-matter damage and impaired performance, as seen in Multiple Sclerosis (MS). Glial cell intermediaries facilitate the ability of neurons to adequately convey metabolic needs to cerebral vasculature for sufficient oxygen and nutrient perfusion. In this study, we isolated measurements of the HRF that could quantify the extent to which white-matter affects neural-vascular coupling and cognitive performance. HRFs were modeled from multiple brain regions during multiple cognitive tasks using piecewise cubic spline functions, an approach that minimized assumptions regarding HRF shape that may not be valid for diseased populations, and were characterized using two shape metrics (peak amplitude and time-to-peak). Peak amplitude was reduced, and time-to-peak was longer, in MS patients relative to healthy controls. Faster time-to-peak was predicted by faster reaction time, suggesting an important role for vasodilatory speed in the physiology underlying processing speed. These results support the hypothesis that intact neural-glial-vascular communication underlies optimal neural and cognitive functioning.

Introduction: Laryngoscopy and endotracheal intubation during induction of general anaesthesia are extremely strong nociceptive stimuli, which often lead to unintended stimulating of the sympathetic nervous system manifested by increased arterial pressure and tachycardia.1 The present study aimed to assess usefulness of neuromuscular monitoring with peripheral nerve stimulator in reducing the haemodynamic response to laryngoscopy and tracheal intubation using vecuronium. Material and Methods: This study included 100 cases classified randomly into two group (Each n= 50). Group I (C) (n=50): control group: Laryngoscopy and tracheal intubation done at the end of 3 minutes after administration of 0.1mg/kg body weight of intravenous iv vecuronium. Group II (N) n=50: Neuromuscular monitoring done after giving 0.1mg/kg body weight of intravenous vecuronium using TOF with supramaximal stimuli of current intensity 50 mA at right ulnar nerve, and the response of the thumb is monitored every 10 seconds, once all the responses for TOF are lost, the time noted and laryngoscopy and endotracheal intubation were performed. Statistical Analysis: Independent- Samples t test, Cross tabs and Repeated Measure ANOVA were used. SPSS for windows (version 17.0) was employed for data analysis. p Results: Group-N (study group) showed statistically significant decreased haemodynamic response to laryngoscopy and intubation after iv Vecuronium, when compared to Group-C (control group). Conclusion: Neuromuscular monitoring by using PNS at AP is useful to have good intubation condition and to reduce the haemodynamic response to laryngoscopy and intubation. Keywords: Peripheral nerve stimulator, Train of four, Adductor pollicis muscle, Vecuronium, Intubation, Haemodynamic response.

Objective: Present study was performed to compare the effectiveness of bupivacaine and ropivacaine for scalp block on the haemodynamic response during skull-pin insertion. Materials and Method: Ninety patients who underwent elective craniotomy were divided into two equal groups (n=45). After routine induction, patients were intubated. All the patients received scalp blocks with 20 ml of either 0.5% bupivacaine (group B) or 0.5% ropivacaine (group R) approximately 5 minutes before skull-pins insertion. Heart rate (HR) and mean arterial pressure (MAP) were recorded at 60sec, 120 sec and 300 sec following head pin insertion. Results: MAP and HR were stable during and after head pinning in both the groups at all time points. Conclusion: Both bupivacaine and ropivacaine for scalp block are equally effective for blunting hemodynamic responses during head pinning. Ropivacaine being less toxic can be a safe alternative for scalp block. Keywords: Anaesthesia, Local anaesthesia, Scalp block, Bupivacaine, Ropivacaine, Hemodynamic.

The physiological changes caused by laryngoscopy and intubation are due to sympathetic discharge leads to increase in blood pressure, heart rate, oxygen consumption, leading to haemodynamic instability which may cause myocardial ischemia, left ventricular failure or cerebral hemorrhage. Aims And Objective: To assess the efficacy and safety of dexmedetomedine in attenuating haemodynamic stress response to laryngoscopy and endotracheal intubation. Materials and Methods: After institutional review board approval, 100 patients posted for planned surgery were randomized in to two groups to receive 100 ml of normal saline in Group C and Inj. dexmedetomidine 1?g/kg in 100 ml of normal saline in Group D intravenously over 10 minutes, 30 minutes before induction. Standard general anesthesia was given to all patients. Patients were monitored for haemodynamic changes and Sedation score at various specific timings as per the protocol. Result: There was significant decrease in heart rate and blood pressure after giving infusion of dexmedetomedine and remain stable during and after laryngoscopy and intubation. Conclusion: We conclude that dexmedetomidine in a dose of 1?g/kg given half an hour before induction effectively blunts the haemodynamic response to laryngoscopy and endotracheal intubation. Keywords: Hemodynamic stress response, Laryngoscopy, General anaesthesia, Dexmeditomidine.

