Endogenous Vasopressin and Renin-Angiotensin Systems Support Blood Pressure after Epidural Block in Humans

Hemodynamic effects of angiotensin inhibitors in elderly hypertensives undergoing total knee arthroplasty under regional anesthesia

“…ACEIs and ARBs are first line antihypertensives which act via inhibition of the renin-angiotensin system and cause both reduced venous return and arterial vasodilatation. 3 ACEI and ARB interference with the renin-angiotensin system, a main determinant of blood pressure stability, 8 compounds the effects of epidural anesthesia on lowering blood pressure. Also, both chronic ACEI use and epidural anesthesia have effects on cardiac function, altering the heart's ability to compensate for acute reductions in preload.…”

“…This effect poses unique concerns for patients chronically treated with ACEIs and ARBs for two reasons. First, hemodynamic stability during epidural induced hypotension is largely maintained by the interplay of the renin-angiotensin, sympathetic and vasopressin systems, 3,8 and secondly, intraoperative hypotension compounded by preoperative fasting is a risk factor for stroke 9 and cardiac ischemia which may occur silently in the anesthetized patient. 10 Importantly, perioperative use of ACEIs and ARBs has been associated with early postinduction hypotension requiring the use of vasopressors in vascular and general surgery patients under general anesthesia.…”

Role of vasopressin in current anesthetic practice

“…Epidural anesthesia (up to T2) often causes only a small decrease in blood pressure despite the widespread sympathetic block, even in the presence of an angiotensin-converting enzyme inhibitor (ACEI); however, additional blockade of V 1 receptors with a vasopressin antagonist produces profound hypotension [26]. In fact, AVP is a backup system for blood pressure control and cardiovascular sympathetic modulation.…”

“…Thus, renin release in response to hypotension may also be abolished, while AVP concentrations increase [2644]. Consequently, patients with epidural anesthesia are at risk of hypotension, where exogenous AVP and TP may be suitable vasopressors.…”

Analgosedierung mit (S)-Ketamin/Propofol vs. (S)-Ketamin/Midazolam: Steuerbarkeit, Stressreaktion und Hämodynamik - Eine kontrollierte Anwendungsbeobachtung bei operativen Intensivpatienten

“…auch zu vergleichbaren EEG-Veränderungen führen.Die endokrinen Stressparameter lagen initial in beiden Kollektiven deutlich über dem Normalbereich und belegen damit den bekannten postoperativen Stresszustand[18]. Die höheren Konzentrationen von Noradrenalin, ADH und Cortisol im SK/ M-Kollektiv sind vor allem durch den nicht randomisierten Untersuchungsansatz zu erklären, wonach die initial kreislaufinstabilen Patienten der SK/M-Gruppe zugeordnet wurden.Neben den höheren Noradrenalin-Konzentrationen können auch ADH[19] und Cortisol[20] zur Blutdruckstabilisierung beitragen, wobei die entsprechenden Zusammenhänge nicht vollständig geklärt sind. Die durchgehend niedrigeren Noradrenalin-Konzentrationen im SK/P-Kollektiv beruhen auf der Propofol-induzierten Verminderung der peripheren Noradrenalin-Freisetzung[21], die als entscheidende Ursache der kreislaufdepressiven Substanzeffekte gilt.…”