Table 2 Search strategy of PubMed for randomized control trials

 #1

“The elderly” [tiab]

 #2

“The old man” [tiab]

 #3

“The old patient” [tiab] OR “The elderly patients” [tiab]

 #4

“The aged” [tiab] OR “The greybeard” [tiab]

 #5

#1 OR #2 OR #3 OR #4

 #6

“Intraoperative sedation” [Mesh] OR “Intraoperative anesthesia” [Mesh] OR “Intraoperative analgesia” [Mesh]

 #7

“Surgical sedation” [tiab]

 #8

“Surgical anesthesia” [tiab] OR “Surgical analgesia” [tiab]

 #9

#6 OR #7 OR #8

 #10

#5 AND #9

 #11

“Dexmedetomidine” [Mesh]

 #12

“Dexmedetomidine hydrochloride” [tiab] OR “Hydrochloride, dexmedetomidine” [tiab] OR “Dexmedetomidine” [tiab]

 #13

#11 OR #12

 #14

“Midazolam” [Mesh]

 #15

“Benzodiazepine” [tiab] OR “Benzodiazepines” [tiab]

 #16

“Azepines” [tiab]

 #17

“Hydrochloride, midazolam” [tiab] OR “Midazolam hydrochloride” [tiab]

 #18

“Midazolam maleate” [tiab] OR “Maleate, midazolam”

 #19

#14 OR #15 OR #16 OR #17 OR #18

 #20

“Randomized controlled trial” [pt]

 #21

“Controlled clinical trial” [pt]

 #22

“Randomized” [tiab] OR “randomly” [tiab] OR “trial” [tiab] OR “groups” [tiab]

 #23

#20 OR #21 OR #22

 #24

#10 AND #13 AND #19 AND #23