scholarly journals Heart Rate and Arterial Pressure Changes during Whole-Body Deep Hypothermia

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Giacomo Cavallaro ◽  
Luca Filippi ◽  
Genny Raffaeli ◽  
Gloria Cristofori ◽  
Federico Schena ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Mild Hypothermia ◽  
Clinical Signs ◽  
Deep Hypothermia ◽  
Whole Body ◽  
Arterial Blood ◽  
Significant Difference ◽  
Pressure Changes ◽  
Ischemic Encephalopathy

Whole-body deep hypothermia (DH) could be a new therapeutic strategy for asphyxiated newborn. This retrospective study describes how DH modified the heart rate and arterial blood pressure if compared to mild hypothermia (MH). Fourteen in DH and 17 in MH were cooled within the first six hours of life and for the following 72 hours. Hypothermia criteria were gestational age ≥36 weeks; birth weight ≥1800 g; clinical signs of moderate/severe hypoxic-ischemic encephalopathy. Rewarming was obtained in the following 6–12 hours (0.5°C/h) after cooling. Heart rates were the same between the two groups; there was statistically significant difference at the beginning of hypothermia and during rewarming. Three babies in the DH group and 2 in the MH group showed HR < 80 bpm and QTc > 520 ms. Infant submitted to deep hypothermia had not bradycardia or Qtc elongation before cooling and after rewarming. Blood pressure was significantly lower in DH compared to MH during the cooling, and peculiar was the hypotension during rewarming in DH group. Conclusion. The deeper hypothermia is a safe and feasible, only if it is performed by a well-trained team. DH should only be associated with a clinical trial and prospective randomized trials to validate its use.

scholarly journals Caudal bupivacaine - midazolam for post operative analgesia in children

2014 ◽  
Vol 23 (1) ◽  
pp. 8-13
Author(s):  
Idris Ali ◽  
Amirul Islam ◽  
Golam Morshed ◽  
Nurul Islam ◽  
Ashia Ali ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Anaesthetic Agent ◽  
Caudal Block ◽  
Arterial Blood ◽  
Post Operative Period ◽  
Caudal Analgesia ◽  
Significant Difference ◽  
Group B

Background: Adjuvant used with local anaesthetic agent in caudal is more effective for post operative analgesia in children . Aim and objective: To find out the duration and quality of caudal analgesia in children undergoing genitourinary surgery by combination of bupivacaine and midazolam. Methods: A total number of sixty patients ASA grade I&II were selected randomly as per inclusion & exclusion criteria in two groups. Thirty in each group. In group A, caudal block was given by bupivacainemidazolam mixture and in group B, caudal block was given by bupivacaine in lateral decubitus position, just after completion of surgery before reversed from GA. In post operative period arterial blood pressure, heart rate, and duration of analgesia were recorded. Results: There was no significant difference between the groups of blood pressure, heart rate, and pain score up to 30 min but after one hour of post operative period pain scores were significant(p<0.05). Conclusion: Midazolam improves the duration and quality of analgesic effect of bupivacaine. DOI: http://dx.doi.org/10.3329/jbsa.v23i1.18152 Journal of BSA, 2010; 23(1): 8-13

scholarly journals Heat stress alters hemodynamic responses during the Valsalva maneuver

2010 ◽  
Vol 108 (6) ◽  
pp. 1591-1594 ◽  
Author(s):  
Scott L. Davis ◽  
Craig G. Crandall
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heat Stress ◽  
Phase Ii ◽  
Valsalva Maneuver ◽  
Late Phase ◽  
Thermal Conditions ◽  
Whole Body ◽  
Hemodynamic Responses ◽  
Arterial Blood

