scholarly journals Determination of the Minimum Infusion Rate of Alfaxalone Combined with Electroacupuncture in Goats

Animals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2989
Author(s):  
Lingling Liu ◽  
Mahmoud M. Abouelfetouh ◽  
Eman Salah ◽  
Rui Sun ◽  
Sha Nan ◽  
...  
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Rectal Temperature ◽  
Infusion Rate ◽  
Companion Animals ◽  
Noxious Stimulation ◽  
Nociceptive Threshold ◽  
Intravenous Anesthesia ◽  
Hemoglobin Oxygen Saturation

Total intravenous anesthesia (TIVA) is increasingly used in companion animals. The effect of electroacupuncture (EA) on alfaxalone-based TIVA has not been previously reported in goats. Therefore, the objective of this study was to determine the minimum infusion rate (MIR) of alfaxalone required to prevent purposeful movement of the extremities in response to standardized noxious stimulation during its combination with EA in goats. Twelve clinically healthy goats weighing 18.5 ± 2 kg were randomly assigned to two groups (six goats/group). Alfaxalone alone (ALF group) and alfaxalone combined with EA (EA-ALF group). In the EA-ALF, alfaxalone was administered 30 min after EA stimulation. For induction of anesthesia, a bolus of alfaxalone was given at 3 mg/kg IV, and an infusion dose of 9.6 mg/kg/h was initially set for maintenance. The MIR of alfaxalone in both groups was determined by testing for responses to stimulation (clamping on a digit with Vulsellum forceps) at 10-min intervals after induction of anesthesia till the entire period of the experiment. Cardiopulmonary parameters and nociceptive threshold were measured throughout anesthesia. The median alfaxalone MIR was significantly lower in the EA-ALF group than the ALF group [9 (4.8–9.6) and 12 (11.4–18)], respectively; p = 0.0035). In the ALF group, goats anesthetized with MIR showed a significant increase in heart rate and cardiac output (p < 0.0001 and 0.0312, respectively), and decrease in respiratory rate (p < 0.0001), hemoglobin oxygen saturation (p = 0.0081), and rectal temperature (p = 0.0046) compared with those in the EA-ALF. Additionally, goats in the EA-ALF showed a higher nociceptive threshold than those in the ALF group (p < 0.0001). EA provided analgesia, reduced the MIR of alfaxalone-based IV anesthesia and thereby alleviated the adverse cardiorespiratory effects associated with alfaxalone anesthesia in goats.

Stress and cocaine elicit similar cardiac output responses in individual rats

1993 ◽  
Vol 265 (2) ◽  
pp. H779-H782 ◽  
Author(s):  
M. M. Knuepfer ◽  
C. A. Branch ◽  
P. J. Mueller ◽  
Q. Gan
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Cardiovascular Responses ◽  
Aortic Blood Flow ◽  
Conscious Rats ◽  
Air Jet ◽  
Behavioral Stress ◽  
Pressor Responses ◽  
Output Only

Cocaine use and behavioral stress elicit variable cardiovascular responses in individuals. In the present study, we examined the effects of cocaine or stress on arterial pressure, heart rate, and cardiac output in conscious rats. Rats were instrumented for determination of ascending aortic blood flow as an index of cardiac output using pulsed Doppler flow-metry. Cocaine administration elicited consistent decreases in cardiac output in some rats, whereas others had increases. In contrast, the pressor and heart rate responses were similar in these two groups of animals. Air jet stress also elicited a decrease in cardiac output only in a subset of conscious rats, yet produced equivalent pressor responses in all rats. Cardiac output responses to cocaine and air jet stress were closely correlated in individual rats, indicating that these stimuli evoke similar hemodynamic responses in individual rats. These observations suggest that the rat may provide a model for understanding differential cardiovascular sensitivity to cocaine and/or stress in humans.

