Epidural phenylephrine attenuates hypotension induced by alkalinized lidocaine epidural anesthesia

In this double-blinded, randomized study, we examined the hemodynamic effects of lumbar epidural injection of alkalinized lidocaine with phenylephrine in 81 patients undergoing inguinal herniorrhaphy. Patients assigned to four equal groups received 20 mL of alkalinized lidocaine (17 mL of 2% lidocaine + 3 mL of 7% sodium bicarbonate) with one of four doses of phenylephrine: 0 (Group 1), 50 (Group 2), 100 (Group 3), or 200 microg (Group 4) injected via a lumbar epidural catheter. Blood pressure, heart rate, and skin temperature on the foot were recorded every 5 min for 1 h after injection and were compared among groups. Hypotension was defined as mean arterial pressure < 80% of baseline. The incidence of hypotension was 45%, 55%, 35%, and 15% in Groups 1-4, respectively. Patients in Group 4 showed the smallest reduction in blood pressure compared with Groups 1 and 2 (one-sided Fisher's exact test, P < 0.05). We conclude that the 200-microg dose of epidural phenylephrine (1:100,000 concentration) reduced the incidence of hypotension after epidural anesthesia with alkalinized lidocaine.

Hypotension after epidural anesthesia is common in general clinical practice. Phenylephrine administered epidurally in combination with alkalinized lidocaine may reduce the incidence of hypotension.