Complications of Sedation for Endoscopy

Daniel J. Bjorkman, MD, MSPH(HAS), SM(Epid.)


Major complications occurred in 1 out of 10,000 procedures in a large prospective


Most adverse events during endoscopy are due to sedation. To prospectively assess risk for complications during endoscopy, researchers analyzed data from more than 350,000 endoscopies conducted across dozens of centers in Germany.


Sedation was used in 89% of procedures. Propofol alone was used in 62% and propofol in combination with midazolam in 23%. Half of the procedures were done with two-person teams and the other half with three-person teams in which one person was responsible only for sedation. Results were as


  • Major complications occurred in 0.01% and minor complications in 0.3% of patients with sedation, compared with 0.007% and 0.05%, respectively, in unsedated patients.
  • Mortality was 0.004% with sedation and 0.002% without sedation.
  • Of the minor complications, 33% were respiratory and 12% were hypotension.
  • Only 6% of patients with respiratory complications required mask ventilation.
  • Of the 38 patients with major complications, 26 required intubation and 13 died.
  • Risk factors for complications of sedation included American Society of Anesthesiologists class >2, emergency or therapeutic endoscopy, longer duration of endoscopy, and three-person clinical teams.
  • Colonoscopy, endoscopic retrograde cholangiopancreatography, and endoscopic ultrasound were each associated with a lower risk for complications compared with upper endoscopy.

  • The use of propofol alone was associated with a lower risk for complications compared with midazolam alone.

    This is the largest prospective study of endoscopy complications performed to date. However, the method of sedation was not controlled and varied between centers and providers. As the authors note, the increased risk for complications seen with three-person clinical teams likely represents
    selection bias, as high-risk patients and procedures are more likely to have additional personnel. These results are consistent with previous findings showing that serious sedation complications are uncommon
    but still require vigilance, particularly in high-risk patients and procedures.


    Behrens A et al. Acute sedation-associated complications in GI endoscopy (ProSed 2 Study): Results from the prospective multicentre electronic registry of sedation-associated complications. Gut 2015 Jan 3; [e-pub]


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