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Context: Blood flow restriction resistance exercise studies often require caffeine abstinence to avoid cardiovascular effects that could change the blood flow restriction stimulus. However, effects may be attenuated for habituated users. Objective: To compare cardiovascular responses to blood flow restriction resistance exercise when habituated users consume or abstain from caffeine. Design: Thirty participants completed a 3-visit within-subject study beginning with familiarization and caffeine intake questionnaire. Methods: Visits 2 and 3 consisted of blood flow restriction resistance exercise (3 sets bicep curls to failure, 30% 1-repetition max, 40% arterial occlusion pressure [AOP]), following participants' normal caffeine consumption (CAFF) or abstaining (ABS). AOP, systolic (SBP) and diastolic (DBP) blood pressure, and heart rate were measured preexercise and postexercise. Prevalues and preexercise to postexercise change scores for SBP, DBP, AOP (all millimeters of mercury), heart rate (in beats per minute), and repetitions were compared between conditions. Results are represented as mean (SD). Results: Preexercise AOP was similar for CAFF (137.8 [14.4]) and ABS (137.1 [14.9], BF10 = 0.2), although pre-SBP was higher for CAFF (115.4 [9.8]) than ABS (112.3 [9.4], BF10 = 1.9). Pre-DBP was similar between conditions. The exercise-induced change in AOP was greater for CAFF (18.4 [11.2]) than ABS (13.2 [14.9]), though evidence was anecdotal (BF10 = 0.7). Exercise-induced changes in SBP, DBP, and heart rate were similar between conditions (all BF10 ≤ 0.40). More repetitions were completed for CAFF (63 [26]) than ABS (57 [17], BF10 = 2.1). Conclusions: The findings of this study suggest that for habituated users, maintaining daily caffeine habits will not have substantial effects on common cardiovascular variables relevant to blood flow restriction. [ABSTRACT FROM AUTHOR]

Abstract The objective was to assess if post‐exercise ingestion of carbonated water in a hot environment ameliorates hypotension, enhances cerebral blood flow and heat loss responses, and positively modulates perceptions and mood states. Twelve healthy, habitually active young adults (five women) performed 60 min of cycling at 45% peak oxygen uptake in a hot climate (35°C). Subsequently, participants consumed 4°C carbonated or non‐carbonated (control) water (150 and 100 mL for males and females regardless of drink type) at 20 and 40 min into post‐exercise periods. Mean arterial pressure decreased post‐exercise at 20 min only (P = 0.032) compared to the pre‐exercise baseline. Both beverages transiently (∼1 min) increased mean arterial pressure and middle cerebral artery mean blood velocity (cerebral blood flow index) regardless of post‐exercise periods (all P ≤ 0.015). Notably, carbonated water ingestion led to greater increases in mean arterial pressure (2.3 ± 2.8 mmHg vs. 6.6 ± 4.4 mmHg, P

The purpose of this study was to compare sex-based differences in the mean arterial blood pressure (MAP) response to limb and inspiratory metaboreflex activation, during relative and absolute workloads. Healthy males (n = 9) and females (n = 8) completed pulmonary function testing, forearm volume and circumference measurements, and bouts of limb and inspiratory muscle exercise. The exercises performed included bouts of rhythmic handgrip exercise (RHG) and inspiratory pressure threshold loading (PTL) to task failure, performed in a randomized order and separated by 30 minutes of rest. Participants performed both RHG and PTL at predetermined relative (R) and absolute (A) workloads, while cardiopulmonary measurements were recorded continuously. A time-dependent rise in MAP was observed in all participants, regardless of sex, muscle, or workload (P < 0.001). MAP was greater in males than females during all exercise bouts regardless of muscle group or workload (P < 0.001). The change in MAP from baseline was also greater in males (R-RHG: Δ31 ± 12 mmHg; R-PTL: Δ31 ± 9; A-RHG: Δ35 ± 6; and A-PTL: Δ30 ± 7) than females (R-RHG: Δ21 ± 7 mmHg; R-PTL: Δ13 ± 7; A-RHG: Δ21 ± 7; and A-PTL: Δ14 ± 3) (P < 0.001). Results from this study show that when the forearm and diaphragm perform the same relative or absolute work, the blood pressure response is statistically similar, and both responses are greater in males than females. The findings from the present study suggest that the sex-based difference in the response to metaboreflex activation is similar between the limb and respiratory musculature. NEW & NOTEWORTHY: With rhythmic handgrip exercise and inspiratory pressure threshold loading there was a time-dependent rise in the blood pressure that was significantly lower in females than males. The blunted blood pressure response in females was present whether handgrip or inspiratory workload was relative or absolute. An attenuated cardiovascular response to high levels of limb or respiratory muscle work may have implications for whole body exercise in health and disease. [ABSTRACT FROM AUTHOR]

The objective was to assess if post‐exercise ingestion of carbonated water in a hot environment ameliorates hypotension, enhances cerebral blood flow and heat loss responses, and positively modulates perceptions and mood states. Twelve healthy, habitually active young adults (five women) performed 60 min of cycling at 45% peak oxygen uptake in a hot climate (35°C). Subsequently, participants consumed 4°C carbonated or non‐carbonated (control) water (150 and 100 mL for males and females regardless of drink type) at 20 and 40 min into post‐exercise periods. Mean arterial pressure decreased post‐exercise at 20 min only (P = 0.032) compared to the pre‐exercise baseline. Both beverages transiently (∼1 min) increased mean arterial pressure and middle cerebral artery mean blood velocity (cerebral blood flow index) regardless of post‐exercise periods (all P ≤ 0.015). Notably, carbonated water ingestion led to greater increases in mean arterial pressure (2.3 ± 2.8 mmHg vs. 6.6 ± 4.4 mmHg, P < 0.001) and middle cerebral artery mean blood velocity (1.6 ± 2.5 cm/s vs. 3.8 ± 4.1 cm/s, P = 0.046) at 20 min post‐exercise period compared to non‐carbonated water ingestion. Both beverages increased mouth exhilaration and reduced sleepiness regardless of post‐exercise periods, but these responses were more pronounced with carbonated water ingestion at 40 min post‐exercise (mouth exhilaration: 3.1 ± 1.4 vs. 4.7 ± 1.7, P = 0.001; sleepiness: −0.7 ± 0.91 vs. −1.9 ± 1.6, P = 0.014). Heat loss responses and other perceptions were similar between the two conditions throughout (all P ≥ 0.054). We show that carbonated water ingestion temporarily ameliorates hypotension and increases the cerebral blood flow index during the early post‐exercise phase in a hot environment, whereas it enhances mouth exhilaration and reduces sleepiness during the late post‐exercise phase. What is the central question of this study?Post‐exercise hypotension can cause syncope, and an established practical countermeasure to mitigate this response is currently lacking: does ingestion of carbonated water restore post‐exercise hypotension and positively modulate mood states?What is the main finding and its importance?Carbonated water ingestion transiently increased blood pressure and cerebral blood flow index post‐exercise in the heat. Additionally, carbonated water ingestion increased exhilaration for the mouth and decreased sleepiness post‐exercise. Thus, carbonated water ingestion may mitigate post‐exercise hypotension, increase cerebral perfusion and improve mood states. [ABSTRACT FROM AUTHOR]

Background: We compared the effects of oral clonidine and gabapentin as premedicant in attenuation of hemodynamic response to laryngoscopy and intubation in normotensive patients undergoing elective surgery. Methods: A total of 70 patients undergoing general anesthesia were enrolled in the study and were randomly allocated into two groups of 35 each. Group C patients received oral clonidine 0.3 mg and Group G patients received oral gabapentin 900 mg, 90 min prior to induction of anesthesia. Results: Both groups were matched for age, sex, weight and ASA grade. We observed that the difference in raise in SBP was lesser in group G as compared to group C at it was significant (p<0.05) at 3rd, 5th and 10th minute. The MAP was also lesser in group G than group C and was significant (p,0.05) at 3rd minute. Heart rate increase was lesser in group G than group C and was significant at the first minute. (p<0.005). Conclusion: Oral gabapentin (900 mg) is better as compared to oral clonidine (0.3 mg) premedication, in attenuating the hemodynamic response to laryngoscopy and intubation. [ABSTRACT FROM AUTHOR]

