Catecholamines and regional hemodynamics during isovolemic hemodilution in anesthetized pigs

Woerkens, E. C. S. M. Van; Trouwborst, A.; Duncker, Dirk J.; Koning, M. M. G.; Boomsma, Frans; Verdouw, Pieter D.

doi:10.1152/jappl.1992.72.2.760

Cited by 67 publications

(33 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…They concluded that ''an intact autonomic nervous system is necessary for the total circulatory response to anemia''. 70 Although one study was unable to demonstrate an increase in systemic catecholamines after acute hemodilution, 71 another more recent study demonstrated a sudden acute fourfold increase in systemic noradrenalin levels, suggestive of increased sympathetic activity. 14 The sudden increase in systemic noradrenalin occurred much earlier than increases in adrenaline and dopamine, suggesting that spillover from adrenergic nerve activity may have played a role.…”

Section: Hemodilution Results In Activation Of the Sympathetic Nervoumentioning

confidence: 99%

Reassessing the risk of hemodilutional anemia: Some new pieces to an old puzzle

Tsui

Dattani

Marsden

et al. 2010

Can J Anesth/J Can Anesth

View full text Add to dashboard Cite

Section: Hemodilution Results In Activation Of the Sympathetic Nervoumentioning

confidence: 99%

Reassessing the risk of hemodilutional anemia: Some new pieces to an old puzzle

Tsui

Dattani

Marsden

et al. 2010

Can J Anesth/J Can Anesth

View full text Add to dashboard Cite

“…Furthermore, we closely monitored heart rate and blood pressure, which quickly respond to pain, and found no sudden increases throughout the experiment. The doses of anesthetics are in the range commonly used for anesthesia in pigs with (20,29,45) and without (16) muscle relaxants. This procedure is in accordance with the American Physiological Society "Guiding Principles in the Care and Use of Animals," which states that muscle relaxants may be used in conjunction with drugs known to produce adequate anesthesia.…”

Section: Methodsmentioning

confidence: 99%

Myocardial O₂consumption in porcine left ventricle is heterogeneously distributed in parallel to heterogeneous O₂delivery

Alders¹,

Groeneveld²,

Kanter³

et al. 2004

American Journal of Physiology-Heart and Circulatory Physiology

View full text Add to dashboard Cite

and correlated well (r ϭ 0.85, P ϭ 0.02, n ϭ 7) with oxygen consumption calculated from blood flow, hemoglobin, and blood gas measurements (mean 22.8 Ϯ 4.7 mol⅐min Ϫ1 ⅐g dry wt Ϫ1). Local blood flow and oxygen consumption were significantly correlated (r ϭ 0.63 for pooled normalized data, P Ͻ 0.0001, n ϭ 60). We calculate that, in the heart at normal workload, the variance of left ventricular oxygen delivery at submilliliter resolution is explained for 43% by heterogeneity in oxygen demand. regional blood flow; metabolism; myocardium; magnetic resonance spectroscopy MYOCARDIAL BLOOD FLOW is highly heterogeneous, as demonstrated in many different species, with various methods (radioactive, colored and fluorescent microspheres, molecular tracers, MRI, and PET), and under different experimental circumstances, such as open-versus closed-chest and anesthetized versus awake animals (5,9,19,22,26,27). Myocardial perfusion shows similar heterogeneity in the human heart (47). This heterogeneity is largely of spatial nature, although there is also some temporal variation (27). Local blood flow can differ by a factor five among small areas of the left ventricle, even in the normal heart. Interestingly, regional blood flow is rather stable over a substantial time period, at least for several hours, but some data even indicate a relatively stable local blood flow over days (44). From an anatomic and mechanical point of view, this heterogeneity is difficult to understand because the heart appears rather homogeneous and biomechanical models predict homogeneous contraction. The question thus remains: which factors contribute to heterogeneous blood flow? Heterogeneity in oxygen consumption (V O 2 ) between different areas of the left ventricle may explain at least part of the heterogeneity of myocardial blood flow. Indeed, it has been shown in previous studies (9,19) that indirect indicators of local aerobic metabolism show heterogeneity. For instance, a correlation between local blood flow and fatty acid uptake has been shown (24). Others (38, 39) have reported a rather good correlation between local myocardial blood flow and local myocardial V O 2 (MV O 2 ) measured by [18 O]water in the isolated buffer-perfused rabbit heart. Low-flow areas had lower V O 2 and highflow areas had higher V O 2 . Further studies showed that areas of the left ventricle that receive a relatively low amount of blood flow are not in a hypoxic state, suggesting local adaptation of blood flow to oxygen demand (8,11,14). However, direct measurement of aerobic metabolic flux in small myocardial regions became possible only recently. Regional V O 2 and regional blood flow can be estimated with PET, although this technique still does not permit analysis at sufficiently high spatial resolution to study cardiac heterogeneity in small tissue areas (1,34,37).To investigate the distribution of MV O 2 at high spatial resolution, a new combination of isotope labeling protocol and mathematical analysis of 13 C incorporation into the tricarboxylic acid (TCA) cycle ...

