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This study presents the first implementation of functional ultrasound (fUS) imaging of the spinal cord to monitor local hemodynamic response to epidural electrical spinal cord stimulation (SCS) on two small and large animal models. SCS has been successfully applied to control chronic refractory pain and recently was evolved to alleviate motor impairment in Parkinson's disease and after spinal cord injury. At present, however, the mechanisms underlying SCS remain unclear, and current methods for monitoring SCS are limited in their capacity to provide the required sensitivity and spatiotemporal resolutions to evaluate functional changes in response to SCS. fUS is an emerging technology that has recently shown promising results in monitoring a variety of neural activities associated with the brain. Here we demonstrated the feasibility of performing fUS on two animal models during SCS. We showed in vivo spinal cord hemodynamic responses measured by fUS evoked by different SCS parameters. We also demonstrated that fUS has a higher sensitivity in monitoring spinal cord response than electromyography. The high spatial and temporal resolutions of fUS were demonstrated by localized measurements of hemodynamic responses at different spinal cord segments, and by reliable tracking of spinal cord responses to patterned electrical stimulations, respectively. Finally, we proposed optimized fUS imaging and post-processing methods for spinal cord. These results support feasibility of fUS imaging of the spinal cord and could pave the way for future systematic studies to investigate spinal cord functional organization and the mechanisms of spinal cord neuromodulation in vivo. [ABSTRACT FROM AUTHOR]

Recently, a standing desk is being installed as a behavior change strategy to reduce sitting time in the workplace. However, the standing posture has been suggested to decrease forehead oxygenated hemoglobin (oxy-Hb), which might impair task performances. Therefore, we examined whether prolonged standing impairs speed and accuracy of computer subtraction task associated with a decrease in forehead oxy-Hb. Nine healthy young males completed 4 × 15-min computer tasks under two conditions, i.e., sitting and standing. In the computer tasks, all subjects were required to subtract a two-digit number from a four digit number written on the paper and to input the answer to the answer colomn on the computer. Task performances were evaluated as the number of achievements and accuracy rate every 15 minutes. Moreover, oxy- Hb and deoxygenated-hemoglobin (deoxy-Hb) in the site of left forehead area and lower limb were monitored throughout the experimental period by near-infrared spectroscopy. Forehead oxy-Hb was significantly associated with the number of achievements during computer tasks (p < 0.001). In addition, forehead oxy-Hb and task performances did not differ between sitting and standing. The number of achievements of subtraction task under standing condition was significantly decreased as time proceeds. Our results demonstrate that prolonged standing might impair computer subtraction task performances irrespective of the change in forehead oxy-Hb. [ABSTRACT FROM AUTHOR]

Purpose: in order to assess the adaptive hemodynamic responses formed in humans during cyclic stay (daily, for 2 hours, 15 sessions in total) in normobaric hypoxic gaseous environment with oxygen content in nitrogen of 15% (NHGE-15).Materials and methods: a study has been conducted with participation of 12 male test subjects aged 25-52. In course of cyclic stay in NHGE-15, systemic and cerebral blood flow parameters were evaluated in the test subjects.Results: in response to stay in NHGE, at the initial stage of the testing procedure, the test subjects showed hyperkinetic systematic circulation reactions: cardiac acceleration, increase in systemic blood pressure and cardiac output, with decrease in peripheral vascular resistance. At the same time, an increase in blood flow to cerebral vessels and hypersthenia in major cerebral vessels were revealed. Further stay in NHGE-15 was accompanied by a statistically significant reduction in severity of the above responses reflecting a gradual decrease in «stressfulness» of hypoxic effect due to formation in the body of primary adaptational structural and functional alterations in oxygen transport systems, regulatory and plastic processes. The fact of systemic and regional hemodynamics parameter optimizing was also revealed, recorded under normal conditions of gaseous environment, in course of the cyclic hypoxic impact.Summary: hypoxic exposure on the human body leads to centralization of the circulatory system, aimed at the maintenance of oxygen supply of vital organs. The result of hypoxic training is to reduce the severity of the reaction by increasing the reliability of functioning of the system of hemodynamics and its regulatory mechanisms.

This research aims to investigate the development of muscle fatigue and the recovery process revealed by tissue oxygenation. The tissue hemodynamics were measured by near-infrared spectroscopy (NIRS) during a 30-min pre-exercise rest, a 40-cycle heel-lift exercise and a 30-min post-exercise recovery. Wavelet transform was used to obtain the normalized wavelet energy in six frequency intervals (I–VI) and inverse wavelet transform was applied to extract exercise-induced oscillations from the hemodynamic signals. During the exercise phase, the contraction-related oscillations in the total hemoglobin signal (ΔtHb) showed a decreasing trend while the fluctuations in the tissue oxygenation index (TOI) displayed an increasing tendency. The mean TOI value was significantly higher (p < 0.001) under recovery (65.04% ± 2.90%) than that under rest (62.35% ± 3.05%). The normalized wavelet energy of the ΔtHb signal in frequency intervals I (p < 0.001), II (p < 0.05), III (p < 0.05) and IV (p < 0.01) significantly increased by 43.4%, 23.6%, 18.4% and 21.6% during the recovery than that during the pre-exercise rest, while the value in interval VI (p < 0.05) significantly decreased by 16.6%. It could be concluded that NIRS-derived hemodynamic signals can provide valuable information related to muscle fatigue and recovery.