Background & objective: The anesthesiologists have been trying various strategies to lessen the adverse effects of endotracheal intubation on hemodynamic parameters. The aim of this study was to explore a better and safer drug to attenuate the pressor response to laryngoscopy and intubation by comparing dexmedetomidine (Precedex; Brookes Pharma), fentanyl (Fentra; Brookes Pharma), and lidocaine (Xylocaine; Barret Hodgson). Methodology: In this double-blind, randomized controlled trial, a total of 90 patients of ASA physical status I and II, undergoing laparoscopic cholecystectomy under general anesthesia were included. Sample size was calculated using OPEN EPI sample size calculator. Patients were randomized into three groups by sealed envelope method. Patients in Group D received intravenous dexmedetomidine 0.6 μg/kg, Group F received intravenous fentanyl 2 μg/kg and Group L received intravenous lidocaine 1.5 mg/kg over 10 min before induction. Hemodynamic variables were recorded at baseline, at laryngoscopy, 1, 3, 5 and 10 min after intubation. Perioperative complications and postoperative sedation and recovery were also noted at 0 and 10 min in Post Anesthesia Care Unit (PACU). Results: As compared to dexmedetomidine, there was no significant impact of lidocaine (P = 0.774) and fentanyl (P = 0.992) in managing the heart rate (HR) of patients, while time had a significant impact on the HR. There was no substantial effect of fentanyl (P = 0.123) or lidocaine (P = 0.616) in managing SBP and no effect of fentanyl (P = 0.580) or lidocaine (P = 0.752) in managing DBP, in contrast to dexmedetomidine. Although statistically significant reduction in HR, SBP and DBP was observed in Group D, soon after study drug infusion, but overall long-term stability was noticed. Ramsey sedation scores were significantly higher in the Group D at arrival in PACU, but after 10 min all three study groups showed almost similar results. Aldrete score was statistically significant in the fentanyl group compared to Group D and L in PACU, both at arrival and after 10 min (P = 0.001 and 0.010 respectively). Conclusion: We conclude that intravenous dexmedetomidine demonstrated better attenuation of hemodynamic response to laryngoscopy and intubation in patients undergoing laparoscopic cholecystectomy by controlling rise in heart rate and by providing long-term stability in systolic and diastolic blood pressure. Fentanyl and lidocaine showed inconsistencies in heart rate, systolic and diastolic blood pressure over time. Fentanyl showed better hemodynamic profile compared to lidocaine. Patients included in fentanyl group exhibited early recovery than dexmedetomidine and lidocaine. [ABSTRACT FROM AUTHOR]

Introduction: An increase in blood pressure and heart rate is observed during laryngoscopy and insertion of the endotracheal tube. Melatonin is used for sedation in the Intensive Care Unit. Our study was based on the hypothesis that administrating 3 mg and 6 mg of melatonin 90 minutes before induction attenuates hemodynamic responses encountered during laryngoscopy and intubation. Materials and Methods: Seventy-five adult patients scheduled for elective surgical procedures, ASA I and II, were assigned into 3 groups (25 patients in each group) to receive oral placebo, melatonin 3 mg, or melatonin 6 mg 90 minutes prior to induction of anesthesia. Hemodynamic variables were recorded at baseline, before induction, and at 3, 6, 9, 12, 15, and 30 minutes after induction. Analysis of variance (ANOVA) was used for intergroup analysis of data. Categorical variables were compared using non-parametric tests like the Chi-square test or Fisher’s exact test. Bonferroni correction was applied for intergroup analysis. Statistical significance was considered when p < 0.05. Results: An increase in heart rate and blood pressure at 3, 6, and 9 minutes after induction of general anesthesia was observed in the control group compared to the melatonin 3 mg and 6 mg groups administered 90 minutes prior to induction. Oral administration of 6 mg of melatonin was found to provide greater attenuation than 3 mg of melatonin. Conclusion: Oral administration of 3 mg and 6 mg melatonin effectively attenuates the hemodynamic pressor changes observed during laryngoscopy and tracheal intubation.

ABSTRACTIntroduction Endotracheal intubation (ETI) is one of the commonly used maneuvers in the daily anesthetic practice, it is commonly associated with hemodynamic stimulation leading to marked tachycardia, hypertension, and myocardial ischemia.Aim and objectives In this study, we compared three doses of lidocaine for prophylaxis against pressor response of ETI. We hypothesized that the larger dose (2 mg/Kg) will be more effective for attenuation of the pressor response.Methods After randomization, post induction of anesthesia patients were categorized into three groups according to the dose of lidocaine: group A received 1 mg/Kg, group B received 1.5 mg/Kg, and group C received 2 mg/Kg. To achieve blinding, the study drug was prepared by a research assistant and was diluted to 10 mL in all groups. Heart rate measurement after 1 minute of lidocaine injection was carried out. Heart rate, cardiac output and stroke volume were continuously measured and were recorded every 30 seconds starting from baseline pre-induction reading till 5 minutes zafter ETI, systolic and diastolic blood pressure were measured at 1-minute intervals starting from baseline reading till 5-minute after ETI.Results Pressor response was lower in group C receiving 2 mg/Kg with P value = 0.021 defined by an increase in the heart rate, cardiac output, or systolic blood pressure by 20% or more which was evaluated after ETI continuously for 5 minutes.Conclusion Lidocaine in the dose of (2mg/Kg) is more effective than lower doses in attenuation of the pressor response of the ETI.

This article examines the impact of gabapentin on the pressor response to laryngoscopy and tracheal intubation in patients undergoing elective cholecystectomy. The study reveals that gabapentin significantly decreases systolic, diastolic, and mean arterial pressure following intubation when compared to a placebo. Gabapentin is commonly used as an anticonvulsant medication for seizures and neuropathic pain. The findings suggest that gabapentin may be beneficial in reducing the hemodynamic response to endotracheal intubation. [Extracted from the article]

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Introduction: Endotracheal intubation (ETI) is one of the commonly used maneuvers in the daily anesthetic practice, it is commonly associated with hemodynamic stimulation leading to marked tachycardia, hypertension, and myocardial ischemia. Aim and objectives: In this study, we compared three doses of lidocaine for prophylaxis against pressor response of ETI. We hypothesized that the larger dose (2 mg/Kg) will be more effective for attenuation of the pressor response. Methods: After randomization, post induction of anesthesia patients were categorized into three groups according to the dose of lidocaine: group A received 1 mg/Kg, group B received 1.5 mg/Kg, and group C received 2 mg/Kg. To achieve blinding, the study drug was prepared by a research assistant and was diluted to 10 mL in all groups. Heart rate measurement after 1 minute of lidocaine injection was carried out. Heart rate, cardiac output and stroke volume were continuously measured and were recorded every 30 seconds starting from baseline preinduction reading till 5 minutes zafter ETI, systolic and diastolic blood pressure were measured at 1-minute intervals starting from baseline reading till 5-minute after ETI. Results: Pressor response was lower in group C receiving 2 mg/Kg with P value = 0.021 defined by an increase in the heart rate, cardiac output, or systolic blood pressure by 20% or more which was evaluated after ETI continuously for 5 minutes. Conclusion: Lidocaine in the dose of (2mg/Kg) is more effective than lower doses in attenuation of the pressor response of the ETI. [ABSTRACT FROM AUTHOR]

Background: Laryngoscopy and endotracheal intubation are frequently linked to hypertension and tachycardia because of the sympathoadrenal stimulation. To combat the pressor response several medications like local anaesthetic, B blockers and opioids. Alpha 2 agonist, Dexmedetomidine (1ug/kg) has been used as premedication 10minutes prior to induction of general anaesthesia in order to assess the pressor response of laryngoscopy and endotracheal intubation. Material and Methods: After ethical clearance 60 patients aged 18-60 years old were randomised and divided into two groups, Group A(n=30) and group B(n=30). Group A received IV normal saline 20ml and group B received IV Dexmedetomidine, 1 μg/kg diluted in 20ml of normal saline which was administered over 10 minutes and started 10 minutes prior to induction of general anaesthesia. Hemodynamic parameters were were recorded at preinduction, after induction of anaesthesia, HR, SBP, DBP and MAP were recorded at. base line (T0) after 10 minutes of the administration of the study drug (T1), after 3 minutes of the administration of the neuromuscular blocker T2, T3, T4, T5, T6, T7 and T8 recorded after 1min, 2 min,3 min,5min,10min,15min and 20min after intubation. Results: There was significant difference in heart rate, systolic, diastolic and mean blood pressre at T1, T2, T3, T4, T5, T6, T7 and T8. (P<0.05). There was significant decrease in hemodynamic parametres at different time interval post laryngoscopy and induction of general anaesthesia. Conclusion: The pressor response to tracheal intubation and laryngoscopy was observed to be successfully attenuated by dexmedetomidine (1 μg/kg) IV, given 10 min before induction, with no major adverse effects. [ABSTRACT FROM AUTHOR]

