IMMEDIATE EFFECTS OF RAPID HEMORRHAGE ON HEMODYNAMICS IN THE DOG

1956 ◽  
Vol 34 (5) ◽  
pp. 827-834
Author(s):  
Russell A. Waud ◽  
Douglas R. Waud

Dogs were anesthetized by the intravenous injection of sodium pentobarbital. Viscosity, hematocrit, blood pressure, cardiac index, stroke output, cardiac output, heart rate, peripheral resistance, red blood cell count, blood volume/body surface area, cell volume/area, plasma volume/area, plasma protein, hemoglobin, specific gravity of whole blood, cell size, color index, and sedimentation rate were determined in 16 dogs, before and following hemorrhage, and in seven controls. The following points were demonstrated: following hemorrhage the viscosity, hematocrit, blood pressure, stroke output, minute output, blood volume, and cell volume were markedly decreased. The decrease in blood volume, by limiting the venous return, was probably the cause of the decreased minute output and fall in blood pressure; this, by reducing the capillary flow, deprived the tissues of an adequate supply of oxygen. There was no significant change in the heart rate. The total peripheral resistance (T.P.R.) was greatly increased. The fall in hematocrit indicates a hemodilution which was probably the main factor in reducing the viscosity. It would appear that the decreased blood volume was the primary cause of the fall in blood pressure following hemorrhage and that a lowering of viscosity was not a large factor. There was no significant change following hemorrhage in the cardiac index, color index, cell size, white cell count, specific gravity of plasma, or sedimentation rate.

1956 ◽  
Vol 34 (1) ◽  
pp. 827-834
Author(s):  
Russell A. Waud ◽  
Douglas R. Waud

Dogs were anesthetized by the intravenous injection of sodium pentobarbital. Viscosity, hematocrit, blood pressure, cardiac index, stroke output, cardiac output, heart rate, peripheral resistance, red blood cell count, blood volume/body surface area, cell volume/area, plasma volume/area, plasma protein, hemoglobin, specific gravity of whole blood, cell size, color index, and sedimentation rate were determined in 16 dogs, before and following hemorrhage, and in seven controls. The following points were demonstrated: following hemorrhage the viscosity, hematocrit, blood pressure, stroke output, minute output, blood volume, and cell volume were markedly decreased. The decrease in blood volume, by limiting the venous return, was probably the cause of the decreased minute output and fall in blood pressure; this, by reducing the capillary flow, deprived the tissues of an adequate supply of oxygen. There was no significant change in the heart rate. The total peripheral resistance (T.P.R.) was greatly increased. The fall in hematocrit indicates a hemodilution which was probably the main factor in reducing the viscosity. It would appear that the decreased blood volume was the primary cause of the fall in blood pressure following hemorrhage and that a lowering of viscosity was not a large factor. There was no significant change following hemorrhage in the cardiac index, color index, cell size, white cell count, specific gravity of plasma, or sedimentation rate.


1998 ◽  
Vol 9 (1) ◽  
pp. 105-113 ◽  
Author(s):  
G Ligtenberg ◽  
P J Blankestijn ◽  
H A Koomans

Sudden dialysis-related hypotension is characterized by paradoxical vasodilation, suggestive of sympathoinhibition. A similar hypotensive reaction can be evoked by lower body negative pressure (LBNP), which thus allows the study of the numerous factors involved in dialysis hypotension separately. This article examines the influence of changes in volume status on the hemodynamic response to LBNP (45 mmHg up to the iliac crest, maximum 60 min) in 12 healthy subjects. LBNP caused a decrease in cardiac index and pulse pressure, and an increase in heart rate and total peripheral resistance, most of which developed within the first 3 min of LBNP. Six subjects developed sudden hypotension characterized by vasodilation after 9 +/- 4 min of LBNP. After saline expansion (25 ml/kg), which increased blood volume by approximately 8%, five subjects endured LBNP for the full 60 min. However, after 60 min of LBNP, the circulatory parameters suggested a similar critical situation as that observed before presyncope in their first experiment. The other six subjects endured the full 60 min of LBNP. After furosemide-induced volume reduction associated with 1.6 +/- 0.2 kg weight loss and approximately 7% blood volume reduction, five of them developed vasodilatory presyncope after 17 +/- 5 min of LBNP. Comparison of presyncopal and nonpresyncopal experiments within subjects, as well as between subjects, showed that the early (3 min) response to LBNP was different: Despite similar decreases in cardiac index, the values for systolic pressure, pulse pressure, peripheral resistance, and stroke volume were lower, and the heart rate was higher in the experiments ending in presyncope. It is concluded that the volume status is a determinant of the tolerance to LBNP, probably by affecting the vasoconstrictive response. By inference, this study suggests that the vasoconstrictive response to the hemodynamic stress of hemodialysis is also influenced by the volume status.


