Comment on: “Priming with different doses of metoclopramide preceded by tourniquet alleviates propofol induced pain: A comparative study with lidocaine”

Dear Editor of Egyptian Journal of Anaesthesia,

I read an interesting article published in the July 2018 issue [1]. This study had compared the effects various doses of Metoclopramide with lidocaine in reducing the pain during propofol injection [1]. The article was informative.

I wish to make some comments on that article [1]. In the abstract as well as in the results section the authors had stated that “174 patients (54.4%) had no pain, 94 patients (29.4%) had mild pain and only 68 patients (21.25%) had moderate pain, while no patient had severe injection pain during initiation of trial dose injection”. The point of contention here is that the total number of patients become 336 [174 + 94 + 68], whereas, the total number of patients in the study was 320 only as per the consort flow chart. The total percentage mentioned in the brackets also exceeds hundred. However, the total calculation as well as the percentage is correct with regard to the other parameter i.e., “Pain at the end of the total trial drug injection”. Further, on closer observation, I found that the total number of patients in the Metoclopramide group 3 [Group M₃] is 96 with regard to initiation of propofol injection, whereas it is 80 with regard to “end of trial injection” as per the Table 3 of the article [1]. I am not sure whether this disparity in the numbers would have affected the statistical analyses or not. Furthermore, there is confusion with regard to the total number of patients as per the Table 1 of the article [1]. According to Table 1, the total number of patients becomes 160 only with regard to two parameters i.e ASA status and sex of the subjects. To add confusion, the sex ratio (male: female) is mentioned as 120:40. However, if we calculate the total of male versus female patients, it becomes 110:50.

I also have some concerns with regard to citation of one reference in the article [1]. The study by Fujii Y, Nakayama M, published in the year 2005, had been retracted by the concerned journal in the year 2013 [2]. It is unfortunate that the retracted article was cited in the current study [1], despite its retraction notice issued five years ago. In addition, many other articles by the author Fujii Y and coauthors [cited as references in the current study] were retracted a few months ago [3]. However, as the current study [1] was accepted and published before this notice of retraction [3], the authors cannot be held responsible with regard to citation of those articles.

In the Discussion section also the authors had misquoted the reference number 24, instead of reference number 16 [“These finding go in hand with Fujii & Nakayama [24] found the combination of lidocaine/metoclopramide is more effective than lidocaine alone for reducing pain on injection of propofol in a peripheral vein.”], in addition to forgetting that it was in contradiction to the previous sentence.

Disclosure statement

No potential conflict of interest was reported by the author.