The pressor response induced by a voluntary hypoxic apnea is mediated largely by increased sympathetic outflow. The neural control of blood pressure is altered in recovery from acute heat exposure, but its effect on the pressor response to a voluntary hypoxic apnea has never been explored. Therefore, we tested the hypothesis that prior heat exposure would attenuate the pressor response induced by a voluntary hypoxic apnea. Eleven healthy adults (five women) were exposed to whole body passive heating (water-perfused suit) sufficient to increase body core temperature by 1.2°C. Voluntary hypoxic apneas were performed at baseline and in recovery when body core temperature returned to ≤ 0.3°C of baseline. Participants breathed gas mixtures of varying FIO2 (21%, 16%, and 12%; randomized) for 1 min followed by a 15-s end-expiratory apnea. The change in arterial oxygen saturation during each apnea did not differ from baseline to recovery (P = 0.6 for interaction), whereas the pressor response induced by a voluntary hypoxia apnea was reduced (FIO2 21%, baseline 17 ± 7 mmHg vs. recovery 14 ± 7 mmHg; FIO2 16%, baseline 24 ± 8 mmHg vs. recovery 18 ± 7 mmHg; FIO2 12%, baseline 28 ± 11 mmHg vs. recovery 24 ± 11 mmHg; P = 0.01 for main effect of time). These data suggest that prior heat exposure induces a cross-stressor effect such that the pressor response to a voluntary hypoxic apnea is attenuated. [ABSTRACT FROM AUTHOR]

This paper assessed the blood pressure, heart rate, and mouth-pressure responses to indoor rock climbing (bouldering) and associated training exercises. Six well-trained male rock climbers (mean ± SD age, 27.7 ± 4.7 yr; stature, 177.7 ± 7.3 cm; mass, 69.8 ± 12.1 kg) completed two boulder problems (6b and 7a+ on the Fontainebleau Scale) and three typical training exercises [maximum voluntary contraction (MVC) isometric pull-up, 80% MVC pull-ups to fatigue, and campus board to fatigue]. Blood pressure and heart rate were measured via an indwelling femoral arterial catheter, and mouth pressure via a mouthpiece manometer. Bouldering evoked a peak systolic pressure of 200 ± 17 mmHg (44 ± 21% increase from baseline), diastolic pressure of 142 ± 26 mmHg (70 ± 32% increase), mean arterial pressure of 163 ± 18 mmHg (56 ± 25% increase), and heart rate of 176 ± 22 beats/min (76 ± 35% increase). The highest systolic pressure was observed during the campus board exercise (218 ± 33 mmHg), although individual values as high as 273/189 mmHg were recorded. Peak mouth pressure during climbing was 31 ± 46 mmHg, and this increased independently of climb difficulty. We concluded that indoor rock climbing and associated exercises evoke a substantial pressor response resulting in high blood pressures that may exceed those observed during other upper-limb resistance exercises. These findings may inform risk stratification for climbers.NEW & NOTEWORTHY This case study provides original data on the exercise pressor response to indoor rock climbing and associated training exercises through the use of an indwelling femoral arterial catheter. Our subjects exhibited systolic/diastolic blood pressures that exceeded values often reported during upper-limb resistance exercise. Our data extend the understanding of the cardiovascular stress associated with indoor rock climbing.

Background and Aims: Following induction of general anaesthesia, direct laryngoscopy and endotracheal intubation usually cause tachycardia and hypertension due to increased sympathetic activity. This response is generally exaggerated in hypertensive patients. This study aimed to evaluate the effectiveness of preoperative lignocaine nebulisation in attenuating the pressor response to laryngoscopy and endotracheal intubation in patients with severe preeclampsia undergoing caesarean delivery. Methods: After ethical approval, we conducted this randomised, double-blind study, which included 110 patients with severe preeclampsia who underwent caesarean delivery under general anaesthesia. These patients were randomly allocated into two groups to receive either preoperative nebulisation of lignocaine 2% in a dose of 4.5 mg/kg (not exceeding 400 mg) in the lignocaine group or nebulisation of an equivalent volume of 0.9% NaCl in the saline group. The primary objective was the systolic blood pressure after tracheal intubation. The secondary objectives included heart rate, maternal serum cortisol and blood glucose levels, grade of cough during emergence, postoperative sore throat and hoarseness of voice, neonatal Apgar score and umbilical blood gas. Results: The systolic blood pressure was significantly lower in the lignocaine group compared to the saline group at 1, 3 and 5 min after endotracheal intubation and after delivery of the foetus (P = 0.001, 0.003, 0.002 and 0.019, respectively). Similarly, the heart rate was significantly lower in the lignocaine group versus saline group at 1 and 3 min after endotracheal intubation (P = 0.041 and 0.042, respectively). Conclusion: Preoperative lignocaine nebulisation in a dose of 4.5 mg/kg effectively attenuated the pressor response to laryngoscopy and endotracheal intubation in patients with severe preeclampsia undergoing caesarean delivery.

Background and Aims: Following induction of general anaesthesia, direct laryngoscopy and endotracheal intubation usually cause tachycardia and hypertension due to increased sympathetic activity. This response is generally exaggerated in hypertensive patients. This study aimed to evaluate the effectiveness of preoperative lignocaine nebulisation in attenuating the pressor response to laryngoscopy and endotracheal intubation in patients with severe preeclampsia undergoing caesarean delivery. Methods: After ethical approval, we conducted this randomised, double-blind study, which included 110 patients with severe preeclampsia who underwent caesarean delivery under general anaesthesia. These patients were randomly allocated into two groups to receive either preoperative nebulisation of lignocaine 2% in a dose of 4.5 mg/kg (not exceeding 400 mg) in the lignocaine group or nebulisation of an equivalent volume of 0.9% NaCl in the saline group. The primary objective was the systolic blood pressure after tracheal intubation. The secondary objectives included heart rate, maternal serum cortisol and blood glucose levels, grade of cough during emergence, postoperative sore throat and hoarseness of voice, neonatal Apgar score and umbilical blood gas. Results: The systolic blood pressure was significantly lower in the lignocaine group compared to the saline group at 1, 3 and 5 min after endotracheal intubation and after delivery of the foetus (P = 0.001, 0.003, 0.002 and 0.019, respectively). Similarly, the heart rate was significantly lower in the lignocaine group versus saline group at 1 and 3 min after endotracheal intubation (P = 0.041 and 0.042, respectively). Conclusion: Preoperative lignocaine nebulisation in a dose of 4.5 mg/kg effectively attenuated the pressor response to laryngoscopy and endotracheal intubation in patients with severe preeclampsia undergoing caesarean delivery. [ABSTRACT FROM AUTHOR]

Excessive arterial pressure elevation induced by resistance exercise (RE) attenuates peripheral vasodilatory function, but its effect on cerebrovascular function is unknown. We aimed to evaluate the effect of different pressor responses to RE on hypercapnia-induced vasodilation of the internal carotid artery (ICA), an index of cerebrovascular function. To manipulate pressor responses to RE, 15 healthy young adults (11M/4F) performed two RE: high intensity with low repetitions (HL) and low intensity with high repetitions (LH) dynamic knee extension. ICA dilation, induced by 3 min of hypercapnia, was measured before and 10 min after RE using Doppler ultrasound. HL exercise elicited a greater pressor response than LH exercise. In relaxation phases of RE, ICA blood velocity increased in both HL and LH trials. However, ICA shear rate did not significantly increase in either trial (P = 0.06). Consequently, neither exercise altered post-exercise hypercapnia-induced ICA dilation (HL, 3.9 ± 1.9% to 5.1 ± 1.7%; LH, 4.6 ± 1.4% to 4.8 ± 1.8%; P > 0.05 for all). When viewed individually, the changes in ICA shear rate were positively correlated with changes in end-tidal partial pressure of carbon dioxide (PETCO2) (r = 0.46, P < 0.01) than with mean arterial pressure (r = 0.32, P = 0.02). These findings suggest that the effects of RE-induced pressor response on cerebrovascular function may be different from peripheral arteries. An increase in PETCO2 during the relaxation phase may play a more crucial role than elevated pressure in increasing cerebral shear during dynamic RE. [ABSTRACT FROM AUTHOR]

BACKGROUND: Reduced muscle strength is one symptom of Parkinson's disease (PD). Strength can be increased by strength training, which may cause exaggerated blood pressure (BP) rise. It is believed that exercises performed on vibrating platform can strengthen leg muscles without excessive BP increase. OBJECTIVE: To measure the pressor response to static exercises performed during whole body vibration in PD patients. METHODS: Twenty-four aged PD patients and twelve healthy young volunteers participated in the study. PD subjects performed six repetitions of deep-, semi-squat, and calves at vibration frequency of 30 Hz. Each 30 s exercise was followed by 30 s rest. The young volunteers performed two sessions of above-mentioned exercises with and without vibration. BP was measured continuously. RESULTS: In PD patients, the highest BP values were observed during deep squat; systolic blood pressure rose 10 mmHg in 'weak responders', and 50 mmHg in 'strong responders'. This difference correlated with the rise in pulse pressure suggesting indirectly the role of stoke volume in individual response. In healthy subjects pressor response was also individually differentiated and not influenced by vibration. CONCLUSION: Deep and semi squat can evoke a strong cardiovascular response in some PD and healthy subjects. Low-magnitude vibrations likely did not affect pressor response. [ABSTRACT FROM AUTHOR]

