scholarly journals FLUORESCEIN CIRCULATION TIME AS A PROGNOSTIC SIGN IN EXPERIMENTAL TRAUMATIC SHOCK

1946 ◽  
Vol 84 (6) ◽  
pp. 549-558 ◽  
Author(s):  
S. C. Wang ◽  
E. E. Painter ◽  
R. R. Overman
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Vascular System ◽  
Peripheral Circulation ◽  
Traumatic Shock ◽  
Systemic Circulation ◽  
The Other ◽  
Circulation Time ◽  
Peripheral Vascular ◽  
Made In

Repeated determinations of the circulation time by the fluorescein method were made in normal and shocked dogs. In normal animals the circulation time ranges from 9 to 16 seconds with an average of 12.6 seconds. In traumatic shock the circulation time is invariably prolonged. For prognosis in the traumatized animal two determinations of fluorescein circulation time separated by an interval of 1 hour are essential. If the second circulation time is longer than the first and both are over 30 seconds, the animal will not survive without therapy. On the other hand, if the second circulation time is below 25 seconds or is considerably shorter than the first, the prognosis is good. In many of these experiments the change in circulation time appeared to be the earliest index of eventual recovery or death. It gave a clue to the fate of the animal when no decisive judgment could be made from the blood pressure and heart rate. In three dogs the cyanide and fluorescein circulation times were compared during shock. It was found that the cyanide circulation time, though increased in shock, remained at a fairly constant value while over the same period the fluorescein circulation time showed progressive changes. This discrepancy between the cyanide and fluorescein methods may be explained by the fact that the former does not include the minute peripheral systemic circulation. Since the study of shock is concerned with tissue anoxia and is primarily a phenomenon of the failure of the peripheral circulation, it is important to choose procedures such as the fluorescein method as a measure of the condition of the peripheral vascular system.

Intraventricular blood pressures in the chicken

1960 ◽  
Vol 198 (1) ◽  
pp. 153-154 ◽  
Author(s):  
H. E. Bredeck
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Systolic Pressure ◽  
Left Ventricular Pressure ◽  
Left Ventricular ◽  
The Other ◽  
Blood Pressures ◽  
Left And Right ◽  
The Right ◽  
Made In

Direct heart punctures were made in two groups of unanesthetized chickens to determine the left and right intraventricular blood pressures. One group was composed of nonlaying birds 28–30 weeks old and the other of laying hens 65–67 weeks of age. Heart rates and the respiratory influence on pressure were also measured. Average pressures obtained were 144/0 and 21/ - 1 mm Hg for the left and right ventricle, respectively. Respiratory efforts caused a mean fluctuation in systolic pressure of approximately 8 mm Hg in the left ventricle and 4 mm Hg in the right. With the exception of the right ventricular diastolic blood pressure, there were no significant pressure or pulse rate differences between the two groups. The heart rate and left ventricular pressure were found to be significantly correlated ( P < .01) in both groups of birds.

A comparison of propofol with other injectable anaesthetics in a rat model for measuring cardiovascular parameters

1993 ◽  
Vol 27 (3) ◽  
pp. 250-257 ◽  
Author(s):  
A. Brammer ◽  
C. D. West ◽  
S. L. Allen
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Muscle Relaxation ◽  
The Other ◽  
Laboratory Rats ◽  
Anaesthetic Agents ◽  
Normal Limits ◽  
System A ◽  
Free Induction ◽  
Made In

Prolonged, stable, non-recovery anaesthesia is required for the assessment of the effects of novel compounds on the cardiovascular system. A comparison of injectable anaesthetic agents and combinations (thiobarbital, fentanyl-fluanisone and midazolam, propofol, fentanyl-fluanisone and propofol, and alphaxalone/alphadolone) was made in laboratory rats and the following parameters assessed over 3 h: blood pressure, heart rate and rhythm, respiration rate and depth, analgesia, ease of induction and maintenance of anaesthesia. It was found that propofol, with fentanyl-fluanisone premedication, provided stress-free induction, easily controlled anaesthesia, good analgesia and muscle relaxation for surgery, for up to 3 h duration. Heart rate, blood pressure and respiration remained stable and within normal limits during this time. The other anaesthetics/combinations assessed did not rate as highly in these respects. Propofol, following fentanyl-fluanisone premedication, would appear to be a useful and safe anaesthetic for use in rodents, which avoids significant effects on heart rate or blood pressure.

scholarly journals Effects of Preoperative Intravenous Clonidine in Patients Undergoing Cataract Surgery: A Double-Blind, Randomized Trial

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Ana Ellen Queiroz Santiago ◽  
Adriana Machado Issy ◽  
Rioko Kimiko Sakata
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Intraocular Pressure ◽  
Myocardial Ischemia ◽  
Cataract Surgery ◽  
The Other ◽  
Intraocular Lens Implantation ◽  
Double Blind ◽  
Lens Implantation ◽  
Lidocaine Gel