Background and Aims: The role of nitro-glycerine (NTG) lingual spray for attenuation of the hemodynamic response associated with intubation is not much investigated. We conducted this study to evaluate the efficacy of NTG lingual pump or pen spray in attenuation of intubation induced hemodynamic responses and to elucidate the optimum dose. Material and Methods: In a prospective randomized controlled trial, 90 adult patients of ASA I, II, 18-60 year posted for elective general surgery under general anesthesia with intubation were randomly allocated to three groups as Group C (control) - receiving no NTG spray, Group N1 - receiving 1 NTG spray and Group N2 - receiving 2 NTG spray one minute before intubation. Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate were recorded at baseline, just before intubation (i.e., 60 s just after induction and NTG spray), immediately after intubation, at 1, 2, 5 and 10 min after intubation. Results: Incidence of hypertension was significantly higher in Group C (60%, n = 18) as compared to Group N1 and N2 (10%, n = 3 each), P < 0.01. Mean value of SBP, DBP and MAP showed a significant rise as compared to baseline, following intubation in control group (15.31% in SBP, 12.12% in DBP, 17.77% in MAP) that persisted till 5 min, while no significant rise was observed in Group N1 and N2. There was a trend toward fall in blood pressure in Group N2 (4.95% fall in SBP, 4.72% fall in MAP) 1-min following spray, which was clinically insignificant. Mean value of SBP, DBP and MAP was significantly higher in Group C than in Group N1, which was in turn greater than Group N2 (Group C > N1> N2), P < 0.05. However, incidence of tachycardia was comparable in three groups (70% in group C, 63.33% in Group N1 and 67.77% in Group N2, P > 0.05). Conclusions: We concluded that the NTG lingual spray in dose of 0.4 mg (1 spray) or 0.8 mg (2 sprays) was effective in attenuation of intubation induced hemodynamic response, in terms of preventing significant rise in SBP, DBP and MAP compared to control group.

Aim: The aim of this study was to compare the effects of direct laryngoscopy and videolaryngoscopy on the intubation conditions and hemodynamic responses, in the patients scheduled for tympanoplasty and mastoidectomy operation and intubated without muscle relaxation. Material and Methods: This randomized, prospective study was performed in 62 patients aged 18-65 years with ASA (American Society of Anesthesiologists) I-II and Mallampati score I-II and scheduled for elective tympanoplasty and mastoidectomy with general anesthesia. The patients were divided into two groups as the direct laryngoscopy group (Group D) and the videolaryngoscopy group (Group V). The induction of anesthesia was performed with 1 mg / kg lidocaine, 3 µg / kg remifentanil and 2.5 mg / kg propofol for both groups. Hemodynamic responses (heart rate, systolic arterial pressure, diastolic arterial pressure, and mean arterial pressure), number of intubation attempts, duration of laryngoscopy, duration of intubation, intubation conditions (degree of coughing, jaw relaxation, ease of laryngoscopy and position of vocal cords), and postoperative hoarseness and sore throat were evaluated. Results: Hemodynamic responses to intubation were similar in both groups. There were no statistically significant differences between the groups in terms of the number of intubation attempts and the duration of laryngoscopy. The duration of intubation was significantly longer in Group V (29.19 sec) than in Group D (22.19 sec). Intubation conditions showed no significant difference between the groups. Conclusion: In patients without intubation difficulty, McGrath® MAC video laryngoscope showed no superiority in intubation conditions compared with Macintosh direct laryngoscope, during intubation without muscle relaxants; the effects on hemodynamic responses were also similar. [ABSTRACT FROM AUTHOR]

Highlights • Physical principles of various neuro-imaging techniques and their advancements. • Structural and functional aspects of brain from neuro-imaging techniques. • Combined study advantages of different techniques to improve spatial and temporal resolutions. Abstract The aim of this article is to highlight current approaches for imaging elderly brain, indispensable for cognitive neuroscience research with emphasis on the basic physical principles of various non-invasive neuroimaging techniques. The first part of this article presents a quick overview of the primary non-invasive neuroimaging modalities used by cognitive neuroscientists such as transcranial magnetic stimulation (TMS), transcranial electrical stimulation (tES), electroencephalography (EEG), magnetoencephalography (MEG), single photon emission computed tomography (SPECT), positron emission tomography (PET), magnetic resonance spectroscopic imaging (MRSI), Profusion imaging, functional magnetic resonance imaging (fMRI), near infrared spectroscopy (NIRS) and diffusion tensor imaging (DTI) along with tractography and connectomics. The second part provides a comprehensive overview of different multimodality imaging techniques for various cognitive neuroscience studies of aging brain. [ABSTRACT FROM AUTHOR]

Background & Objective: The induction of anesthesia, laryngoscopy and endotracheal intubation can be associated with adverse hemodynamic response and increased intraocular pressure. The aim of this study was to evaluate intraocular pressure and hemodynamic changes after laryngoscopy and endotracheal intubation with three methods of laryngoscopy (Macintosh, Maccoy and Video laryngoscope).Materials & Methods: One hundred and eighty patients with American Society of Anesthesiology (ASA) classification of I and II, aged 20-70 year, were enrolled in a randomized clinical trial (RCT). Anesthesia was induced by administration of Propofol 2 mg/kg, Fentanyl 1µg/kg and Cisatracurium 0.1mg/kg. the Hemodynamic information of the patients and intraocular pressures were documented and assessed in three stages (after induction of anesthesia and endotracheal intubation, and 5 minutes after endotracheal intubation using Maccoy, Macintosh and Video laryngoscope).Results: Hemodynamic parameters' of patients increased in these three groups compared with those of pre anesthesia measures, but this increase was not significant. Evaluation of intraocular pressure (IOP) in Video laryngoscope group showed that there is a significant drop in intraocular pressure (IOP) compared with other groups. There weren’t any significant differences of IOP after intubation in Maccoy compared to the Macintosh group. Nevertheless there was not any significant difference in IOP, before and five minutes after intubation in these groups.Conclusion: According to a low degree of augment of IOP in Video laryngoscope group and no changes in the Hemodynamic parameters, it seems that the use of Video laryngoscope in eye surgeries might be more suitable for endotracheal intubation.