Abstract Objective Acute mental stress (MS) increases arm blood pressure (BP); however, it remains unclear whether a stress-induced pressor response is also observed in other vessels. This study aimed to examine the impact of acute MS on ankle BP. Fifty-six young, healthy men aged 19–24 years were divided into the MS (n = 29) and control (CON) (n = 27) groups; each group performed 5-min MS (mental arithmetic) or CON tasks. Systolic and diastolic BPs (SBP and DBP, respectively) of both the brachial and posterior tibial arteries were simultaneously measured at the baseline and 5 and 30 min after the task. Results In the MS group, brachial BP measures significantly increased (P

Excessive sympathetic activity during exercise causes heightened peripheral vasoconstriction, which can reduce oxygen delivery to active muscles, resulting in exercise intolerance. Although both patients suffering from heart failure with preserved and reduced ejection fraction (HFpEF and HFrEF, respectively) exhibit reduced exercise capacity, accumulating evidence suggests that the underlying pathophysiology may be different between these two conditions. Unlike HFrEF, which is characterized by cardiac dysfunction with lower peak oxygen uptake, exercise intolerance in HFpEF appears to be predominantly attributed to peripheral limitations involving inadequate vasoconstriction rather than cardiac limitations. However, the relationship between systemic hemodynamics and the sympathetic neural response during exercise in HFpEF is less clear. This mini review summarizes the current knowledge on the sympathetic (i.e., muscle sympathetic nerve activity, plasma norepinephrine concentration) and hemodynamic (i.e., blood pressure, limb blood flow) responses to dynamic and static exercise in HFpEF compared to HFrEF, as well as non-HF controls. We also discuss the potential of a relationship between sympathetic over-activation and vasoconstriction leading to exercise intolerance in HFpEF. The limited body of literature indicates that higher peripheral vascular resistance, perhaps secondary to excessive sympathetically mediated vasoconstrictor discharge compared to non-HF and HFrEF, drives exercise in HFpEF. Excessive vasoconstriction also may primarily account for over elevations in blood pressure and concomitant limitations in skeletal muscle blood flow during dynamic exercise, resulting in exercise intolerance. Conversely, during static exercise, HFpEF exhibit relatively normal sympathetic neural reactivity compared to non-HF, suggesting that other mechanisms beyond sympathetic vasoconstriction dictate exercise intolerance in HFpEF.

Background: Laryngoscopy and endotracheal intubation is often associated with hypertension and tachycardia because of the sympathoadrenal stimulation which is usually transient and lasts for 5-10 minutes. Aims and Objectives: To evaluate the effects of single premedication dose of 1ug/kg body weight in 20 ml normal saline over 10 min I.V dexmedetomidine in attenuating pressor response to laryngoscopy & endotracheal intubation in elective surgeries under general anaesthesia. Materials and Methods: 60 patients aged 18-60 years old were assigned randomly into two groups. 10 min before induction these two groups received, group I (n=30): received 20 ml normal saline (NS) IV over 10 min, group II (n=30): received dexmedetomidine 1µg/kg body weight diluted to 20 ml NS IV over 10 min. After induction of anaesthesia, HR, SBP, DBP and MAP were recorded at various time intervals like before induction, after induction and 1, 2.5, 5, 10, 15 and 20 min after laryngoscopy and intubation. Results: It was noted that in group I, following laryngoscopy and intubation, the mean rise in HR, systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP) were found to be 7.05 bpm(6.99%), 3.38mmHg(2.57%), 3.64 mmHg(4.28%) and 3.25 mmHg(3.26%) respectively, one minute after intubation. In group II, the mean of HR was increased by only 1.58bpm(1.74%) while the SBP, DBP and MAP were decreased by 8.03 mmHg (5.7%), 0.25 mmHg(0.28%) and 3.05 mmHg(2.93%) respectively compared to basal values which was statistically significant (p=0.01). Conclusions: Dexmedetomidine (1µg/kg) IV, given 10 min before induction was seen to effectively attenuate the pressor response to laryngoscopy and tracheal intubation without any side effect. [ABSTRACT FROM AUTHOR]

Objectives: To compare the attenuation of pressor responses by intravenous clonidine and preservative-free lignocaine to laryngoscopy and endotracheal intubation. Materials and Methods: A randomized, prospective, comparative, double-blinded study was conducted in 80 adult patients who were randomized into two groups of 40 each, group clonidine (Group C) and group lignocaine (Group L). Group C patients were given 2 µg/kg clonidine in 20 ml of normal saline as a slow infusion over 10 min prior to intubation. Group L patients were given 1.5 mg/kg of preservative-free 2% lignocaine in 20 ml of normal saline as a single-dose infusion over 3 min prior to intubation. Baseline vital and hemodynamic parameters were monitored during the perioperative period at 1-, 5-, and 10-min post-intubation. Results: The attenuation of heart rate (HR) after intubation was much better with clonidine than lignocaine as there is statistically significant difference in the mean HR between the two groups at 1, 5, and 10 min after intubation with the HR significantly lesser in the Group C than the Group L at all times after intubation. Both clonidine and lignocaine were effective in attenuating systolic blood pressure response after intubation, but clonidine was more effective than lignocaine as systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) in the Group C remained much lower than the Group L and the difference between the two groups was statistically significant at all times after intubation. Conclusion: Premedicating with a single slow infusion of 2 µg/kg i.v. clonidine has been proven to be effective in maintaining perioperative hemodynamic stability at 1, 5, and 10 min post-intubation than lignocaine. [ABSTRACT FROM AUTHOR]

Introduction: Age-related stiffening of the large elastic arteries (e.g., common carotid artery [CCA]) may impair wall dynamics (i.e., strain) and amplify transmission of pulsatile blood flow into the brain with large increases in pressure that occur during maximal resistance exercise (RE). The purpose of this study was to compare CCA arterial wall dynamics, central hemodynamics, and cerebral blood velocity responses during maximal RE between young and older adults.Methods: Thirty-one young (YA; 26 ± 5 yrs; 23.8 ± 3.3 kg/m2) and 25 older adults (OA; 60 ± 6 yrs; 30.0 ± 5.5 kg/m2) performed a unilateral maximal isokinetic knee flexion/extension exercise protocol (i.e., maximal RE). All measures were recorded at baseline and during the last 10 s of maximal RE. Common carotid artery strain, CCA strain time to peak, and CCA strain rate (i.e., variables of arterial wall dynamics) were analyzed using 2D speckle tracking software from circumferential ultrasound images. Transcranial Doppler was used to measure right middle cerebral artery (MCA) blood velocity. Non-invasive arterial blood pressure measurements were obtained using finger photoplethysmography.Results: Older adults had greater reductions in CCA strain time to peak from baseline to maximal RE (345 ± 39 to 242 ± 52 ms) than YA (308 ± 35 to 247 ± 42 ms; interaction effect, p < 0.01). MCA velocity was similar between YA and OA during maximal RE (p = 0.48), despite a greater arterial pressor response in OA (p < 0.01).Conclusion: These data suggest cerebral blood velocity responds similarly during maximal RE among OA compared to YA, despite subtle age-related differences in the pressor and extracranial vascular response during maximal RE. [ABSTRACT FROM AUTHOR]

Objective: Acute mental stress (MS) increases arm blood pressure (BP); however, it remains unclear whether a stress-induced pressor response is also observed in other vessels. This study aimed to examine the impact of acute MS on ankle BP. Fifty-six young, healthy men aged 19–24 years were divided into the MS (n = 29) and control (CON) (n = 27) groups; each group performed 5-min MS (mental arithmetic) or CON tasks. Systolic and diastolic BPs (SBP and DBP, respectively) of both the brachial and posterior tibial arteries were simultaneously measured at the baseline and 5 and 30 min after the task. Results: In the MS group, brachial BP measures significantly increased (P < 0.05) until 30 min after the task; ankle BP measures were also significantly (P < 0.05) elevated during this time. In the CON group, no significant changes were found in brachial BP measures or ankle SBP, whereas a significant increase (P < 0.05) in ankle DBP was observed 30 min after the task. Our findings indicate that both brachial and ankle BP exhibit a sustained elevation after acute MS, suggesting a systemic pressor response by stress exposure. The measurement of ankle BP in addition to arm BP may be important to assess the stress response. Trial Registration: UMIN Clinical Trials Registry UMIN000047796 Registered on: 20th May 2022. [ABSTRACT FROM AUTHOR]

