scholarly journals Regulation of blood volume in lowlanders exposed to high altitude

2017 ◽  
Vol 123 (4) ◽  
pp. 957-966 ◽  
Author(s):  
Christoph Siebenmann ◽  
Paul Robach ◽  
Carsten Lundby
Keyword(s):  
Blood Cell ◽  
High Altitude ◽  
Cell Volume ◽  
Blood Volume ◽  
Plasma Volume ◽  
Red Blood Cell ◽  
Hemoglobin Concentration ◽  
Circulating Blood Volume ◽  
Oxyhemoglobin Saturation ◽  
Physiological Relevance

Humans ascending to high altitude (HA) experience a reduction in arterial oxyhemoglobin saturation and, as a result, arterial O2content ([Formula: see text]). As HA exposure extends, this reduction in [Formula: see text] is counteracted by an increase in arterial hemoglobin concentration. Initially, hemoconcentration is exclusively related to a reduction in plasma volume (PV), whereas after several weeks a progressive expansion in total red blood cell volume (RCV) contributes, although often to a modest extent. Since the decrease in PV is more rapid and usually more pronounced than the expansion in RCV, at least during the first weeks of exposure, a reduction in circulating blood volume is common at HA. Although the regulation of hematological responses to HA has been investigated for decades, it remains incompletely understood. This is not only related to the large number of mechanisms that could be involved and the complexity of their interplay but also to the difficulty of conducting comprehensive experiments in the often secluded HA environment. In this review, we present our understanding of the kinetics, the mechanisms and the physiological relevance of the HA-induced reduction in PV and expansion in RCV.

Blood Volume Changes during Three-Week Residence at High Altitude

1970 ◽  
Vol 16 (1) ◽  
pp. 7-14 ◽  
Author(s):  
L G Myhre ◽  
D B Dill ◽  
F G Hall ◽  
D K Brown
Keyword(s):  
Carbon Monoxide ◽  
Blood Cell ◽  
High Altitude ◽  
Cell Volume ◽  
Plasma Volume ◽  
Red Blood Cell ◽  
Hemoglobin Concentration ◽  
Red Cell ◽  
Volume Changes ◽  
Cell Volumes

Abstract Circulating red blood cell volumes were determined by the carbon monoxide method, and plasma volumes were calculated in four men 20, 29, 71, and 75 years old, and two women 29 years of age before, during, and after exposure to an altitude of 3800 m. In the four youngest subjects there were early increases in hemoglobin concentration during the first days at the stated altitude attributed to decreases in plasma volume. At the same time, hemoglobin concentration decreased and plasma volume increased in the oldest subject. Red cell volumes were slow to change, and it was concluded that 3 weeks or more of exposure to this altitude are required to affect significantly the red cell volume in man.

Importance of Monitoring the Circulating Blood Volume in Patients with Cerebral Vasospasm after Subarachnoid Hemorrhage

Neurosurgery ◽  
1981 ◽  
Vol 9 (5) ◽  
pp. 514-520 ◽  
Author(s):  
Tadashi Kudo ◽  
Shigeharu Suzuki ◽  
Takashi Iwabuehi
Keyword(s):  
Blood Cell ◽  
Cell Volume ◽  
Blood Volume ◽  
Red Blood Cell ◽  
Cerebral Aneurysms ◽  
Neurological Deterioration ◽  
Red Cell ◽  
Dilution Technique ◽  
Circulating Blood Volume ◽  
Time Of Admission

Abstract We used the isotope dilution technique to monitor circulating blood volume (CBV) in three patients with ruptured cerebral aneurysms who developed pre- or postoperative ischemic symptoms that responded well to intravascular volume expansion therapy with blood transfusion and plasma expanders. In the first and second cases, predeterioration CBVs were obtained. Both of these patients showed hypovolemia and a decreased red blood cell volume at the time of neurological deterioration. A predeterioration CBV was not available for the third patient for comparison, but his red cell volume was also markedly decreased. Postrecovery CBVs were obtained in the second and third cases. Our data suggested that a depleted red blood cell volume was more responsible for neurological deterioration than was a lowered plasma volume. To prevent the occurrence of hypovolemia and anemia in aneurysm patients, we should monitor CBV not only at the time of neurological deterioration, but also at the time of admission and during the immediate postoperative period.

Plasma volume, red cell volume, and thoracic duct lymph flow in hypothermia

1977 ◽  
Vol 233 (5) ◽  
pp. H605-H612 ◽  
Author(s):  
R. Y. Chen ◽  
S. Chien
Keyword(s):  
Blood Cell ◽  
Cell Volume ◽  
Plasma Volume ◽  
Red Blood Cell ◽  
Thoracic Duct ◽  
Protein Concentration ◽  
Lymph Flow ◽  
Thoracic Duct Lymph ◽  
Circulating Blood Volume ◽  
Duct Lymph

The effects of hypothermia on plasma volume (125I-albumin), red blood cell volume (51 Cr-RBC), and capillary permeability (thoracic duct lymph flow and protein concentration) were determined on dogs anesthetized with pentobarbital, paralyzed with succinylcholine, and mechanically ventilated. Red blood cell volume and plasma protein concentration did not change significantly after cooling. Reductions in plasma volume and total plasma proteins indicate that whole plasma was excluded from the effective circulating blood volume. Except for a lesser increase in hematocrit, chronically splenectomized dogs showed essentially the same changes as normal dogs in response to hypothermia. Following application of ice bags, there was a biphasic response in lymph flow. The early increase in lymph flow accompanying a slight decrease in plasma volume was attributable to transcapillary fluid loss into interstitial space, probably due to cold-induced sympathetic activity. The later decrease in lymph flow in hypothermia resulted from a decrease of lymph production secondary to a decrease in available capillary diffusion area. This decrease in lymph flows and the continued reduction in plasma volume suggest an intravascular sequestration of whole plasma.

