scholarly journals Hemodynamic variables in piglets anesthetized with isoflurane or propofol, kept under spontaneous ventilation and FIO2 of 0.5

2019 ◽  
Vol 71 (6) ◽  
pp. 1846-1852
Author(s):  
C.K. Ido ◽  
P.E.S. Silva ◽  
H.R.A. Silva ◽  
E.G.F. Biteli ◽  
R.L. Carneiro ◽  
...  

ABSTRACT This study aimed to evaluate comparatively the effects of propofol or isoflurane on hemodynamic variables in piglets that received inspired oxygen fraction (FIO2) of 0.5 under spontaneous ventilation. Therefore, sixteen piglets weighing 16±1.1kg, were randomly divided into two groups: GI (Isoflurane and FIO2 of 0.5) and GP (Propofol and FIO2 of 0.5). Heart rate (HR), systolic, diastolic and mean arterial pressure (SAP, DAP and MAP), central venous pressure (CVP), cardiac output (CO), mean pulmonary arterial pressure (mPAP) and mean capillary pulmonary pressure (mCPP) were assessed 40 minutes after anesthetic induction (T0), followed by 15 minutes intervals (from T15 to T60). The variables cardiac index (CI), stroke volume (SV), stroke index (SI), total peripheral resistance (TPR), total peripheral resistance index (TPRI), pulmonary vascular resistance (PVR), and pulmonary vascular resistance index (PVRI) were calculated. SAP and TPRI were significantly different between groups at T30 and T60 (P< 0.05) with higher GP values being recorded. There were no differences in the other variables, however, GP presented mean closer to normality on most of the analyzed variables. Therefore, we conclude that total intravenous anesthesia with propofol presented greater stability of the hemodynamic variables evaluated.

1987 ◽  
Vol 252 (5) ◽  
pp. H894-H899 ◽  
Author(s):  
Y. W. Chien ◽  
E. D. Frohlich ◽  
N. C. Trippodo

To examine mechanisms by which administration of atrial natriuretic peptide (ANP) decreases venous return, we compared the hemodynamic effects of ANP (0.5 microgram X min-1 X kg-1), furosemide (FU, 10 micrograms X min-1 X kg-1), and hexamethonium (HEX, 0.5 mg X min-1 X kg-1) with those of vehicle (VE) in anesthetized rats. Compared with VE, ANP reduced mean arterial pressure (106 +/- 4 vs. 92 +/- 3 mmHg; P less than 0.05), central venous pressure (0.3 +/- 0.3 vs. -0.7 +/- 0.2 mmHg; P less than 0.01), and cardiac index (215 +/- 12 vs. 174 +/- 10 ml X min-1 X kg-1; P less than 0.05) and increased calculated resistance to venous return (32 +/- 3 vs. 42 +/- 2 mmHg X ml-1 X min X g; P less than 0.01). Mean circulatory filling pressure, distribution of blood flow between splanchnic organs and skeletal muscles, and total peripheral resistance remained unchanged. FU increased urine output similar to that of ANP, yet produced no hemodynamic changes, dissociating diuresis, and decreased cardiac output. HEX lowered arterial pressure through a reduction in total peripheral resistance without altering cardiac output or resistance to venous return. The results confirm previous findings that ANP decreases cardiac output through a reduction in venous return and suggest that this results partly from increased resistance to venous return and not from venodilation or redistribution of blood flow.


1975 ◽  
Vol 03 (03) ◽  
pp. 245-261 ◽  
Author(s):  
Do Chil Lee ◽  
Myung O. Lee ◽  
Donald H. Clifford

The cardiovascular effects of moxibustion at Jen Chung (Go-26) in 10 dogs under halothane anesthesia were compared to 5 dogs under halothane anesthesia without moxibustion and 5 dogs under halothane anesthesia in which moxibustion was effected at a neutral or non-acupuncture site. Cardiac output, stroke volume, heart rate, mean arterial pressure, central venous pressure, total peripheral resistance, pH, PaCO2, PaO2 and base deficit were measured over a two-hour period. A significant increase in cardiac output and stroke volume and a significant decrease in the total peripheral resistance were observed in the group which was stimulated by moxibustion at Jen Chun (Go-26). Heart rate, mean arterial pressure and pulse pressure were significantly increase during the early part of the two-hour period in the same group. The cardiovascular effects of moxibustion at Jen Chung (Go-26) which were observed at the end of the two hours were also present in two dogs in which measurements were continued for two additional hours.