Introduction: Laparoscopy, a minimally invasive technique causes several physiological fluctuations. There can be deleterious sympathetic responses during carbon dioxide insufflation, which is done to create a pneumoperitoneum. Aim: To assess the impact of clonidine and magnesium sulphate on sympathetic response to carbon dioxide insufflation in patients undergoing laparoscopic surgeries. Materials and Methods: A double-blinded randomised clinical study was conducted in Dr. D.Y. Patil Medical College, Hospital and Research Centre, Pimpri, Pune, Maharshtra, India, from June 2020 to September 2021, included 52 patients, posted for elective laparoscopic surgeries. Patients were randomized into two groups i.e, group M (n=26) received 30 mg/kg of magnesium sulphate and group C (n=26) received 1 μg/kg of clonidine after premedication. The vital parameters like heart rate, systolic, diastolic and mean arterial pressure, end tidal carbon dioxide, saturation were observed and noted at predetermined interval in perioperative period. Also, Visual Analogue Score (VAS) and sedation score were recorded in the recovery room. The statistical software SPSS version 16 was used. The p-value <0.05 was considered as significant. Results: The mean age in group C and group M was 35.46± 8.5 years and 35.38±9.02 years (p-value=0.751). Both groups were compared for change in heart rate, systolic, diastolic and mean blood pressure changes after pneumoperitoneum and showed no significant variations in both groups at different time intervals (p-value >0.05). Also, both groups showed less than 20% variation from the baseline parameters, thus, effectively attenuating the pressor response. The VAS and sedation score were comparable in both the groups and showed no significant variations in both groups at different time intervals. Conclusion: Intravenous administration of clonidine 1 μg/kg, or magnesium sulfate 30 mg/kg prior to pneumoperitoneum was effective in suppressing the pressor response during laparoscopic procedures. At the above used dosages, groups C and M showed insignificant difference in the measured parameters, thus proving to be equally effective in blunting the pressor response. [ABSTRACT FROM AUTHOR]

Purpose: Water drinking has been proposed for the treatment of orthostatic hypotension because it can increase blood pressure in patients. This study aimed to investigate whether drinking water with a cold or carbonation stimulus would cause a more effective pressor response, and whether it would be greater in older than in younger adults.Methods: We assessed blood pressure and heart rate from non-invasive arterial pressure (a volume-clamp method) and type II electrocardiography in 13 healthy young adults (6 females, 7 males; mean age, 19.9 ± 1.1 years) and nine healthy older adults (all females; mean age, 71.4 ± 4.2 years) who drank 200 mL of cold, cold carbonated, and room temperature water.Results: The pressor response to the drinking of cold and cold carbonated water was greater than that to room temperature water in both younger and older participants (p < 0.05; changes in systolic blood pressure of room temperature water, cold water and cold carbonated water in young: 15.31 ± 9.66, 22.56 ± 11.51 and 32.6 ± 17.98 mmHg, respectively; changes in systolic blood pressure of room temperature water, cold water and cold carbonated water in elderly: 21.84 ± 14.31, 41.53 ± 19.82 and 48.16 ± 16.77 mmHg, respectively). In addition, the pressor response to cold and cold carbonated water was persistent during the recovery period by about 5–10 mmHg (p < 0.05). Furthermore, the pressor response during the drinking and recovery periods was greater in the older than in the younger participants (p < 0.05).Conclusion: Our data suggest that even smaller amounts of water are able to elicit a sustained pressor response, in particular if the water is cold and carbonated. We speculate that the pressor effect may render cold and carbonated water an appropriate first aid method against certain forms of acute hypotension.

Purpose: Water drinking has been proposed for the treatment of orthostatic hypotension because it can increase blood pressure in patients. This study aimed to investigate whether drinking water with a cold or carbonation stimulus would cause a more effective pressor response, and whether it would be greater in older than in younger adults. Methods: We assessed blood pressure and heart rate from non-invasive arterial pressure (a volume-clamp method) and type II electrocardiography in 13 healthy young adults (6 females, 7 males; mean age, 19.9 ± 1.1 years) and nine healthy older adults (all females; mean age, 71.4 ± 4.2 years) who drank 200 mL of cold, cold carbonated, and room temperature water. Results: The pressor response to the drinking of cold and cold carbonated water was greater than that to room temperature water in both younger and older participants (p < 0.05; changes in systolic blood pressure of room temperature water, cold water and cold carbonated water in young: 15.31 ± 9.66, 22.56 ± 11.51 and 32.6 ± 17.98 mmHg, respectively; changes in systolic blood pressure of room temperature water, cold water and cold carbonated water in elderly: 21.84 ± 14.31, 41.53 ± 19.82 and 48.16 ± 16.77 mmHg, respectively). In addition, the pressor response to cold and cold carbonated water was persistent during the recovery period by about 5–10 mmHg (p < 0.05). Furthermore, the pressor response during the drinking and recovery periods was greater in the older than in the younger participants (p < 0.05). Conclusion: Our data suggest that even smaller amounts of water are able to elicit a sustained pressor response, in particular if the water is cold and carbonated. We speculate that the pressor effect may render cold and carbonated water an appropriate first aid method against certain forms of acute hypotension. [ABSTRACT FROM AUTHOR]

Background: Laryngoscopy followed by tracheal intubation is the commonest technique of securing airway. However, laryngoscopy time more than 15 seconds leads to exaggerated pressor response. It can also result into a cardiovascular catastrophe in vulnerable elderly patients. Materials and Methods: A prospective and randomised single centre study was conducted upon patients belonging to American Society of Anaesthesiologist (ASA) physical status I and II who were scheduled for elective surgery under general anaesthesia. Sixty (60) patients were randomly allocated to two groups (I & II) of 30 each by sealed envelope technique. In group I, conventional laryngoscopy and intubation was carried out and in group II, intubation was carried out using intubating laryngeal mask airway (ILMA), fastrach. Results: Haemodynamic parameters (heart rate and mean arterial blood pressure) were compared between the two groups. Two tailed independent t test was used for comparison of the parameters. Rise in heart rate (HR) and mean arterial pressure (MAP) was statistically significant at stage-2 in group I (p >0.001). Conclusion: ILMA insertion and intubation using it can be recommended for patients vulnerable to cardiovascular event. [ABSTRACT FROM AUTHOR]

We previously demonstrated that muscle sympathetic nerve activity (MSNA) increases to contracting muscle as well as to non-contracting muscle, but this was only assessed during isometric exercise at ∼10% of maximum voluntary contraction (MVC). Given that high-intensity isometric contractions will release more metabolites, we tested the hypothesis that the metaboreflex is expressed in the contracting muscle during high-intensity but not low-intensity exercise. MSNA was recorded continuously via a tungsten microelectrode inserted percutaneously into the right common peroneal nerve in 12 participants, performing isometric dorsiflexion of the right ankle at 10, 20, 30, 40, and 50% MVC for 2 min. Contractions were immediately followed by 6 min of post-exercise ischemia (PEI); 6 min of recovery separated contractions. Cross-correlation analysis was performed between the negative-going sympathetic spikes of the raw neurogram and the ECG. MSNA increased as contraction intensity increased, reaching mean values (± SD) of 207 ± 210 spikes/min at 10% MVC (P = 0.04), 270 ± 189 spikes/min at 20% MVC (P < 0.01), 538 ± 329 spikes/min at 30% MVC (P < 0.01), 816 ± 551 spikes/min at 40% MVC (P < 0.01), and 1,097 ± 782 spikes/min at 50% MVC (P < 0.01). Mean arterial pressure also increased in an intensity-dependent manner from 76 ± 3 mmHg at rest to 90 ± 6 mmHg (P < 0.01) during contractions of 50% MVC. At all contraction intensities, blood pressure remained elevated during PEI, but MSNA returned to pre-contraction levels, indicating that the metaboreflex does not contribute to the increase in MSNA to contracting muscle even at these high contraction intensities. [ABSTRACT FROM AUTHOR]

We previously demonstrated that muscle sympathetic nerve activity (MSNA) increases to contracting muscle as well as to non-contracting muscle, but this was only assessed during isometric exercise at ∼10% of maximum voluntary contraction (MVC). Given that high-intensity isometric contractions will release more metabolites, we tested the hypothesis that the metaboreflex is expressed in the contracting muscle during high-intensity but not low-intensity exercise. MSNA was recorded continuously via a tungsten microelectrode inserted percutaneously into the right common peroneal nerve in 12 participants, performing isometric dorsiflexion of the right ankle at 10, 20, 30, 40, and 50% MVC for 2 min. Contractions were immediately followed by 6 min of post-exercise ischemia (PEI); 6 min of recovery separated contractions. Cross-correlation analysis was performed between the negative-going sympathetic spikes of the raw neurogram and the ECG. MSNA increased as contraction intensity increased, reaching mean values (± SD) of 207 ± 210 spikes/min at 10% MVC (P = 0.04), 270 ± 189 spikes/min at 20% MVC (P < 0.01), 538 ± 329 spikes/min at 30% MVC (P < 0.01), 816 ± 551 spikes/min at 40% MVC (P < 0.01), and 1,097 ± 782 spikes/min at 50% MVC (P < 0.01). Mean arterial pressure also increased in an intensity-dependent manner from 76 ± 3 mmHg at rest to 90 ± 6 mmHg (P < 0.01) during contractions of 50% MVC. At all contraction intensities, blood pressure remained elevated during PEI, but MSNA returned to pre-contraction levels, indicating that the metaboreflex does not contribute to the increase in MSNA to contracting muscle even at these high contraction intensities.

