Direct vascular effect of ropivacaine in femoral artery and vein of the dog

TLDR: It is concluded that ropivacaine is a potent vasoconstrictor, although its constrictive effect is slight at 10‐2 mol 1‐1, which may be relevant to the clinical local concentration.

Abstract: A study was conducted to examine the direct vascular effect of ropivacaine, in comparison with the effect of bupivacaine and lidocaine. Changes in tension induced by ropivacaine (10-5-3 × mol 1-1), bupivacaine (10-5-3 times 10-3 mol 1-1) and lidocaine (10-5-10-2 mol 1-1) were examined cumulatively in vascular rings of dog femoral artery and vein under basal tension, or in those which had been precontracted with phenylephrine submaximally in Krebs' bicarbonate solution at 37°C aerated with 95% O2 and 5% CO2 (pH 7.4). The change in tension induced by lo-2 moll-1 ropivacaine was tested under basal tension in vascular rings bathed in HEPES buffer (pH 6.8). Ropivacaine induced greater constriction than bupivacaine at concentrations over 10-5 mol 1-1 in vascular rings under basal tension (P<0.01). The maximal contraction was induced by ropivacaine at mol 1-1, averaging 51.5± 2.8% (n = 11) and 27.0± 3.7% (n= 12) of the maximal contraction induced by epinephrine in the artery and vein, respectively, and the contractions induced by ropivacaine at 10-3 mol 1-1 were 16.3± 2.0% (n=11)and 5.5± 1.1% (n=9), respectively. Phenylephrine (10-6mol 1-1)-precontracted artery was contracted significantly by ropivacaine at 3 times 10-4 mol 1-1 and mol 1-1, and by bupivacaine at 3 times 10-3 mol 1-1, whereas the phenylephrine 10-6mol 1-1)-precontracted vein was relaxed by these anesthetics. Lidocaine did not exert constricting effects. It is concluded that ropivacaine is a potent vasoconstrictor, although its constrictive effect is slight at 10-2 mol 1-1, which may be relevant to the clinical local concentration.