Fluid replacement and glucose infusion during exercise prevent cardiovascular drift

1991 ◽  
Vol 71 (3) ◽  
pp. 871-877 ◽  
Author(s):  
M. T. Hamilton ◽  
J. Gonzalez-Alonso ◽  
S. J. Montain ◽  
E. F. Coyle
Keyword(s):  
Heart Rate ◽  
Body Weight ◽  
Cardiac Output ◽  
Rectal Temperature ◽  
Prolonged Exercise ◽  
Blood Glucose Concentration ◽  
Fluid Replacement ◽  
O2 Uptake ◽  
Trained Subjects ◽  
Cardiovascular Drift

This study examined the influence of both hydration and blood glucose concentration on cardiovascular drift during exercise. We first determined if the prevention of dehydration during exercise by full fluid replacement prevents the decline in stroke volume (SV) and cardiac output (CO) during prolonged exercise. On two occasions, 10 endurance-trained subjects cycled an ergometer in a 22 degrees C room for 2 h, beginning at 70 +/- 1% maximal O2 uptake (VO2max) and in a euhydrated state. During one trial, no fluid (NF) replacement was provided and the subject's body weight declined 2.09 +/- 0.19 kg or 2.9%. During the fluid replacement trial (FR), water was ingested at a rate that prevented body weight from declining after 2 h of exercise (i.e., 2.34 +/- 0.17 1/2 h). SV declined 15% and CO declined 7% during the 20- to 120-min period of the NF trial while heart rate (HR) increased 10% and O2 uptake (VO2) increased 6% (all P less than 0.05). In contrast, SV was maintained during the 20- to 120-min period of FR while HR increased 5% and thus CO actually increased 7% (all P less than 0.05). Rectal temperature, SV, and HR were similar during the 1st h of exercise during NF and FR. However, after 2 h of exercise, rectal temperature was 0.6 degree C higher (P less than 0.05) and SV and CO were 11–16% lower (P less than 0.05) during NF compared with FR.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Cardiovascular functions in two macruran decapod crustaceans (Procambarus clarkii and Homarus americanus) during periods of inactivity, tail flexion and cardiorespiratory pauses

1997 ◽  
Vol 200 (7) ◽  
pp. 1103-1113 ◽  
Author(s):  
C Reiber ◽  
B Mcmahon ◽  
W Burggren
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Stroke Volume ◽  
Procambarus Clarkii ◽  
Homarus Americanus ◽  
Peak Height ◽  
Wave Form ◽  
In Situ Calibration ◽  
Tail Movement

Arterial hemolymph flow was measured in restrained crayfish (Procambarus clarkii) and lobsters (Homarus americanus). Implanted pulsed Doppler flow transducers were used to measure arterial flows in the anterior aorta, posterior aorta, sternal artery, lateral artery, ventral thoracic artery and ventral abdominal artery, allowing determination of flow simultaneously in several arteries over a period of 4 days. Calculated Doppler hemolymph flow showed a strong correlation (P&lt;0.05) with 'pumped' hemolymph flow as determined by in situ calibration. Arterial flow patterns remained constant during quiet conditions. In crayfish, cardiac output was 7.5&plusmn;1.1 ml min-1 (252 ml kg-1 min-1), of which the anterior aorta received 1.3&plusmn;0.15 ml min-1 (20.1&plusmn;4.0 %), the posterior aorta received 0.8&plusmn;0.1 ml min-1 (12.3&plusmn;2.7 %) and the sternal artery received 5.2&plusmn;1.4 ml min-1 (67.5&plusmn;37.0 %). Mean heart frequency at rest was 125.6&plusmn;5.2 beats min-1 and stroke volume was 0.06&plusmn;0.01 ml beat-1 (1.98 ml kg-1 beat-1). In lobsters, cardiac output was 60.8&plusmn;4.4 ml min-1 (93.6&plusmn;6.8 ml kg-1 min-1), with the anterior aorta receiving 7.8&plusmn;0.8 ml min-1 (12.8&plusmn;2.7 %), the lateral arteries receiving 0.6&plusmn;0.2 ml min-1 (1.0&plusmn;0.5 %), the posterior aorta receiving 12.6&plusmn;1.0 ml min-1 (20.7&plusmn;3.3 %) and the sternal artery receiving 38.9&plusmn;4.1 ml min-1 (64.0&plusmn;13.4 %). Flows in the branches of the sternal artery were 0.3&plusmn;0.05 ml min-1 (0.5&plusmn;2 %) in the ventral abdominal artery and 4.0&plusmn;0.1 ml min-1 (6.5&plusmn;0.3 %) in the ventral thoracic artery. Lobster heart rate was 82.5&plusmn;2.9 beats min-1 and stroke volume was 0.7&plusmn;0.05 ml beat-1. Periods of constant hemolymph flow were interrupted by tail flexions (abdominal flexion) and, in lobsters, periods of cardiac/respiratory pause. Tail movement increased flow (peak height and minimum flow values) in both crayfish and lobsters, although the general wave form of hemolymph flow and pressure did not change. In lobsters, periodic respiratory pauses were observed during which all arteries received hemolymph, despite the low heart rate.

