Effect of reduced hemoglobin concentration on leg oxygen uptake during maximal exercise in humans

1993 ◽  
Vol 75 (2) ◽  
pp. 491-498 ◽  
Author(s):  
W. Schaffartzik ◽  
E. D. Barton ◽  
D. C. Poole ◽  
K. Tsukimoto ◽  
M. C. Hogan ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Venous Blood ◽  
Hemoglobin Concentration ◽  
Random Order ◽  
Barometric Pressure ◽  
Whole Body ◽  
Cell Spacing ◽  
O2 Delivery

Maximum oxygen uptake (VO2max) is affected by hemoglobin concentration ([Hb]). Whether this is simply due to altered convection of O2 into the muscle microcirculation or also to [Hb]-dependent diffusive transport of O2 out of the muscle capillary is unknown in humans. To examine this, seven healthy volunteers performed four maximal cycle exercise bouts at sea level immediately after 8 wk at altitude (3,801 m, barometric pressure 485 Torr), a sojourn designed to increase [Hb]. The first two bouts were at ambient [Hb] of 15.9 +/- 0.7 g/100 ml breathing 21 or 12% O2 in random order. [Hb] was then decreased to a prealtitude level of 13.8 +/- 0.6 g/100 ml by venesection and isovolemic replacement with 5% albumin in 0.9% saline, and the exercise bouts were repeated. At whole body VO2max, PO2, PCO2, pH, and O2 saturation were measured in radial arterial and femoral venous blood. Femoral venous thermodilution blood flow was determined for calculation of leg VO2. Mean muscle capillary PO2 and muscle diffusing capacity (DO2) were computed by Bohr integration between measured arterial and femoral venous PO2. Averaged over both fractional concentrations of inspired O2, leg VO2 at maximum decreased by 17.7 +/- 4.3% as [Hb] was lowered while leg O2 delivery decreased by 17.5 +/- 2.6% and DO2 decreased by 10.7 +/- 2.7% (all P < 0.05). The relative contributions of decreases in leg O2 delivery and DO2 to the decrease in VO2max were computed to be 64 and 36%, respectively. These findings suggest that [Hb] is an important determinant of O2 diffusion rates into working muscle in humans. Possible mechanisms include 1) dependence of DO2 on intracapillary red blood cell spacing, 2) changes in the total rate of dissociation of O2 from [Hb], and 3) increased red blood cell flow heterogeneity as [Hb] is reduced.

Footstrike is the major cause of hemolysis during running

2003 ◽  
Vol 94 (1) ◽  
pp. 38-42 ◽  
Author(s):  
R. D. Telford ◽  
G. J. Sly ◽  
A. G. Hahn ◽  
R. B. Cunningham ◽  
C. Bryant ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Random Order ◽  
Peak Oxygen Uptake ◽  
Red Cell ◽  
Free Hemoglobin ◽  
Serum Haptoglobin ◽  
Total Hemoglobin ◽  
Exercise Induced

There is a wide body of literature reporting red cell hemolysis as occurring after various forms of exercise. Whereas the trauma associated with footstrike is thought to be the major cause of hemolysis after running, its significance compared with hemolysis that results from other circulatory stresses on the red blood cell has not been thoroughly addressed. To investigate the significance of footstrike, we measured the degree of hemolysis after 1 h of running. To control for the potential effects of oxidative and circulatory stresses on the red blood cell, the same subjects cycled for 1 h at equivalent oxygen uptake. Our subjects were 10 male triathletes, who each completed two separate 1-h sessions of running and cycling at 75% peak oxygen uptake, which were performed in random order 1 wk apart. Plasma free hemoglobin and serum haptoglobin concentrations were measured as indicators of hemolysis. We also measured methemoglobin as a percentage of total hemoglobin immediately postexercise as an indicator of red cell oxidative stress. Plasma free hemoglobin increased after both running ( P < 0.01) and cycling ( P < 0.01), but the increase was fourfold greater after running ( P < 0.01). This was reflected by a significant fall in haptoglobin 1 h after the running trials, whereas no significant changes occurred after cycling at any sample point. Methemoglobin increased twofold after both running and cycling ( P < 0.01), with no significant differences between modes of exercise. The present data indicate that, whereas general circulatory trauma to the red blood cells associated with 1 h of exercise at 75% maximal oxygen uptake may result in some exercise-induced hemolysis, footstrike is the major contributor to hemolysis during running.

scholarly journals Ion fluxes and hematological parameters of two teleosts from the Rio Negro, Amazon, exposed to hypoxia