Objectives. The aim of this study was to assess the effects of clonidine on intraoperative analgesia, sedation, intraocular and blood pressure, arrhythmia, and ischemia.Methods. Forty patients undergoing cataract surgery were allocated into two groups. They were monitored with Holter machine, the pupil was dilated, and 30 minutes later, 20 patients received clonidine (4 µg/kg), while the other 20 patients were given a 0.9% saline intravenously. Twenty minutes later, 2% lidocaine gel was applied. There were assessed intraoperative analgesia, intraocular pressure, blood pressure, heart rate, and the occurrence of arrhythmias and myocardial ischemia.Results. Pain intensity was lower in G1 during the phacoemulsification, irrigation, aspiration, and intraocular lens implantation. The HR and BP were lower with clonidine. The IOP was lower with clonidine after 15 minutes and at the end of the surgery. Sedation was higher with clonidine. The incidence of arrhythmia was lower at the end of surgery with clonidine. The incidence of myocardial ischemia did not differ between the groups.Conclusions. Clonidine (4 µg/kg) before a phacoemulsification reduced the intensity of pain during cataract surgery. It also induced sedation, reduction of BP, HR, and incidence of arrhythmia at the end of the surgery, and did not alter myocardial ischemia. This trial is registered with Clinicaltrials.govNCT01677351.

Differential effect of behavior on cardiac and vasomotor baroreflex responses

1986 ◽  
Vol 251 (1) ◽  
pp. R126-R136 ◽  
Author(s):  
C. A. Combs ◽  
O. A. Smith ◽  
C. A. Astley ◽  
E. O. Feigl
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Flow ◽  
Peripheral Circulation ◽  
Baroreceptor Reflex ◽  
Aortic Blood Flow ◽  
Renal Vasoconstriction ◽  
Bilateral Carotid Occlusion ◽  
Bilateral Carotid ◽  
Carotid Sinus Baroreflex

Bilateral carotid occlusion was performed in seven baboons during dynamic leg exercise, static arm exercise, feeding, rest, and sleep. The baroreceptor reflex effects on blood pressure, heart rate and interval, renal blood flow, and terminal aortic blood flow were determined during each behavior. The carotid sinus baroreflex increase in blood pressure and heart rate was greatest during sleep and least during exercise. The hindlimb and renal vasomotor responses followed different patterns. The baroreceptor reflex sensitivity for renal vasoconstriction was greatest during rest and least during sleep. The reflex sensitivity in the hindlimb was unaltered by behavior. Thus behavior modifies baroreceptor reflex responses in the heart and peripheral circulation in different patterns.

Analysis of heart rate-based control of arterial blood pressure

1996 ◽  
Vol 271 (2) ◽  
pp. H812-H822 ◽  
Author(s):  
W. C. Rose ◽  
J. S. Schwaber
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Arterial Pressure ◽  
Stroke Volume ◽  
Vascular System ◽  
Reciprocal Relation ◽  
Arterial Baroreflex ◽  
Arterial Blood ◽  
Limited Effectiveness ◽  
Filling Time

Vagal control of the heart is the most rapidly responding limb of the arterial baroreflex. We created a mathematical model of the left heart and vascular system to evaluate the ability of heart rate to influence blood pressure. The results show that arterial pressure depends nonlinearly on rate and that changes in rate are of limited effectiveness, particularly when rate is increased above the basal level. A 10% change in heart rate from rest causes a change of only 2.4% in arterial pressure due to the reciprocal relation between heart rate and stroke volume; at higher rates, insufficient filling time causes stroke volume to fall. These findings agree well with published experimental data and challenge the idea that changes in heart rate alone can strongly and rapidly affect arterial pressure. Possible implications are that vagally mediated alterations in inotropic and dromotropic state, which are not included in this model, play important roles in the fast reflex control of blood pressure or that the vagal limb of the baroreflex is of rather limited effectiveness.

