Microvascular pressure profile of serosal vessels of rat trachea

1993 ◽  
Vol 264 (6) ◽  
pp. 1-1
Author(s):  
S. T. Ballard ◽  
R. H. Nations ◽  
A. E. Taylor
Keyword(s):  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Pressure Profile ◽  
Calibration Error ◽  
Tracheal Mucosa ◽  
Capillary Pressures ◽  
Function Range ◽  
Logistical Function ◽  
Microvascular Resistance ◽  
Rat Trachea

Pages H1303–H1304: S. T. Ballard, R. H. Nations, and A. E. Taylor. “Microvascular pressure profile of serosal vessels of rat trachea.” Measurements of microvessel diameter were overestimated because of a calibration error. The corrected vessel diameters are 0.56 times those originally reported. The corrected diameter ranges for arterioles, venules, and venular sinuses should be 6–53, 11–42, and 67–236 μm, respectively. When it is assumed that capillaries fall between 10-μm arterioles and venules, capillary pressures predicted by a four-parameter logistical function range from 34.5 and 12.7% of mean arterial pressure. Therefore, when the average large venular pressure was 5% of mean arterial pressure, fractional precapillary (systemic to 10-μm-diam arterioles), capillary (10-μm-diam arterioles to 10-μm-diam venules), and postcapillary (10-μm-diam venules to large venules) resistances would represent 69, 23, and 8%, respectively, of the total microvascular resistance. A revised Fig. 1 comparing experimental data with those of Nordin et al. (3), who measured microvascular pressure in rabbit tracheal mucosa, follows. (See PDF)

Microvascular pressure profile of serosal vessels of rat trachea

1993 ◽  
Vol 264 (1) ◽  
pp. 1-1
Author(s):  
S. T. Ballard ◽  
R. H. Nations ◽  
A. E. Taylor
Keyword(s):  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Pressure Profile ◽  
Calibration Error ◽  
Tracheal Mucosa ◽  
Capillary Pressures ◽  
Function Range ◽  
Logistical Function ◽  
Microvascular Resistance ◽  
Rat Trachea

Pages H1303–H1304: S. T. Ballard, R. H. Nations, and A. E. Taylor. “Microvascular pressure profile of serosal vessels of rat trachea.” Measurements of microvessel diameter were overestimated because of a calibration error. The corrected vessel diameters are 0.56 times those originally reported. The corrected diameter ranges for arterioles, venules, and venular sinuses should be 6–53, 11–42, and 67–236 μm, respectively. When it is assumed that capillaries fall between 10-μm arterioles and venules, capillary pressures predicted by a four-parameter logistical function range from 34.5 and 12.7% of mean arterial pressure. Therefore, when the average large venular pressure was 5% of mean arterial pressure, fractional precapillary (systemic to 10-μm-diam arterioles), capillary (10-μm-diam arterioles to 10-μm-diam venules), and postcapillary (10-μm-diam venules to large venules) resistances would represent 69, 23, and 8%, respectively, of the total microvascular resistance. A revised Fig. 1 comparing experimental data with those of Nordin et al. (3), who measured microvascular pressure in rabbit tracheal mucosa, follows. (See PDF)

Microvascular pressure profile of serosal vessels of rat trachea

1992 ◽  
Vol 262 (4) ◽  
pp. H1303-H1304 ◽  
Author(s):  
S. T. Ballard ◽  
R. H. Nations ◽  
A. E. Taylor
Keyword(s):  
Mean Arterial Pressure ◽  
Pressure Drop ◽  
Important Determinant ◽  
Pressure Profile ◽  
Left Femoral Artery ◽  
Video Microscope ◽  
Capillary Pressures ◽  
Systemic Arteries ◽  
Rat Trachea ◽  
Arteriolar Diameter