2008 ◽  
Vol 68 (3) ◽  
pp. 571-575 ◽  
Author(s):  
B. Baldisserotto ◽  
AR. Chippari-Gomes ◽  
NP. Lopes ◽  
JEPW. Bicudo ◽  
MN. Paula-Silva ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Oxygen Supply ◽  
Hematological Parameters ◽  
Ion Fluxes ◽  
Whole Body ◽  
Rio Negro ◽  
Ion Efflux ◽  
Gill Ventilation

The aim of this study was to describe the effect of hypoxia on whole body ion fluxes and hematological parameters in two Amazonian teleosts: Serrasalmus eigenmanni and Metynnis hypsauchen. The increase of Na+ and Cl- effluxes on M. hypsauchen exposed to hypoxia may be related to an increase of gill ventilation and effective respiratory surface area, to avoid a reduction in the oxygen uptake, and/or with the decrease of pHe, that could inhibit Na+ and Cl- transporters and, therefore, reduce influx of these ions. Effluxes of Na+ and Cl- were lower in hypoxia than in normoxia for S. eigenmanni, possibly because in hypoxia this species would reduce gill ventilation and oxygen uptake, which would lead to a decrease of gill ion efflux and, consequently, reducing ion loss. The increase on hematocrit (Ht) during hypoxia in M. hypsauchen probably was caused by an increase of the red blood cell volume (MCV). For S. eigenmanni the increase on glucose possibly results from the usage of glucose reserve mobilization. Metynnis hypsauchen showed to be more sensitive to hypoxia than Serrasalmus eigenmanni, since the first presented more significant alterations on these osmoregulatory and hematological parameters. Nevertheless, the alterations observed for both species are strategies adopted by fishes to preserve oxygen supply to metabolizing tissues during exposure to hypoxia.

scholarly journals The Sensitivity and Specificity of a Red Blood Cell Agglutination D-Dimer Assay for Venous Thromboembolism When Performed on Venous Blood

2002 ◽  
Vol 162 (2) ◽  
pp. 217 ◽  
Author(s):  
Sanjeev D. Chunilal ◽  
Patrick A. Brill-Edwards ◽  
Pamela B. Stevens ◽  
Jody P. Joval ◽  
Joanne A. McGinnis ◽  
...  
Keyword(s):  
Venous Thromboembolism ◽  
Blood Cell ◽  
Sensitivity And Specificity ◽  
Red Blood Cell ◽  
Venous Blood ◽  
Cell Agglutination ◽  
D Dimer

Oxygen transport to exercising leg in chronic hypoxia

1988 ◽  
Vol 65 (6) ◽  
pp. 2592-2597 ◽  
Author(s):  
P. R. Bender ◽  
B. M. Groves ◽  
R. E. McCullough ◽  
R. G. McCullough ◽  
S. Y. Huang ◽  
...  
Keyword(s):  
Blood Flow ◽  
Sea Level ◽  
Chronic Hypoxia ◽  
Peripheral Resistance ◽  
Hemoglobin Concentration ◽  
Barometric Pressure ◽  
Ambient Air ◽  
Leg Blood Flow ◽  
State Cycle ◽  
O2 Delivery

Residence at high altitude could be accompanied by adaptations that alter the mechanisms of O2 delivery to exercising muscle. Seven sea level resident males, aged 22 +/- 1 yr, performed moderate to near-maximal steady-state cycle exercise at sea level in normoxia [inspired PO2 (PIO2) 150 Torr] and acute hypobaric hypoxia (barometric pressure, 445 Torr; PIO2, 83 Torr), and after 18 days' residence on Pikes Peak (4,300 m) while breathing ambient air (PIO2, 86 Torr) and air similar to that at sea level (35% O2, PIO2, 144 Torr). In both hypoxia and normoxia, after acclimatization the femoral arterial-iliac venous O2 content difference, hemoglobin concentration, and arterial O2 content, were higher than before acclimatization, but the venous PO2 (PVO2) was unchanged. Thermodilution leg blood flow was lower but calculated arterial O2 delivery and leg VO2 similar in hypoxia after vs. before acclimatization. Mean arterial pressure (MAP) and total peripheral resistance in hypoxia were greater after, than before, acclimatization. We concluded that acclimatization did not increase O2 delivery but rather maintained delivery via increased arterial oxygenation and decreased leg blood flow. The maintenance of PVO2 and the higher MAP after acclimatization suggested matching of O2 delivery to tissue O2 demands, with vasoconstriction possibly contributing to the decreased flow.

scholarly journals Preliminary Study on the Clinical and Genetic Characteristics of Hereditary Spherocytosis in 15 Chinese Children

