I read with interest the article by Stangerup et al1 and was particularly astonished by the section entitled "Pain During and After Treatment." The authors mention that phenylephrine hydrochloride and tetracaine were used for anesthesia for the tamponade group, while lidocaine gel alone was used for the hot-water irrigation group.
Experimental design should call for the same anesthesia between groups. Perhaps phenylephrine or tetracaine irritated or altered the nasal mucosa of some patients and accounted for some of the differences seen. Clearly, phenylephrine, a potent vasoconstrictor, could have some effect on bleeding in and of itself. Furthermore, this medication could have caused enough vasoconstriction to be responsible in part for the additional damage observed on rhinoscopy in the tamponade group.
Seidman MD. Hot-Water Irrigation in the Treatment of Posterior Epistaxis. Arch Otolaryngol Head Neck Surg. 1999;125(11):1285. doi: