The number of subjects did not meet the requirements

It is commonly recommended that patients should refrain from driving for 24 hours after sedation for endoscopy，however，this recommendation has been queried recently．To investigate the effect of sedation on early postoperative cognitive function in patients undergoing endoscopy.

One hundred adult patients undergoing sedative esophagogastroduodenoscopy ( EGD) were randomly recruited，and another 100 adult patients undergoing conventional（without sedation） EGD were served as controls． All patients had an education level more than 9 years． Cognitive function was assessed by Montreal Cognitive Assessment（MoCA）1 week before EGD exam, 10 mins before propofol sedation or the beginning of endoscopic procedure, 30mins after EGD exam, and 2 week after exam.

Inclusion Criteria:

1. The scores of MMSE are more than 26.
2. The AHA grade I and II.

Exclusion Criteria:

1. The AHA grade III, IV or V.
2. binge drinking.
3. Take sedatives, sleeping agents and some drug which may affect the study in a month.
4. Psychiatric disorders.
5. The dysfunction of heart, lung, liver and kidney.

Radom select patients who undergo EGD in Renji Hospital, School of Medicine, Shanghai Jiaotong University. Patients who are recruited all received nine year compulsory education and fit for the inclusion criteria. Moreover, all patients received approval from the local institutional review board.