Mechanism of circulatory responses to systemic hypoxia in the anesthetized dog

1965 ◽  
Vol 209 (2) ◽  
pp. 397-403 ◽  
Author(s):  
Hermes A. Kontos ◽  
H. Page Mauck ◽  
David W. Richardson ◽  
John L. Patterson
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Cardiac Output ◽  
Vascular Resistance ◽  
The Other ◽  
Arterial Flow ◽  
Arterial Blood ◽  
Systemic Hypoxia ◽  
Anesthetized Dogs ◽  
Spontaneously Breathing

The possibility that mechanisms secondary to the increased ventilation may contribute significantly to the circulatory responses to systemic hypoxia was explored in anesthetized dogs. In 14 spontaneously breathing dogs systemic hypoxia induced by breathing 7.5% oxygen in nitrogen increased cardiac output, heart rate, mean arterial blood pressure, and femoral arterial flow, and decreased systemic and hindlimb vascular resistances. In 14 dogs whose ventilation was kept constant by means of a respirator pump and intravenous decamethonium, systemic hypoxia did not change cardiac output, femoral arterial flow, or limb vascular resistance; it significantly decreased heart rate and significantly increased systemic vascular resistance. In seven spontaneously breathing dogs arterial blood pCO2 was maintained at the resting level during systemic hypoxia. The increase in heart rate was significantly less pronounced but the other circulatory findings were not different from those found during hypocapnic hypoxia. Thus, mechanisms secondary to increased ventilation contribute significantly to the circulatory responses to systemic hypoxia. Hypocapnia accounts partly for the increased heart rate, but not for the other circulatory responses.

scholarly journals PERIPHERAL VASCULAR REACTIONS IN ANAPHYLAXIS OF THE MOUSE

1949 ◽  
Vol 89 (6) ◽  
pp. 583-596 ◽  
Author(s):  
Philip D. McMaster ◽  
Heinz Kruse
Keyword(s):  
Blood Pressure ◽  
Anaphylactic Shock ◽  
Blood Stream ◽  
The Other ◽  
Vascular Changes ◽  
Peripheral Vascular ◽  
Arterial Spasm ◽  
Vascular Spasm ◽  
Arteries And Veins ◽  
Large Vessels

Pronounced vascular changes occurring in the ears and claws of mice during anaphylactic shock are described. Practically at once after a foreign serum (pig, horse, or rabbit) enters the blood stream of sensitized animals both the arterial and venous vessels undergo marked, local or generalized constriction in the organs mentioned. Usually spasm of the vessel walls occurs simultaneously in the arteries and veins, but it may appear first in the arteries, or occasionally in the veins. When venous spasm precedes arterial spasm, the true capillaries become distended with cells; if the reverse order holds, the ears appear bloodless. There is no active constriction or dilatation of capillaries; the capillary behavior follows passively the changes in the large vessels. Peripheral vascular spasm occurs while the carotid blood pressure is high, but a few minutes later, while this still holds true, the ear vessels begin to relax and the circulation is resumed. Shortly afterwards the blood pressure falls to levels far below normal, but the vessels remain open. If the circulation of one ear is obstructed while anaphylactic shock is produced, no vascular spasm occurs in it. Release of the obstruction during the animal's recovery results in belated constriction of the blood vessels of this ear although by now the vessels in the other ear are dilated and the general systolic blood pressure is very low. The vascular reactions in the ears appear to be uninfluenced by the blood pressure in the large vessels, and they are not a response to nervous stimuli. They are local in origin. The vascular changes are often not clearly perceptible in the gross but are plainly to be seen under a low power of the microscope. They occur in some sensitized mice exhibiting no manifest signs of shock, differing only in degree from the changes taking place when shock is severe or fatal.

Contrasting neurovascular findings in chronic orthostatic intolerance and neurocardiogenic syncope

2003 ◽  
Vol 104 (4) ◽  
pp. 329-340 ◽  
Author(s):  
Julian M. STEWART ◽  
Amy WELDON
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Flow ◽  
Orthostatic Intolerance ◽  
Peripheral Vascular ◽  
Neurocardiogenic Syncope ◽  
Control Subjects ◽  
Arterial Resistance ◽  
Vascular Physiology ◽  
Venous Resistance

Simple faint (neurocardiogenic syncope) and postural tachycardia syndrome (POTS) characterize acute and chronic orthostatic intolerance respectively. We explored the hypothesis that vascular function is similar in the two conditions. We studied 29 patients with POTS and compared them with 20 patients with neurocardiogenic syncope who were otherwise well, and with 15 healthy control subjects. We measured continuous heart rate, respiration and blood pressure, and used venous occlusion strain gauge plethysmography to measure calf and forearm blood flow, peripheral arterial resistance, peripheral venous resistance and venous pressure (Pv). Upright tilt was performed to 70° for 10min, during which calf blood flow and volume were measured. Calf Pv was increased (to 27.2±2.0mmHg) in a subgroup of POTS patients, who also had increased arterial resistance (57±6mmHg·ml-1·min-1·100ml-1 tissue), increased venous resistance (2.4±0.3mmHg·ml-1·min-1·100ml-1 tissue), and decreased peripheral flow (1.0±0.2ml·min-1·100ml-1 tissue) in the calf; other POTS patients with a normal Pv had decreased arterial resistance (18±2mmHg·ml-1·min-1·100ml-1 tissue) and increased blood flow (3.8±0.3ml·min-1·100ml-1 tissue). Syncope patients were not different from controls (Pv = 11.4±0.5mmHg; calf flow = 3.1±0.2ml·min-1·100ml-1 tissue; arterial resistance = 27±2mmHg·ml-1·min-1·100ml-1 tissue; venous resistance = 1.2±0.3mmHg·ml-1·min-1·100ml-1 tissue). When upright, syncope patients and control subjects had similar increases in heart rate and calf volume, stable blood pressure, and decreases in blood flow. POTS patients had markedly increased heart rate and calf blood flow, unstable blood pressure, and pooling in the lower extremities, regardless of subgroup. We conclude that peripheral vascular physiology in patients with POTS is abnormal, in contrast with normal peripheral vascular physiology in neurocardiogenic syncope.

