Background: There has been a recent increase in the number of reported cases of acute renal failure (ARF) in cystic fibrosis (CF). We conducted a case control study to determine the factors which are associated with an increased risk of ARF.
Methods: Our initial survey confirmed 24 cases of ARF, in CF patients from 20 UK CF Centres, presenting between 1997 & 2004. Using the UK CF database, we identified sex and age matched controls. Informed consent was sought from the control patients / parents for access to the case notes. Analysis of risk factors was by conditional logistic regression and Mantel Haenzsel analysis, using Stata (version 9).
Results: In the group of patients with ARF, 21/24 had received an aminoglycoside at the time of their episode of ARF or in the preceding week, compared with only 3/42 controls for the same time period (OR 81.8, 95% CI 4.7 to 1427, p<0.001). In the year prior to the episode of ARF, significantly more cases than controls received gentamicin (19/24 cases vs. 1/42 controls, p<0.001). The numbers receiving tobramycin were similar (9/24 cases vs. 15/42 controls, p=0.9). A known risk factor for renal impairment (prior renal disease, acute dehydration or long term nephrotoxic drug treatment) was present in 18/24 cases & 7/42 controls (OR 24.0, 95% CI 3.1 to 186.6, p = 0.002).
Conclusions: In CF patients, the use of an intravenous aminoglycoside is a risk factor for ARF and gentamicin is more nephrotoxic than tobramycin. The majority of patients who develop ARF have a risk factor which necessitates withholding aminoglycosides or more closely monitoring their use.
- acute renal failure
- cystic fibrosis