Background: Laryngoscopy and tracheal intubation initiate tremendous changes in heart rate (HR) and blood pressure which could be associated with deleterious consequences in susceptible individuals. Methods: The effect of gabapentin on the haemodynamic responses to laryngoscopy and intubation in adults undergoing elective non-cardiac surgeries was investigated in the present study. Sixty adult patients of the American Society of Anaesthesiologists Grade I aged between 18–65 years and scheduled for different types of elective non-cardiac surgeries under general anaesthesia were randomly allocated to receive gabapentin 1200 mg or placebo capsules, at 6 h intervals starting the evening before surgery. After standard routine induction, succinylcholine was used to facilitate intubation. HR, systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP) were recorded before and after the administration of the induction agent, immediately after laryngoscopy and intubation and at 1, 3, 5 and 10 min thereafter. Results: Patient characteristics were similar in both the groups. When compared to placebo group, Gabapentin group showed significantly lower HR (at post-induction, 0, 1 and 3 min; P < 0.05), SBP (at 0, 1 and 3 min; P < 0.05), DBP (at 0 and 1 min, P < 0.05) and MAP (at 0, 1 and 3 min, P = 0.05) after laryngoscopy and intubation. Conclusions: Gabapentin, under the present study design, attenuated the pressor response to laryngoscopy and intubation in terms of HR, SBP, DBP and MAP in patients undergoing elective non-cardiac surgeries.

Introduction: Endotracheal intubation (ETI) is the highest quality level for airway management. LMA ProSeal™ (PLMA) insertion under gum elastic bougie (GEB) guidance has got 100% first attempt success rate, but it also requires laryngoscopy for its success; hence nullifying its advantage of being a supraglottic airway device. We compared the hemodynamic responses associated with laryngoscopy assisted GEB guided PLMA placement with that of conventional endotracheal intubation. Method: One hundred normotensive ASA I or II patients of either sex (age 18 to 40 y) undergoing general anesthesia for elective surgery were included and evaluated for the pressor response. Following a uniform premedication and standard anesthesia technique (thiopentone + vecuronium), either of airway was placed and heart rate (HR) and mean blood pressure (MAP) were recorded at Tb = base line, T0 = just before laryngoscopy and PLMA/ETT placement, T1 = 1 min, T3 = 3 min, T5 = 5 min, T7 = 7 min after placement. Statistical analysis was done to find the significance. Results: Patients demographics between the PLMA and ETT groups were similar. Following laryngoscopy and PLMA/ETT placement, both were associated with statistically significant increases in HR and MAP with respect to its basal value. Although it was less marked in case of PLMA Group, when compared to the ETT Group. Duration of laryngoscopy and the time to successful placement were longer in PLMA Group as compared to ETT Group (35.71 and 12.69 sec. vs 21.30 and 10.76 sec. respectively). ETT insertion was related with a higher incidence of cough (p < 0.05), but was equivalent for sore throat and hoarseness (p > 0.05). Conclusion: Hence GEB guided PLMA method must be used as a reinforcement method in cases where standard insertion methods of airway management fail and in failed tracheal intubation. The bougie proves helpful in quick control of the airway route when used with PLMA. [ABSTRACT FROM AUTHOR]

Background In today's era of anesthesia, balanced anesthesia is the main basis of patient care and pain management. Of all the medications given during general anesthesia, premedication, induction agents, and muscle relaxants play a major role in keeping the hemodynamics properly under control. When laryngoscopy is performed to intubate, a pain stimulus will be generated, leading to a rise in blood pressure and heart rate. This stimulus can be avoided without any complications if appropriate premedication is given to the patient at the appropriate dosage. In this research, we compare the influence of injection esmolol and oral clonidine during the time of induction as premedications to suppress the hemodynamic response. Material and methods In a prospective randomized controlled trial, 90 patients were divided into three groups: Group E (esmolol) received 2 mg/kg IV esmolol diluted in 0.9% NS two minutes pre-anesthesia; Group C (clonidine) received oral clonidine 4 mcg/kg 90 minutes pre-anesthesia; and Group P (placebo) received IV normal saline and oral water. Blood pressure, heart rate, and mean arterial pressure were measured at baseline and seven subsequent time points. Results The study compared systolic blood pressure (SBP), mean arterial pressure (MAP), and diastolic blood pressure (DBP) changes over seven minutes in three groups, clonidine (Group C), placebo (Group P), and esmolol (Group E). At one minute, Group E showed a consistent MAP decrease from 95.21 mmHg to 85.92 mmHg, while Group C and Group P exhibited fluctuating trends. DBP decreased across all groups, with Group P ending highest (77.7 mmHg) and Group C lowest (66.8 mmHg). Group E's SBP decreased steadily from 126.2 mmHg to 118.0 mmHg, Group C decreased from 128 mmHg to 116.1 mmHg, and Group P showed more erratic fluctuations in SBP, DBP, and MAP. Conclusion These findings suggest that intravenous esmolol shows a good hemodynamic response having superior control over heart rate and getting the pressure under control quickly without major drop compared with the clonidine and placebo groups., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. GSL Medical College & General Hospital, Rajahmundry, GSLMC/ME/ME2/86/DISS/2018 issued approval M166403080. Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Mudiganti et al.)

K-complexes are a key marker of nonrapid eye movement sleep, specifically during stages II sleep. Recent evidence suggests the heart rate responses to a K-complexes may differ between men and women. The purpose of this study was to compare beat-to-beat blood pressure responses to K-complexes in men and women. We hypothesized that the pressor response following a spontaneous K-complex would be augmented in men compared with women. Ten men [age: 23 ± 2 yr, body mass index (BMI): 28 ± 4 kg/m2] and ten women (age: 23 ± 5 yr, BMI: 25 ± 4 kg/m2) were equipped with overnight finger plethysmography and standard 10-lead polysomnography. Hemodynamic responses to a spontaneous K-complex during stable stage II sleep were quantified for 10 consecutive cardiac cycles, and measurements included systolic arterial pressure (SAP), diastolic arterial pressure (DAP), and heart rate. K-complex elicited greater pressor responses in men when blood pressures were expressed as SAP (cardiac cycle ( sex: P = 0.007) and DAP (cardiac cycle ( sex: P = 0.004). Heart rate trended to be different between men and women (cardiac cycle ( sex: P = 0.078). These findings suggest a divergent pressor response between men and women following a spontaneous K-complex during normal stage II sleep. These findings could contribute to sex-specific differences in cardiovascular risk that exist between men and women. [ABSTRACT FROM AUTHOR]

Autonomic blood pressure control is fundamentally altered during a single bout of exercise, as evidenced by the downward resetting of the baroreflex following exercise (postexercise hypotension). However, it is unclear if an acute bout of exercise is also associated with a change in the sensitivity of the exercise pressor response to a controlled stimulus, such as a static contraction. This study tested the hypothesis that the blood pressure response to a controlled static contraction would be attenuated after unilateral cycling of the contralateral (opposite) leg, but preserved after cycling of the ipsilateral (same) leg. To test this, the blood pressure response to 90 s of isometric plantar flexion [50% maximal voluntary contraction (MVC)] was compared before and after 20 min of contralateral and ipsilateral single-leg cycling at 20% peak oxygen consumption and rest (control) in 10 healthy subjects (three males and seven females). The mean arterial pressure response was significantly attenuated after contralateral single-leg cycling (+9.8 ± 7.5% ∆mmHg vs. +6.7 ± 6.6% ∆mmHg pre and postexercise, respectively, P = 0.04) and rest (+9.0 ± 7.5% ∆mmHg vs. +6.6 ± 5.2% ∆mmHg pre and postexercise, respectively, P = 0.03). In contrast, the pressor response nonsignificantly increased following ipsilateral single-leg cycling (+5.5 ± 5.2% ∆mmHg vs. +8.9 ± 7.2% ∆mmHg pre and postexercise, respectively, P = 0.08). The heart rate, leg blood flow, and leg conductance responses to plantar flexion were not affected by any condition (P ≥ 0.12). These results are consistent with the notion that peripheral, but not central mechanisms promote exercise pressor reflex sensitivity after exercise. [ABSTRACT FROM AUTHOR]