1957 ◽  
Vol 190 (2) ◽  
pp. 317-319 ◽  
Author(s):  
Esther M. Greisheimer ◽  
Dorothy W. Ellis ◽  
George H. Stewart ◽  
Lydia Makarenko ◽  
M. J. Oppenheimer

Fifty-five determinations of cardiovascular functions were made on eight dogs under chloralose-urethane anesthesia and forty-one on six dogs under 21-hydroxypregnane-3,20 dione sodium succinate (Viadril). No preanesthetic medication was used. Cardiac output was determined by the dye dilution technique, using the cuvette oximeter. Blood pressure was determined by strain gauge. The mean values found under chloralose-urethane were: cardiac index 4.08, mean blood pressure 146 mm Hg, peripheral resistance 5709 dynes/sec/cm–5, heart rate 149 beats/min. and stroke index 27 cc. The mean values found under 21-hydroxypregnane-3, 20 dione sodium succinate were: cardiac index 5.15, mean blood pressure 104 mm Hg, peripheral resistance 3997 dynes/sec/cm–5, heart rate 172 beats/min. and stroke index 29 cc. When successive determinations were made within a short period of time, the cardiac index and stroke index increased, peripheral resistance decreased and blood pressure and heart rate remained fairly steady.


2006 ◽  
Vol 291 (2) ◽  
pp. H904-H913 ◽  
Author(s):  
Julian M. Stewart ◽  
Marvin S. Medow ◽  
Neil S. Cherniack ◽  
Benjamin H. Natelson

Previous investigations have demonstrated a subset of postural tachycardia syndrome (POTS) patients characterized by normal peripheral resistance and blood volume while supine but thoracic hypovolemia and splanchnic blood pooling while upright secondary to splanchnic hyperemia. Such “normal-flow” POTS patients often demonstrate hypocapnia during orthostatic stress. We studied 20 POTS patients (14–23 yr of age) and compared them with 10 comparably aged healthy volunteers. We measured changes in heart rate, blood pressure, heart rate and blood pressure variability, arm and leg strain-gauge occlusion plethysmography, respiratory impedance plethysmography calibrated against pneumotachography, end-tidal partial pressure of carbon dioxide (PetCO2), and impedance plethysmographic indexes of blood volume and blood flow within the thoracic, splanchnic, pelvic (upper leg), and lower leg regional circulations while supine and during upright tilt to 70°. Ten POTS patients demonstrated significant hyperventilation and hypocapnia (POTSHC) while 10 were normocapnic with minimal increase in postural ventilation, comparable to control. While relative splanchnic hypervolemia and hyperemia occurred in both POTS groups compared with controls, marked enhancement in peripheral vasoconstriction occurred only in POTSHC and was related to thoracic blood flow. Variability indexes suggested enhanced sympathetic activation in POTSHC compared with other subjects. The data suggest enhanced cardiac and peripheral sympathetic excitation in POTSHC.


2003 ◽  
Vol 284 (6) ◽  
pp. H1985-H1994 ◽  
Author(s):  
Walkyria O. Sampaio ◽  
Antônio A. S. Nascimento ◽  
Robson A. S. Santos