The distribution of intravascular pressures within the pulmonary airway microcirculation is an important determinant of transvascular liquid balance. Intravascular pressures were measured in the serosal vessels of the trachea in anesthetized, ventilated rats. The ventral portion of the trachea was surgically exposed and suffused with warm (37 degrees C) Krebs-Ringer bicarbonate. The serosal microvasculature was observed with a video microscope, and microvessel pressures and diameters were measured using the servo-null technique and video calipers, respectively. Mean arterial pressure (MAP) was monitored from the left femoral artery and averaged 106.1 +/- 5.2 mmHg (n = 14). The highest pressure (77% of MAP) was measured in a large (95-microns diam) transverse arteriole. As arteriolar diameter decreased from 39 to 11 microns, pressures fell from 62 to 18% of MAP. Capillaries drained into venular networks that formed extensive arcades. Pressures in these postcapillary venules (20-75 microns diam) were 7.7 +/- 5.5% of MAP (n = 9). These vessels in turn drained into large venous sinuses (120-425 microns diam) where pressures averaged 5.7 +/- 2.3% of MAP (n = 7). A four-parameter logistical model of these data predicts that capillary pressures range from 27 to 15% of MAP. We conclude that 1) a substantial resistance exists across precapillary arterioles less than 40 microns diam and 2) a small pressure drop occurs between systemic arteries and primary feed arterioles in this tissue.

scholarly journals Automated Ambulatory Blood Pressure Measurements and Intraoperative Hypotension in Patients Having Noncardiac Surgery with General Anesthesia

2019 ◽  
Vol 131 (1) ◽  
pp. 74-83 ◽  
Author(s):  
Bernd Saugel ◽  
Philip C. Reese ◽  
Daniel I. Sessler ◽  
Christian Burfeindt ◽  
Julia Y. Nicklas ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
General Anesthesia ◽  
Pressure Profile ◽  
Noncardiac Surgery ◽  
Normal Blood ◽  
Normal Blood Pressure ◽  
Physical Status Classification ◽  
The Difference

Abstract Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New Background Normal blood pressure varies among individuals and over the circadian cycle. Preinduction blood pressure may not be representative of a patient’s normal blood pressure profile and cannot give an indication of a patient’s usual range of blood pressures. This study therefore aimed to determine the relationship between ambulatory mean arterial pressure and preinduction, postinduction, and intraoperative mean arterial pressures. Methods Ambulatory (automated oscillometric measurements at 30-min intervals) and preinduction, postinduction, and intraoperative mean arterial pressures (1-min intervals) were prospectively measured and compared in 370 American Society of Anesthesiology physical status classification I or II patients aged 40 to 65 yr having elective noncardiac surgery with general anesthesia. Results There was only a weak correlation between the first preinduction and mean daytime mean arterial pressure (r = 0.429, P < 0.001). The difference between the first preinduction and mean daytime mean arterial pressure varied considerably among individuals. In about two thirds of the patients, the lowest postinduction and intraoperative mean arterial pressures were lower than the lowest nighttime mean arterial pressure. The difference between the lowest nighttime mean arterial pressure and a mean arterial pressure of 65 mmHg varied considerably among individuals. The lowest nighttime mean arterial pressure was higher than 65 mmHg in 263 patients (71%). Conclusions Preinduction mean arterial pressure cannot be used as a surrogate for the normal daytime mean arterial pressure. The lowest postinduction and intraoperative mean arterial pressures are lower than the lowest nighttime mean arterial pressure in most patients.

scholarly journals Increased intima-media thickness of the carotid artery wall, normal blood pressure profile and normal left ventricular mass in subjects with primary hyperparathyroidism

2002 ◽  
pp. 453-459 ◽  
Author(s):  
V Nuzzo ◽  
L Tauchmanova ◽  
F Fonderico ◽  
R Trotta ◽  
MR Fittipaldi ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Mean Arterial Pressure ◽  
Carotid Artery ◽  
Primary Hyperparathyroidism ◽  
Arterial Pressure ◽  
Cardiovascular System ◽  
Pressure Profile ◽  
Left Ventricular ◽  
Relative Role ◽  
Blood Pressure Profile

