Blood Pressure Response and Plasma Fentanyl Concentrations during High-and Very High-Dose Fentanyl Anesthesia for Coronary Artery Surgery

Clinical applications of fentanyl pharmacokinetics and pharmacodynamics: roles of fentanyl in anesthesia

“…However, the lack of circulatory depression turned out to be disadvantageous in relatively robust patients undergoing coronary artery surgery. Hypertension associated with opioid anesthesia and surgical stimulation was not completely controlled by increasing the dose [26]. Respiratory depression associated with opioid anesthesia was both a disadvantage and an advantage.…”

Inhibitory Effect of Fentanyl on Phenylephrine-Induced Contraction of the Rat Aorta

“…Fentanyl significantly attenuated phenylephrine-induced contraction at concentrations of 10 -6 and 3×10 -6 M, which are higher than clinically relevant concentration (9.52×10 -8 M) 3. However, the rapid redistribution of fentanyl (octanol: water partition coefficient = 813) to lipid-rich tissue may create a discrepancy between the serum concentration and actual tissue concentration 31.…”

“…Any clinical implications of fentanyl on regional hemodynamics must be tempered by the fact that a large conduit artery, the aorta, was used in this in vitro experiment, whereas the resistance vessels with the arterioles of a diameter of 100-300 µm control most organ blood flow 30. Even with these limitations, since 3×10 -7 M fentanyl (plasma fentanyl concentration 100 µg/mL) did not alter phenylephrine-induced contraction, the indirect mechanism for vasodilation, which is mediated by decreased central sympathetic outflow induced by fentanyl, might be involved in the hypotension observed in the previous in vivo studies 1-3,27…”

“…Fentanyl administered intravenously at the clinical dose (4.5 µg/kg) has been shown to slightly decrease systemic blood pressure and vascular resistance, whereas high doses (40-160 µg/kg) have been shown to significantly decrease mean peripheral blood pressure 1,2. In addition, the hypotension produced by high-dose fentanyl (75 µg/kg) is associated with an increased need for the use of alpha-adrenergic agonists to maintain blood pressure 3. Fentanyl has been shown to inhibit the α 1 -adrenoceptor agonist-induced contraction in isolated aorta and pulmonary arteries 4-6…”

Role of reninangiotensin system in cardiopulmonary bypass hypertension

“…t~ Furthermore, the incidcnce of hypertension can be correlated with plasma fentanyl concentration. 13 In the present study patients were anaesthetized with high dose fentanyi and ventilated with 100 per cent oxygen. A non-pulsatile pump was used during CPB despite earlier reports that this might encourage the development of hypertension 14 and stimulate renin release.…”