The systemic and regional hemodynamics effects of ANG-(1–7) were examined in urethane-anesthetized rats. The blood flow distribution (kidneys, skin, mesentery, lungs, spleen, brain, muscle, and adrenals), cardiac output, and total peripheral resistance were investigated by using fluorescent microspheres. Blood pressure and heart rate were recorded from the brachial artery. ANG-(1–7) infusion (110 fmol · min−1 · 10 min−1 iv) significantly increased blood flow to the kidney (5.10 ± 1.07 to 8.30 ± 0.97 ml · min−1 · g−1), mesentery (0.73 ± 0.16 to 1.17 ± 0.49 ml · min−1 · g−1), brain (1.32 ± 0.44 to 2.18 ± 0.85 ml · min−1 · g−1), and skin (0.07 ± 0.02 to 0.18 ± 0.07 ml · min−1 · g−1) and the vascular conductance in these organs. ANG-(1–7) also produced a significant increase in cardiac index (30%) and a decrease in total peripheral resistance (2.90 ± 0.55 to 2.15 ± 0.28 mmHg · ml−1 · min · 100 g). Blood flow to the spleen, muscle, lungs, and adrenals, as well as the blood pressure and heart rate, were not altered by the ANG-(1–7) infusion. The selective ANG-(1–7) antagonist A-779 reduced the blood flow in renal, cerebral, mesenteric, and cutaneous beds and blocked the ANG-(1–7)-induced vasodilatation in the kidney, mesentery, and skin, suggesting a significant role of endogenous ANG-(1–7) in these territories. The effects of ANG-(1–7) on the cerebral blood flow, cardiac index, systolic volume, and total peripheral resistance were partially attenuated by A-779. A high dose of ANG-(1–7) (11 pmol · min−1 · 10 min−1) caused an opposite effect of that produced by the low dose. Our results show for the first time that ANG-(1–7) has a previously unsuspected potent effect in the blood flow distribution and systemic hemodynamics.


1987 ◽  
Vol 65 (11) ◽  
pp. 2205-2211 ◽  
Author(s):  
David G. Penney ◽  
Michael S. Baylerian

The effects of carbon monoxide (CO), polycythemia (PC), and cardiomegaly (CM) on cardiovascular function were investigated in adult rats in which the latter two conditions were induced by 500 ppm CO inhalation for 5–6 weeks. Using an anesthetized open-chest preparation, these rats were compared with normal rats. With CO + PC + CM present, resting cardiac index, stroke index, stroke work, and minute work were elevated (heart rate also in the conscious state), while left ventricle end-diastolic pressure (LVDP) was normal. With PC + CM after CO washout, cardiac index and stroke index returned to normal at normal LVDP. Minute work, peripheral resistance, heart rate, and blood pressure, however, remained above normal. With CM alone, minute work, +dP/dtmax, +dF/dtmax, peripheral resistance, blood pressure, and LVDP declined from the condition with PC + CM. Although most cardiovascular parameters increased in the three conditions above with acutely increased LVDP, only with CM alone was performance augmentation normal. The results (i) reveal several characteristics of the hemodynamic response to chronic carboxyhemoglobinemia, (ii) suggest that the transient hypertension attending CO elimination in the presence of PC results from rapid reversal of peripheral vasodilatation, (iii) demonstrate decreased cardiac functional reserve with CO and (or) polycythemia upon preload challenge, and (iv) provide evidence for the benign nature of CO-induced cardiomegaly alone, on heart function.


2019 ◽  
Vol 70 (5) ◽  
pp. 1754-1757
Author(s):  
Marius Toma Papacocea ◽  
Ioana Anca Badarau ◽  
Mugurel Radoi ◽  
Ioana Raluca Papacocea

Traumatic brain injuries (TBI) represent a high impact public health problem due to a high rate of death , long term disability and occurrence especially in young adults. Despite several promising animal studies, several parameters were proposed as biological markers and were assessed for this aim. Our study proposes the study of the early biochemical changes in association to hematological parameters for severe TBI patients prognosis. 43 patients with acute TBI were included in study based on clinical, laboratory and imagistic findings. The severity of the TBI was established by Glasgow Coma Scale GCS 3-8. In all patients were evaluated hematologic parameters (Red blood cell count - RBC, Hematocrit, blood Hemoglobin, White blood cell - WBC, Platelet count and biochemical parameters (glucose, urea, creatinine, electrolytes). Outcome was expressed as Glasgow Outcome Scale (GOS), between 1-5. Values were compared to control group -15 cases. Significant early differences in body temperature, heart rate, and systolic blood pressure were observed in TBI group versus control (p[0.05). After correlation, laboratory findings significantly associated to severe outcome - GOS = 1, 2 - (p[0.05) were plasma Na decrease and significant glucose increase. An early increase of temperature and decrease of Na may predict a severe outcome in patients with acute TBI; association with shifts in heart rate and blood pressure, imposes aggressive treatment measures.


2021 ◽  
pp. 247553032110007
Author(s):  
Eric Munger ◽  
Amit K. Dey ◽  
Justin Rodante ◽  
Martin P. Playford ◽  
Alexander V. Sorokin ◽  
...  

