Fentanyl vs. pethidine as sedation for gastrointestinal endoscopy: Author’s reply to Hayee et al.

Abstract

Sirs, On behalf of the authors, I wanted to write and thank Dr Hayee et al.1 for their interest in our paper2 and congratulate them on their recent publication3 in this area. I would concur that the results of the two studies suggest that the use of fentanyl (as opposed to meperidine (pethidine)) may shorten recovery times. While our difference in recovery time between those receiving fentanyl (63 min) and those receiving meperidine (76.2 min) did not reach conventional levels of statistical significance (P value = 0.07), we do believe that this factor was the main driver of shorter total procedure times observed in our study. Our study size was driven by power calculation. We sought to detect a 10-min difference in total procedure time comparing the two narcotics. The study was not powered to look separately at colonoscopy or oesophagogastroduedonoscopy (EGD) and so it is not surprising that we did not find a statistical difference in procedure time in this subgroup analysis (likely beta error). The trends in both total procedure time and recovery time were similar (favouring fentanyl) across both EGD and colonoscopy suggesting that the observed pharmacological effect was present irrespective of the procedure. Certainly, you could argue that EGD does not require narcotics. Our institutional practice is to combine a narcotic with midazolam for EGD and so that is what we studied. The specifics of how the narcotic and midazolam were dosed are outlined in the methods. There was no standardization. The dosing of the unit equivalents of narcotics or midazolam were left ‘solely to the discretion of the endoscopist based on the patient’s clinical status’. The reported mean doses of narcotic used represent cumulative dose given during the procedures. Finally, with regard to assessment of discomfort, we simply assessed patient pain by VAS score. We could not use nursing assessment of pain as they were not blinded to treatment allocation. Declaration of personal and funding interests: None.