Fig. 3From: Intrathecal magnesium sulfate does not reduce the ED50 of intrathecal hyperbaric bupivacaine for cesarean delivery in healthy parturients: a prospective, double blinded, randomized dose-response trial using the sequential allocation methodDuration of spinal anesthesia. Cumulative percentages of patient remaining no pain after spinal injection in patients with “effective anesthesia” in the Magnesium group (solid line, red area) and in the Control group (dotted line, blue area), obtained using the Kaplan–Meier survival analysis. Log-rank differences between the two groups were significant (P < 0.001)Back to article page