The Valsalva maneuver can be used as a noninvasive index of autonomic control of blood pressure and heart rate. The purpose of this investigation was to test the hypothesis that sympathetic mediated vasoconstriction, as referenced by hemodynamic responses during late phase II (phase IIb) of the Valsalva maneuver, is inhibited during whole body heating. Seven individuals (5 men, 2 women) performed three Valsalva maneuvers (each at a 30-mmHg expiratory pressure for 15 s) during normothermia and again during whole body heating (increase sublingual temperature ∼0.8°C via water-perfused suit). Each Valsalva maneuver was separated by a minimum of 5 min. Beat-to-beat mean arterial blood pressure (MAP) and heart rate were measured during each Valsalva maneuver, and responses for each phase were averaged across the three Valsalva maneuvers for both thermal conditions. Baseline MAP was not significantly different between normothermic (88 ± 11 mmHg) and heat stress (84 ± 9 mmHg) conditions. The change in MAP (ΔMAP) relative to pre-Valsalva MAP during phases IIa and IIb was significantly lower during heat stress (IIa = −20 ± 8 mmHg; IIb = −13 ± 7 mmHg) compared with normothermia (IIa = −1 ± 15 mmHg; IIb = 3 ± 13 mmHg). ΔMAP from pre-Valsalva baseline during phase IV was significantly higher during heat stress (25 ± 10 mmHg) compared with normothermia (8 ± 9 mmHg). Counter to the proposed hypothesis, the increase in MAP from the end of phase IIa to the end of phase IIb during heat stress was not attenuated. Conversely, this increase in MAP tended to be greater during heat stress relative to normothermia ( P = 0.06), suggesting that sympathetic activation may be elevated during this phase of the Valsalva while heat stressed. These data show that heat stress does not attenuate this index of vasoconstrictor responsiveness during the Valsalva maneuver.

The Influence of Physical Activity on Arterial Pressure during Ambulatory Recordings in Man

1980 ◽  
Vol 58 (1) ◽  
pp. 115-117 ◽  
Author(s):  
D. B. Rowlands ◽  
T. J. Stallard ◽  
R. D. S. Watson ◽  
W. A. Littler
Keyword(s):  
Physical Activity ◽  
Blood Pressure ◽  
Heart Rate ◽  
Arterial Pressure ◽  
Ambulatory Blood Pressure ◽  
Physical Activities ◽  
Hypertensive Patients ◽  
Arterial Blood ◽  
Significant Difference ◽  
Hypotensive Therapy

1. Ambulatory blood pressure recordings were made over a 48 h period on six hypertensive patients. The conditions of study were standardized, particularly with regard to physical activity, and during one period of each day the patients were randomly allocated to be active or inactive. 2. Results show that blood pressure was highest during physical activity and lowest during sleep. There was no significant difference between the arterial pressures measured during the same physical activities carried out at the same time each day. However, during the same time on consecutive days when activity was randomized, there was a significant difference between the pressure recordings during physical activity compared with those during inactivity. Heart rate changes showed a similar trend during the randomized period. 3. Physical activity and sleep have a profound effect on continuous arterial blood pressure recordings and these are independent of time alone. These observations should be taken into account when using this ambulatory system to assess hypotensive therapy.

Measurement Of Bradykinin-Induced Venous Dilation By Ultrasound And Correlation With Heart Rate, Arterial And Venous Pressure And Endothelial Damage

1981 ◽  
Author(s):  
G J Stewart ◽  
R G Schaub ◽  
R E Cartee
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Arterial Blood Pressure ◽  
Carotid Arteries ◽  
Jugular Vein ◽  
Venous Pressure ◽  
Cardiovascular Responses ◽  
Endothelial Damage ◽  
Whole Body ◽  
Arterial Blood