Background: Psoriasis is associated with accelerated non-calcified coronary plaque burden (NCB) by coronary computed tomography angiography (CCTA). Machine learning (ML) algorithms have been shown to effectively identify cardiometabolic variables with NCB in cross-sectional analysis. Objective: To use ML methods to characterize important predictors of change in NCB by CCTA in psoriasis over 1-year of observation. Methods: The analysis included 182 consecutive patients with 80 available variables from the Psoriasis Atherosclerosis Cardiometabolic Initiative, a prospective, observational cohort study at baseline and 1-year using the random forest regression algorithm. NCB was assessed at baseline and 1-year from CCTA. Results: Using ML, we identified variables of high importance in the context of predicting changes in NCB. For the cohort that worsened NCB (n = 102), top baseline variables were cholesterol (total and HDL), white blood cell count, psoriasis area severity index score, and diastolic blood pressure. Top predictors of 1-year change were change in visceral adiposity, white blood cell count, total cholesterol, c-reactive protein, and absolute lymphocyte count. For the cohort that improved NCB (n = 80), the top baseline variables were HDL cholesterol related including apolipoprotein A1, basophil count, and psoriasis area severity index score, and top predictors of 1-year change were change in apoA, apoB, and systolic blood pressure. Conclusion: ML methods ranked predictors of progression and regression of NCB in psoriasis over 1 year providing strong evidence to focus on treating LDL, blood pressure, and obesity; as well as the importance of controlling cutaneous disease in psoriasis.


1988 ◽  
Vol 254 (4) ◽  
pp. H811-H815 ◽  
Author(s):  
D. G. Parkes ◽  
J. P. Coghlan ◽  
J. G. McDougall ◽  
B. A. Scoggins

The hemodynamic and metabolic effects of long-term (5 day) infusion of human atrial natriuretic factor (ANF) were examined in conscious chronically instrumented sheep. Infusion of ANF at 20 micrograms/h, a rate below the threshold for an acute natriuretic effect, decreased blood pressure by 9 +/- 1 mmHg on day 5, associated with a fall in calculated total peripheral resistance. On day 1, ANF reduced cardiac output, stroke volume, and blood volume, effects that were associated with an increase in heart rate and calculated total peripheral resistance and a small decrease in blood pressure. On days 4 and 5 there was a small increase in urine volume and sodium excretion. On day 5 an increase in water intake and body weight was observed. No change was seen in plasma concentrations of renin, arginine vasopressin, glucose, adrenocorticotropic hormone, or protein. This study suggests that the short-term hypotensive effect of ANF results from a reduction in cardiac output associated with a fall in both stroke volume and effective blood volume. However, after 5 days of infusion, ANF lowers blood pressure via a reduction in total peripheral resistance.


1993 ◽  
Vol 265 (5) ◽  
pp. R1132-R1140 ◽  
Author(s):  
N. B. Olivier ◽  
R. B. Stephenson

Open-loop baroreflex responses were evaluated in eight conscious dogs before and during congestive heart failure to determine the effects of failure on baroreflex control of blood pressure, heart rate, cardiac output, and total peripheral resistance. Heart failure was induced by rapid ventricular pacing. Baroreflex function was determined by calculation of the range and gain of the open-loop stimulus-response relationships for the effect of carotid sinus pressure on blood pressure, heart rate, cardiac output, and total peripheral resistance. The range and gain of blood pressure responses were substantially reduced as early as 3 days after induction of heart failure (161 +/- 6 to 99 +/- 8 mmHg and -2.7 +/- 0.3 to -1.5 +/- 0.1, respectively) and remained depressed for the 21 days of heart failure. This depression in baroreflex control of blood pressure was associated with similar depressions in reflex range and gain for heart rate (125 +/- 9 to 78 +/- 11 beats/min and -2.05 +/- 0.2 to -1.16 +/- 0.2 beats/min, respectively) and cardiac output (1.74 +/- 0.2 to 0.46 +/- 0.2 l/min and -0.81 +/- 0.02 to -0.027 +/- 0.008 l/min, respectively). The group-averaged range and gain for reflex control of vascular resistance were not altered by heart failure. In three dogs, discontinuation of rapid ventricular pacing led to resolution of heart failure within 7 days and partial restoration of the range and gain of reflex control of blood pressure. We conclude that heart failure reversibly depresses baroreflex control of blood pressure principally through a concurrent reduction in reflex control of cardiac output, whereas reflex control of vascular resistance is not consistently affected.


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