Influence of the spleen on blood volume and haematocrit in the brush-tailed possum (Trichosurus vulpecula)

1968 ◽  
Vol 16 (4) ◽  
pp. 603 ◽  
Author(s):  
TJ Dawson ◽  
MJS Denny
Keyword(s):  
Body Weight ◽  
Blood Cell ◽  
Blood Volume ◽  
Plasma Volume ◽  
Red Blood Cell ◽  
Blood Cells ◽  
Trichosurus Vulpecula ◽  
Circulating Blood Volume ◽  
Significant Function ◽  
Blood Reservoir

The blood volume of T. vulpecula was measured and the influence of the spleen on the circulating blood volume investigated. The circulating blood volume of "normal" restrained animals was 57.4 � 3.19 ml, the plasma volume being 31.2 � 1.93 ml, and the red blood cell volume 26.2 � 2.08 ml per kilogram body weight. These values tended to be lower than those of eutherian mammals and it is suggested that this might be associated with a possible lower metabolic rate. The spleen was found to have a significant function as a blood reservoir. Measurement of volume of circulating red blood cells after injections of adrenaline (to cause splenic emptying) and chlorpromazine (to achieve maximum filling of the spleen) showed that the splenic reserve of erythrocytes was approximately 11.0 ml/kg body weight.

Cerebral blood flow, blood volume, and brain tissue hematocrit during isovolemic hemodilution with hetastarch in rats

1992 ◽  
Vol 263 (1) ◽  
pp. H75-H82 ◽  
Author(s):  
M. M. Todd ◽  
J. B. Weeks ◽  
D. S. Warner
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Blood Cell ◽  
Cell Volume ◽  
Brain Tissue ◽  
Blood Volume ◽  
Plasma Volume ◽  
Red Blood Cell ◽  
Isovolemic Hemodilution ◽  
Blood Cell And Plasma

The influence of isovolemic hemodilution with 6% hetastarch [hematocrits (Hct) ranging from 43 to 20%] on cerebral blood flow (CBF), cerebral red blood cell and plasma volumes, total cerebral blood volume (CBV), and cerebral Hct was examined in normothermic, normocarbic, halothane-anesthetized Sprague-Dawley rats. CBF was measured via the indicator-fractionation method ([3H]nicotine), red blood cell volume was measured using 99mTc-labeled red blood cells, while plasma volume was measured using [14C]dextran. Brain tissue was fixed in situ by microwave irradiation. All data plots (e.g., CBF vs. Hct) were fitted by linear regression methods. Hemodilution was associated with a progressive increase in forebrain CBF (from a fitted value of 78 ml.100 g-1.min-1 at Hct = 43%, to 171 ml.100 g-1.min-1 at 20%). Cerebral plasma volume also rose, while red blood cell volume decreased. Total CBV (i.e., the sum of red blood cell and plasma volumes) increased in parallel with CBF (from 2.51 ml/100 g at Hct = 43 to 4.94 ml/100 g at Hct = 20%). This increase is larger than can be explained by a simple increase in the diameter of arterial/arteriolar resistance vessels and may be due to either capillary recruitment or to an increase in the volume of postarteriolar structures. Calculated cerebral tissue hematocrit decreased. The magnitude of this decrease was larger than the reduction in arterial Hct; the ratio of cerebral to arterial Hct decreased from 0.780 at an arterial Hct equaling 43% to 0.458 at Hct equaling 20%.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Red Blood Cell Volume and the Capacity for Exercise at Moderate to High Altitude

2012 ◽  
Vol 42 (8) ◽  
pp. 643-663 ◽  
Author(s):  
Robert A. Jacobs ◽  
Carsten Lundby ◽  
Paul Robach ◽  
Max Gassmann
Keyword(s):  
Blood Cell ◽  
High Altitude ◽  
Cell Volume ◽  
Red Blood Cell

Actively circulating blood volume in endotoxin shock measured by indicator dilution

1979 ◽  
Vol 236 (2) ◽  
pp. H291-H300 ◽  
Author(s):  
C. F. Rothe ◽  
R. H. Murray ◽  
T. D. Bennett
Keyword(s):  
Blood Cell ◽  
Blood Volume ◽  
Red Blood Cell ◽  
Mixing Time ◽  
Volume Of Distribution ◽  
Endotoxin Shock ◽  
Circulating Blood Volume ◽  
Arterial Blood ◽  
Concentration Changes ◽  
Volumes Of Distribution

To estimate the size of the actively circulating blood volume of splenectomized dogs during control conditions and after endotoxin infusion, the pattern of concentration changes of 51Cr-labeled erythrocytes and 125I-labeled albumin was monitored. A dual exponential equation was fitted to the data. The total red blood cell and albumin volumes of distribution were determined from the slow exponential disappearance curves. The active red blood cell and albumin volumes were 89.8 +/- 5.3% and 92.0 +/- 2.0% of the total volumes, respectively. After endotoxin shock (mean arterial blood pressure 49.1 +/- 17.8 mmHg) the active volumes fell to only 60.0 +/- 10.3% and 56.2 +/- 20.0% of the total volumes, respectively. The fast-mixing time constants were similar (3.1 +/- 1.4 min and 2.5 +/- 2.7 min, respectively) and did not change significantly during the endotoxin shock, indicating that the albumin tag mixed into its larger volume of distribution as rapidly as the cells mixed into their indicated volume. We conclude that 1) an active blood volume can be distinguished, 2) it decreases for both red blood cells and albumin in endotoxin shock, and 3) a major part of the "extravascular plasma volume," as estimated by albumin dilution, is in the actively circulating circulation.

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