Findings

• In this series, 84% of patient was discharged from ED, 55.3% with antibiotic. Only 1.5% had elbow aspiration in ED. 88% had resolution at follow-up.

Bottom line

• Author concluded that aspiration in ED is not necessary even when septic bursitis is suspected, and most can be managed with outpatient antibiotic
• Performing a CRP blood test, and/or referral to orthopedic service, is associated with admission and antibiotic administration
  

Efficacy of empiric antibiotic management of septic olecranon bursitis without bursal aspiration in emergency department patients

What is this paper about

• Retrospective observational cohort “study” (chart review) of 266 cases of suspected olecranon bursitis, and management in the ED

Study design

• Retrospective observational cohort study   (hard to design a RCT with this topic or hide the intervention)
• ED at Mayo Clinic Hospital-Saint Mary’s Campus, Rochester, Minnesota
• EHR search with “olecranon bursitis”, “bursitis” but excluding “prepatellar bursitis”
• Chart review by 2 medical students and 1 research nurse.
• All chart with bursal aspiration in ED or following the ED were also reviewed by principle investigator to ensure accuracy
• Complication including ED revisits, follow-up, admission, surgery, adverse effect from antibiotics were recorded up to 6 months post initial ED
• Uncomplicated resolution is defined as resolution of bursitis without need for subsequent aspiration of the bursa, surgery or hospitalization
• Data analysis is by
  • Kruskal-wallis
  • chi-square
  • Fisher’s test
• Confidence interval is reported, 2 sided and p-values <0.05 considered statistically significant

Population

• Adult ED patient presenting with olecranon bursitis between 1st January 2011 to 31st December 2018
• Exclusion:
  • Decline consent
  • underlying fracture
  • had surgery on that joint < 3/12 prior to ED visit
• 458 patients visits identified, 266 included after exclusion criteria (Figure 1 in paper), assessed by doctors (85.3%) vs nurse practitioner (14.7%)

Characteristic (Table 1)

• Median age 57 (42-69)
• 85% male
• Most common presenting symptoms
  • Swelling (94%), erythema (77%) and pain (85%)
• Complex pt
  • 15% on active steroid
  • 14% known diabetes
• 91% completed study
  • 86% had at least 3 months follow-up
  • 83% had at least 6 months follow-up
• 24 pt (9%) lost to follow-up
  • 83% male, age 51.5

Findings

• Investigation in ED (percentage of patients)
  • Blood works
    • white cell count performed (46%)
    • ESR (34%)
    • CRP (36%)
      • High in admitted pt (50 µg/dl, 22-89)
      • Lowest in discharged pt without antibiotic (11 µg/dl, 5-61)
  • Xray (61%)
  • Orthopedic team consulted in 26% of patient
  • Aspiration of bursa performed in ED (4 pt, 1.5%)
    • 2 pts grew MRSA (1 pt subsequently lost to follow-up)
    • 1 grew C Streptococcus
    • 1 no growth or crystal
    • None develop complication or fistula or need future operation
• Management
  • Admitted to hospital (39 pt, 15%)
  • Discharged without antibiotic therapy (76 pt, 29%)
  • Discharged from ED with antibiotic therapy for suspected septic olecranon bursitis (147, 56%)
  • 2 pt underwent arthrocentesis, both negative for organism
• Characteristic of pt admitted to hospital
  • Higher CRP, reported fever (23%), associated cellulitis (44%) and had a orthopedic consult in ED (74%)
• Antibiotic used
  • Cephalosporin (1st/ 2nd/ 3rd) most common prescribed, followed by penicillin. 38% of admitted pt also receive IV vancomycin
  • 1 patient developed antibiotic allergic reaction
• Readmissions
  • 9 pt (7%) of discharged pt subsequently requires hospitalisation, 8 had subsequent bursal aspiration

Weakness of study design

• Based on their definition, a lot of these patient may have non infective bursitis despite raised CRP and they admit to this in their conclusion (Stell et al 1999 found that 50% of these ED patient actually has septic olecranon bursitis)
• No report of IV drug use or trauma to soft tissue / break in tissue integrity in those patient with suspected septic olecranon bursitis
• Whilst referral to orthopedic service is an independent predictor of needing admission, antibiotic and aspiration; author did not describe why these referral occur in the first place (? sicker patient ? more clinical sign indicating infection), but author postulated that these patient maybe sicker because 77% received MRSA coverage (vs 33% of discharged pt). It is likely that these pt are critically unwell/ hypotensive and are therefore self selected out for aggressive management.
• Using “bursitis” and “olecranon bursitis” as search code, may miss a bunch of pt with “septic arthritis” or “septic joint” who actually has bad cellulitis or septic olecranon bursitis
• The usual weakness of retrospective chart review (good description of what they did to minimise this)
• Significant lost to follow-up (24pt)
• Ultimately this paper does not change what we are doing, which is to treat pt based on clinical features, perform CRP only when infection is suspected (WCC not useful to predict disposition in this series). It is useful to know that most pt tolerate antibiotic well despite many of them probably does not need them to start with.