Outpatient parenteral antibiotic therapy effective for SSTIs
Outpatient parenteral antibiotic therapy (OPAT) yields desirable outcomes for community-acquired skin and soft tissue infections (SSTI), a new single-centre retrospective study in Singapore reveals.Particularly, IV ceftriaxone or IV cefazolin is effective and results in a low hospital readmission rate.
“In this report, we describe the successful outcomes of OPAT treatment in patients with SSTIs referred directly from [the emergency department] to OPAT for continuation of IV antibiotics,without intervening hospital admission in a Singapore university hospital,” said investigators
Over the 41-month duration of the study, 120 SSTI patients (median age 56 years; 63 percent male) were treated with OPAT, of which 90 percent showed clinical improvements. The remaining 10 percent (n=12) required hospitalization. A total of 318 hospital bed days were saved with 6 days (range, 4 to 8 days) per month. [BMC Infect Dis 2017;17:474]
The resulting success rate of OPAT aligns well with those published in other regions like the UK, Canada and New Zealand.
“Of 963 patients with cellulitis treated in Glasgow, UK, success rate was 87 percent, hospital admission occurred in 6 percent, adverse events in 7 percent with progression of infection in 2.8 percent,” researchers said. [Int J Antimicrob Agents 2011;38:243-248]
“In Alberta, Canada, a five-centre ED retrospective studyof 416 patients, 11 percent required change in antibiotic therapy and 7 percent were hospitalized,” they added. “A randomized controlled trial in Christchurch, New Zealand comparing cellulitis treatment at home or in the hospital had 11.8 percent readmission rate for 101 patients on home treatment.” [Am J Emerg Med 2001;19:535-540; BMJ 2005;330:129]
Of the 12 patients that were hospitalized, seven presented with worsening cellulitis and were given further IV antibiotics. Acute renal impairment due to the antibiotics was detected in one patient but was resolved after cessation of antibiotics.
Four patients had to receive surgery under general anaesthesia to drain the abscesses. One patient tested positive for Staphylococcus aureus and Klebsiella pneumonia, both of which were sensitive to methicillin, ceftriaxone and cefazolin.
Patients who received prior antibiotics before attendance to the emergency department tended to have significantly longer symptom duration (p<0.001), more ulceration (p<0.001) and more trauma (p=0.04) compared to those without prior antibiotics.
Between patients who completed treatment (n=108) and those who required readmission (n=12), there were no significant differences laboratory findings and antibiotics used.
Among the limitations of the present study are the lack of standardization and assessment of the severity of SSTIs, and the incomplete follow-up data, both of which may have led to inconsistencies in the need and observed effects of the antibiotics.
“Reassuringly, the data from our study is broadly similar to findings of other outpatient cohorts of SSTIs treated with IV antibiotics,” researchers said.
Patients were recruited from the OPAT service of the Tan Tock Seng Hospital. Only those with lymphangitis-associated cellulitis or cellulitis not showing improvements with oral antibiotics were included.
Patients with new diabetes mellitus and other comorbidities, on immunosuppressants, with haemodynamic instability and with cellulitis due to surgery, or with underlying bone or joint involvement were excluded.
“In conclusion, our report supports that OPAT treatment of community-acquired SSTIs in a selected patient population has good outcomes in Singapore. Treatment was successful in the majority with low readmission rates comparable to other studies internationally,” they said.