Nasotracheal and orotracheal intubation are both associated with a about a 12% incidence of bacteremia but this may not be clinically significant

Valdes et al did a prospective study of 110 patients undergoing surgery under general anesthesia.  Venous blood samples were obtained before and then 30 seconds after intubation.  Bacteremia after tracheal intubation was detected in 6 of 50 patients who had orotracheal intubation and 7 of 60 patients after nasotracheal intubation.  Seven of the isolates (54%) were resistant to oxicillin.  Two patients had positive pre intubation blood cultures.  The authors discuss the controversy concerning the need of antibiotic prophylaxis for tracheal intubation in patients at risk for bacterial endocarditis.  They suggest that antibiotic prophylaxis should be considered after both orotracheal and nasotracheal intubation.  Valdes C et al: The incidence of bacteraemia associated with tracheal intubation.  Anaesthesia 2008;63:588-592.

PJ Brennan, an infectious disease specialist at the University of Pennsylvania raises concerns about the potential conclusions of this article. “I just want to note that bacteremia after events involving disturbance of colonized mucosal surfaces results in transient bacteremia very frequently. Dental procedures are best known for such events but many other procedures including tooth brushing, endoscopy, bowel movements and child birth are all associated with the common occurrence of bacteremia – most of these are reported to be more common than the incidence reported here after intubation. I suspect that any interruption of a mucosal surface, however minor, can cause bacteremia. The key issue is the incidence of endovascular infection after such events. In all other settings bacteremia is transient and the establishment of an endovascular infection is rare. The factors in determining prophylaxis include not only the bacteremia, which is a given, but the cardiovascular risk as well. I would not want to see this become a practice we adopt given the frequency of the index event (intubation), the infrequent nature of the adverse event (endovascular infection), the tenuous cause and effect association and the hazard of antibiotics and drug resistance.”

PJ Brennan M.D. is Professor of Medicine, Division of Infectious Diseases and Chief Medical Officer for UPHS.

David S. Smith, M.D., Ph.D.