Background: The aim of this study was to evaluate intraocular pressure (IOP) and hemodynamic responses following insertion of laryngeal mask airway (LMA) or endotracheal tube (ETT) after anesthesia induction with propofol and remifentanil in cataract surgery. Materials and Methods: In a randomized controlled study, 50 adults scheduled for elective cataract extraction procedure under general anesthesia were allocated to LMA insertion (n = 25) or ETT (n = 25) groups. IOP, systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) were measured after insertion of the airway device every minute up to 5 min. Results: There were no significant differences between LMA and ETT groups in SBP, DBP, HR, and IOP immediately after airway instrumentation up to 5 min, except in 4th min in DBP, 2nd min in HR, and 5th min in IOP (7.9 ± 2.3 mmHg in LMA and 9.4 ± 2.5 mmHg in ETT group; P = 0.030). There was good surgeon satisfaction for providing acceptable surgical field in both groups (88% in LMA and 80% in ETT group; P = 0.702). Conclusion: Propofol combined with remifentanil provides good and excellent conditions for insertion of LMA or ETT with minimal hemodynamic disturbances in cataract surgery. Considering LMA insertion is less traumatic than ETT, using LMA may be better than ETT for airway securing in these patients.

OBJECTIVES: We compared hemodynamic responses and upper airway morbidity following tracheal intubation via conventional laryngoscopy or intubating laryngeal mask airway in hypertensive patients. METHODS: Forty-two hypertensive patients received a conventional laryngoscopy or were intubated with a intubating laryngeal mask airway. Anesthesia was induced with propofol, fentanyl, and cis-atracurium. Measurements of systolic and diastolic blood pressures, heart rate, rate pressure product, and ST segment changes were made at baseline, preintubation, and every minute for the first 5 min following intubation. The number of intubation attempts, the duration of intubation, and airway complications were recorded. RESULTS: The intubation time was shorter in the conventional laryngoscopy group than in the intubating laryngeal mask airway group (16.33 ± 10.8 vs. 43.04±19.8 s, respectively) (p

Objective: Exercise training has assumed a major role in cardiac rehabilitation, mostly because of its positive effects on myocardial perfusion in patient with coronary artery disease. Improvement of peripheral vascular system and myocardial contractile function have been suggested as potential adaptations. The purpose of this study was to determine the effect of concurrent training on hemodynamic responses in patients with coronary artery disease. Materials & Methods: In this interventional and experimental study twenty four patient (50-75 years old) with coronary artery disease were selected by sample of convenience and through a directive goal oriented sampling and were randomly divided to two subgroups, experimental (n=12) and control (n=12) groups. The experimental group participated in 3 months concurrent training, 3 times/week for 60 to 80 minute at 70% to 85% of MHR and 40% to 60% of 1RM. Investigation variables were assessed at baseline and at the end of the protocol by the impedance cardiography method. Data were analyzed by T test. Results: A significant training effect was documented by an decrease in heart rate and blood pressure at rest. Stroke volume (SV) increased from 60±8 to 81±13 ml/beats, Stroke index (SI) increased from 33±4 to 44±6 ml/beat/m2, Cardiac output (CO) increased from 4±1 to 5±1 l/min and Cardiac index (CI) increased from 2±0.5 to 3±0.5 l/min/m2 (P

Purpose The study investigated the acute effects of different initial restrictive pressures ( IRP; tightness of cuffs before inflation with air) on heart rate ( HR), systolic ( SBP) and diastolic blood pressure ( DBP), rating of perceived exertion ( RPE), respiratory exchange ratio ( RER) and energy expenditure ( EE) during constant-load upright cycling. Methods In a within subject study design, 34 obese men (age = 24·3, n = 18) and women (age = 23·1, n = 16) completed three cycling sessions (two blood flow restriction and one control sessions). The cycling exercise was performed with an external load of 1kp at 50 rpm for 20 min with 1-min rest after the 10th-min. The blood flow restriction ( BFR) cuffs were placed on the thigh of both legs during BFR sessions and IRP and IRP of ~40 or ~60 mmHg were applied in random order. Results There were significant condition × time interactions for HR, SBP, RPE and RER and time × gender interactions for HR and SBP. There were also significant condition and time main effects for HR, SBP, RPE and RER ( P<0·01) and a significant condition effect for EE ( P<0·05). Conclusion The intensity of exercise with BFR was higher and affected by IRP, but the subjects perceived the effort as 'light'. Low-intensity cycling with BFR shows potential to reduce the time requirement per session to elicit greater EE while placing greater demands on the circulatory system. [ABSTRACT FROM AUTHOR]

Cognitive decline is a natural phenomenon of aging. Although there exists a consensus that sensitivity to acoustic features of music is associated with such decline, no solid evidence has yet shown that structural elements and contexts of music explain this loss of cognitive performance. This study examined the extent and the type of cognitive decline that is related to the contour identification task (CIT) using tones with different pitches (i.e., melodic contours). Both younger and older adult groups participated in the CIT given in three listening conditions (i.e., focused, selective, and alternating). Behavioral data (accuracy and response times) and hemodynamic reactions were measured using functional near-infrared spectroscopy (fNIRS). Our findings showed cognitive declines in the older adult group but with a subtle difference from the younger adult group. The accuracy of the melodic CITs given in the target-like distraction task (CIT2) was significantly lower than that in the environmental noise (CIT1) condition in the older adult group, indicating that CIT2 may be a benchmark test for age-specific cognitive decline. The fNIRS findings also agreed with this interpretation, revealing significant increases in oxygenated hemoglobin (oxyHb) concentration in the younger (p < 0.05 for Δpre - on task; p < 0.01 for Δon - post task) rather than the older adult group (n.s for Δpre - on task; n.s for Δon - post task). We further concluded that the oxyHb difference was present in the brain regions near the right dorsolateral prefrontal cortex. Taken together, these findings suggest that CIT2 (i.e., the melodic contour task in the target-like distraction) is an optimized task that could indicate the degree and type of age-related cognitive decline. [ABSTRACT FROM AUTHOR]

