Comment on: Guidelines for the prevention of endocarditis: report of the Working Party of the British Society for Antimicrobial Chemotherapy

Dear Sir, We would like to comment on the recommended prophylactic regimen for nasal packing and nasal intubation contained within the Working Party Guidelines for the prevention of endocarditis. In these guidelines, flucloxacillin or clindamycin is recommended for these procedures when they are performed in patients at risk of endocarditis (not just high-risk individuals singled out for dental prophylaxis). The reference given for this recommendation describes a case of prosthetic valve endocarditis due to Staphylococcus aureus complicating anterior nasal packing for epistaxis in a 69 year old man. Six days prior to admission for S. aureus endocarditis, the man had been treated for 4 days with an anterior nasal pack. A further case of staphylococcal endocarditis complicating septorhinoplasty is described by Coursey. Can we extrapolate from these case reports to say that antibiotic prophylaxis with flucloxacillin is indicated for nasal intubation? Nasal intubation is frequently performed in adults and children both in the ICU setting and in operating theatres. In our paediatric ICU, the predominant method of intubation is nasal, and we estimate that 700 children are intubated via this route each year, at least 40% of whom will have a significant cardiac anomaly. Many of these children are given flucloxacillin as part of their peri-operative prophylaxis, so presumably re-intubations, which are often done urgently, would be covered by this antibiotic or would be expected to use the alternative agent given (clindamycin). This needs to be explicit in the guidelines. Although antibiotic prophylaxis has been advocated by other authors, the actual results presented are not convincing, as many of the positive cultures may have been due to skin contamination. Lockhart et al. assessed the impact of amoxicillin prophylaxis in children after nasal intubation for dental procedures and noted a significant reduction when compared with placebo; S. aureus was not isolated from any patient. Berry et al. noted a 12% incidence of bacteraemia in children; the most common isolates, were alpha-haemolytic streptococci, and again S. aureus was not among the list of organisms isolated from blood cultures drawn at the time of intubation. Bacteraemia does occur during nasal intubation but is mainly due to commensals of the oropharynx and (in some ways) is similar to the bacteraemia observed with dental procedures. The Working Party state that the evidence base for prophylaxis in dental procedures is not strong and that ideally there would be a prospective double-blind trial to evaluate the risk/benefit of prophylactic antibiotics. As this is not possible, because many clinicians would be reluctant to accept the radical, but logical, step of withholding antibiotics, are we right to add another low-risk procedure to the list of indications for prophylaxis? We would recommend that such a trial is performed in patients undergoing nasal intubation before antibiotics are recommended for this procedure. Furthermore, prophylaxis is not recommended by the European Society of Cardiology or the British Cardiac Society.