Pteridines ◽  
2003 ◽  
Vol 14 (3) ◽  
pp. 94-101 ◽  
Author(s):  
Remigiusz Zieba ◽  
Elzbieta Czarnecka ◽  
Małgorzata Wągrowska-Danilewicz ◽  
Malgorzata Dzielska-Olczak ◽  
Julita Graczyk

Abstract The aim of this study was to establish the effect of naturally occurring antioxidant - carnosine - on the doxorubicin induced cardiotoxicity in a rabbit model. For this purpose we evaluated the influence of doxorubicin administration alone and in a combined therapy with carnosine on the haemodynamic parameters and on the degree of cardiac muscle cells alterations in rabbits. The rabbits were divided into four groups. One group of rabbits was injccted with doxorubicin in a dose of 2 mg kg-1 weekly for 7 weeks to induce congestive heart failure. Another group of rabbits received the same doses of doxorubicin simultaneously with carnosine in a dose of 100 mg kg1 p.o. daily for 9 weeks. Administration of carnosine was started 1 week prior to the first dose of doxorubicin and was ended one week after the administration of the last dose of doxorubicin. The control groups of animals received 0.9% NaCl and carnosine alone. The following haemodynamic parameters were estimated: heart rate, mean arterial pressure, cardiac index, stroke index and total peripheral resistance. Registration of the haemodynamic parameters in rabbits was performed by Doppler method. Carnosine normalised the values of mean arterial pressure in rabbits receiving doxorubicin, and increased the values of cardiac index and stroke index. The influence of carnosine on total peripheral resistance was not statistically significant, but there was a decreasing tendency. The degree of cardiac muscle cell alterations was examined by light microscopy using Mean Total Score technique. The histopathological studies revealed smaller damage of cardiac muscle in rabbits which received doxorubicin and carnosine, in comparison to animals receiving doxorubicin alone. Carnosine seems to be car dioprotective during doxorubicin administration


1987 ◽  
Vol 253 (6) ◽  
pp. H1335-H1341 ◽  
Author(s):  
T. L. Smith ◽  
T. G. Coleman ◽  
K. A. Stanek ◽  
W. R. Murphy

A new technique is described that allows minute-to-minute recordings of cardiac output and arterial pressure in unanesthetized rats for periods of 24 h and longer. Rats were instrumented with electromagnetic flow probes and arterial catheters. An electrical and hydraulic swivel was interposed between the rat and recording apparatus to allow free range of movement. Data were collected and analyzed once each minute by computer. Average 24-h values (mean +/- SD) for the following hemodynamic variables were determined in eight rats [expressed where appropriate as a function of body weight (BW)]: cardiac output (98.1 +/- 14.7 ml/min), cardiac index (29.2 +/- 4.4 ml.min-1.100 g BW-1), mean arterial pressure (92.5 +/- 7.8 mmHg), heart rate (347 +/- 45 beats/min), peak aortic flow (403 +/- 32 ml/min), stroke volume (282 +/- 26 microliters), stroke volume index (84.4 +/- 8.1 microliters/100 g BW), and total peripheral resistance index (3.26 +/- 0.46 mmHg.ml-1.min.100 g BW). These results provide a data base of hemodynamic values for unanesthetized adult, Sprague-Dawley male rats, which has not been previously available. In addition, cardiac index, mean arterial pressure, and total peripheral resistance index demonstrated diurnal variation. Diurnal variation contributed substantially to the overall variance observed within these variables. Hourly variance was also substantial and indicates the use of continuous recordings for short-term experiments.


1978 ◽  
Vol 234 (1) ◽  
pp. H67-H73 ◽  
Author(s):  
M. Kumada ◽  
R. A. Dampney ◽  
M. H. Whitnall ◽  
D. J. Reis

The hemodynamic changes associated with hypotension elicited by electrical stimulation of the spinal trigeminal complex (trigeminal depressor response, TDR) or the aortic nerve (aortic depressor reflex, ADR) were compared in rabbits anesthetized with urethan. The hypotension associated with each response was accompanied by bradycardia, a marked fall in total peripheral resistance, a small decrease in cardiac output, and a nonuniform decrease in regional vascular resistances, with the order of magnitude of the decrease being femoral greater than mesenteric greater than renal arterial resistance. In individual experiments the percent decrease in heart rate, total peripheral resistance, or regional resistances was plotted against the percent fall in arterial pressure to obtain a pair of regression lines during the TDR and ADR. There was no significant difference in the slope or y-intercept of the regression line between the TDR and ADR for all of the hemodynamic variables examined. In both responses, however, the slope of the femoral resistance/arterial pressure relationship was significantly greater than that of the renal resistance/arterial pressure relationship. We conclude that the TDR is characterized by a pattern of hemodynamic changes similar to that of the ADR.


1985 ◽  
Vol 249 (2) ◽  
pp. H265-H271 ◽  
Author(s):  
B. L. Pegram ◽  
M. B. Kardon ◽  
N. C. Trippodo ◽  
F. E. Cole ◽  
A. A. MacPhee

