A retrospective study comparing adverse events usin bismuth iodform paraffin paste (BIPP) and Xeroform as dressings for newly fashioned mastoid cavities after mastoidectomy was undertaken. There were 20 patients in each group. Adverse events were defined as offensive packs, mastoid caivity infection and systemic signs of infection. There were no adverse using BIPP packs Whether or not prophylactic antibiotics were used. Xeroform packs were associated with a significantly higher incidence of adverse events compared to BIPP when using on antibiotic porphylaxis (P<0.005) or amoxycillin (P<0.005). Adverse events with Xeroform packs were abolished using ciprofloxacin and metronidazole prophylaxis. We conclude that BIPP is the mastoid dressing of choice.

Bismuth subnitrate, one of the constituents of BIPP is known to cause methaemoglobinaemia. Ten patients had blood estimations for methaemoglobin levels before and after nasal packing with BIPP impregnated gauze. Only one patient exhibited abnormal levels of methaemoglobin and this was most probably the result of the large quantity of BIPP used. It is unlikely that significant methaemoglobinaemia occurs during the routine use of BIPP in the nose.