scholarly journals Blood pressure changes in dogs with babesiosis

Author(s):  
L.S. Jacobson ◽  
R.G. Lobetti ◽  
T. Vaughan-Scott

Systemic arterial blood pressures were measured in 30 dogs with acute babesiosis, 10 each with mild uncomplicated, severe uncomplicated and complicated disease. Ten healthy dogs were used as controls. Hypotension was defined as more than 3 standard deviations below the control mean. Normal mean pressures (±SD) were: systolic arterial pressure 151 (±11) mm Hg, diastolic arterial pressure 89 (±8) mm Hg and mean arterial pressure 107 (±10) mmHg. Hypotension was the most frequent abnormality, and increased strikingly in incidence as disease severity increased, with 5/10 dogs in the complicated group being hypotensive for systolic, diastolic and mean arterial pressures, compared with 2/10 in the severe uncomplicated group and 0/10 in the mild uncomplicated group. Systolic, diastolic and mean arterial pressures in the complicated group and severe uncomplicated group, and systolic pressure in the mild uncomplicated group, were significantly lower than in the controls. There were no significant relationships between arterial pressures and age, pulse rate, respiratory rate, temperature, mucous membrane colour or haematocrit. There was a significant negative correlation between arterial pressures and white cell and immature neutrophil counts. Arterial pressures differed significantly between dogs that were clinically collapsed and those that were not, but not between survivors and non-survivors. Pulse pressure (systolic - diastolic) was low in 7/10 complicated, 1/10 mild uncomplicated, and 1/10 severe uncomplicated cases, and differed significantly between the complicated and control groups. The high incidence of hypotension in clinically severe babesiosis has important implications for therapy.

2006 ◽  
Vol 100 (3) ◽  
pp. 792-799 ◽  
Author(s):  
Shizue Masuki ◽  
John H. Eisenach ◽  
Frank A. Dinenno ◽  
Michael J. Joyner

In the present study, we assessed whether heart rate (HR) or arterial pressure fluctuations are enhanced in healthy young humans with reduced α-adrenergic vasoconstrictor responses and, if so, whether this occurs for both α1- and α2-adrenergic receptor-mediated vasoconstriction. Arterial pressure (brachial artery catheter) and HR (ECG) were monitored continuously, and α1- and α2-adrenergic responsiveness was determined by assessing the effects of brachial artery infusions of phenylephrine (α1-adrenergic agonist) and dexmedetomidine (α2-adrenergic agonist), respectively, on forearm blood flow (strain gauge plethysmography). α1-Adrenergic responsiveness varied markedly among the subjects ( n = 20) and was inversely correlated with coefficient of variation for HR ( R2 = 0.37, P < 0.01), whereas the responsiveness was not correlated with the coefficient of variation for either systolic or diastolic arterial pressure. α1-Adrenergic responsiveness was inversely and more strongly correlated with baroreflex sensitivity ( R2 = 0.62, P < 0.0001), determined from beat-to-beat changes in HR and systolic arterial pressure, than the coefficient of variation for HR. On the other hand, α2-adrenergic responsiveness was not correlated with any of the parameters determined above. These results suggest that, in healthy young subjects, the enhanced HR response to changes in systolic pressure helps maintain the stability of arterial blood pressure when α1-adrenergic responsiveness is reduced.


2014 ◽  
Vol 15 (2) ◽  
pp. 83-88
Author(s):  
Dusko Kornjaca ◽  
Vladimir Zivkovic ◽  
Nevena Barudzic ◽  
Vladimir Jakovljevic ◽  
Dragan Djuric

