Inappropriate Antimicrobial Use in the Emergency Department for Skin and Soft Tissue Infections

Acute bacterial skin and skin structure infections (ABSSSIs) remain among the leading reasons patients visit the emergency department (ED). A retrospective study performed between 1997 and 2005 estimated 14.2 million ambulatory visits for skin and soft tissue infections (SSTIs), and the proportion of ED visits increased nearly 4-fold over the duration of the study.¹ Skin and soft tissue infections lead to ABSSSIs, which are characterized by the US Food and Drug Administration as involving lesions with a size area of at least 75 cm.² These lesions can include non-purulent cellulitis, purulent cellulitis, abscesses, and wound infections,³ some of which occur concurrently making it difficult when choosing antimicrobial therapy based on visual assessment alone. Studies have also shown high rates of inappropriate antibiotic prescribing and opportunity for improvement when it comes to ABSSSIs.²

One of the contributing factors to this is the knowledge gap in the understanding of and delivery in care regarding ABSSSIs. In a study evaluating the knowledge and attitudes of emergency room physicians, data showed a positive correlation between diagnosis and management of ABSSSIs and education levels. Of the 103 study participants, 73% had seen at least 2 patients with an ABSSSI diagnosis within the month prior to the survey administration. Practicing physicians answered the survey questions correctly at an average rate of 65.3%, third-year medical residents answered correctly at an average rate of 61.1%, and third-year medical students answered correctly at an average rate of 30.89%. Furthermore, when asked about the Infectious Diseases Society of America (IDSA) guidelines for diagnosing and treating skin and soft tissue infections, only 34.4% admitted to being knowledgeable, a figure that correlated with the level of education (p<0.001).⁴

Treatment of ABSSSIs is dependent on the causal pathogens and can vary according to the type. Depending on the individual risk factors, patients can be at risk of developing cellulitis, an abscess, or both.⁵ Thorough clinical evaluation, including rapid diagnostic assays, are necessary for the diagnosis and appropriate management of each individual case. By doing so, physicians also aid in the fight to manage the persistent spread of community acquired methicillin-resistant Staphylococcus aureus (CA-MRSA), now considered to be the primary cause of ABSSSIs in the United States and the subsequent rise in related ED visits.⁶

In a retrospective study looking at a tertiary center in Texas, investigators found that only 44% of those diagnosed with an abscess of mild severity received appropriate incision and drainage (I&D) as recommended by the IDSA. For a mild abscess, considered in the purulent category of SSTIs, guidelines stress I&D along with culture and gram stain of fluid collection with no follow-up prescription of oral antimicrobials unless otherwise indicated. The investigators in the Texas study determined that trimethoprim/sulfamethoxazole was prescribed most often, against IDSA guidelines, following an I&D for outpatients. Current IDSA recommendations suggest antimicrobials including cephalosporins, penicillins, or clindamycin for patients with moderate infection with systemic signs or severe infection. Of the patients enrolled in the study who were diagnosed with moderate ABSSSI, 30% were admitted to hospital inpatient with none of the patients receiving appropriate antibiotic management. Instead, nearly 90% received vancomycin without microbiological support. On the opposite spectrum, severe infections, for which guidelines suggest the use of vancomycin or other MRSA-resistant therapy, 40% received treatment that would be suboptimal for MRSA-related infection.^7,8

IDSA guidelines acknowledge that best practice methods vary with wound infections. For non-purulent infections, defined as cellulitis or erysipelas of moderate and mild severity, in patients whose health is not significantly impaired, recommendations suggest outpatient treatment. For patients at greater risk for complications related to wound infections who present with systemic inflammatory response syndrome (SIRS), or who are hemodynamically unstable, have comorbidities rendering them immunocompromised, or have recurrent infections, IDSA recommends inpatient care. The study produced results showing that of those with severe skin infection, only 66% received the advised care of hospital staff.⁸ The need to increase awareness relating to current practice guidelines is urgent.