EFFETS DE L'ACIDE ASCORBIQUE SUR PLUSIEURS VARIABLES BIOLOGIQUES NORMALEMENT AFFECTÉES PAR LE FROID

1949 ◽  
Vol 27e (6) ◽  
pp. 349-363 ◽  
Author(s):  
M. Thérien ◽  
J. Leblanc ◽  
O. Héroux ◽  
L. P. Dugal
Keyword(s):  
Blood Pressure ◽  
Ascorbic Acid ◽  
Room Temperature ◽  
Experimental Studies ◽  
The Other ◽  
Histamine Content ◽  
Exposure To Cold ◽  
Thymus Atrophy ◽  
Subsequent Administration ◽  
Made In

It has been shown recently by Dugal and Thérien that during a short or long exposure to cold, the normal hypertrophy of the adrenals is completely prevented by large doses of ascorbic acid, and that, nevertheless, at the same time, resistance is increased towards the same damaging agent. So, the most universally accepted criterion of damage caused by stress is abolished when the animals exposed to cold receive large doses of ascorbic acid. Starting from that observation, it was natural to wonder what would be the effects of the ascorbic acid on the biological changes normally associated with the hypertrophy of the adrenals during exposure to cold. The present paper describes the experimental studies made in that connection; the results obtained show that: (1) ascorbic acid (a) partly inhibits the thymus atrophy normally encountered upon exposure to any stress including cold, (b) accelerates in a very significant way the enlargement of the thyroid, (c) is responsible for an increase in weight of the spleen, whereas the control animals, on the contrary, show a decrease in weight of the same organ; (2) the histamine content of the adrenals, which increases at room temperature under the influence of ascorbic acid, is significantly decreased during exposure to cold under the influence of the same substance; (3) the activity of the adrenals, far from being inhibited by ascorbic acid is even increased if the cholesterol changes are taken as an index of that activity; (4) the initial hypotension—due to cold—found in our controls, is prevented by large doses of ascorbic acid; on the other hand, if hypertension develops after long exposure to cold, the subsequent administration of large doses of ascorbic acid restores the blood pressure to normal. Confirmation has also been obtained for the previously reported observation that ascorbic acid prevents the hypertrophy of the adrenals during exposure to cold.

scholarly journals Identification of stress signs before practical exams in human anatomy

2020 ◽  
Vol 9 (12) ◽  
pp. e1569129974
Author(s):  
Ana Luiza Rodriguez Pereira ◽  
Nayara Thays Paulino ◽  
Ademir Franco ◽  
Jose Eduardo Scabora ◽  
Giuliano Roberto Gonçalves ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Oxygen Saturation ◽  
Undergraduate Students ◽  
Signs And Symptoms ◽  
The Other ◽  
Human Anatomy ◽  
Undergraduate Level ◽  
Stress Symptoms ◽  
Teaching Learning

The teaching-learning process is challenging in human anatomy. In this process, practical exams are necessary to enable a proper evaluation of the students. Students’ performance, on the other hand, reflects not only their knowledge but also their individual reactions to exams. Objective: This study aimed to identify signs and symptoms of stress in undergraduate students before practical exams in human anatomy. Methods: The sample consisted of 93 students (48 females and 45 males, mean age = 20.33 years) enrolled in medical and dental courses at undergraduate level. Blood rate, heart rate and oxygen saturation were assessed 30 minutes before the practical exams. Lipp´s Inventory of Stress Symptoms for Adults (LSSI) was used. Results: Statistically significant differences (p < 0.05) was observed for the systolic blood pressure between females (117.76  11.82 mmHg) and males (120.66  10.09 mmHg). Diastolic rate, respiratory rate and oxygen saturation were similar between sex groups (p > 0.05). A higher report of signs and symptoms of stress was detected in females (p < 0.05) for each of the stress stages described by LSSI, namely alarm, resistance and exhaustion. Medical and dental undergraduate students manifested signs and symptoms of stress before practical exams in human anatomy. The outcomes were more evident in females.

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