Central Venous Pressure and Cardiovascular Responses to Hyperthermia

1994 ◽  
pp. 279-283
Author(s):  
Taketoshi Morimoto ◽  
Akira Takamata ◽  
Hiroshi Nose
1983 ◽  
Vol 244 (2) ◽  
pp. R292-R298
Author(s):  
B. L. Langille

Central venous pressure of ducks rose from resting values of 0.31 +/- 0.16 (SE) to 1.75 +/- 0.20 kPa during forced head immersion. Because a similar increase in mean circulatory pressure (Pmc) was also observed (0.71 +/- 0.16 to 2.15 +/- 0.20 kPa) the rise in central venous pressure was attributed to a venoconstrictor mechanism. When this venoconstrictor-induced rise in central venous pressure was prevented by graded withdrawal of venous blood, then immersion bradycardia was inhibited, and the reduced cardiac output associated with head immersion was largely the result of reduced stroke volume. When compared with normal dives, this intervention resulted in greater myocardial energy requirements, as assessed by the pressure-rate product. It is concluded that venoconstriction increases central venous pressure during head immersion. The increase in central venous pressure alters cardiac function through the Frank-Starling mechanism such that myocardial energy requirements are minimized during this period of low oxygen availability.


2015 ◽  
Vol 119 (12) ◽  
pp. 1411-1420 ◽  
Author(s):  
Jody L. Greaney ◽  
Anna E. Stanhewicz ◽  
David N. Proctor ◽  
Lacy M. Alexander ◽  
W. Larry Kenney

During supine passive heating, increases in skin blood flow (SkBF) and cardiac output (Qc) are both blunted in older adults. The aim here was to determine the effect of acutely correcting the peripheral vasodilatory capacity of aged skin on the integrated cardiovascular responses to passive heating. A secondary aim was to examine the SkBF-Qc relation during hyperthermia in the presence (upright posture) and absence (dynamic exercise) of challenges to central venous pressure. We hypothesized that greater increases in SkBF would be accompanied by greater increases in Qc. Eleven healthy older adults (69 ± 3 yr) underwent supine passive heating (0.8°C rise in core temperature; water-perfused suit) after ingesting sapropterin (BH4, a nitric oxide synthase cofactor; 10 mg/kg) or placebo (randomized double-blind crossover design). Twelve young (24 ± 1 yr) subjects served as a comparison group. SkBF (laser-Doppler flowmetry) and Qc (open-circuit acetylene wash-in) were measured during supine heating, heating + upright posture, and heating + dynamic exercise. Throughout supine and upright heating, sapropterin fully restored the SkBF response of older adults to that of young adults but Qc remained blunted. During heat + upright posture, SkBF failed to decrease in untreated older subjects. There were no age- or treatment-related differences in SkBF-Qc during dynamic exercise. The principal finding of this study was that the blunted Qc response to passive heat stress is directly related to age as opposed to the blunted peripheral vasodilatory capacity of aged skin. Furthermore, peripheral impairments to SkBF in the aged may contribute to inapposite responses during challenges to central venous pressure during hyperthermia.


2017 ◽  
Vol 312 (1) ◽  
pp. R31-R39 ◽  
Author(s):  
Jeroen Brijs ◽  
Erik Sandblom ◽  
Esmée Dekens ◽  
Joacim Näslund ◽  
Andreas Ekström ◽  
...  

Substantial increases in cardiac output (CO), stroke volume (SV), and gastrointestinal blood flow are essential for euryhaline rainbow trout ( Oncorhyncus mykiss) osmoregulation in seawater. However, the underlying hemodynamic mechanisms responsible for these changes are unknown. By examining a range of circulatory and cardiac morphological variables of seawater- and freshwater-acclimated rainbow trout, the present study revealed a significantly higher central venous pressure (CVP) in seawater-acclimated trout (~0.09 vs. −0.02 kPa). This serves to increase cardiac end-diastolic volume in seawater and explains the elevations in SV (~0.41 vs. 0.27 ml/kg) and CO (~21.5 vs. 14.2 ml·min−1·kg−1) when compared with trout in freshwater. Furthermore, these hemodynamic modifications coincided with a significant increase in the proportion of compact myocardium, which may be necessary to compensate for the increased wall tension associated with a larger stroke volume. Following a temperature increase from 10 to 16.5°C, both acclimation groups exhibited similar increases in heart rate (Q10 of ~2), but SV tended to decrease in seawater-acclimated trout despite the fact that CVP was maintained in both groups. This resulted in CO of seawater- and freshwater-acclimated trout stabilizing at a similar level after warming (~26 ml·min−1·kg−1). The consistently higher CVP of seawater-acclimated trout suggests that factors other than compromised cardiac filling constrained the SV and CO of these individuals at high temperatures. The present study highlights, for the first time, the complex interacting effects of temperature and water salinity on cardiovascular responses in a euryhaline fish species.


2006 ◽  
Vol 0 (0) ◽  
Author(s):  
Aline S. C. Belela ◽  
Mavilde L. G. Pedreira ◽  
Maria Angélica S. Peterlini ◽  
Denise M. Kusahara ◽  
Werther B. Carvalho ◽  
...  

2021 ◽  
Vol 30 (4) ◽  
pp. 230-236
Author(s):  
Barry Hill ◽  
Catherine Smith

Patients who present with acute cardiovascular compromise require haemodynamic monitoring in a critical care unit. Central venous pressure (CVP) is the most frequently used measure to guide fluid resuscitation in critically ill patients. It is most often done via a central venous catheter (CVC) positioned in the right atrium or superior or inferior vena cava as close to the right atrium as possible. The CVC is inserted via the internal jugular vein, subclavian vein or via the femoral vein, depending on the patient and their condition. Complications of CVC placement can be serious, so its risks and benefits need to be considered. Alternative methods to CVC use include transpulmonary thermodilution and transoesophageal Doppler ultrasound. Despite its widespread use, CVP has been challenged in many studies, which have reported it to be a poor predictor of haemodynamic responsiveness. However, it is argued that CVP monitoring provides important physiologic information for the evaluation of haemodynamic instability. Nurses have central roles during catheter insertion and in CVP monitoring, as well as in managing these patients and assessing risks.


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