This study was done to correlate known cardiovascular responses to bradykinin (increased heart rate, lowered arterial blood pressure) with recently demonstrated endothelial damage and proposed venous dilation. Healthy dogs of mixed breed were used. Blood pressures and heart rate were monitored and recorded on a Narco physiograph. The diameter of a jugular vein was monitored with an ADR ultrasound machine using a 10 MHz probe with linear array of crystals and recorded on polaroid prints. Jugular veins and carotid arteries were removed and prepared for scanning electron microscopy after removal of blood and partial in situ fixation by whole body perfusion. The response of arterial pressure was dose dependent with no change at 6 ug/min, variable drop at 12 ug/min and 22-40% drop at 60 ug/min and above. Venous pressure increased in 1 dog but was unchanged in 4 others. The increase of heart rate paralled the drop in arterial blood pressure. The diameter of a jugular vein increased in 3 of 3 monitored dogs by 25, 33, 50% of baseline diameter (average increase 36%) with high (300 ug/min) bradykinin. Endothelial damage (microtears) occurred around 70-80% of branches, at some valves and on the main vessel occassionally. The tears were infiltrated with leukocytes and some red cells and platelets indicating that tearing occurred while blood was still circulating, i.e. before dissection for removal of vessels. Carotid arteries showed no tears. Dilation of arteries would be limited by their elastic layers (missing in veins). These observations show that venous dilation and endothelial tearing around side branches are part of the cardiovascular response to blood born bradykinin. They also show that venous dilation can be measured by ultrasound.

Strength training reduces arterial blood pressure but not sympathetic neural activity in young normotensive subjects

2003 ◽  
Vol 94 (6) ◽  
pp. 2212-2216 ◽  
Author(s):  
Jason R. Carter ◽  
Chester A. Ray ◽  
Emily M. Downs ◽  
William H. Cooke
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Resistance Training ◽  
Exercise Training ◽  
Resistance Exercise ◽  
Arterial Blood Pressure ◽  
Whole Body ◽  
Arterial Blood ◽  
Blood Pressures ◽  
Body Resistance

The effects of resistance training on arterial blood pressure and muscle sympathetic nerve activity (MSNA) at rest have not been established. Although endurance training is commonly recommended to lower arterial blood pressure, it is not known whether similar adaptations occur with resistance training. Therefore, we tested the hypothesis that whole body resistance training reduces arterial blood pressure at rest, with concomitant reductions in MSNA. Twelve young [21 ± 0.3 (SE) yr] subjects underwent a program of whole body resistance training 3 days/wk for 8 wk. Resting arterial blood pressure ( n = 12; automated sphygmomanometer) and MSNA ( n = 8; peroneal nerve microneurography) were measured during a 5-min period of supine rest before and after exercise training. Thirteen additional young (21 ± 0.8 yr) subjects served as controls. Resistance training significantly increased one-repetition maximum values in all trained muscle groups ( P < 0.001), and it significantly decreased systolic (130 ± 3 to 121 ± 2 mmHg; P = 0.01), diastolic (69 ± 3 to 61 ± 2 mmHg; P = 0.04), and mean (89 ± 2 to 81 ± 2 mmHg; P = 0.01) arterial blood pressures at rest. Resistance training did not affect MSNA or heart rate. Arterial blood pressures and MSNA were unchanged, but heart rate increased after 8 wk of relative inactivity for subjects in the control group (61 ± 2 to 67 ± 3 beats/min; P = 0.01). These results indicate that whole body resistance exercise training might decrease the risk for development of cardiovascular disease by lowering arterial blood pressure but that reductions of pressure are not coupled to resistance exercise-induced decreases of sympathetic tone.

scholarly journals Effect of adding dexmedetomidine or remifentanil to thiopental in patients with mood disorder candidate for electroconvulsive therapy

2020 ◽  
pp. 1-6
Author(s):  
Faezeh Heidarbeigi ◽  
Hamidreza Jamilian ◽  
Anita Alaghemand ◽  
Alireza Kamali
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Mood Disorders ◽  
Electroconvulsive Therapy ◽  
Recovery Time ◽  
Arterial Oxygen ◽  
Arterial Blood ◽  
Significant Difference ◽  
The Mean ◽  
Remifentanil Group