Background: Laryngoscopy and tracheal intubation initiate tremendous changes in heart rate (HR) and blood pressure which could be associated with deleterious consequences in susceptible individuals. Methods: The effect of gabapentin on the haemodynamic responses to laryngoscopy and intubation in adults undergoing elective non-cardiac surgeries was investigated in the present study. Sixty adult patients of the American Society of Anaesthesiologists Grade I aged between 18-65 years and scheduled for different types of elective non-cardiac surgeries under general anaesthesia were randomly allocated to receive gabapentin 1200 mg or placebo capsules, at 6 h intervals starting the evening before surgery. After standard routine induction, succinylcholine was used to facilitate intubation. HR, systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP) were recorded before and after the administration of the induction agent, immediately after laryngoscopy and intubation and at 1, 3, 5 and 10 min thereafter. Results: Patient characteristics were similar in both the groups. When compared to placebo group, Gabapentin group showed significantly lower HR (at post-induction, 0, 1 and 3 min; P < 0.05), SBP (at 0, 1 and 3 min; P < 0.05), DBP (at 0 and 1 min, P < 0.05) and MAP (at 0, 1 and 3 min, P = 0.05) after laryngoscopy and intubation. Conclusions: Gabapentin, under the present study design, attenuated the pressor response to laryngoscopy and intubation in terms of HR, SBP, DBP and MAP in patients undergoing elective non-cardiac surgeries. [ABSTRACT FROM AUTHOR]

Background and Aims: Laryngoscopy and intubation cause sympathetic stimulation and arousal reactions. We evaluated the role of dexmedetomidine and magnesium sulphate on pressor responses to laryngoscopy and intubation as compared to placebo, when depth of anaesthesia was maintained at a constant bispectral index (BIS) range 40-50 (±5). Methods: One hundred and twenty patients were randomised to receive either dexmedetomidine 1 μg/kg (Group DS), magnesium sulphate 30 mg/kg diluted in 100 ml saline (Group MS) or 100 ml normal saline (Group NS) 15 min before induction of anaesthesia in a double blind manner. After achieving BIS 40–50 (±5), laryngoscopy and intubation were performed. Heart rate (HR), systolic blood pressure (SBP) and diastolic blood pressure (DBP) were recorded pre-drug, after drug, at intubation, at intervals of 1 min till 5 min, then every 2 min till 10 min and every 10 min for 30 min. Statistical analysis was done using Chi-square test and one way analysis of variance Results: SBP, DBP and HR fell in the DS and MS groups. No significant changes in BP were seen in the NS group at induction and after intubation. HR rose in the NS group (P < 0.001) at induction from 86.35 ± 9.05 to 95.35 ± 11.60 at 2 min. Patients in DS and MS groups had significantly lower HR, SBP and DBP at laryngoscopy and intubation. Conclusion: At BIS levels 40-50 (±5) there was no pressor response to intubation in the NS Group. Dexmedetomidine and magnesium sulphate significantly reduced the heart rate and blood pressure from baseline.

Tyramine, formed by the decarboxylation of tyrosine, is a natural constituent of numerous food products. As an indirect sympathomimetic, it can have potentially dangerous hypertensive effects. In vitro data indicated that the pharmacokinetics of tyramine possibly depend on the organic cation transporter OCT1 genotype and on the CYP2D6 genotype. Since tyramine is a prototypic substrate of monoamine oxidase A (MAO-A), genetic polymorphisms in MAO-A may also be relevant. The aims of this study were to identify to what extent the interindividual variation in pharmacokinetics and pharmacodynamics of tyramine is determined by genetic polymorphisms in OCT1, CYP2D6, and MAO-A. Beyond that, we wanted to evaluate tyramine as probe drug for the in vivo activity of MAO-A and OCT1. Therefore, the pharmacokinetics, pharmacodynamics, and pharmacogenetics of tyramine were studied in 88 healthy volunteers after oral administration of a 400 mg dose. We observed a strong interindividual variation in systemic tyramine exposure, with a mean AUC of 3.74 min*µg/ml and a high mean CL/F ratio of 107 l/min. On average, as much as 76.8% of the dose was recovered in urine in form of the MAO-catalysed metabolite 4-hydroxyphenylacetic acid (4-HPAA), confirming that oxidative deamination by MAO-A is the quantitatively most relevant metabolic pathway. Systemic exposure of 4-HPAA varied only up to 3-fold, indicating no strong heritable variation in peripheral MAO-A activity. Systolic blood pressure increased by more than 10 mmHg in 71% of the volunteers and correlated strongly with systemic tyramine concentration. In less than 10% of participants, individually variable blood pressure peaks by >40 mmHg above baseline were observed at tyramine concentrations of >60 µg/l. Unexpectedly, the functionally relevant polymorphisms in OCT1 and CYP2D6, including the CYP2D6 poor and ultra-rapid metaboliser genotypes, did not significantly affect tyramine pharmacokinetics or pharmacodynamics. Also, the MOA-A genotypes, which had been associated in several earlier studies with neuropsychiatric phenotypes, had no significant effects on tyramine pharmacokinetics or its metabolism to 4-HPAA. Thus, variation in tyramine pharmacokinetics and pharmacodynamics is not explained by obvious genomic variation, and human tyramine metabolism did not indicate the existence of ultra-low or -high MAO-A activity.

Objectives: Airway manipulations induce marked fluctuations in heart rate and blood pressure. Strict narcotic legislations limit availability of fentanyl. This study was designed to compare the attenuating effects of intravenous magnesium sulfate with fentanyl on cardiovascular and arousal response following laryngoscopy and intubation, while ensuring anesthetic depth with Bispectral index monitoring. Methods: Seventy-five female patients ASA 1 or 2, scheduled for elective surgery under general anesthesia were randomized into three groups: Group M received 40 mg/kg magnesium sulfate, Group F, 2 μg/kg fentanyl, and Group C received saline prior to induction of anesthesia. Systolic and diastolic blood pressure (SBP, DBP), heart rate (HR), and bispectral index (BIS) were measured at various time points. Maximum change in hemodynamic parameters and arousal response were calculated (ΔSBP, ΔDBP, ΔHR, ΔBIS). Adverse effects related to study drugs were recorded. Results: There was a statistically significant increase in BP and HR following intubation in all three groups compared to prelaryngoscopy levels. ΔSBP and ΔDBP were comparable in M and F groups, but p < 0.000 when compared with control group. Following infusion of the study drug, HR increased in M group p = 0.002, while decreased in F group, p < 0.001. BIS also increased significantly after intubation compared to prelaryngoscopy levels, ΔBIS was 9.2 (SD 2.4)%, 9.9 (1.9)% in F and M groups compared to 31.8 (7.8) in group C, p < 0.000. Hypertension, although transient, occurred in 44% in control group compared to none in other groups. Conclusion: Magnesium sulfate infusion prior to anesthesia induction effectively attenuated hemodynamic and arousal response to tracheal intubation comparable to fentanyl in normotensive patients. Clinical trial registration: The trial was registered in Pan African Clinical Trials Registry (ID: PACTR201802003104179), [ABSTRACT FROM AUTHOR]

Tyramine, formed by the decarboxylation of tyrosine, is a natural constituent of numerous food products. As an indirect sympathomimetic, it can have potentially dangerous hypertensive effects. In vitro data indicated that the pharmacokinetics of tyramine possibly depend on the organic cation transporter OCT1 genotype and on the CYP2D6 genotype. Since tyramine is a prototypic substrate of monoamine oxidase A (MAO-A), genetic polymorphisms in MAO-A may also be relevant. The aims of this study were to identify to what extent the interindividual variation in pharmacokinetics and pharmacodynamics of tyramine is determined by genetic polymorphisms in OCT1, CYP2D6, and MAO-A. Beyond that, we wanted to evaluate tyramine as probe drug for the in vivo activity of MAO-A and OCT1. Therefore, the pharmacokinetics, pharmacodynamics, and pharmacogenetics of tyramine were studied in 88 healthy volunteers after oral administration of a 400 mg dose. We observed a strong interindividual variation in systemic tyramine exposure, with a mean AUC of 3.74 min*µg/ml and a high mean CL/F ratio of 107 l/min. On average, as much as 76.8% of the dose was recovered in urine in form of the MAO-catalysed metabolite 4-hydroxyphenylacetic acid (4-HPAA), confirming that oxidative deamination by MAO-A is the quantitatively most relevant metabolic pathway. Systemic exposure of 4-HPAA varied only up to 3-fold, indicating no strong heritable variation in peripheral MAO-A activity. Systolic blood pressure increased by more than 10 mmHg in 71% of the volunteers and correlated strongly with systemic tyramine concentration. In less than 10% of participants, individually variable blood pressure peaks by >40 mmHg above baseline were observed at tyramine concentrations of >60 µg/l. Unexpectedly, the functionally relevant polymorphisms in OCT1 and CYP2D6, including the CYP2D6 poor and ultra-rapid metaboliser genotypes, did not significantly affect tyramine pharmacokinetics or pharmacodynamics. Also, the MOA-A genotypes, which had been associated in several earlier studies with neuropsychiatric phenotypes, had no significant effects on tyramine pharmacokinetics or its metabolism to 4-HPAA. Thus, variation in tyramine pharmacokinetics and pharmacodynamics is not explained by obvious genomic variation, and human tyramine metabolism did not indicate the existence of ultra-low or -high MAO-A activity. [ABSTRACT FROM AUTHOR]

