Fig. 3From: Real-time evaluation of the independent analgesic efficacy of dexmedetomidineThe population pyramid for the total frequency of hypoxemia in the dexmedetomidine (DEX) and midazolam (MID) groups. The distribution of hypoxemia in the DEX and MID groups was different as assessed by visual inspection of the population pyramids. The Mann–Whitney U test reflects the occurrence of hypoxemiaBack to article page