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Fig. 2 | BMC Anesthesiology

Fig. 2

From: The 50% effective dose of hydromorphone and morphine for epidural analgesia in the hemorrhoidectomy: a double-blind, sequential dose-finding study

Fig. 2

The up-down sequences of administered dose of epidural hydromorphone group (A) and epidural morphine group (B). The patient sequence number (X-axis) is the order of epidural hydromorphone (A) and epidural morphine exposures (B) using the up-down sequential allocation with a biased-coin method. The assigned dose levels are presented on Y-axis. Analgesic “successes” are represented by a point, and analgesic “failures” are represented by a fork. The ED50 was 0.350 mg (95% CI, 0.259–0.376 mg) in hydromorphone group and 1.129 mg (95% CI, 0.903–1.187 mg) in morphine group estimated using isotonic regression and bootstrapping method

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BMC Anesthesiology

ISSN: 1471-2253

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