show abstract

“…Large differences in the tolerance of organ systems to conditions of decreased O 2 delivery (DO 2 ) exist. However, as soon as the systemic oxygen delivery falls below a critical point, compensatory mechanisms are getting insufficient and oxygen consumption (V O 2 ) becomes dependent on supply (4,28,32,36,38). Although compensatory mechanisms preserve vital organ oxygenation over a wide range of decreasing hematocrit, they may impair tissue oxygenation of critical organs (34,37).…”

mentioning

confidence: 99%

Acute decrease in renal microvascular Po₂ during acute normovolemic hemodilution

Johannes

Mik²,

Nohé³

et al. 2007

American Journal of Physiology-Renal Physiology

121

122

View full text Add to dashboard Cite

Johannes T, Mik EG, Nohé B, Unertl KE, Ince C. Acute decrease in renal microvascular PO 2 during acute normovolemic hemodilution. Am J Physiol Renal Physiol 292: F796 -F803, 2007. First published October 31, 2006 doi:10.1152/ajprenal.00206.2006.-Large differences in the tolerance of organ systems to conditions of decreased O2 delivery such as hemodilution exist. The kidney receives ϳ25% of the cardiac output and O2 delivery is in excess of the oxygen demand under normal circumstances. In a rat model of acute normovolemic hemodilution (ANH), we studied the effect of reduced hematocrit on renal regional and microvascular oxygenation. Experiments were performed in 12 anesthetized male Wistar rats. Six animals underwent four steps of ANH (hematocrit 25, 15, 10, and Ͻ10%). Six animals served as time-matched controls. Systemic and renal hemodynamic and oxygenation parameters were monitored. Renal cortical (c) and outer medullary (m) microvascular PO 2 (PO2) and the renal venous PO 2 (PrvO2) were continuously measured by oxygen-dependent quenching of phosphorescence. Despite a significant increase in renal blood flow in the first two steps of ANH, cPO 2 and mPO2 dropped immediately. From the first step onward oxygen consumption (V O2ren) became dependent on oxygen delivery (DO 2ren). With a progressive decrease in hematocrit, a significant correlation between PO 2 and V O2ren could be observed, as well as a PO2 gap between PO2 and P rvO2. Furthermore, there was a high correlation between V O2ren and RBF over a wide range of flows. In conclusion, the oxygen supply to the renal tissue is becoming critical already in an early stage of ANH due to the combination of increased V O2ren, decreased DO2ren, and intrarenal O 2 shunt. This has clinical relevance as recent publications reporting that hemodilution during surgery forms a risk factor for postoperative renal dysfunction.

show abstract

Catecholamines and regional hemodynamics during isovolemic hemodilution in anesthetized pigs

Cited by 67 publications

References 0 publications

Reassessing the risk of hemodilutional anemia: Some new pieces to an old puzzle

Reassessing the risk of hemodilutional anemia: Some new pieces to an old puzzle

Myocardial O₂consumption in porcine left ventricle is heterogeneously distributed in parallel to heterogeneous O₂delivery

Acute decrease in renal microvascular Po₂ during acute normovolemic hemodilution

Contact Info

Product

Resources

About

Catecholamines and regional hemodynamics during isovolemic hemodilution in anesthetized pigs

Cited by 67 publications

References 0 publications

Reassessing the risk of hemodilutional anemia: Some new pieces to an old puzzle

Reassessing the risk of hemodilutional anemia: Some new pieces to an old puzzle

Myocardial O2consumption in porcine left ventricle is heterogeneously distributed in parallel to heterogeneous O2delivery

Acute decrease in renal microvascular Po2 during acute normovolemic hemodilution

Contact Info

Product

Resources

About

Myocardial O₂consumption in porcine left ventricle is heterogeneously distributed in parallel to heterogeneous O₂delivery

Acute decrease in renal microvascular Po₂ during acute normovolemic hemodilution