Different working memory (WM) mechanisms that underlie words, tones, and timbres have been proposed in previous studies. In this regard, the present study developed a WM test with nonverbal sounds and compared it to the conventional verbal WM test. A total of twenty-five, non-music major, right-handed college students were presented with four different types of sounds (words, syllables, pitches, timbres) that varied from two to eight digits in length. Both accuracy and oxygenated hemoglobin (oxyHb) were measured. The results showed significant effects of number of targets on accuracy and sound type on oxyHb. A further analysis showed prefrontal asymmetry with pitch being processed by the right hemisphere (RH) and timbre by the left hemisphere (LH). These findings suggest a potential for employing musical sounds (i.e., pitch and timbre) as a complementary stimuli for conventional nonverbal WM tests, which can additionally examine its asymmetrical roles in the prefrontal regions. [ABSTRACT FROM AUTHOR]

Using functional near-infrared spectroscopy (fNIRS), hemodynamic responses (i.e., changes in oxygenated and deoxygenated hemoglobin) were measured while participants with Parkinson's disease (PD) and healthy controls performed the Timed-Up-and-Go test (TUGT), and differences in cortical activity at baseline and three different intervals were examined between the two groups. Seventeen PD patients and twenty-two controls participated in the study, but two PD patients were excluded from statistical analysis due to the presence of freezing of gait and using walking aids during the TUGT. During the TUGT, activity in the front, left, right and total frontal cortices initially decreased significantly, then significantly increased in PD participants and low-risk faller PD participants, compared to when in a sitting position. ΔHbO (HbO change from baseline) over the front, left and total frontal cortices in the PD group was significantly lower than the control group in interval 1 (P = 0.019, P = 0.014 and P = 0.031, respectively), while significantly higher than the control group in interval 2 over the left frontal cortex (P = 0.010). No significant differences were observed between the high-risk faller and low-risk faller subgroups of PD participants in ΔHbO and ΔHbR in the three intervals (P > 0.05). In the high-risk faller subgroup, ΔHbO over the left frontal cortex was significantly higher than the right frontal cortex in interval 2 and interval 3 (P = 0.015, P = 0.030, respectively). There was a strong positive correlation between education and HbR concentration over the right frontal cortex in PD participants (rho = 0.557, P = 0.031), while there were strong negative correlations between PD duration and HbR concentration over the right and total frontal cortices in the high-risk faller subgroup of PD participants (rho = −0.854, P = 0.014 for the right; rho = −0.784, P = 0.037 for the total). The falls prediction cutoff TUGT time for PD participants was 14.2 s. These results suggest that frontal cognition training, along with exercise training, could be used as an effective training method to improve motor performance in PD patients, especially for those at high-risk for falls. [ABSTRACT FROM AUTHOR]

Background and Aims: The role of nitro-glycerine (NTG) lingual spray for attenuation of the hemodynamic response associated with intubation is not much investigated. We conducted this study to evaluate the efficacy of NTG lingual pump or pen spray in attenuation of intubation induced hemodynamic responses and to elucidate the optimum dose. Material and Methods: In a prospective randomized controlled trial, 90 adult patients of ASA I, II, 18-60 year posted for elective general surgery under general anesthesia with intubation were randomly allocated to three groups as Group C (control) - receiving no NTG spray, Group N1 - receiving 1 NTG spray and Group N2 - receiving 2 NTG spray one minute before intubation. Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate were recorded at baseline, just before intubation (i.e., 60 s just after induction and NTG spray), immediately after intubation, at 1, 2, 5 and 10 min after intubation. Results: Incidence of hypertension was significantly higher in Group C (60%, n = 18) as compared to Group N1 and N2 (10%, n = 3 each), P < 0.01. Mean value of SBP, DBP and MAP showed a significant rise as compared to baseline, following intubation in control group (15.31% in SBP, 12.12% in DBP, 17.77% in MAP) that persisted till 5 min, while no significant rise was observed in Group N1 and N2. There was a trend toward fall in blood pressure in Group N2 (4.95% fall in SBP, 4.72% fall in MAP) 1-min following spray, which was clinically insignificant. Mean value of SBP, DBP and MAP was significantly higher in Group C than in Group N1, which was in turn greater than Group N2 (Group C > N1> N2), P < 0.05. However, incidence of tachycardia was comparable in three groups (70% in group C, 63.33% in Group N1 and 67.77% in Group N2, P > 0.05). Conclusions: We concluded that the NTG lingual spray in dose of 0.4 mg (1 spray) or 0.8 mg (2 sprays) was effective in attenuation of intubation induced hemodynamic response, in terms of preventing significant rise in SBP, DBP and MAP compared to control group. [ABSTRACT FROM AUTHOR]

The aim of this study was to test the cardiovascular responses during an incremental swimming test. Rats were submitted to 25 min of incremental swimming exercise test in individual tanks filled 45 cm with water at 30°C. At the end of each stage (5 min duration each), ~25 µL of blood were obtained from the caudal vein to evaluate lactate concentration and a load increment was added to the tail (0, 2, 4, 6, and 8% of body wt). Simultaneously with exercise, hemodynamic data were recorded by a catheter filled with saline implanted (24 hrs before) into the carotid artery for direct arterial pressure measurements. Our data show that sedentary rats are able to keep a stable blood lactate concentration in workloads up to 6% of body wt. It is interest that the rats' heart rate decreased with the progression of the intensity and duration of the swimming session that was associated with a slight increase in systolic blood pressure, diastolic blood pressure, and mean blood pressure. The findings offer insight into the rats' cardiovascular responses during an incremental swimming exercise test. [ABSTRACT FROM AUTHOR]