2021 ◽  
Vol 12 ◽  
Author(s):  
Chongjun Wu ◽  
Ting Xiong ◽  
Zhongjin Xu ◽  
Chunlei Zhan ◽  
Feng Chen ◽  
...  
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Clinical Characteristics ◽  
Hemoglobin Concentration ◽  
Chinese Children ◽  
Test Results ◽  
Test Analysis ◽  
Genetic Characteristics ◽  
Significant Difference ◽  
Gene Test

ObjectiveTo investigate the clinical and genetic characteristics of hereditary spherocythemia (HS) in Chinese children, and to analyze the potential genotypic/phenotypic associations.MethodsThe clinical data and gene test results of children with HS were collected. All patients were diagnosed by gene test results, and the laboratory results were obtained before splenectomy. The data of red blood cell (RBC), hemoglobin (HB), mean red blood cell volume (MCV), mean red blood cell hemoglobin (MCH), mean red blood cell hemoglobin concentration (MCHC), and hematocrit (HCT) were statistically analyzed according to different mutation genes. Statistical methods for comparison between groups Mann–Whitney test analysis, two-terminal p &lt; 0.05 was considered significant difference.ResultsA total of 15 children were enrolled in our hospital, and 14 variants were found (nine variants have not been reported before), including 10 ANK1 mutations (seven ANK1 truncated mutations) and five SPTB mutations. Patients with ANK1 mutations had more severe anemia than those with SPTB mutations (significantly lower RBC, HB, MCHC, and HCT).ConclusionThis is one of the few studies on the genetic and clinical characteristics of children with HS in China. This study identified the unique genetic and clinical characteristics of Chinese children with HS and analyzed the pathogenic genotype–phenotypic association. The results confirmed that the anemia degree of HS patients caused by ANK1 was more serious than that of patients with SPTB deficiency. However, further study of the correlation between genotype and phenotype requires a larger sample size.

scholarly journals Red Blood Cell Transfusion and the Use of Intravenous Iron in Iron Deficient Patients Presenting to the Emergency Department

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 1-2
Author(s):  
Arvand Barghi ◽  
Robert Balshaw ◽  
Emily Rimmer ◽  
Murdoch Leeies ◽  
Allan Garland ◽  
...  
Keyword(s):  
Emergency Department ◽  
Logistic Regression ◽  
Iron Deficiency ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Hemoglobin Concentration ◽  
Factors Associated ◽  
Iv Iron ◽  
Iron Parameters ◽  
Rbc Transfusion

Background: Red blood cell (RBC) transfusions are often used to treat patients with iron deficiency who present to the emergency department (ED) with symptomatic anemia. Intravenous (IV) iron is the preferred treatment in this setting, as it has been shown to increase hemoglobin concentration rapidly and durably. We aim to determine the incidence of iron deficiency anemia (IDA) and the management of these patients in the ED setting. Objectives: To evaluate the incidence of IDA, the frequency of RBC transfusion and iron supplementation, and factors associated with RBC transfusion. Study Design: Retrospective cohort study of all adult patients presenting to the St Boniface Hospital (Winnipeg, CAN) ED from January 2014 to January 2019. Methods: We used electronic data from the Emergency Department Information System (EDIS) and Laboratory Information Services (LIS) databases to identify patients presenting with IDA, defined as anemia (hemoglobin &lt;120 g/L) with either a transferrin saturation less than 20% or ferritin less than 30 umol/L, or mean corpuscular volume (MCV) of &lt; 75 fL. A ferritin greater than 100 umol was used to exclude IDA, regardless of MCV. We extracted patient demographics, diagnoses, markers of iron storage, RBC transfusion and use of IV iron. Multivariate logistic regression analysis was used to evaluate factors associated with RBC transfusion. Results: Of 39222 patients, 17945 (45%) were anemic. Of the anemic patients, iron parameters were ordered in 1848 (10.3%) patients, and IDA was present in 910 (5.1 %). In the IDA population, 95 patients (10.4 %) received 1 RBC unit, and 197 patients (21.6 %) received 2 or more units. Oral iron and IV iron were prescribed for 64 (7 %) and 14 (1.5 %) patients, respectively. Our logistic regression model demonstrated that hemoglobin concentration was the main determinant of whether patients received RBC transfusion. Other variables including patient age, cardiac symptoms, heart rate, blood pressure, and CTAS score were not associated with increased likelihood of receiving RBC transfusion. Conclusion: Iron parameters were infrequently ordered in the evaluation of anemia in the ED, with limited use of oral and IV iron. The decision to transfuse RBCs was primarily influenced by hemoglobin concentration, but not other surrogates of hemodynamic instability. An interventional study to improve education and access to oral and IV iron is planned to reduce unnecessary RBC transfusions and their associated risks in patients with IDA. Disclosures No relevant conflicts of interest to declare.

