Update your MSSA bacteremia protocols
As a clinical pharmacist, you will see more interest in utilizing Staphylococcus aureus bacteremia protocols. It's the most common nosocomial bacteremia and may lead to death in up to 40% of patients. Now new evidence suggests that closer adherence to the guidelines is associated with reduced in-hospital mortality. Follow these steps...
Work with medical staff and nurses to create standardized protocols. Use prepopulated orders instead of check boxes to help ensure adherence. Start most patients on vancomycin (see table 1) to empirically cover for MRSA. Aim for trough levels of 15 to 20 mcg/mL. If cultures show MSSA, switch to a beta-lactam, such as cefazolin, for more narrow AND effective coverage. Use at least 6 grams of cefazolin per day, such as 2 grams IV every 8 hours adjusted as needed for renal function. Advocate for automatic pharmacy consults for surveillance and antibiotic dosing.
| Table (1). Approach to vancomycin dosing for adults with normal kidney function | |
|---|---|
| DOSE | COMMENT |
| Loading dose for patients with known or suspected severe Staphylococcus aureus infection | Load 20 to 35 mg/kg (based on actual body weight, rounded to the nearest 250 mg increment; not to exceed 3000 mg). Within this range, we use a higher dose for critically ill patients; we use a lower dose for patients who are obese and/or are receiving vancomycin via continuous infusion. |
| Initial maintenance dose and interval | Typically 15 to 20 mg/kg every 8 to 12 hours for most patients (based on actual body weight, rounded to the nearest 250 mg increment). |
| Subsequent dose and interval adjustments | Based on AUC-guided (preferred for severe infection) or trough-guided serum concentration monitoring. |
| + Read our note, "Monitor VANCOMYCIN with AUC/MIC goals". | |
Redraw blood cultures in 2-4 days, even if the patient is improving to document clearance of the bacteremia. If repeat cultures remain positive, evaluate the susceptibility data, antibiotic dosing and possible source of infection. Adjust therapy accordingly. Consider protocol-based redraws to assist with adherence.
Treat UNcomplicated bacteremia for at least 14 days and complicated bacteremia for at least 28 days. Some experts suggest that day one of antibiotic duration is the day of the first negative culture result NOT the first day of therapy. Review the need for automatic case management or social work consults to evaluate outpatient therapy options. Consider an echo to rule out endocarditis, because it is the source in about 10% of patients. If endocarditis is confirmed, treat with IV antibiotics for 6 weeks. Continually evaluate the effectiveness of your Staphylococcus aureus bacteremia protocol. Adjust procedures as needed to improve adherence and patient outcomes.
REFERENCES
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Bai AD, Showler A, Burry L, Steinberg M, Ricciuto DR, Fernandes T, Chiu A, Raybardhan S, Science M, Fernando E, Tomlinson G, Bell CM, Morris AM. Impact of Infectious Disease Consultation on Quality of Care, Mortality, and Length of Stay in Staphylococcus aureus Bacteremia: Results From a Large Multicenter Cohort Study. Clin Infect Dis. 2015 May 15;60(10):1451-61. Available at: https://academic.oup.com/cid/article/60/10/1451/338895?login=false
Liu C, Bayer A, Cosgrove SE, Daum RS, Fridkin SK, Gorwitz RJ, Kaplan SL, Karchmer AW, Levine DP, Murray BE, J Rybak M, Talan DA, Chambers HF; Infectious Diseases Society of America. Clinical practice guidelines by the infectious diseases society of america for the treatment of methicillin-resistant Staphylococcus aureus infections in adults and children. Clin Infect Dis. 2011 Feb 1;52(3):e18-55. Available at: https://academic.oup.com/cid/article/52/3/e18/306145?login=false