OBJECTIVE: Despite the increasing evidence that primary hyperparathyroidism (PHPT) contributes to greater risk of cardiovascular morbidity and mortality, its exact role in the development of cardiovascular changes and its clinical significance are still controversial. Given the multiple influence of PHPT on the cardiovascular system, this study aimed to assess the effects of PHPT on blood pressure profile, and on features of the heart and arterial vessels in normotensive symptomless patients. DESIGN: Twenty patients (8 males and 12 females) with a median age of 51.5 years (range 44 to 65 years) were evaluated and the results were compared with those of 20 controls matched for age, gender and body mass index. Patients' parathyroid hormone levels ranged from 172 to 454 pg/ml and Ca levels ranged from 11.4 to 13.5 mg/dl. Fasting levels of glucose, insulin, total and high density lipoprotein cholesterol and triglycerides were within the normal range in all subjects recruited. METHODS: Twenty-four-hour blood pressure profile, left ventricle (LV) dimension and carotid artery anatomy were investigated, the latter two by ultrasonography. RESULTS: No difference was found between the patients and controls in blood pressure profile, when the following parameters were considered: supine systolic/diastolic pressure, average 24-h systolic, diastolic and mean arterial pressure, day-time mean arterial pressure and fall in nocturnal blood pressure (-17% and -18% respectively). Heart rate and all parameters of LV mass were similar in patients and controls. The only alteration found in patients was in significantly greater carotid intimal-medial thickness (IMT) (P<0.001). Atherosclerotic plaques were more frequent in patients than in controls, with a difference reaching a trend (40% vs 10%, chi(2)=4.8; P=0.091). Considering that the carotid IMT is considered to be a marker of systemic atherosclerosis, our finding suggests early atherosclerotic changes in PHPT. No correlation was found between the severity and cardiovascular manifestation of PHPT. CONCLUSIONS: Vascular changes may occur due to a combination of structural and functional impairments in PHPT patients, likely as a result of altered calcium metabolism and impaired equilibrium of other factors regulating vascular function. Both extent and duration of PHPT can play a relative role in the development of cardiovascular complications. Considering that PHPT is now recognized as a quite common and often symptomless endocrine disorder, the evidence of cardiovascular manifestation in normotensive patients, found by this morphological study, suggests a possible implication for the management of such patients. In this light, screening for abnormalities in cardiovascular system function should be recommended in all PHPT subjects.

scholarly journals Comparison of arterial pressure and plasma ANG II responses to three methods of subcutaneous ANG II administration

2014 ◽  
Vol 307 (5) ◽  
pp. H670-H679 ◽  
Author(s):  
Marcos T. Kuroki ◽  
Gregory D. Fink ◽  
John W. Osborn
Keyword(s):  
Angiotensin Ii ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Pressor Response ◽  
Infusion Pump ◽  
Pressure Profile ◽  
Experimental Hypertension ◽  
Ang Ii ◽  
Gradual Decline ◽  
Induced Hypertension

Angiotensin II (ANG II)-induced hypertension is a commonly studied model of experimental hypertension, particularly in rodents, and is often generated by subcutaneous delivery of ANG II using Alzet osmotic minipumps chronically implanted under the skin. We have observed that, in a subset of animals subjected to this protocol, mean arterial pressure (MAP) begins to decline gradually starting the second week of ANG II infusion, resulting in a blunting of the slow pressor response and reduced final MAP. We hypothesized that this variability in the slow pressor response to ANG II was mainly due to factors unique to Alzet pumps. To test this, we compared the pressure profile and changes in plasma ANG II levels during subcutaneous ANG II administration (150 ng·kg−1·min−1) using either Alzet minipumps, iPrecio implantable pumps, or a Harvard external infusion pump. At the end of 14 days of ANG II, MAP was highest in the iPrecio group (156 ± 3 mmHg) followed by Harvard (140 ± 3 mmHg) and Alzet (122 ± 3 mmHg) groups. The rate of the slow pressor response, measured as daily increases in pressure averaged over days 2–14 of ANG II, was similar between iPrecio and Harvard groups (2.7 ± 0.4 and 2.2 ± 0.4 mmHg/day) but was significantly blunted in the Alzet group (0.4 ± 0.4 mmHg/day) due to a gradual decline in MAP in a subset of rats. We also found differences in the temporal profile of plasma ANG II between infusion groups. We conclude that the gradual decline in MAP observed in a subset of rats during ANG II infusion using Alzet pumps is mainly due to pump-dependent factors when applied in this particular context.