Complex walking conditions (e.g. dual tasking) have been associated with increased prefrontal (PFC) activity. However, most paradigms include a predictable environment, specifically, a predictable walking terrain. In the present study we investigate PFC activity under an unusual walking condition where each foot placement was on unexpected terrain, thus causing a mismatch between visuospatial perception and lower-extremity proprioception.To assess whether PFC activity increases under unstable unpredictable conditions compared to unstable but predictable conditions.This was a prospective study involving twenty healthy adults. Participants walked in two conditions: unstable but predictable, and unstable and unpredictable. To assess walking stability, both stride-time (ST) and stride-time variability (CV) were measured. To assess PFC activity, two wireless near-infrared spectroscopy devices were used. The group hemodynamic response (GHR) was calculated for each condition. For statistical analysis, a linear-mixed-effects model was used.Walking with unpredictable perturbations did not change the ST (t = 0.51, p = 0.61) but significantly increased the parameter CV (t = 11.74, p 0.001). The GHR of both conditions indicated brief per-initiation PFC activity that was similar across conditions. However, when GHRs were calculated relative to normal walking (i.e., the participants' own shoes), continuous activity was evident. Compared to the predictable condition, the unpredictable condition significantly increased this activity during steady-state walking (t = 2.13, p = 0.033).Observations from the present study suggest that at least two neural components are present in the measured signal-a brief one, occurring per-initiation, and a continuous one, sensitive to the predictability of the terrain. The second component was accompanied by a decrease in walking stability. These results may contribute to our understanding of the control mechanism underlying gait and future planning of rehabilitation protocols.

In patients with heart failure, downregulation of adenosine receptor gene expression and impaired adenosine-related signal transduction may result in a diminished response to adenosine. This may have implications for cardiac stress testing. We evaluated the haemodynamic response to intravenous adenosine in patients with left ventricular systolic dysfunction (LVSD) undergoing stress cardiovascular magnetic resonance imaging (CMR).We retrospectively examined 497 consecutive patients referred for clinical stress CMR. Blood pressure and heart rate responses with intravenous adenosine were compared in patients with normal, mild-moderately impaired and severely impaired LV systolic function (ejection fraction [EF] 55%, 36-55% and 35%, respectively). Following 2 min of adenosine infusion, there was a significant difference between the groups in the heart rate change from baseline, with a diminished heart rate response in patients with LVSD (p 0.001). An increase in the dose of adenosine (up to 210 μg/kg/min) was required to achieve a sufficient haemodynamic response in more patients with severe LVSD (41%) than those with mild-moderately impaired and normal LV systolic function (24% and 19%, respectively, p 0.001). Even with increased doses of adenosine in subjects with severe LVSD, peak haemodynamic response remained blunted. With multivariate analysis age (p 0.001) and LVEF (p = 0.031) were independent predictors of heart rate response to adenosine.Patients with reduced LVEF referred for stress CMR may have a blunted heart rate response to adenosine. Further study is warranted to determine whether this may be associated with reduced diagnostic accuracy and also the potential utility of further dose increases or alternative stressors.

BACKGROUND Endotracheal intubation is considered gold standard in patients undergoing general anaesthesia. Direct laryngoscopy and tracheal intubation result in an increase in blood pressure and heart rate, the so called ‘pressor response’. Various techniques and drugs have been used in the past to attenuate the pressor response, however none has been proved to be ideal. We conducted this study to compare any possible blunting of cardiovascular effects of laryngoscopy and tracheal intubation by the use of 150 mg pregabalin or 200mcg clonidine with the group that did not receive any of the two drugs. MATERIALS AND METHODS 90 ASA Grade 1 and 2 patients aged 18-60 years of both genders were recruited for the study with 30 patients in each group. Group A – Received oral pregabalin 150 mg with sip of water 120 min before the surgery. Group B – Received oral clonidine 200 mcg with sip of water 120 min prior to surgery. Group C – Oral placebo (multivitamin) with sip of water 120 min prior to surgery. On arrival in the operating room, HR, SBP, DBP, MAP were recorded at baseline, after induction, 1-, 3-, 5- and 10-mins after laryngoscopy and intubation. RESULTS In this study, there was a significant reduction in HR, SBP, DBP, MAP after laryngoscopy and intubation in pregabalin and clonidine group in comparison to control group. Oral premedication with pregabalin as well as clonidine attenuates the haemodynamic response to laryngoscopy and intubation with clonidine being superior to pregabalin.