ABSTRACT Vibroacoustics, a scientific field that has been intensively studied for the last thirty years, uses the properties of sound waves (infrasound, ultrasound, noise and music) to induce vibrations that, like a sound wave, may have both useful and harmful effects. Th e aim of this study was to examine the effects of vibroacoustically induced microvibrations on arterial blood pressure and markers of oxidative stress in the blood. Th e experiments were performed on Wistar male rats that had a 180-200 g body mass and were divided into control and experimental groups (6 rats in each). In the experimental group, microvibrations were induced using the Vitafon vibroacoustic apparatus (Vitafon, St. Petersburg, Russian Federation), which delivers sound waves of varying frequencies by a process called “phoning”. Up to 60 minutes of phoning time was delivered to the kidney and liver using 4 diff erent regimens that included a 5-minute stabilisation time; up to four 10-minute phoning regimens, with 5-minute breaks between each single regimen, at a 30 Hz-18000 kHz frequency range;, and 2.8 μm-12.3 μm microwave amplitudes. After the completion of a phoning regimen, animals were sacrificed and the oxidative stress markers were measured in blood samples (O2-, H2O2, nitrites, lipid peroxidation index, superoxide dismutase, catalase, and glutathione) and compared with the values of markers in the control group. Systolic arterial pressure was analysed after the acute application of up to four diff erent regimens of vibroacoustic microvibrations. Systolic arterial pressure decreased significantly during the administration of the second regimen in comparison to the control group. Systolic arterial pressure returned, almost completely, to the initial value after the administration of the third and fourth regimens. Th ere was no significant change in diastolic arterial pressure after the acute administration of up to four different regimens, although the pressure decreased slightly after the first and second regimens and returned to the initial value during the administration of the third and fourth regimens. Analysis of oxidative stress markers showed a statistically significant change in the catalase level. No statistically significant differences were found in the other oxidative stress markers analyzeanalysed. Further research is needed to clarify the physiological effects of low compared to high frequencies of vibroacoustically induced microvibrations and their possible therapeutic significance.


2008 ◽  
Vol 104 (5) ◽  
pp. 1402-1409 ◽  
Author(s):  
Kathy L. Ryan ◽  
William H. Cooke ◽  
Caroline A. Rickards ◽  
Keith G. Lurie ◽  
Victor A. Convertino

Inspiratory resistance induced by breathing through an impedance threshold device (ITD) reduces intrathoracic pressure and increases stroke volume (SV) in supine normovolemic humans. We hypothesized that breathing through an ITD would also be associated with a protection of SV and a subsequent increase in the tolerance to progressive central hypovolemia. Eight volunteers (5 men, 3 women) were instrumented to record ECG and beat-by-beat arterial pressure and SV (Finometer). Tolerance to progressive lower body negative pressure (LBNP) was assessed while subjects breathed against either 0 (sham ITD) or −7 cmH2O inspiratory resistance (active ITD); experiments were performed on separate days. Because the active ITD increased LBNP tolerance time from 2,014 ± 106 to 2,259 ± 138 s ( P = 0.006), data were analyzed (time and frequency domains) under both conditions at the time at which cardiovascular collapse occurred during the sham experiment to determine the mechanisms underlying this protective effect. At this time point, arterial blood pressure, SV, and cardiac output were higher ( P ≤ 0.005) when breathing on the active ITD rather than the sham ITD, whereas indirect indicators of autonomic activity (low- and high-frequency oscillations of the R-to-R interval) were not altered. ITD breathing did not alter the transfer function between systolic arterial pressure and R-to-R interval, indicating that integrated baroreflex sensitivity was similar between the two conditions. These data show that breathing against inspiratory resistance increases tolerance to progressive central hypovolemia by better maintaining SV, cardiac output, and arterial blood pressures via primarily mechanical rather than neural mechanisms.


Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Bjarne Madsen Härdig ◽  
Michael Götberg ◽  
Malin Rundgren ◽  
Matthias Götberg ◽  
David Zughaft ◽  
...  