Electroconvulsive therapy (ECT) is one of the appropriate treatments for many neuropsychiatric patients, especially those with mood disorders. Short-term complications of ECT include agitation and postictal. In this study, we compared the addition of dexmedetomidine or remifentanil to thiopental as the main anaesthetic used in ECT. In this double-blind randomised clinical trial, 90 patients with mood disorders (candidates for ECT) were divided into two groups based on their therapy: dexmedetomidine or remifentanil. In the first group (DG), patients were slowly injected intravenously with 0.5 μg/kg dexmedetomidine before induction of anesthesia. In the second group (GR), 100 μg of remifentanil was slowly injected intravenously.In addition, we collected demographic information such as respiratory rate, heart pulse rate, seizure time, mean of arterial blood pressure, recovery duration and the oxygen arterial saturation recorded after recovery. Data obtained were analysed by use of statistical software, SPSS-23. The mean age of both groups was approximately 37 years with the majority being men. There was no significant difference between the two groups in terms of age and sex, blood pressure, heart rate, duration of seizures and arterial oxygen saturation before ECT. The mean blood pressure and heart rate in the recovery group were lower in the dexmedetomidine group than in the remifentanil group and the hemodynamics in the dexmedetomidine group were more stable. The recovery time in the dexmedetomidine group was longer than that of the remifentanil group (p = 0.001). Both groups had approximately the same satisfaction and the rate of agitation after ECT was the same. Both remifentanil and dexmedetomidine as adjuvants lead to a decrease in patients' post-ECT hyperdynamic responses. In our study, we demonstrated that the effect of dexmedetomidine is greater than remifentanil. On the other hand, neither dexmedetomidine nor remifentanil had a negative effect on seizure duration, but dexmedetomidine significantly prolonged recovery time, when compared to remifentanil.

Baroreflex modulation of sympathetic nerve activity to muscle in heat-stressed humans

2002 ◽  
Vol 282 (1) ◽  
pp. R252-R258 ◽  
Author(s):  
Jian Cui ◽  
Thad E. Wilson ◽  
Craig G. Crandall
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heat Stress ◽  
Sympathetic Nerve ◽  
Sympathetic Nerve Activity ◽  
Whole Body ◽  
Arterial Baroreflex ◽  
Nerve Activity ◽  
Arterial Blood ◽  
The Relationship

To identify whether whole body heating alters arterial baroreflex control of muscle sympathetic nerve activity (MSNA), MSNA and beat-by-beat arterial blood pressure were recorded in seven healthy subjects during acute hypotensive and hypertensive stimuli in both normothermic and heat stress conditions. Whole body heating significantly increased sublingual temperature ( P < 0.01), MSNA ( P < 0.01), heart rate ( P< 0.01), and skin blood flow ( P < 0.001), whereas mean arterial blood pressure did not change significantly ( P > 0.05). During both normothermic and heat stress conditions, MSNA increased and then decreased significantly when blood pressure was lowered and then raised via intravenous bolus infusions of sodium nitroprusside and phenylephrine HCl, respectively. The slope of the relationship between MSNA and diastolic blood pressure during heat stress (−128.3 ± 13.9 U · beats−1 · mmHg−1) was similar ( P = 0.31) with normothermia (−140.6 ± 21.1 U · beats−1 · mmHg−1). Moreover, no significant change in the slope of the relationship between heart rate and systolic blood pressure was observed. These data suggest that arterial baroreflex modulation of MSNA and heart rate are not altered by whole body heating, with the exception of an upward shift of these baroreflex curves to accommodate changes in these variables that occur with whole body heating.