Introduction:  Tracheal intubation and laryngoscopy may cause sympathetic stimulation, which can cause tachycardia and hypertension. To abolish the pressor response to laryngoscopy and endotracheal intubation, many medication combinations have been tried with varying degrees of efficacy., Materials and Methods: This randomized comparative study was double-blinded and included 106 subjects. Patients including those aged 18-60 belong to the American Society of Anesthesiologists (ASA) 1 and 2. These subjects were divided into two study groups. Group A received dexmedetomidine 0.5mcg/kg (200mcg diluted in 50ml syringe with normal saline (NS) up to 50cc 4mcg/ml) through an infusion pump over 40min before induction. Group B received dexmedetomidine intranasally (1mcg/kg) in undiluted which is prepared from parental preparation (100mcg/ml) and an equivalent dose of NS to the other group. The intranasal drug was dripped into both nostrils in equal volume using a 1ml syringe in a supine head-down position about 40min before induction. Both groups received an intravenous placebo and an intranasal placebo with normal saline., Results: In our study, intranasal and intravenous groups were compared. There was no statistically significant difference in hemodynamic variables like heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) between the two groups (majority p value >0.05). Hence both routes can be preferred for attenuation of pressor responses., Conclusion:  Study findings demonstrate dexmedetomidine can be utilized as a premedication to lessen hemodynamic surges during endotracheal intubation with more or less the same efficacy via intranasal and intravenous routes. This result could be attributable to the fact that both intravenous and intranasal dexmedetomidine stop central catecholamine levels from rising., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2023, M.K et al.)

Background And Objective: Alpha-2 agonists are being increasingly used as adjuncts in general anaesthesia, Fentanyl an opioid analgesic, is popular as an intraoperative agent due to the cardiovascular stability provided by it, even in critically ill patients. Present study was carried out to evaluate the effect of dexmedetomidine and fentanyl for attenuation of haemodynamic responses during laryngoscopy and tracheal intubation. Methods: Sixty patients scheduled for elective general surgery under general anaesthesia were randomized into two groups: A and B (n=30 in each group). Study group A patients were given inj. dexmedetomidine 1μg kg-1 diluted to 20ml normal saline infused in 10 minutes with infusion pump and group B were given inj. fentanyl 2μg kg-1 diluted to 20ml normal saline infused in 10 minutes with infusion pump, inj. Propofol (2mg/kg) i.v were used as induction agent. Anaesthesia was maintained with 40:60 oxygen: nitrous oxide, isoflurane (0.6%) and muscle relaxant vecuronium bromide in incremental doses throughout the surgery. Haemodynamic parameters were recorded at regular intervals during induction, intubation, surgery and extubation. Results: After induction there was significant decrease in pulse rate with dexmedetomidine and significant decrease in Mean blood pressure was seen with fentanyl group. After laryngoscopy and intubation, increase in pulse rate and mean arterial blood pressure was more in fentanyl group than in dexmedetomidine group. Interpretation and Conclusion: we conclude that dexmedetomidine 1μg/kg is more effective in attenuating hemodynamic pressure responses to laryngoscopy and intubation than 2μg/kg fentanyl when given as premedication. [ABSTRACT FROM AUTHOR]

This study analyzed the effect of resistance exercise sets on resting and exercise heart rate (HR), systolic blood pressure (SBP), and double product (RPP) in 10 trained women. The 6 months of resistance training consisted of 4 series of 10 repetition maximum (RM) using a horizontal leg-press exercise with 2 min of rest between bouts. A one way ANOVA and the post hoc Tuckey test (P⩽0.05) were used to find statistical significance. The findings indicate that SBP, HR, and RPP responses were significantly increased from rest to exercise. Systolic blood pressure was significantly increased between the 3rd and 4th sets vs. the 1st set. The number of sets increased SBP, but only when more than 2 sets were performed. The time of execution of each set and the rest interval between the sets was not high enough to induce a significant increase in HR and RPP. [ABSTRACT FROM AUTHOR]

While the importance of regulating arterial blood pressure within a 'normal' range is widely appreciated, the definition of 'normal' and the means by which humans and other species regulate blood pressure under various conditions remain hotly debated. The effects of diverse physiological, pathological and environmental challenges on blood pressure and the mechanisms that attempt to maintain it at an optimal level are reviewed and critically analyzed in a series of articles published in this themed issue of the European Journal of Applied Physiology. We summarize here the major points made in these reviews, with emphasis on unifying concepts of regulatory mechanisms and future directions for research. [ABSTRACT FROM AUTHOR]

Objective: The aim of the present study was to evaluate the depth of anesthesia provided by halothane or sevoflurane by using the bispectral index (BIS) and 95% spectral edge frequency (SEF) monitoring systems. Methods: Forty patients, between the ages of 20-60 years, scheduled for gynecological surgery under general anesthesia were studied between the years 2001-2002. Anesthesia induction was maintained by conventional spontaneous inhalation induction method with sevoflurane in the group I patients (n=20), with halothane in the group II patients (n=20). SEF and BIS index values were recorded. Results: In both groups, SEF values recorded before intubation, after intubation, before and after skin incision were significantly lower compared with values recorded at baseline (p<0.05). Also, SEF values in both groups recorded after anesthesia induction were significantly higher compared with baseline values (p<0.05). Regarding the recorded SEF values after extubation, there were statistically significant differences between the two groups (p<0.05). In both groups, BIS values recorded after anesthesia induction, before intubation, after intubation, before and after skin incision were significantly lower compared with values recorded at baseline and after extubation (p<0.05). Regarding the recorded BIS values before intubation and 1 min after intubation, there were statistically significant differences between the two groups (p<0.05). Conclusion: We conclude that BIS index and SEF values will only be helpful in the evaluation of the hypnosis component of anesthesia and it is not sufficient in showing the autonomous response, which is formed against the perioperative sympathetic and surgical stimulations. [ABSTRACT FROM AUTHOR]