Objectives and Method: This porcine study was designed to explore the effect of repetitive epinephrine (EPI) doses on physiologic parameters during CPR. Thirty-six adult pigs were randomized to four injections of: EPI 0.02 mg/kg/dose, EPI 0.03 mg/kg/dose or saline control, given during 15 minutes of CPR. The effect on systolic, diastolic and mean arterial blood pressures (ABP), cerebral perfusion pressure (CePP), end tidal carbon dioxide (ETCO2), SpO2, cerebral tissue oximetry (SctO2), were analyzed immediately prior to each injection and at peak arterial systolic pressure. Arterial blood gases was analyzed after the baseline and after 15 min. Result: Prior to and following 4 minutes of baseline chest compressions without drug administration, there were no significant differences between the three groups. In the group given a 0.02 mg/kg/dose, there were increases in all ABP’s and CePP at the first 3 pressure peaks; at the 4th only mean ABP was increased. Decreased ETCO2 following peak 1 and beyond was seen. SctO2 and SpO2 were lowered following injection 2 and beyond. In the group given a 0.03 mg/kg/dose, all ABP’s and CePP increased at the first 3 pressure peaks. Lower ETCO2 was seen at peak 1 and beyond. SctO2 and SpO2 were lower following injection 2 and beyond. In the saline control group the systolic ABP was significantly lower at pressure peak 1 and beyond, no other parameter changed significantly compared to baseline. In the two EPI groups, pH and Base Excess were lower and lactate levels higher compared to baseline as well as compared to control. Conclusion: Repetitive EPI doses increased ABP’s and CePP, but this did not translate into better organ or brain perfusion.


1994 ◽  
Vol 22 (5) ◽  
pp. 571-575 ◽  
Author(s):  
D. P. Riley ◽  
R. W. Burgess

External aortic compression is an emergency manoeuvre proposed to reduce postpartum haemorrhage and permit time for resuscitation and control of bleeding. To assess this technique, a prospective study was performed on twenty normal non-bleeding parturients. The abdominal aorta was compressed by firm pressure with a closed fist just above the umbilicus. Leg and arm arterial blood pressures were measured and femoral artery pulsation felt before, during and after compression. Leg blood pressure was completely obliterated in 55% and significantly reduced (P < 0.01) in a further 10% of subjects. All of these subjects with reduced or absent leg blood pressure also had obliteration of the femoral pulse with compression. Systemic arterial blood pressure was not significantly elevated by successful aortic occlusion. Discomfort with the manoeuvre was significantly increased (P < 0.05) in the group of subjects that had successful aortic occlusion. It is recommended that external aortic compression be considered in severe life-threatening postpartum haemorrhage, particularly during stabilisation or transport of the patient. This simple manoeuvre may be used as an adjunct to other measures and could prove of benefit, especially in locations or situations where advanced medical assistance is geographically or temporally removed.


Author(s):  
Ian Mark Greenlund ◽  
Carl A. Smoot ◽  
Jason R. Carter

K-complexes are a key marker of non-rapid eye movement sleep (NREM), 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 to women. Ten men (Age: 23 ± 2 years, BMI: 28 ± 4 kg/m2) and ten women (Age: 23 ± 5 years, 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.


1997 ◽  
Vol 83 (2) ◽  
pp. 371-375 ◽  
Author(s):  
Oommen P. Mathew

Mathew, Oommen P. Effects of transient intrathoracic pressure changes (hiccups) on systemic arterial pressure. J. Appl. Physiol. 83(2): 371–375, 1997.—The purpose of the study was to determine the effect of transient changes in intrathoracic pressure on systemic arterial pressure by utilizing hiccups as a tool. Values of systolic and diastolic pressures before, during, and after hiccups were determined in 10 intubated preterm infants. Early-systolic hiccups decreased systolic blood pressure significantly ( P < 0.05) compared with control (39.38 ± 2.72 vs. 46.46 ± 3.41 mmHg) and posthiccups values, whereas no significant change in systolic blood pressure occurred during late-systolic hiccups. Diastolic pressure immediately after the hiccups remained unchanged during both early- and late-systolic hiccups. In contrast, diastolic pressure decreased significantly ( P < 0.05) when hiccups occurred during diastole (both early and late). Systolic pressures of the succeeding cardiac cycle remained unchanged after early-diastolic hiccups, whereas they decreased after late-diastolic hiccups. These results indicate that transient decreases in intrathoracic pressure reduce systemic arterial pressure primarily through an increase in the volume of the thoracic aorta. A reduction in stroke volume appears to contribute to the reduction in systolic pressure.