scholarly journals Determination of Minimum Infusion Rate and Cardiorespiratory Effects of Total Intravenous Anesthesia of Ketofol With or Without Lidocaine, Fentanyl or Dexmedetomidine in Dogs

2021 ◽  
Author(s):  
Hadi Imani Rastabi ◽  
Hadi Naddaf ◽  
Bahman Mosallanejad ◽  
Mahmood Khannejad ◽  
Majid Keramat
Keyword(s):  
Phase I ◽  
Respiratory Depression ◽  
Phase Ii ◽  
Infusion Rate ◽  
Cardiovascular Effects ◽  
Total Intravenous Anesthesia ◽  
Intravenous Anesthesia ◽  
Predetermined Interval ◽  
The Times

Abstract Background: Ketofol is a 1:1 mixture of ketamine and propofol that has been proposed for induction and maintenance of anesthesia aiming to provide more cardiovascular stability and less undesirable impacts compared to the use of propofol and ketamine alone. However, it has been associated with exacerbated respiratory depression in dogs. Diminishing the dose of ketofol may improve cardiovascular effects and attenuate respiratory depression. The present study was designed to evaluate the effect of adding lidocaine, fentanyl or dexmedetomidine at the required dose and cardiorespiratory variables in dogs undergoing total intravenous anesthesia (TIVA) with ketofol. In phase I, twelve dogs were induced and maintained with two out of four anesthetic regimens of KET: ketofol (4 mg/kg and 0.3 mg/kg/min, respectively), KLD; ketofol and lidocaine (1.5 mg/kg and 0.25 mg/kg/min, respectively), KFN: ketofol and fentanyl (LD: 5 µg/kg and 0.1 µg/kg/min, respectively) and KDX: ketofol and dexmedetomidine (2 µg/kg and 2 mg/kg/h, respectively). Minimum infusion rate (MIR) of ketofol was determined in this phase. Subsequently, in phase II, other twelve dogs were given the same anesthetic regimens for 60 min similar to the previous phase, except the infusion rate of ketofol. Cardiorespiratory variables were recorded in predetermined interval. Results: In phase I, mean MIR of ketofol for KET, KLD, KFN and KDX were determined to have decreasing manner as 0.35, 0.23, 0.15, and 0.08 mg/kg/min, respectively. In phase II, the times of recovery events were shorter in KFN and KDX than KET and KLD. Notably, HR was significantly higher than baseline during anesthesia in KET and KLD, which also was significantly lower than baseline in KFN and KDX at several time points. Significant higher values of MAP were observed over time in KDX. In all treatments, there was a decrease in respiratory rate and pH as well as an increase in PCO2 during the anesthesia session. Conclusions: It was concluded that despite decreasing the dose of ketofol, none of the added drugs attenuated respiratory depression caused by ketofol.

scholarly journals Determination of differentiated hemodynamics types based on assessment of integral circulation indicators in healthy people and patients with hypertension

2015 ◽  
Vol 96 (6) ◽  
pp. 911-917 ◽  
Author(s):  
Yu E Teregulov ◽  
S D Mayanskaya ◽  
E T Teregulova
Keyword(s):  
Rheumatoid Arthritis ◽  
Heart Rate ◽  
Cardiac Output ◽  
Data Analysis ◽  
Arterial Hypertension ◽  
Vascular Resistance ◽  
Peripheral Vascular Resistance ◽  
Peripheral Vascular ◽  
Circulation Types

