May 26, 2016

ARTICLE REVIEW

In the era of pathogen multi-drug resistance, antibiotic stewardship is a must. Prophylactic antimicrobial therapy is widely used in many clinical settings, some with good evidence base and others with less convincing proof.

Extracorporeal life support, of which ECMO is a prime example, is becoming an increasingly common occurrence in general and cardiac critical care units across the world. Most centres use antimicrobial prophylaxis for the ECMO patients, though the evidence behind this practice has so far not been established. On the contrary, the evidence shows (also in this recent paper under review) that nosocomial infections in ECMO patients are associated with significantly increased morbidity and mortality (OR 1.91, 95% confidence interval, 1.75 – 2.08; (1, 2)).

This systematic review from the Mayo Clinic aims to answer two important questions with regards to ECMO management – how common are nosocomial infections in the ECMO patients and how solid is the evidence behind using a blanket antimicrobial prophylactic regimen in this population (2).

The authors of the study have performed a wide literature search, using all the relevant databases since their inception until January 2014. Of all the published studies targeting all modalities of both adult and paediatric ECMO, only 9 studies, one multicentre, based on the ELSO registry, and 8 single centre studies were finally selected, in accordance with the PRISMA systematic review guidelines (3). In total, this amounts to 22,181 patients. Of note, some of the patients may have been duplicated by inclusion in both the ELSO registry and in the local database.

The overall prevalence of nosocomial infections in ECMO patients varied widely, from 6.1% in the neonatal population, to just over one in five patients in the adult cohort. The highest incidence of infections was observed in the cardiac ECMO population, both in adults and in children. Coagulase negative Staphylococci were responsible for the greatest percentage of infections in most of the papers analysed, while Candida spp. and Gram negative bacteria were also commonly associated with nosocomial infections in ECMO patients. The most common sites were bloodstream infections, followed by surgical site, urinary tract and respiratory infections.

There was no evidence of reduced risk of infections in patients given an antimicrobial prophylaxis regimen in any of the papers analysed. This finding is mirrored by the document published by the Extracorporeal Life Support Organisation (ELSO) Task Force for Infectious Diseases in 2012. Antimicrobial prophylaxis is not routinely recommended either for the pediatric or the adult patients outside the groups at risk – prolonged open chest or abdomen or immunocompromised (4).

While disproving ubiquitous antibiotic prophylaxis, the present study raises an important question – should we focus on establishing an “ECMO bundle” rather than one isolated intervention to prevent nosocomial sepsis in ECMO patients?

Take home message
There is no evidence that antimicrobial prophylaxis is beneficial for the ECMO patients. However, it may be that a bundle of care, similar to the one used for central venous catheters or the prevention of ventilator-associated pneumonia may be the answer. In other words, we may soon be able to define an ECMO FAST HUG strategy to give our patients at least once a day (5).

Article review submitted by ESICM Journal Review Club member Oana Cole on behalf of the Acute Respiratory Failure Section.


References

1. Bizzarro MJ, Conrad SA, Kaufman DA, Rycus P; Extracorporeal Life Support Organisation Task Force on Infections, Extracorporeal Membrane Oxygenation: Infections acquired during extracorporeal membrane oxygenation in neonates, children, and adults. Pediatr Crit Care Med 12: 277–281, 2011.

2. O’Horo JC, Cawcutt KA et al. The Evidence-Based for Prophylactic Antibiotics in Patients Receiving Extracorporeal Membrane Oxygenation. ASAIO Journal 2016; 62: 6 – 10

3. Moher D, Liberati A, Tetzlaff J et al. Preferred Reporting Items for Systematic Reviews and Meta-Analyses: The PRISMA Statement. Ann Intern Med, 151(4), 2009

4. Extracorporeal Life Support Organization. ELSO ID Task Force Recommendation Summary [Internet], Ann Arbor, MI, USA, 2012, p. 8. Available at: http://www.elso.org/downloads/resources/committees/infectious-disease-and-antibiotic/ELSO-ID-Task-Force-Recommendations-Summary.pdf. Accessed 2nd May 2016.

5.Vincent JL. Give your patient a fast hug (at least) once a day. Crit Care Med 33(6): 1225 – 1229, 2005

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