Growth of Microorganisms in Propofol, Thiopental, and a 1

Abstract

To assess and compare the growth of four microorganisms in solutions of intravenous anesthetics, known quanta of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans were inoculated into propofol, thiopental, a 1:1 mixture of propofol and thiopental, and normal saline. All microorganisms were taken from standard stock cultures and incubated for 24 h (48 h for C. albicans). Growth of microorganism in each drug was compared by counting the number of colony forming units (CFUs) grown from a subculture of each inoculated anesthetic at 0, 3, 6, 12, and 24 h. The study shows that propofol strongly supports the growth of E. coli and C. albicans but is bacteriostatic toward S. aureus and weakly bactericidal toward P. aeruginosa. In contrast, both thiopental and the 1:1 mixture of propofol and thiopental behaved differently, exhibiting markedly bactericidal properties toward E. coli, S. aureus, and P. aeruginosa and a bacteriostatic effect on C. albicans. This finding supports recommendations that a strict aseptic technique should be used when handling propofol and that the contents of an ampoule should be used within 6 h of aspirating. The measured high pH of both thiopental and the 1:1 mixture of propofol and thiopental compared to propofol alone suggests pH to be a major factor in determining whether a given drug will support microbial growth.

Patient Outcomes After Axillary Lymph Node Dissection for Breast Cancer: Use of Postoperative Continuous Local Anesthesia Infusion

“…The literature contains numerous reports regarding the bactericidal and bacteriostatic properties of injectable and topical local anesthetics [45][46][47][48], however we were concerned whether chronic infusion of study drug would increase the likelihood of wound infection. None of the patients in the study experienced surgical site or catheter insertion site infections.…”

A Novel, Lipid-Free Nanodispersion Formulation of Propofol and Its Characterization

“…The key component, soybean oil, can cause lipid overload in those patients who are infused for a long duration (>3 days) of the formulation (5)(6)(7)(8)(9). The lipid emulsions support microbial growth, and they have to be handled under strict aseptic conditions to avoid bacterial contamination (10)(11)(12). Also, the emulsions need to be stored under controlled temperatures (4-22°C) (9).…”

Microbial contamination of syringes during preparation: The direct influence of environmental cleanliness and risk manipulations on end-product quality

“…It is well-known that the contamination of syringes may increase the risk P R A C t i C e R e P O R t Am J Health-Syst Pharm-Vol 66 Nov 15, 2009 of infection, and several serious cases of such infection have been reported in the literature. [2][3][4][5][6][7][8][9][10][11][12][13] To minimize the risk of end-product contamination, United States Pharmacopeia (USP) chapter 797 requirements limit the storage of drugs in prefilled syringes to a one-hour period. 14 The two main factors that contribute to microbial contamination of drugs are the cleanliness of the work environment and the competency and care of the operator; however, no published data have quantified their respective impact.…”