The relationship between pressure and volume when using Rapid Rhino(r) packs in the management of epistaxis.

Despite the popularity of Rapid Rhino packs, there are no clear guidelines regarding the volume of air to be inflated when used in the management of epistaxis. The manufacturers suggest that subjective assessment by pilot cuff palpation is used to guide inflation. However, studies have clearly demonstrated that clinicians are poor at judging balloon pressure by pilot cuff palpation when used in other settings. Our objective was to investigate the relationship between the volume of air inflated and the resultant intra-nasal pressure generated by nasal balloon packing. Twelve healthy subjects were packed with 5.5 cm Rapid Rhino packs, which were connected to a manometer and 20 ml syringe via a 3-way tap in a closed circuit. Increments of 2.5 mls of air were inflated and the resultant intra-nasal pack pressure was measured. There appeared to be a linear relationship between increasing volume and pack pressure. However, between individuals, there was a large variation in the intra-nasal pack pressure produced for a given fixed volume of air inflated. This is presumably due to variations in nasal anatomy. It may be that a manometer-measured, pressure guided nasal pack inflation technique would represent best practice, especially for less experienced staff.