Background: Pulmonary hypertension (PH) of various causes leads to a poor prognosis. Pulmonary vasoreactivity testing during right heart catheterization (RHC) has prognostic and therapeutic consequences. Objective: To characterize the acute hemodynamic response to short-term oxygen supplementation (SHOT) in adult PH patients and its impact on prognosis. Methods: After a stable baseline period, 104 patients with PH [pulmonary arterial hypertension (PAH; n = 56), chronic thromboembolic (PH; n = 22) or respiratory diseases (PH; n = 26)], who were mainly therapy-naïve (86.5%) (mean pO2 64.5 ± 1.2 mm Hg), received a standardized SHOT during RHC and hemodynamic response was assessed for its prognostic potential. Results: SHOT significantly reduced heart rate (HR: 78.9 ± 1.5 to 74 ± 1.5 beats/min), cardiac output (4 ± 0.1 to 3.8 ± 0.1 l/min), pulmonary arterial pressure (46.4 ± 1.3 to 42.3 ± 1.3 mm Hg) and pulmonary vascular resistance (10.1 ± 0.5 to 9.6 ± 0.5 Wood units; all p < 0.001) compared to baseline. The magnitude of this effect varied between the different PH groups. During a median follow-up of 25.1 months (range: 0.2-73.3 months), HR <72 beats/min in response to SHOT was associated with a better prognosis in patients with PH due to chronic thromboembolism to the lung and PH from chronic lung disease. Conclusions: SHOT leads to characteristic hemodynamic responses across different forms of PH. The preserved capability to acutely respond to SHOT with HR reduction is of prognostic significance in patients with non PAH PH. Copyright © 2012 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

To investigate neural mechanisms of local thermotherapy to reduce mental stress, participants were required to perform mental arithmetic after treatment by a heat- and steam-generating sheet on the facial eyelid region while hemodynamic activity and ECGs were monitored. The results indicated that thermotherapy decreased hemodynamic activity in the anterior dorsomedial prefrontal cortex ( aDMPFC) involved in sympathetic activity. Consistently, thermotherapy increased parasympathetic activity while it decreased sympathetic activity. Furthermore, thermotherapy increased hemodynamic activity in the dorsolateral prefrontal cortex ( DLPFC) during mental arithmetic. These hemodynamic responses in the DLPFC during mental arithmetic were negatively correlated with that in the aDMPFC during thermotherapy. The results suggest that thermotherapy in the facial eyelid region is useful to ameliorate mental fatigue through its effects on the prefrontal cortex. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to evaluate intraocular pressure (IOP) and hemodynamic responses following insertion of laryngeal mask airway (LMA) or endotracheal tube (ETT) after anesthesia induction with propofol and remifentanil in cataract surgery. Materials and Methods: In a randomized controlled study, 50 adults scheduled for elective cataract extraction procedure under general anesthesia were allocated to LMA insertion (n = 25) or ETT (n = 25) groups. IOP, systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) were measured after insertion of the airway device every minute up to 5 min. Results: There were no significant differences between LMA and ETT groups in SBP, DBP, HR, and IOP immediately after airway instrumentation up to 5 min, except in 4th min in DBP, 2nd min in HR, and 5th min in IOP (7.9 ± 2.3 mmHg in LMA and 9.4 ± 2.5 mmHg in ETT group; P = 0.030). There was good surgeon satisfaction for providing acceptable surgical field in both groups (88% in LMA and 80% in ETT group; P = 0.702). Conclusion: Propofol combined with remifentanil provides good and excellent conditions for insertion of LMA or ETT with minimal hemodynamic disturbances in cataract surgery. Considering LMA insertion is less traumatic than ETT, using LMA may be better than ETT for airway securing in these patients. [ABSTRACT FROM AUTHOR]

BACKGROUND: Cardiovascular disorders are an important public health problem worldwide. They are also the leading cause of mortality and morbidity. Therefore, American Heart Association proposed cardiac rehabilitation program as an essential part of care for cardiac patients to improve functional capacity. The aim of this study was to evaluate the effectiveness of cardiac rehabilitation program on functional status and some hemodynamic responses in patients after coronary artery bypass graft (CABG) surgery. METHODS: Thirty two patients were selected for this study. All patients underwent cardiac surgery two months before admission. They were allocated to two groups. While the rehabilitation group (n =17, mean age: 62 ± 12 years) completed the cardiac rehabilitation program for two months, the reference group (n = 15, mean age: 58.5 ± 12.5 years) did not have any supervised physical activity during this period. Cardiac rehabilitation program consisted of exercise, nutritional, psychological consultation and risk factor management. At the beginning of the study, functional capacity of patients was evaluated by exercise test, 6-minute walking test and echocardiography. Functional capacity was evaluated for a second time after two months of cardiac rehabilitation. Data were analyzed by SPSS15. For comparing the mean of outcomes, Mann-Whitney test and Wilcoxon signed ranks test were used. RESULTS: As a result of cardiac rehabilitation, a significant improvement was observed in the distance walked in the rehabilitation group (P < 0.01) compared to the reference group (P = 0.33). It also caused a significant development in hemodynamic responses to exercise such as resting and maximum systolic and diastolic blood pressure, resting and maximum heart rate, ejection fraction and rate pressure product. CONCLUSION: Cardiac rehabilitation significantly improves functional capacity and some hemodynamic responses post coronary artery bypass grafting. Therefore, patients need to be referred to rehabilitation units. [ABSTRACT FROM AUTHOR]