Aim. To develop a method for determination of the differentiated types of hemodynamics based on the data analysis of integral circulation indicators. Methods. The method for determination of the differentiated hemodynamics types was developed based on the data analysis of integral circulation indicators - cardiac output, heart rate, total peripheral vascular resistance and modulus of volume elasticity. The types of hemodynamics - hyperkinetic, eukinetic, hypokinetic - were determined by cardiac output. Tachy-, normo- and bradisistolic subtypes were determined by the heart rate, subtypes with a predominance of vascular resistance and arterial stiffness were determined by the modulus of volume elasticity and total peripheral vascular resistance ratio. Four groups of patients were examined. The first group included 63 patients with I-III degree of arterial hypertension aged 18 to 77 years, mean age 48.9±12.38 (M±σ). The second group - 82 patients with primary hypothyroidism and I-III degree of arterial hypertension aged of 41 to 75 years, 59.8±7.9 years (M±σ). The third group - 33 patients with rheumatoid arthritis and I-III degree of arterial hypertension aged 17 to 67 years, 47.2±8.12 years (M±σ). The control group included 32 healthy volunteers aged 21 to 37 years, 24.7±5.34 years (M±σ). Results. Eukinetic and hyperkinetic circulation types with predominance of peripheral vascular resistance were mostly identified in healthy volunteers. Eukinetic type of hemodynamic with predominance of peripheral vascular resistance is typical for patients with hypothyroidism and arterial hypertension, and for patients with rheumatoid arthritis and arterial hypertension hyperkinetic and eukinetic types with predominance of the arterial system rigidity are characteristic. Eukinetic and hypokinetic circulation types with predominance of both peripheral resistance and arterial stiffness are mostly present in essential hypertension. Conclusion. Developed method of distinguishing the differentiated types of hemodynamics allows determining the hemodynamic heterogeneity in both healthy people and patients with hypertension.

The effect of minimal differences in the skin-to-air vapor pressure gradient at various dry-bulb temperatures on self-paced exercise performance

2021 ◽  
Author(s):  
Felicity M. Bright ◽  
Brad Clark ◽  
Ollie Jay ◽  
Julien D. Periard
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Relative Humidity ◽  
Vapor Pressure ◽  
Pressure Gradient ◽  
Rectal Temperature ◽  
Exercise Performance ◽  
Perceived Exertion ◽  
Ratings Of Perceived Exertion ◽  
Vapor Pressure Gradient

The effects of dry-bulb temperature on self-paced exercise performance, along with thermal, cardiovascular and perceptual responses, were investigated by minimizing differences in the skin-to-air vapor pressure gradient (Psk,sat-Pa) between temperatures. Fourteen trained male cyclists performed 30-km time trials in 13˚C and 44% relative humidity (RH), 20˚C and 70% RH, 28˚C and 78% RH, and 36˚C and 72% RH. Power output was similar in 13˚C (275±31 W; mean and SD) and 20˚C (272±28 W; P=1.00), lower in 36˚C (228±36 W) than 13˚C, 20˚C and 28˚C (262±27 W; P<0.001) and lower in 28˚C than 13˚C and 20˚C (P<0.001). Peak rectal temperature was higher in 36˚C (39.6±0.4˚C) than all conditions (P<0.001) and higher in 28˚C (39.1±0.4˚C) than 13˚C (38.7±0.3˚C; P<0.001) and 20˚C (38.8˚C±0.3˚C; P<0.01). Heart rate was higher in 36˚C (163±14 beats·min-1) than all conditions (P<0.001) and higher in 20˚C (156±11 beats·min-1; P=0.009) and 28˚C (159±11 beats·min-1; P<0.001) than 13˚C (153±11 beats·min-1). Cardiac output was lower in 36˚C (16.8±2.5 l·min-1) than all conditions (P<0.001) and lower in 28˚C (18.6±1.6 l·min-1) than 20˚C (19.4±2.0 l·min-1; P=0.004). Ratings of perceived exertion were higher in 36˚C than all conditions (P<0.001) and higher in 28˚C than 20˚C (P<0.04). Self-paced exercise performance was maintained in 13˚C and 20˚C at a matched evaporative potential, impaired in 28˚C and further compromised in 36˚C in association with a moderately lower evaporative potential and marked elevations in thermal, cardiovascular and perceptual strain.

