Fig. 4From: Bilateral posterior Quadratus Lumborum block for pain relief after cesarean delivery: a randomized controlled trialKaplan-Meier plot of time to first request for morphine (pain-free period) at the final analysis, Log-rank test: p = 0.238. Abbreviations: IT, intrathecal; QLB, quadratus lumborum block; IV, intravenous; PCA, patient-controlled analgesia; h, hoursBack to article page