The present study tested the hypothesis that the exercise protocol (continuous vs. intermittent) would affect the physiological response and the perception of effort during aquatic cycling. Each protocol was divided on four stages. Heart rate, arterial blood pressure , blood lactate concentration, central and peripheral rate of perceived exertion were collected in both protocols in aquatic cycling in 10 women (values are mean ± SD): age=32.8 ± 4.8 years; height=1.62 ± 0.05 cm; body mass=61.60 ± 5.19 kg; estimated body fat=27.13 ± 4.92%. Protocols were compared through two way ANOVA with Scheffé's post-hoc test and the test of Mann-Whitney for rate of perceived exertion with α=0.05. No systematic and consistent differences in heart rate, arterial blood pressure, double product and blood lactate concentration were found between protocols. On the other hand, central rate of perceived exertion was significantly higher at stage four during continuous protocol compared with intermittent protocol (p=0.01), while the peripheral rate of perceived exertion presented higher values at stages three (p=0.02) and four (p=0.00) in the continuous protocol when compared to the results found in intermittent protocol. These findings suggest that although the aquatic cycling induces similar physiologic demands in both protocols, the rate of perceived exertion may vary according to the continuous vs. intermittent nature of the exercise. [ABSTRACT FROM AUTHOR]

Impaired cardiovascular function increases the risk for fatal and non-fatal cardiovascular disease, renal disease and all-cause mortality. Research has demonstrated an inverse relationship between these cardiovascular impairments and exercise. However, previous research has mainly focused on aerobic training since regular resistance-trained men tend to display higher blood pressures due to decreased arterial compliance and increased arterial stiffness. Thus, the aim of the study was to determine the effects of eight weeks of progressive resistance training on cardiovascular functioning as depicted by resting heart rate (RHR), systolic blood pressure (RSBP), diastolic blood pressure (RDBP), rate-pressure product (RRPP) and mean arterial pressure (RMAP). Twenty eight inactive men were assigned to either a resistance training group (ResG) (n 13) or non-exercising control group (ConG) (n = 15). Eight weeks of resistance training resulted in significant (p <.0.05) changes in cardiovascular parameters, which are: RSBP (p < 0.001), RDBP (p <0.001), RMAP (p <0.001) and RRPP (p < 0.001), but not RHR (p = 0.441). This study indicates that resistance training improves cardiovascular function in adult men possibly resulting in cardioprotective benefits. [ABSTRACT FROM AUTHOR]

To investigate relationships between hemodynamic responses and neural activities in the somatosensory cortices, hemodynamic responses by near infrared spectroscopy (NIRS) and electroencephalograms (EEGs) were recorded simultaneously while subjects received electrical stimulation in the right median nerve. The statistical significance of the hemodynamic responses was evaluated by a general linear model (GLM) with the boxcar design matrix convoluted with Gaussian function. The resulting NIRS and EEGs data were stereotaxically superimposed on the reconstructed brain of each subject. The NIRS data indicated that changes in oxy-hemoglobin concentration increased at the contralateral primary somatosensory (SI) area; responses then spread to the more posterior and ipsilateral somatosensory areas. The EEG data indicated that positive somatosensory evoked potentials peaking at 22 ms latency (P22) were recorded from the contralateral SI area. Comparison of these two sets of data indicated that the distance between the dipoles of P22 and NIRS channels with maximum hemodynamic responses was less than 10 mm, and that the two topographical maps of hemodynamic responses and current source density of P22 were significantly correlated. Furthermore, when onset of the boxcar function was delayed 5–15 s (onset delay), hemodynamic responses in the bilateral parietal association cortices posterior to the SI were more strongly correlated to electrical stimulation. This suggests that GLM analysis with onset delay could reveal the temporal ordering of neural activation in the hierarchical somatosensory pathway, consistent with the neurophysiological data. The present results suggest that simultaneous NIRS and EEG recording is useful for correlating hemodynamic responses to neural activity. [ABSTRACT FROM AUTHOR]

This study compared the effects of fast and slow music on cardiovascular and hemodynamic responses during submaximal treadmill exercise. Six males and five females completed three, 15- minute steady-state exercise sessions jogging at 5.5 mph at 0% grade while listening to fast music (Treatment 1), slow music (Treatment 2), and no music (Control). An ANOVA with repeated measures was used to compare the three conditions, and a post hoc Scheffe test was performed to determine which groups differed (p<.05). Oxygen consumption (VO2), cardiac output (Q), stroke volume (SV), minute ventilation (VE), and frequency of breaths (Fb) significantly increased while listening to fast music compared to the slow music and no music. Systemic vascular resistance (SVR) significantly decreased while listening to fast music compared to slow music and no music. These findings suggest that listening to fast music during steady-state treadmill exercise produces cardiovascular and respiratory responses that are significantly different from how the body responds to the same exercise intensity when listing to slow or no music. The data indicate that listening to fast music decreased the subjects' cardiovascular efficiency since the subjects were able to perform the same steady-state treadmill exercise with either slow music or no music with a lower SV, Q, and VO2. [ABSTRACT FROM AUTHOR]

Background : The purposes of this study were to further identify the hemodynamic responses to orotracheal intubation in children, using a fiberoptic bronchoscope (FOB) and a direct laryngoscope (DLS), and to validate whether the FOB can attenuate the hemodynamic response to orotracheal intubation compared with the DLS. Methods : Forty-three children, ASA PS I–II scheduled for elective plastic surgery under general anesthesia requiring orotracheal intubation were randomly allocated to either the DLS group ( n = 20) or the FOB group ( n = 23). Noninvasive systolic blood pressure (SBP) and heart rate (HR) were recorded before (baseline values) and after anesthesia induction (postinduction values), at intubation and every minute for the first 5 min after intubation. The maximal values of SBP and HR during the observation were also recorded. The product of HR and SBP [rate pressure product (RPP)] at each time point was calculated. Results : In the DLS group, SBP, HR, and RPP at intubation and 1 min after intubation were significantly higher than postinduction values, but did not exceed baseline values. In the FOB group, SBP, HR, and RPP at intubation increased significantly compared with baseline and postinduction values. In the two groups, the maximal values of SBP, HR, and RPP during the observation were significantly higher than baseline values. Except for the HR at intubation, there were no significant differences in other hemodynamic parameters during the observation and the time required to reach maximal values of SBP, HR, and RPP between the two groups. Conclusions : Orotracheal intubation using FOB and DLS in children may cause similar increases in SBP and HR. Compared with the DLS, the FOB had no advantage in attenuating the hemodynamic responses to orotracheal intubation. [ABSTRACT FROM AUTHOR]