scholarly journals Kinetics of Cardiac Output at the Onset of Exercise in Precapillary Pulmonary Hypertension

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Frédéric Lador ◽  
Aurélien Bringard ◽  
Samir Bengueddache ◽  
Guido Ferretti ◽  
Karim Bendjelid ◽  
...  
Keyword(s):  
Heart Rate ◽  
Pulmonary Hypertension ◽  
Cardiac Output ◽  
Steady State ◽  
Cycle Ergometer ◽  
Healthy Controls ◽  
Sudden Drop ◽  
Exercise Onset ◽  
Kinetics Of

Purpose.Cardiac output (CO) is a cornerstone parameter in precapillary pulmonary hypertension (PH). The Modelflow (MF) method offers a reliable noninvasive determination of its beat-by-beat changes. So MF allows exploration of CO adjustment with the best temporal resolution.Methods.Fifteen subjects (5 PH patients, 10 healthy controls) performed a submaximal supine exercise on a cycle ergometer after 5 min of rest. CO was continuously determined by MF (COMF). Kinetics of heart rate (HR), stroke volume (SV), and CO were determined with 3 monoexponential models.Results.In PH patients, we observed a sudden and transitory drop of SV upon exercise onset. This implied a transitory drop of CO whose adjustment to a new steady state depended on HR increase. The kinetics of HR and CO for PH patients was slower than that of controls for all models and for SV in model 1. SV kinetics was faster for PH patients in models 2 and 3.Conclusion.This is the first description of beat-by-beat cardiovascular adjustments upon exercise onset in PH. The kinetics of HR and CO appeared slower than those of healthy controls and there was a transitory drop of CO upon exercise onset in PH due to a sudden drop of SV.

scholarly journals Changes of lidocaine concentration and physiological indices in dogs during anaesthesia with lidocaine and isoflurane combined with ketamine or fentanyl

2016 ◽  
Vol 85 (1) ◽  
pp. 91-97
Author(s):  
Shi-Xia Zhang ◽  
Xin Li ◽  
Qing-Ming Ren ◽  
Dong-Liang Niu ◽  
Li Gao ◽  
...  
Keyword(s):  
Heart Rate ◽  
Arterial Pressure ◽  
Rectal Temperature ◽  
Systolic Arterial Pressure ◽  
Intravenous Anaesthesia ◽  
Physiological Variables ◽  
Lidocaine Concentration ◽  
Lidocaine Administration ◽  
The Impact

Fentanyl and ketamine are often used as adjuvants in intravenous anaesthesia to prolong analgesia. The aim of this study was to compare changes of the basic physiological variables of intravenous lidocaine administration in combination with ketamine or fentanyl, and to evaluate the impact of addition of fentanyl or ketamine to lidocaine on serum lidocaine concentrations in dogs after intravenous administration. During general anaesthesia, dogs of group L received 2% lidocaine intravenously, dogs of group LF received 2% lidocaine and fentanyl, and dogs of the group LK received 2% lidocaine and ketamine. The heart rate, systolic arterial pressure, diastolic arterial pressure, mean arterial pressure and rectal temperature decreased in all groups, and group LF showed the biggest effect on the basic physiological variables, with the lowest heart rate during the test, significantly decreased rectal temperature, and the most decreased values of arterial pressure. Blood for determination of serum lidocaine concentration was taken before anaesthesia and 5, 30, 60, 90, 120, 150 and 180 min after initial intravenous injection of drugs. Fentanyl and ketamine did not cause significant changes of serum lidocaine concentration in dogs and may be used as adjuvant in intravenous anaesthesia without a significant increase in lidocaine absorption.

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