Partially purified low (LMW) and high-(HMW) molecular-weight atrial natriuretic extracts were administered intravenously (540 micrograms protein/kg) to conscious Wistar-Kyoto (WKY) and spontaneously hypertensive (SHR) rats. Both LMW and HMW atrial natriuretic extracts produced an immediate decrease in mean arterial pressure that reached maximum within 5 min and returned to control levels within 30 min. In both strains, cardiac output decreased approximately 14% following administration of LMW. Total peripheral resistance increased only in SHR. Organ blood flow was significantly decreased to skin, brain, heart, kidneys, and splanchnic organs of WKY and to skin, muscle, heart, and splanchnic organs of SHR following administration of LMW. Corresponding increases in organ vascular resistance index were observed in brain, heart, and splanchnic organs of WKY and in skin, heart, and splanchnic organs of SHR. To some extent, the changes in organ blood flow may be a reflection of the decrease in cardiac output induced by LMW. After administration of HMW, no significant changes were observed in cardiac output or total peripheral resistance, although they tended to decrease. Organ vascular resistance was decreased to skin, muscle, brain, and splanchnic organs of SHR. Little difference was observed between WKY and SHR responses to atrial natriuretic extracts. These data indicate that atrial natriuretic extracts have an effect on systemic and regional hemodynamics in conscious rats that differs markedly from those of vasodilators such as nitroglycerin or hydralazine.


1993 ◽  
Vol 265 (5) ◽  
pp. H1727-H1733 ◽  
Author(s):  
D. S. Martin ◽  
J. R. Haywood

The present study was undertaken to determine the hemodynamic responses associated with stimulation of the hypothalamic paraventricular nucleus (PVN). Male Sprague-Dawley rats (n = 21) were instrumented with guide cannulas directed bilaterally at the PVN, with an electromagnetic flow probe placed on the ascending aorta and with femoral venous and arterial catheters. Bicuculline methiodide (BMI, 2 mM) was infused bilaterally (100 nl/20 min) into the PVN region before and after treatment with the beta 1-adrenergic antagonist, metoprolol bitartrate (2 mg/kg iv) or the alpha 1-adrenergic receptor antagonist, prazosin hydrochloride (2 mg/kg iv). Infusion of BMI into the PVN increased mean arterial pressure by 17 +/- 2 mmHg, and heart rate rose by 91 +/- 8 beats/min. Cardiac index increased 17 +/- 3%, whereas total peripheral resistance index was not altered significantly. After metoprolol treatment, the mean arterial pressure response to BMI was similar to control (16 +/- 2 mmHg), but the tachycardia was reduced significantly (10 +/- 4 beats/min). In addition, the blood flow response was changed qualitatively. Total peripheral resistance increased 13 +/- 3%, whereas the cardiac index response was abolished (1 +/- 2%). After prazosin treatment, BMI administration into the PVN failed to increase arterial pressure (-1 +/- 4 mmHg). Nevertheless, the BMI infusion was associated with significant hemodynamic effects. Total peripheral resistance index decreased (-24 +/- 6%), whereas cardiac index and stroke volume index increased 34 +/- 8 and 17 +/- 5%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)


Respiration ◽  
2000 ◽  
Vol 67 (5) ◽  
pp. 502-506 ◽  
Author(s):  
Akira Nakamura ◽  
Norio Kasamatsu ◽  
Ikko Hashizume ◽  
Takushi Shirai ◽  
Suguru Hanzawa ◽  
...  

1996 ◽  
Vol 271 (2) ◽  
pp. H602-H613 ◽  
Author(s):  
M. P. Kunert ◽  
J. F. Liard ◽  
D. J. Abraham

Tissue O2 delivery in excess of metabolic demand may be a factor in the development of high vascular resistance in experimental models of volume-expanded hypertension. This hypothesis was previously tested in rats with an exchange transfusion of red blood cells treated with inositol hexaphosphate or an intravenous infusion of RSR-4, allosteric effectors of hemoglobin. The binding of these drugs with hemoglobin effect a conformational change in the molecule, such that the affinity for O2 is reduced. However, in both preparations, the changes in vascular resistance could have been nonspecific. The present studies used intravenous infusions of RSR-13, which did not share some of the problematic characteristics of RSR-4 and inositol hexaphosphate. Conscious instrumented rats (an electromagnetic flow probe on ascending aorta or an iliac, mesenteric, or renal Doppler flow probe) were studied for 6 h after an RSR-13 infusion of 200 mg/kg in 15 min. This dose significantly increased arterial P50 (PO2 at which hemoglobin is 50% saturated) from 38 +/- 0.8 to 58 +/- 1.4 mmHg at 1 h after the start of the infusion. In the 3rd h cardiac output fell significantly from a control value of 358 +/- 33 to 243 +/- 24 ml.kg-1.min-1 and total peripheral resistance significantly increased from 0.31 +/- 0.03 to 0.43 +/- 0.04 mmHg.ml-1.kg.min. Cardiac output and P50 returned toward control over the next few hours. Neither cardiac output nor total peripheral resistance changed in the group of rats receiving vehicle alone. In a separate group of rats, iliac flow decreased significantly to 60% of control and iliac resistance increased to 160% of control. Iliac flow increased significantly in the group of rats that received vehicle only. Although the mechanism of these changes has not been established, these results suggest that a decreased O2 affinity leads to an increased total peripheral resistance and regional vascular resistance and support the hypothesis that O2 plays a role in the metabolic autoregulation of blood flow.


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