Context: Laryngoscopy and endotracheal intubation result in an increase in heart rate and blood pressure; they evoke life-threatening complications. The esmolol is short-acting cardioselective beta-blocker and brings advantages to the perioperative management of tachycardia and hypertension. Aims: The aim of this study was to compare the efficacy of a bolus dose of esmolol and bolus dose of lignocaine for attenuation of the pressor response to laryngoscopy and intubation. Settings and Design: Sixty patients of both sex, aged 20-50 years, belonging to the American Society of Anesthesiologists physical Status I and II randomly allocated into two groups (n = 30). Materials and Methods: The study drugs diluted in 10-ml normal saline. Group I received esmolol 1.5 mg/kg and Group II received lignocaine 1.5 mg/kg 2 min before inducing the patients with thiopentone 5 mg/kg and suxamethonium 1.5 mg/kg. The heart rate, systolic blood pressure, and diastolic blood pressure were measured at basal, during intubation, and 1, 2, 3, and 5 min after intubation, and based on these values, the mean arterial pressure (MAP) and rate pressure product (RPP) was calculated. Statistical Analysis Used: The Student's t-test and data were represented by mean standard deviation and graphs. Results: The mean pulse rate, mean of MAP, and mean of RPP at intubation and at 1, 2, 3, and 5 min after intubation in lignocaine group showed a significant rise in these values but in esmolol group it remained nearer to or less than baseline values. Conclusions: Esmolol 1.5 mg/kg is effective in attenuating the pressor response in comparison with lignocaine 1.5 mg/kg during laryngoscopy and intubation. [ABSTRACT FROM AUTHOR]

Background: Tracheal extubation causes significant hemodynamic stimulation resulting in transient increase in blood pressure and heart rate. Aim and Objectives: To compare the efficacy of Esmolol and Dexmedetomidine given intravenously to attenuate the pressor and airway response to emergence from general anaesthesia and tracheal extubation. Materials and Methods: After obtaining institutional ethical committee approval and written informed consent, 90 ASA grade I and II patients, in the age group of 20-70 years, of either sex, undergoing elective surgery under general anaesthesia were included. At the end of surgery, patients received IV Esmolol 1.5 mg/kg (Group E) two minutes prior to extubation or IV Dexmedetomidine 0.5 mcg/kg (Group D) over ten minutes prior to extubation or no drug in the control group (Group C). Hemodynamic parameters were assessed before giving study drugs, before extubation and after extubation upto 15 minutes. Extubation quality was rated using 5 point cough grading. Sedation scoring was done using Modified Ramsay Sedation scale. Results: All hemodynamic parameters showed attenuation upto 15 minutes post extubation, in both Group E and Group D as compared to Group C. However, even though Injection Esmolol successfully controlled the hemodynamic response to extubation, the attenuation was more evident with Injection Dexmedetomidine, as the parameters were below the baseline values at all times after extubation, without excessive bradycardia or hypotension. None of the patients showed incidence of desaturation. The cough grading, and hence the quality of extubation, was better with Group D as compared to Group C and E. Patients in the Dexmedetomidine group, were significantly sedated as compared to Esmolol and Control group, but this aided a smooth extubation without any agitation. Conclusion: We conclude that IV Esmolol 1.5 mg/kg attenuates the pressor response, but IV Dexmedetomidine attenuates both pressor as well as the airway responses to extubation.

It is known that circulating angiotensin II (ANG-II) acts on the circumventricular organs (CVOs), which partially lack a normal blood-brain barrier, to stimulate pressor responses, vasopressin (AVP), and oxytocin (OT) secretion, as well as sodium and water intake. Although ANG-II type 1 receptors (AT1R) are expressed in neurons and astrocytes, the involvement of CVOs glial cells in the neuroendocrine, cardiovascular and behavioral responses induced by central ANG II remains to be further elucidated. To address this question, we performed a set of experiments combining in vitro studies in primary hypothalamic astrocyte cells (HACc) and in vivo intracerebroventricular (icv) microinjections into the lateral ventricle of awake rats. Our results showed that ANG-II decreased glutamate uptake in HACc. In addition, in vivo studies showed that fluorocitrate (FCt), a reversible glial inhibitor, increased OT secretion and mean arterial pressure (MAP) and decreased breathing at rest. Furthermore, previous FCt decreased AVP secretion and sodium intake induced by central ANG-II. Together, our findings support that CVOs glial cells are important in mediating neuroendocrine and cardiorespiratory functions, as well as central ANG-II-induced AVP release and salt-intake behavior in awake rats. In the light of our in vitro studies, we propose that these mechanisms are, at least in part, by ANG-II-induced astrocyte mediate reduction in glutamate extracellular clearance.

Background and Aims: Laryngoscopy and endotracheal intubation are considered as potent stimuli which lead to an increase in heart rate and blood pressure. Melatonin (N-acetyl-5-methoxytryptamine) has been studied for pre-operative anxiolysis and sedation in Intensive Care Unit. We made a hypothesis that melatonin can provide haemodynamic stability during laryngoscopy and intubation when given 120 min before the procedure. Methods: Sixty American Society of Anesthesiologists physical status Grade I and II patients of either gender, 20-45 years old, 40-65 kg body weight, scheduled to undergo elective surgical procedures under general anaesthesia were assigned into two equal groups - Group C (control) and Group M (melatonin). They received oral placebo or melatonin tablets 6 mg, respectively, 120 min before surgery. The haemodynamic parameters were recorded preoperatively, during laryngoscopy and endotracheal intubation and thereafter at 1, 3, 5 and 10 min. Unpaired t-test was used for between-group comparison of ratio and interval scale data. For within-group comparison of ratio and interval scale data, repeated-measures ANOVA and post hoc Bonferroni t-tests were used. Results: It was observed that in the control group, there was a significant increase in heart rate and blood pressure at laryngoscopy and intubation and persisted till 10 min post-intubation. In melatonin group, there was an insignificant increase in heart rate at the time of laryngoscopy and intubation which however settled within 1 min post-intubation. Conclusion: Melatonin is an effective drug for attenuation of cardiovascular responses to laryngoscopy and endotracheal intubation.

Background and Aims: Swapping of the endotracheal tube with laryngeal mask airway (LMA) before emergence from anaesthesia is one of the methods employed for attenuation of pressor response at extubation. We decided to compare the placement of ProSeal ™ LMA (PLMA) before endotracheal extubation versus conventional endotracheal extubation in controlled hypertensive patients scheduled for elective surgeries under general anaesthesia. Methods: Sixty consenting adult patients were randomly allocated to two groups of thirty each; Group E in whom extubation was performed using standard technique and Group P in whom PLMA was inserted before endotracheal extubation (Bailey manoeuvre). The primary outcome parameter was heart rate (HR). The secondary outcomes were systolic, diastolic and mean blood pressure (MBP), electrocardiogram, oxygen saturation and end-tidal carbon dioxide. Two-tailed paired Student's t-test was used for comparison between the two study groups. The value of P< 0.05 was considered as statistically significant. Results: The patient characteristics, demographic data and surgical procedures were comparable in the two groups. A statistically significant decrease was observed in HR in Group P as compared to Group E. Secondary outcomes such as systolic, diastolic and MBP depicted a statistically insignificant difference. Conclusion: Bailey manoeuvre was not effective method to be completely relied upon during extubation when compared to standard extubation.

This study was designed to compare the hemodynamic and arousal responses to blind orotracheal intubation through Air Q laryngeal mask airway versus flexible fiberoptic guided. 100 adult patients ASA I and II undergoing elective surgeries under general anesthesia with orotracheal intubation were divided into two groups according to the technique of intubation through Air-Q ILA Group І (n= 50) patients intubated blindly through Air-Q ILA Group ІІ (n=50) patients intubated through Air-Q ILA guided by flexible fiberoptic bronchoscope. The following parameters were recorded: heart rate, systolic, diastolic and mean arterial blood pressure and Bispectral Index (BIS) values: preinduction, after induction of anesthesia, then at 1 and 5 minutes after intubation, arterial oxygen saturation (SpO2): before, during and after intubation, time of insertion(in seconds) and number of attempts of insertion of the endotracheal tube and airway complications; injury to the gums or teeth damage, hoarseness of the voice, bleeding, sore throat. Systolic and mean arterial blood pressures were statistically significant lower in the fiberoptic group than the blind group. There was no statistically significant difference between the two groups in the heart rate and diastolic blood pressure.There was statistically significant lower time of intubation and less number of attempts in fiberoptic group than in blind group, the success rate of intubation in the fiberoptic group was 100% compared to 76% in blind group. There was statistically significant lower BIS value in the fiberoptic group 1 minute after intubation than in the blind group. Endotracheal intubation through the Air-Q ILA guided by flexible fiberoptic bronchoscope is associated with less hemodynamic and arousal responses than blind endotracheal intubation through the Air-Q ILA, the number of attempt and time of successful intubation were statistically significantly lower in the fiberoptic group than the blind group. [Med-Science 2015; 4(3.000): 2388-400]