To the Editor: We read with interest the “Diagnostic Dilemma” by Peter et al.1 The case raises interesting management issues. The first is initiation of antibiotics. Despite 1 week of fever, rigors, haematuria and loin pain, we are informed that the patient was in no distress at initial assessment. In this situation there is, despite the anxieties of resident staff, no urgent need to administer antibiotics; hospitals are controlled, monitored environments in which observation, review and investigation can be undertaken, within reason, if a diagnosis is not immediately made. The second issue is antibiotic selection. The provisional diagnosis was a urinary tract infection, and ceftriaxone and gentamicin were administered. The justification for the use of two agents with a similar spectrum of antimicrobial activity is not given.2 Likewise, no justification is given for the use of a potent nephrotoxin in the presence of moderately severe acute renal failure.

Flucloxacillin was added “to broaden the gram-positive antibiotic cover”. It is not apparent why staphylococcal cover was sought at this stage. All cultures (blood, urine and pleural fluid) remained negative. At Day 14, ceftriaxone and gentamicin were changed to ticarcillin/clavulanic acid and ciprofloxacin “because of persistent fever and rising [white cell count]”; this decision in the absence of positive cultures is not explained.

The patient’s renal function deteriorated further and he became profoundly acidotic. In fact, the patient’s renal function had performed heroically, given administration of gentamicin for 2 weeks in the presence of acute renal failure at admission. In the intensive care unit, flucloxacillin was replaced with vancomycin; the rationale is not explained.

This case illustrates important points regarding antibiotic use. Despite significant renal impairment at admission, the patient was administered a 2-week course of a nephrotoxic antibiotic, which contributed to renal collapse. This situation would have been terminal if not for supportive intensive care. The treating team appears to have managed the patient as if sepsis were a given, and yet all cultures remained negative. This illustrates a basic but crucial teaching point — fevers, chills, rigors, raised inflammatory markers and neutrophilia do not necessarily equate with sepsis. If this experience reflects routine practice elsewhere (and it is our experience that it does), is it any wonder that we have reached an era in which we now encounter organisms so resistant that they are essentially untreatable?3

In reply: Boyd and Hedger have raised concerns regarding the initiation and choice of antibiotics in our recent case report.1 Several aspects of this correspondence need to be addressed. The primary focus of the article was to highlight an important and probably underrecognised cause of unexplained metabolic acidosis, and discussion regarding antibiotic choice was not within the scope of the article.

Further, the patient’s management before admission to the intensive care unit was by a different treating team. Subsequent case-note review did not reveal reasons for initiation or choice of antibiotics other than described in our article, although it was evident that gentamicin doses were adjusted based on drug levels. We agree that a less nephrotoxic agent could have been chosen and that the profligate use of antibiotics in the absence of strong evidence of infection could have been avoided.

The excessive use of antibiotics in the current medical milieu may stem from a physician’s lack of confidence, or even legal ramifications of “watching and waiting” in the setting of “fevers, chills, rigors, raised inflammatory markers and neutrophilia”, as encountered in our patient.