A clinical and microbiological study of venous catheterization.

In a prospective study of 210 intravenous catheters and needles 31 (15%) swabs yielded 34 microbial isolates. Twenty-eight were "non-pathogenic" skin commensals and six were "pathogenic" organisms. Commensals were isolated predominantly from catheters left in situ for only a short time (up to two days) and pathogenic organisms most frequently from specimens left in situ for a longer time. Correlation was not confirmed between colonization and infection, antibiotic therapy or phlebitis. All samples of IV fluids were sterile on culture. Changing the IV catheter at least every two days is recommended.