Alterations in glucose kinetics induced by pentobarbital anesthesia

1987 ◽  
Vol 253 (6) ◽  
pp. E657-E663 ◽  
Author(s):  
C. H. Lang ◽  
G. J. Bagby ◽  
D. M. Hargrove ◽  
P. M. Hyde ◽  
J. J. Spitzer
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Body Temperature ◽  
Glucose Metabolism ◽  
Carbohydrate Metabolism ◽  
Whole Body ◽  
Metabolic Clearance ◽  
Glucose Kinetics ◽  
Arterial Blood ◽  
Anesthetized Rats

Because pentobarbital is often used in investigations related to carbohydrate metabolism, the in vivo effect of this drug on glucose homeostasis was studied. Glucose kinetics, assessed by the constant intravenous infusion of [6-3H]- and [U-14C]glucose, were determined in three groups of catheterized fasted rats: conscious, anesthetized and body temperature maintained, and anesthetized but body temperature not maintained. After induction of anesthesia, marked hypothermia (5 degrees C decrease in core temperature) developed in rats not provided with external heat. Anesthetized rats that developed hypothermia showed a decrease in mean arterial blood pressure (25%) and heart rate (40%), whereas no differences were seen in blood pressure and heart rate of conscious and euthermic anesthetized rats. Likewise, the plasma lactate concentration and the rates of glucose appearance, recycling, and metabolic clearance were reduced by 30-50% in the hypothermic anesthetized rats. Changes in whole-body carbohydrate metabolism were prevented when body temperature was maintained. Because plasma pentobarbital levels were similar between the euthermic and hypothermic rats during the first 2 h of the experiment, the rapid reduction in glucose metabolism in this latter group appears related to the decrease in body temperature. The continuous infusion of epinephrine produced alterations in glucose kinetics that were not different between conscious animals and anesthetized rats with body temperature maintained. However, marked differences were seen in hypothermic rats. Thus pentobarbital-anesthetized rats became hypothermic when kept at room temperature and exhibited marked decreases in glucose metabolism. Such changes were absent when body temperature was maintained during anesthesia.

Carotid baroreflex responsiveness in heat-stressed humans

2000 ◽  
Vol 279 (4) ◽  
pp. H1955-H1962 ◽  
Author(s):  
C. G. Crandall
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heat Stress ◽  
Orthostatic Intolerance ◽  
Whole Body ◽  
Functional Reserve ◽  
Arterial Blood ◽  
Carotid Baroreflex ◽  
Maximal Gain ◽  
Increased Susceptibility

The effects of whole body heating on human baroreflex function are relatively unknown. The purpose of this project was to identify whether whole body heating reduces the maximal slope of the carotid baroreflex. In 12 subjects, carotid-vasomotor and carotid-cardiac baroreflex responsiveness were assessed in normothermia and during whole body heating. Whole body heating increased sublingual temperature (from 36.4 ± 0.1 to 37.4 ± 0.1°C, P < 0.01) and increased heart rate (from 59 ± 3 to 83 ± 3 beats/min, P < 0.01), whereas mean arterial blood pressure (MAP) was slightly decreased (from 88 ± 2 to 83 ± 2 mmHg, P < 0.01). Carotid-vasomotor and carotid-cardiac responsiveness were assessed by identifying the maximal gain of MAP and heart rate to R wave-triggered changes in carotid sinus transmural pressure. Whole body heating significantly decreased the responsiveness of the carotid-vasomotor baroreflex (from −0.20 ± 0.02 to −0.13 ± 0.02 mmHg/mmHg, P < 0.01) without altering the responsiveness of the carotid-cardiac baroreflex (from −0.40 ± 0.05 to −0.36 ± 0.02 beats · min−1 · mmHg−1, P = 0.21). Carotid-vasomotor and carotid-cardiac baroreflex curves were shifted downward and upward, respectively, to accommodate the decrease in blood pressure and increase in heart rate that accompanied the heat stress. Moreover, the operating point of the carotid-cardiac baroreflex was shifted closer to threshold ( P = 0.02) by the heat stress. Reduced carotid-vasomotor baroreflex responsiveness, coupled with a reduction in the functional reserve for the carotid baroreflex to increase heart rate during a hypotensive challenge, may contribute to increased susceptibility to orthostatic intolerance during a heat stress.

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