Effect of anemia on cardiac function, microvascular structure, and capillary hematocrit in rat hearts

2001 ◽  
Vol 280 (3) ◽  
pp. H1407-H1414 ◽  
Author(s):  
Karel Rakusan ◽  
N. Cicutti ◽  
F. Kolar
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Diastolic Pressure ◽  
Experimental Situation ◽  
Young Male ◽  
Left Ventricular ◽  
Male Rats ◽  
Capillary Length ◽  
Chronic Anemia ◽  
Cell Spacing

The effect of anemia on the coronary microcirculation was studied in young male rats. Chronic anemia resulted in increased left ventricular end-diastolic pressure and decreased functional reserve. Cardiac mass in anemic animals increased by 25%. Capillary and arteriolar densities in these hearts remained unchanged, indicating angiogenesis in this experimental situation (estimated aggregate capillary length in the left ventricle of anemic hearts was 3.06 km compared with 2.35 km in control hearts). Capillary hematocrit was decreased in chronic anemia less than systemic hematocrit: from 25 to 18% in anemia versus 45 to 28% in controls. Capillary hematocrit and red blood cell spacing were also studied after acute blood withdrawal. Here, capillary hematocrit was preserved even more: 22 versus 24% in systemic hematocrit. Finally, the same was studied in isolated hearts perfused with solutions of various hematocrits. After perfusion with low-hematocrit solution (14%), the capillary hematocrit (24%) was even higher than the perfusate hematocrit! In conclusion, we found evidence of angiogenesis in cardiomegaly induced by chronic anemia. Microvascular growth was accompanied by advantageous regulation of red blood cell spacing within these vessels. This was even more pronounced during acute hemodilution and in isolated perfused hearts.

Red blood cell deformability and venous blood PO2 in diabetics

2016 ◽  
Vol 8 (2) ◽  
pp. 171-181
Author(s):  
Y. Kikuchi ◽  
T. Koyama ◽  
N. Ohshima ◽  
K. Oda
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Venous Blood ◽  
Cell Deformability ◽  
Red Blood Cell Deformability

Systemic and diaphragmatic oxygen delivery-consumption relationships during hemorrhage

1994 ◽  
Vol 77 (2) ◽  
pp. 653-659 ◽  
Author(s):  
M. E. Ward ◽  
H. Chang ◽  
F. Erice ◽  
S. N. Hussain
Keyword(s):  
Work Of Breathing ◽  
Venous Blood ◽  
The Body ◽  
Extraction Ratio ◽  
Whole Body ◽  
Critical Threshold ◽  
Inferior Phrenic Artery ◽  
Left Hemidiaphragm ◽  
O2 Extraction ◽  
O2 Delivery

When tissue O2 delivery falls below a critical threshold, tissue O2 uptake (VO2) becomes limited. We compared critical O2 delivery and critical and maximum O2 extraction ratios of the resting and contracting left hemidiaphragm with those of nondiaphragmatic tissues in seven dogs. The left hemidiaphragm was perfused through the left inferior phrenic artery with blood from the left femoral artery. Phrenic venous blood was sampled through a catheter in the inferior phrenic vein. Systemic O2 delivery was reduced in stages by controlled hemorrhage. Left diaphragmatic VO2 during rest and during 3 min of continuous stimulation (3 Hz) of the left phrenic nerve and VO2 of the remaining nonleft hemidiaphragmatic tissues were measured at each stage. Critical diaphragmatic O2 delivery for the resting diaphragm averaged 0.8 +/- 0.16 ml.min-1.100 g-1 with a critical O2 extraction ratio of 65.5 +/- 6%. In the contracting diaphragm, they averaged 5.1 +/- 0.9 ml.min-1.100 g-1 and 81 +/- 5%, respectively. Whole body O2 delivery at which resting diaphragmatic VO2 became supply limited was similar to that for nondiaphragmatic tissues. By comparison, supply limitation of VO2 occurred at a higher systemic O2 delivery in the contracting diaphragm than in the rest of the body despite the increase in critical diaphragmatic extraction ratio. Thus, oxygenation of the isolated diaphragm does not appear to be preferentially preserved during generalized reductions in O2 delivery. These results suggest that, in diseases associated with increased work of breathing and decreased O2 delivery, the diaphragm may become metabolically impaired before limitation of VO2 is observed systemically.

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