Accurate estimates of the BOLD hemodynamic response function (HRF) are crucial for the interpretation and analysis of event-related functional MRI data. To date, however, there have been no comprehensive measurements of the HRF in white matter (WM) despite increasing evidence that BOLD signals in WM change after a stimulus. We performed an event-related cognitive task (Stroop color-word interference) to measure the HRF in selected human WM pathways. The task was chosen in order to produce robust, distributed centers of activity throughout the cortex. To measure the HRF in WM, fiber tracts were reconstructed between each pair of activated cortical areas. We observed clear task-specific HRFs with reduced magnitudes, delayed onsets and prolonged initial dips in WM tracts compared with activated grey matter, thus calling for significant changes to current standard models for accurately characterizing the HRFs in WM and for modifications of standard methods of analysis of functional imaging data., The hemodynamic response function (HRF) describes how changes in brain activity manifest as a transient signal (BOLD) that is detected by fMRI imaging. Here, the authors show that the HRF in white matter shows reduced magnitudes, delayed onsets, and prolonged initial dips compared to the grey matter HRF.

The physiological consequences of freely chosen cadence during cycling remains poorly understood. We sought to determine the effect of cadence on the respiratory and hemodynamic response to cycling exercise.Eleven cyclists (10 males, 1 female; age, 27 ± 6 yr; V˙O2max = 60.8 ± 3.7 mL·kg·min) completed four, 6-min constant-load cycling trials at 10% below their previously determined gas exchange threshold (i.e., 63% ± 5% peak power) while pedaling at 60, 90, and 120 rpm, and a freely chosen cadence (94.3 ± 6.9 rpm) in randomized order. Standard cardiorespiratory parameters were measured and an esophageal electrode balloon catheter was used to assess electromyography of the diaphragm (EMGdi) and the work of breathing (Wb). Leg blood flow index (BFI) was determined on four muscles using near-infrared spectroscopy with indocyanine green dye injections.Oxygen uptake (V˙O2) increased as a function of increasing cadence (all pairwise comparisons, P0.05). The EMGdi and Wb were significantly greater at 120 rpm compared with all other conditions (all P0.01). Vastus medialis and semitendinosus BFI were significantly greater at 120 rpm compared with 60 and 90 rpm (all P0.05). Gastrocnemius BFI was higher at 120 rpm compared with all other cadences (all P0.01). No difference in BFI was found in the vastus lateralis (P = 0.06). Blood flow index was significantly correlated with the increase in V˙O2 with increasing cadence in the medial gastrocnemius (P0.001) and approached significance in the vastus lateralis (P = 0.09), vastus medialis (P = 0.06), and semitendinosus (P = 0.09). There was no effect of cadence on Borg 0-10 breathing or leg discomfort ratings (P0.05).High cadence cycling at submaximal exercise intensities is metabolically inefficient and increases EMGdi, Wb, and leg muscle blood flow relative to slower cadences.

β-Thalassemia major (β-TM) patients are at increased risk for cardiovascular diseases. Determination of subclinical cardiac involvement is essential for preventive measures. Thus, we aimed to evaluate the role of stress echocardiography for identification of subclinical cardiac dysfunction in β-TM patients. In this prospective study, 45 β-TM patients who were referred for cardiac evaluation, were enrolled. Exclusion criteria included non sinus rhythm and overt cardiac disease. Stress echocardiography levels and cardiac magnetic resonance imaging (MRI) results were obtained from β-TM patients. Patients were divided into two groups of normal vs. iron overload from cardiac T2* greater or less than 20 msec, respectively. Resting and peak exercise right ventricular stroke volume (RVSV) and left ventricular SV (LVSV) were significantly lower in iron overload vs. normal β-TM patients, respectively (p value

Background and Purpose— Small-vessel damage in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is associated with impaired vascular constriction and dilation. We used a functional magnetic resonance imaging task with an event-related design of stimulus to explore the anticipated abnormally decreased blood oxygen level dependent effect in CADASIL. Methods— Twenty-one CADASIL patients and 16 healthy controls performed a Go/No-go task exploring reactive and proactive phases of inhibition control in a 3-T magnet. Results— Error number and reaction times were not different between patients and controls. Analysis of the reactive inhibition (No-go/baseline contrast) did not show clusters of lower or higher blood oxygen level dependent effect in patients or controls. Analysis of the proactive inhibition (alertness contrast) in CADASIL patients revealed a lower blood oxygen level dependent effect in the alerting network (anterior cingulate cortex and insula, thalamus), lower brain stem and left cerebellar hemisphere (crus I) that is involved in executive functions. Conclusions— In CADASIL patients, an event-related Go/No-go task reveals a lower blood oxygen level dependent effect in the alerting network and areas involved in executive functions possibly reflecting the altered hemodynamic response secondary to small-vessel changes. Our observation extends the role of MR in demonstrating one of the fundamental pathophysiological changes of CADASIL.