How we significantly reduced oesophagectomy leaks and the significance of Mean Arterial Pressure

2017 ◽  
Author(s):  
C Reissfelder ◽  
T Mees ◽  
S Schölch ◽  
A Remer ◽  
A Seifert ◽  
...  
Keyword(s):  
Mean Arterial Pressure ◽  
Arterial Pressure

Daily arterial pressure profile in young individuals with hereditary burden due to arterial hypertension

2019 ◽  
Vol 17 (2) ◽  
pp. 42-48
Author(s):  
I. A. Grebenkina ◽  
◽  
A. A. Popova ◽  
S. D. Mayanskaya ◽  
S. V. Tretyakov ◽  
...  
Keyword(s):  
Arterial Pressure ◽  
Arterial Hypertension ◽  
Pressure Profile

CHARACTERISTICS OF 24-HOUR BLOOD PRESSURE INDICATORS IN PATIENTS WITH HYPERTENSION AND CHRONIC OBSTRUCTIVE PULMONARY DISEASE

2020 ◽  
pp. 31-41
Author(s):  
M.A. Bubnova ◽  
O.N. Kryuchkova
Keyword(s):  
Blood Pressure ◽  
Chronic Obstructive Pulmonary Disease ◽  
Mean Arterial Pressure ◽  
High Risk ◽  
Arterial Pressure ◽  
Pulmonary Disease ◽  
Comparison Group ◽  
Cardiovascular Complications ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease

Patients with hypertension (HT) and chronic obstructive pulmonary disease (COPD) have a high risk of cardiovascular complications. Up to now, there is no optimal strategy for combined antihypertensive therapy. Still, the data of 24-hour blood pressure monitoring (BPM) are important while choosing treatment tactics. The aim of the paper is to study the features of indicators in patients with arterial hypertension (AH) and COPD. Materials and methods. 130 patients with HT were included in the study. The main group (n=90) included comorbid patients with HT and COPD, their average age was 61.30±1.01; the comparison group (n=40) consisted of patients with HT, their average age was 59.10±1.53. All patients underwent 24-hour BPM. Results. Comorbid patients revealed an increase in the mean 24-hour and night systolic and mean arterial pressure values as well as a significant increase in the load index of systolic, diastolic and mean arterial pressure. Also, comorbid patients demonstrated higher blood pressure in contrast to the patients of the comparison group. They had increased systolic, diastolic and mean blood pressure variability and a quicker rate of morning blood pressure rise. According to 24-hour blood pressure dynamics, pathological types of the 24-hour blood pressure curve, a higher frequency of the night-peaker profile dominated in patients with COPD if compared to patients with HT. Conclusion. The obtained data indicated a high risk of cardiovascular complications in comorbid patients, early target organ damage and an unfavorable disease prognosis. It means that both further study of hypertension clinical course in such patients and personalization of antihypertensive therapy are relevant. Keywords: hypertension, chronic obstructive pulmonary disease, 24-hour monitoring, blood pressure. Пациенты с артериальной гипертензией (АГ) и хронической обструктивной болезнью легких (ХОБЛ) имеют высокий риск возникновения кардиоваскулярных осложнений. В настоящее время в лечении не определена наиболее оптимальная стратегия комбинированной антигипертензивной терапии. Для выбора тактики терапии важную роль играют показатели суточного мониторирования артериального давления (СМАД). Цель. Изучить особенности показателей СМАД у пациентов с АГ на фоне ХОБЛ. Материалы и методы. В исследование включено 130 пациентов с АГ. В основную группу (n=90) вошли пациенты с АГ и ХОБЛ (средний возраст – 61,30±1,01 года), в группу сравнения (n=40) – больные только АГ (средний возраст – 59,10±1,53 года). Всем пациентам проведено СМАД. Результаты. У пациентов с коморбидностью выявлены следующие особенности суточных показателей артериального давления: увеличение значений среднесуточных и средненочных показателей систолического и среднего артериального давления; существенное повышение индекса нагрузки систолическим, диастолическим и средним артериальным давлением. Также эти больные отличались от пациентов группы сравнения более высокими значениями пульсового давления, имели повышенную вариабельность систолического, диастолического и среднего артериального давления, у них наблюдалось увеличение скорости утреннего подъема артериального давления. Суточная динамика артериального давления у пациентов с ХОБЛ характеризовалась преобладанием патологических типов суточной кривой АД, более высокой частотой профиля night-peaker по сравнению с больными только АГ. Выводы. Выявленные особенности свидетельствуют о высоком риске сердечно-сосудистых осложнений у пациентов с коморбидностью, раннем поражении органов-мишеней и неблагоприятном прогнозе заболевания, что требует дальнейшего изучения особенностей клинического течения АГ у таких больных и индивидуализации антигипертензивной терапии. Ключевые слова: артериальная гипертензия, хроническая обструктивная болезнь легких, суточное мониторирование, артериальное давление.

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