648. Renal Toxicity Related to Antibiotic-Containing Orthopedic Cement
Session: Poster Abstract Session: Pharmacokinetics and Adverse Drug Reactions
Friday, October 21, 2011
Room: Poster Hall B1
Background: It is common practice to load antibiotics into orthopedic cement for some procedures to prevent or treat infection, particularly during two-stage revision of an infected prosthetic joint. In order to achieve longer elution times, the doses of aminoglycosides (AG) have been increased to over 6 g of tobramycin in an antibiotic spacer. There is very little known about the toxicity of this approach. Methods: We reviewed 109 treatments of 89 patients who had antibiotic-containing cement (ACC) placed in procedures between 2004 and March 2011. Through chart review we identified factors including the total dose of antibiotic used, as well as the creatinine prior to surgery, in the month following surgery, and in the period until the cement was removed or 1 year if not removed. Change in renal function was expressed as the ratio of the peak creatinine after to the level immediately before surgery (CR). Results: Doses of aminoglycosides (gentamicin and tobramycin) ranged from 0.5 to 19.2 g; in 13 treatments only vancomycin was used. Where creatinines were measured before and after surgery, 46 of 99 (46%, 95% binomial confidence interval 36 to 57%) episodes were associated with some acute kidney injury (AKI) (CR > 1.2). In cases where an AG was used, 10 of 88 had severe AKI (CR 2.0 in 11%, CI 6-20%), 5 had moderate AKI (CR 1.5-1.99 in 6%, CI 2-13%) and 28 had mild AKI (CR 1.2-1.5 in 32%, CI 22 - 43%). AG doses were significantly correlated with greater renal toxicity by logistic regression (P = 0.007). Though most cases recovered normal renal function, one patient remains on permanent hemodialysis. Conclusion: There is a dose related toxicity of aminoglycosides used in orthopedic cement. Caution should be used in including AG in antibiotic-containing cement.

Subject Category: N. Hospital-acquired and surgical infections, infection control, and health outcomes including general public health and health services research

Mark Shelly, MD1,2, Judianne Slish, Pharm. D., BCPS3, Lynne Brown, RN, MBA1, Polly Moore, RN1, Melissa Schiff, MD1 and Gail Quinlan, RN, MSN4, (1)Highland Hospital, Rochester, NY, (2)University of Rochester Medical Center, Rocheseter, NY, (3)St. John Fisher School of Pharmacy, Rochester, NY, (4)University of Rochester Medical Center, Rochester, NY

Disclosures:

M. Shelly, None

J. Slish, None

L. Brown, None

P. Moore, None

M. Schiff, None

G. Quinlan, None

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