2014 ◽  
Vol 17 (1) ◽  
pp. 173-175 ◽  
Author(s):  
W. Zygner ◽  
O. Gójska-Zygner

Abstract Acute tubular necrosis (ATN) was described in canine babesiosis. Hypotension is considered as one of the factors which influence the development of hypoxic renal damage. In this study hypotension defined as mean arterial pressure (MAP) < 80 mmHg was detected in 7 out of 48 dogs (14.6%) infected with Babesia canis. Lower systolic arterial pressure (SAP), diastolic arterial pressure (DAP) and MAP were detected in azotaemic dogs infected with B. canis. Statistically significant negative correlations between blood pressures (SAP, DAP and MAP) and serum creatinine and urea concentrations showed the influence of decreased blood pressure on the development of azotaemia and is probably also associated with ATN in canine babesiosis.


2018 ◽  
Vol 46 (4) ◽  
pp. 400-403 ◽  
Author(s):  
D. A. Cook ◽  
N. Widdicombe

An audit of ten years’ experience in all patients undergoing withdrawal of cardiorespiratory support (WCRS) in the context of donation after circulatory death (DCD) was conducted in Queensland, Australia (2008 to 2017). One hundred and seventy-one patients proceeded to donation after declaration of death by circulatory criteria with loss of pulsatile arterial blood pressure (circulatory arrest) for five minutes. The demographics, times and haemodynamic observations were abstracted, de-identified and collated. The average age of patients was 43 years (standard deviation 16.1 years) and 63% were male. The median and mean times to an agonal systolic blood pressure below 50 mmHg were 10 and 11 minutes and the median and mean times from WCRS to circulatory arrest were 14 and 16 minutes. After systolic blood pressure fell to 50 mmHg or lower, 33 patients (19.3%) had spontaneous return of systolic pressure to above 50 mmHg. Following periods of circulatory arrest, five patients were documented to have spontaneous return of pulsatile arterial pressure. Two patients had return of circulation after two minutes, but less than five minutes of circulatory arrest and three patients had return of circulation where circulatory arrest had been documented for less than two minutes. Following WCRS, transient restoration of circulation following circulatory arrest may occur, even following two minutes of circulatory asystole, albeit rarely.


1979 ◽  
Vol 237 (6) ◽  
pp. H720-H723 ◽  
Author(s):  
L. R. Klevans ◽  
G. Hirkaler ◽  
J. L. Kovacs

The Doppler ultrasonic recording technique was used to measure systolic and diastolic blood pressures indirectly in renal hypertensive cats. The accuracy of the method was evaluated by comparing indirect blood pressures from one leg of a cat with direct pressure measurements from the other leg. A linear relationship existed between indirect and direct systolic and diastolic pressures. The consistency of the method was assessed by measuring blood pressure during a 5-h monitoring period in normotensive and renal hypertensive cats. No significant variation occurred over this period. The sensitivity of the method to blood pressure changes was determined also. A significant reduction in systolic and diastolic pressure induced by hydralazine, 10 mg/kg po, was recorded during a 5-h monitoring period. The development of renovascular hypertension was followed for approximately 70 days. Systolic pressure rose in a logarithmic fashion from 160 to a maximum of 240 mmHg. It was concluded that the Doppler ultrasonic technique is a simple and reliable method for recording indirect blood pressure acutely and chronically in conscious unrestrained cats.


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