Abstract: Modern non-invasive imaging techniques utilize the coupling between neural activity and changes in blood flow, volume and oxygenation to map the functional architecture of the human brain. An understanding of how the hemodynamic response is influenced by pre-stimulus baseline perfusion is important for the interpretation of imaging data. To address this issue, the present study measured hemodynamics with optical imaging spectroscopy and laser Doppler flowmetry, while multi-channel electrophysiology was used to record local field potentials (LFP) and multi-unit activity (MUA). The response to whisker stimulation in rodent barrel cortex was recorded during baseline (normocapnia) and elevated perfusion rates produced by two levels of hypercapnia (5 and 10%). With the exception of the ‘washout’ of deoxyhemoglobin, which was attenuated, all aspects of the neural and hemodynamic response to whisker stimulation were similar during 5% hypercapnia to those evoked during normocapnia. In contrast, 10% hypercapnia produced cortical arousal and a reduction in both the current sink and MUA elicited by stimulation. Blood flow and volume responses were reduced by a similar magnitude to that observed in the current sink. The deoxyhemoglobin ‘washout’, however, was attenuated to a greater degree than could be expected from the neural activity. These data suggest that imaging techniques based on perfusion or blood volume changes may be more robust to shifts in baseline than those based on the dilution of deoxyhemoglobin, such as conventional BOLD fMRI. [Copyright &y& Elsevier]

Background: Induced stimulation while endotracheal intubating affects hemodynamic status. The present study compares the hemodynamic changes caused by endotracheal intubating after administering two doses of intranasal Dexmedetomidine., Methods: In an experimental (before-after) trial, 88 patients undergoing general anesthesia enrolled in the study. The Iranian Register of Clinical Trial (IRCT) code of the study was IRCT20160307026950N15 (https://en.irct.ir/trial/39269). Patients were allocated to two intervention groups and one control group by random. Intranasal Dexmedetomidine and Normal saline 0.9% were administrated 30 minutes before induction of anesthesia. (1 μg/kg Dexmedetomidine in group 1, 2 μg/kg Dexmedetomidine in group 2 and 1 mg Normal saline 0.9% in group 3). Vital signs and hemodynamic parameters were measured and recorded in minutes 1, 3, 5, and 10th after induction. Data analysis was done by ANOVA and Chi-square tests., Results: Heart rate, systolic and diastolic blood pressure, and mean arterial pressure were reduced in patients receiving dexmedetomidine (P<0.05), but there were no significant changes in the control group. In arterial oxygenation (P>0.05), there was no significant difference between the three groups in the arterial blood oxygen amount., Conclusion: Premedication of intranasal dexmedetomidine influences the hemodynamic changes due to anesthesia induction. The dose of 2 µg/kg is better than one µg/kg in improving the hemodynamic state following intubation., Competing Interests: None., (IJPPP Copyright © 2022.)

We investigated the effect of a new ultrashort-acting β-blocker, ONO-1101, on hemodynamic responses to isoflurane inhalation and tracheal intubation. Fifty-four ASA PS 1 or 2 patients were randomly allocated to receive either ONO-1101, 0.04 mg·kg−1·min−1, or saline prior to tracheal intubation. Anesthesia was induced with thiamylal, 4 mg·kg−1, and vecuronium, 0.15 mg·kg−1. Tracheal intubation was carried out after 3 min controlled mask ventilation with 66% N2O and 3% inspired isoflurane in oxygen. Heart rate and blood pressure were continuously recorded from the start of induction until 5 min after intubation. Plasma concentrations of catecholamines were measured before induction, 3 min after initiating inhalation of isoflurane, and 1 min after tracheal intubation. Significant increases in heart rate occurred in both groups in response to isoflurane inhalation and tracheal intubation, but the magnitude of the increase was significantly less in the ONO-1101 group. Blood pressure increased after tracheal intubation in the saline group but remained unchanged in the ONO-1101 group. Plasma concentrations of norepinephrine increased after induction and intubation in both groups, with no significant difference between the groups. ONO-1101 infusion is effective for the attenuation of hemodynamic responses to isoflurane inhalation and tracheal intubation. [ABSTRACT FROM AUTHOR]

The hemodynamic responses to rapid atrial and ventricular pacing were examined in 10 closed-chest anesthetized dogs in an attempt to distinguish hemodynamically stable from unstable tachycardias. Pressure monitoring catheters were placed in the femoral artery, right atrium, and right ventricle to measure mean arterial pressure, mean right atrial pressure, and mean right ventricular pressure at baseline heart rate and after rapid high right atria! and right ventricular apex pacing. Pressures recorded during rapid pacing (average of the pressures at 30 and 60 seconds of pacing) at pacing rates of 180, 250, and 280/minute were compared to those recorded initially at baseline heart rates. Rapid right ventricular apex pacing resulted in significant increases in mean right atrial pressure (from 6 ± 1 mmHg (mean ± standard error) to 12 ± 1 mmHg, a 100% increase, P < 0.001) and mean right ventricular pressure (from 11 ± 1 mmHg to 16 ± 1 mmHg, a 45% increase, p < 0.02) with marked hemodynamic compromise (mean arterial pressure decreased from 85 ± 6 mmHg to 50 ± 6 mmHg, a 41% decrease, P < 0.01). These parameters remained stable (no statistically significant difference from baseline) during high right atrial pacing. In half of the dogs high right atrial pacing at rates ≥ 250 resulted in atrioventricular Wenckebach. Thus, it is concluded that mean right atrial pressure and mean right ventricular pressure may be useful in distinguishing hemodynamically significant tachycardias, and in the future design of antitachycardia devices. [ABSTRACT FROM AUTHOR]