Peridural Anesthesia and the Distribution of Blood in Supine Humans

Arndt, J. O.; Höck, A.; Stanton‐Hicks, Michael; Stühmeier, Klaus-Dieter

doi:10.1097/00000542-198512000-00011

Cited by 100 publications

(15 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In surgery, preservation of the central blood volume is challenged by factors such as bleeding, capillary leakage and evaporation. Also anaesthetic drugs applied in spinal and epi(peri)dural anaesthesia reduce the central blood volume (Arndt et al 1985) as a result of redistribution. Establishment of normovolaemia to maintain an optimal oxygen delivery to organs is intuitively rational.…”

Section: Applications To Clinical Medicinementioning

confidence: 99%

A definition of normovolaemia and consequences for cardiovascular control during orthostatic and environmental stress

2010

View full text Add to dashboard Cite

The Frank–Starling mechanism describes the relationship between stroke volume and preload to the heart, or the volume of blood that is available to the heart—the central blood volume. Understanding the role of the central blood volume for cardiovascular control has been complicated by the fact that a given central blood volume may be associated with markedly different central vascular pressures. The central blood volume varies with posture and, consequently, stroke volume and cardiac output () are affected, but with the increased central blood volume during head-down tilt, stroke volume and do not increase further indicating that in the supine resting position the heart operates on the plateau of the Frank–Starling curve which, therefore, may be taken as a functional definition of normovolaemia. Since the capacity of the vascular system surpasses the blood volume, orthostatic and environmental stress including bed rest/microgravity, exercise and training, thermal loading, illness, and trauma/haemorrhage is likely to restrict venous return and . Consequently the cardiovascular responses are determined primarily by their effect on the central blood volume. Thus during environmental stress, flow redistribution becomes dependent on sympathetic activation affecting not only skin and splanchnic blood flow, but also flow to skeletal muscles and the brain. This review addresses the hypothesis that deviations from normovolaemia significantly influence these cardiovascular responses.

show abstract

Section: Applications To Clinical Medicinementioning

confidence: 99%

A definition of normovolaemia and consequences for cardiovascular control during orthostatic and environmental stress

2010

View full text Add to dashboard Cite

show abstract

“…The gastrointestinal effects probably account for the nausea accompanying vasovagal syncope and possibly an increase in splanchnic blood¯ow. 3 Lewis postulated that there was a vascular component to fainting reactions, as the associated hypotension was not reversed when atropine was administered to correct the bradycardia. 48 Studies of forearm blood¯ow using venous occlusion plethysmography and cardiac output 6 13 con-®rmed this.…”

Section: Efferent Responsesmentioning

confidence: 99%

Perioperative bradycardia and asystole: relationship to vasovagal syncope and the Bezold–Jarisch reflex

Kinsella

Tuckey

2001

British Journal of Anaesthesia

288

237

View full text Add to dashboard Cite

Reflex cardiovascular depression with vasodilation and bradycardia has been variously termed vasovagal syncope, the Bezold-Jarisch reflex and neurocardiogenic syncope. The circulatory response changes from the normal maintenance of arterial pressure, to parasympathetic activation and sympathetic inhibition, causing hypotension. This change is triggered by reduced cardiac venous return as well as through affective mechanisms such as pain or fear. It is probably mediated in part via afferent nerves from the heart, but also by various non-cardiac baroreceptors which may become paradoxically active. This response may occur during regional anaesthesia, haemorrhage or supine inferior vena cava compression in pregnancy; these factors are additive when combined. In these circumstances hypotension may be more severe than that caused by bradycardia alone, because of unappreciated vasodilation. Treatment includes the restoration of venous return and correction of absolute blood volume deficits. Ephedrine is the most logical choice of single drug to correct the changes because of its combined action on the heart and peripheral blood vessels. Epinephrine must be used early in established cardiac arrest, especially after high regional anaesthesia.

show abstract

“…Spinal anaesthesia allows relative hypovolaemia to develop in the torso by shifting blood to the legs in healthy volunteers 15 and in patients with cardiac disease. 16 The preferential distribution of infused¯uid to the central plasma volume, together with the slower transport of¯uid to a more remote body¯uid space, is a meaningful adaptation, as infused¯uid then restores cardiac preload more effectively.…”

Section: Figmentioning

confidence: 99%

Volume kinetics of Ringer's solution during induction of spinal and general anaesthesia

Ewaldsson

Hahn

2001

British Journal of Anaesthesia

View full text Add to dashboard Cite

The kinetics of an i.v. infusion of 20 ml x kg(-1) of Ringer's solution over 60 min was studied in patients undergoing spinal (n=10) and general (n=10) anaesthesia. The induction resulted in similar changes in volume kinetic parameters in both groups. When a one-volume model was employed (n=8), however, the infusion expanded a smaller body fluid space in the four patients who had received preoperative enteric lavage (3.3 vs 8.3 litres), which is consistent with hypovolaemia. When a two-volume model was statistically justified (n=12), the induction reduced the rate of fluid equilibration between a fairly small central (V1, mean 1.4 litres) and a peripheral body fluid space by about 50% (P<0.01). The kinetic analysis suggested that a rapid fluid load of 350 ml given over 2 min just after the induction could possibly prevent arterial hypotension because of central hypovolaemia. This was confirmed in five additional patients.

show abstract

Peridural Anesthesia and the Distribution of Blood in Supine Humans

Cited by 100 publications

References 0 publications

A definition of normovolaemia and consequences for cardiovascular control during orthostatic and environmental stress

A definition of normovolaemia and consequences for cardiovascular control during orthostatic and environmental stress

Perioperative bradycardia and asystole: relationship to vasovagal syncope and the Bezold–Jarisch reflex

Volume kinetics of Ringer's solution during induction of spinal and general anaesthesia

Contact Info

Product

Resources

About