A randomized trial of povidone-iodine compared with iodine tincture for venipuncture site disinfection: effects on rates of blood culture contamination.
BACKGROUND
Contamination of blood cultures creates problems in their interpretation and unneeded resource utilization. Because skin flora comprise the major group of contaminant species, more effective skin disinfection at the venipuncture site could reduce contamination.


METHODS
We performed a randomized trial in adult inpatients at a tertiary care teaching hospital. Antecubital venipuncture sites were randomly disinfected with povidone-iodine or iodine tincture, and blood cultures (two bottles, 10 mL of blood) were drawn by professional phlebotomists. Scoring of contaminant species was restricted to skin flora. Hospital resource utilization was compared among patients with contaminated blood cultures and those with sterile blood cultures.


RESULTS
Of the 3,851 blood cultures collected during the study, 120 (3.1%) were contaminated with skin flora. The contamination rate for blood cultures collected after povidone-iodine was 3.8% (74 of 1,947), compared with a rate of 2.4% (46 of 1,904, P = 0.01) after iodine tincture. The difference in mean total hospital costs for patients with contaminated blood cultures and those with sterile blood cultures was $4,100 (95% confidence interval: $740 to $7,400, P = 0.02).


CONCLUSIONS
Iodine tincture is superior to povidone-iodine for venipuncture site antisepsis before blood culture sampling. Because of the high costs associated with contaminated blood cultures, hospitals should consider switching from povidone-iodine to iodine tincture. Reduction of the contamination rate may improve the quality of patient care and reduce hospital costs.
Little
J R
JR
Division of Infectious Diseases, Washington University School of Medicine, St. Louis, Missouri 63110-1093, USA.
Murray
P R
PR
Traynor
P S
PS
Spitznagel
E
E
D000328:Adult; D000891:Anti-Infective Agents, Local / Q000627:therapeutic use*; D001769:Blood / Q000382:microbiology*; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D007455:Iodine / Q000627:therapeutic use*; D008297:Male; D018962:Phlebotomy / Q000379:methods*; D011205:Povidone / Q000627:therapeutic use*; D012867:Skin / Q000382:microbiology*; D016896:Treatment Outcome
D000891:Anti-Infective Agents, Local; D007455:Iodine; D011205:Povidone