Review for 10.1186/s12876-018-0897-5 (2018)

Revie wer’s report  
 
Title: Dexmedetomidine is safe and reduces the additional  dose of midazolam for sedation 
during Endoscopic retrograde cholangiopancreatography in very elderly patients  
 
Version: 0 Date: 20 May 2018  
 
Reviewer: Daisuke Masuda  
 
Reviewer's report:  
 
Authors described the usefulness of dexmetomidine during ERCP for very elderly patients.  In 
this study, authors showed that the combined use of DEX was found to significantly reduce the 
amount of midazolam, resulting in a decrease in the frequency of respiratory suppression events 
in very elderly patients undergoing ERCP.  In addition, they showed although DEX tended to 
lower the minimum blood pressure and heart rate during examination, complications related to 
serious circulatory dynamics did not occur.   
 
 
In this study, authors demonstrated for the first time that the combined use of DEX with low 
respiratory depression was effective and safe for ERCP in very elderly patients.  
 
 
In this results, the minimum systolic blood pressure and heart rate during and after the 
examination decreased significantly with DEX when compared to that with conventional 
sedation.  Authors described that although catecholamine and atropine were used in some 
patients, the blood pressure and heart rate recovered promptly after discontinuing the 
administration of DEX, and there was no serious respiratory or circulatory failur e that would 
cause clinical problems during the recovery period in the all patients.   Why occurred decrease of 
systolic blood pressure and heart rate after examination in DEX group, even if discontinuing 
DEX.   
 
 
Systolic blood pressure in patients using m idazolam only is also more promptly recovered in 
DEX patients in this results although amount of midazolam were decreased in DEX group.  
Using DEX is thought to be more safe than propofol or midazolam during ERCP for elderly 
patients?  
 
 
 What of dexmetomidi ne was thought to result in reduce of respiratory depression?  Authors 
think simply reduce amount of using  midazolam in DEX group?  
 
 
 
 
 
Are the methods appropriate and well described?  
If not, please specify what is required in your comments to the authors.  
 
Yes 
 
Does the work include the necessary controls?  
If not, please specify which controls are required in your comments to the authors.  
 
Yes 
 
Are the conclusions drawn adequately supported by the data shown?  
If not, please explain in your comments to the authors.  
 
Yes 
 
Are you able to assess any statistics in the manuscript or would you re commend an 
additional statistical review?  
If an additional statistical review is recommended, please speci fy what aspects require further 
assessment in your comments to the editors.  
 
I am able to assess the statistics  
 
Quality of written English  
Please indic ate the quality of language in the manuscript:  
 
Not suitable for publication unless extensively edited  
 
Declaration of competing interests  
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