With recurrent visits to the ED, risk of hospitalization also increases. A recent study showed that failure to effectively treat ABSSSIs on initial visits can result in approximately 3 additional days as an inpatient, incurring costs that can range from $11,995 to $23,655.⁸ Due to the fast-paced environment of the ED, adherence to clinical prescribing guidelines is often challenging. In 2016, the rate of antibiotic prescriptions in the ED was reported to be 14.7 million for all causes with an estimated rate of 70% accuracy.¹⁰ The high prescribing rate of antimicrobials is involved in promoting growth of multidrug-resistant superbugs and a marked increase in CA-MRSA infections.

With the ED acting as the primary care setting for many Americans, the push for antimicrobial stewardship is pertinent but, with the complexity in evaluating ABSSSIs per IDSA guidelines and the demanding dynamics of the ED, this is a challenge not yet overcome. Antimicrobial stewardship in the ED is necessary for improving management of ABSSSI, for those who have been in practice as well as our future physicians.

Sarah Melvin is a nurse and a graduate student at the Anti-Infective Research Lab at Wayne State University (WSU) in Detroit, MI. She achieved her nursing degree from Everest and is now completing her Masters of Public Health Methods at WSU, College of Medicine. Sarah plans to continue her education to accomplish a Doctorate of Philosophy in Biostatistics.

References:

1. Hersh AL, Chambers HF, Maselli JH, Gonzales R. National trends in ambulatory visits and antibiotic prescribing for skin and soft-tissue infections. Arch Intern Med. 2008 Jul 28;168(14):1585-91. doi: 10.1001/archinte.168.14.1585.
2. Hurley HJ, Knepper BC, Price CS, Mehler PS, Burman WJ, Jenkins TC. Avoidable antibiotic exposure for uncomplicated skin and soft tissue infections in the ambulatory care setting. Am J Med. 2013 Dec;126(12):1099-106. doi: 10.1016/j.amjmed.2013.08.016.
3. U.S. Department of Health and Human Services, Food and Drug Administration, Center for Drug Evaluation and Research. Guidance for industry acute bacterial skin and skin structure infections: developing drugs for treatment. FDA.gov. www.fda.gov/downloads/Drugs/Guidances/ucm071185.pdf. Published October 2013. Accessed February 3, 2019.
4. Beatty N, August J, Saenz JA, Nix DE, Matthias KR, Mohajer MA. Knowledge, attitude, and practices associated with the diagnosis and management of skin and soft-tissue infections among medical students, residents, and attending physicians. Avicenna J Med. 2018 Jul-Sep;8(3):104-106. doi: 10.4103/ajm.AJM_200_17.
5. Moran GJ, Abrahamian FM, Lovecchio F, Talan DA. Acute bacterial skin infections: developments since the 2005 Infectious Diseases Society of America (IDSA) guidelines. J Emerg Med. 2013 Jun;44(6):e397-412. doi: 10.1016/j.jemermed.2012.11.050.
6. Edelsberg J, Berger A, Weber DJ, Mallick R, Kuznik A, Oster G. Clinical and economic consequences of failure of initial antibiotic therapy for hospitalized patients with complicated skin and skin-structure infections. Infect Control Hosp Espidemiol. 2008 Feb;29(2):160-9. doi: 10.1086/526444.
7. Kamath RS, Sudhakar D, Gardner JG, Hemmige V, Safar H, Musher DM. Guidelines vs actual management of skin and soft tissue infections in the emergency department. Open Forum Infect Dis. 2018 Jan 12;5(1):ofx188. doi: 10.1093/ofid/ofx188.
8. Stevens DL, Bisno AL, Chambers HF, et al. Practice guidelines for the diagnosis and management of skin and soft tissue infections: 2014 update by the Infectious Diseases Society of America. Clin Infect Dis. 2014 Jul 15;59(2):e10-52. doi: 10.1093/cid/ciu444.
9. Hicks LA, Bartoces MG, Roberts RM, et al. US outpatient antibiotic prescribing variation according to geography, patient population, and provider specialty in 2011. Clin Infect Dis. 2015 May 1;60(9):1308-16. doi: 10.1093/cid/civ076.
10. US Centers for Disease Control and Prevention. Outpatient antibiotic prescriptions — United States, 2014. www.cdc.gov/antibiotic-use/community/programs-measurement/state-local-activities/outpatient-antibiotic-prescriptions-US-2016.html. Published December 27, 2017. Accessed February 2, 2019.