Faster infection diagnostics for intensive care unit (ICU) patients

ABSTRACT

Introduction

The patient admitted to intensive care units (ICU) is critically ill, to some extent immunosuppressed, with a high risk of infection, sometimes by multidrug-resistant microorganisms. In this context, the intensivist expects from the microbiology service quick and understandable information so that appropriate antimicrobial treatment for that particular patient and infection can be initiated.

Areas covered

In this review of recent literature (2015–2021), we identified diagnostic methods for the most prevalent infections in these patients through a search of the databases PubMed, evidence-based medicine online, York University reviewers group, Cochrane, MBE-Trip, and Sumsearch using the terms: adult, clinical laboratory techniques, critical care, early diagnosis, microbiology, molecular diagnostic techniques, spectrometry and metagenomics.

Expert opinion

There has been an exponential surge in diagnostic systems used directly on blood and other samples to expedite microbial identification and antimicrobial susceptibility testing of pathogens. Few studies have thus far assessed their clinical impact; final outcomes will also depend on preanalytical and post-analytical factors. Besides, many of the resistance mechanisms cannot yet be detected with molecular techniques, which impairs the prediction of the actual resistance phenotype. Nonetheless, this is an exciting field with much yet to explore.

KEYWORDS:

• Adult
• clinical microbiological techniques
• critical care
• early diagnosis
• microbiology
• molecular diagnostic techniques
• spectrometry
• metagenomics

Acknowledgments

The authors would like to thank Ana Burton BSc for editing and proofreading assistance.

Author contributions

All authors were involved in the conception and design, analysis and interpretation of the data; the drafting of the paper; and the final approval of the version to be published; and all authors agree to be accountable for all aspects of the work.

Article highlights

• The rapid and correct diagnosis of the aetiology of infection in critically ill patients is essential.

• Employing these new diagnostic methods will allow a more accurate aetiological diagnosis, the discovery of new pathogens and the ascription of some of the already known to new diseases, and, globally, better patient management.

• Implementing these methods requires training of clinicians and laboratory staff, availability of equipment and reagents, and a significant investment.

• Diagnostic stewardship is mandatory. To determine to which patients, with what clinical background, presenting clinical syndromes or specific clinical features, at which point in the progression of the infection, how often, on which type of specimen, these tests should be applied.

• The interpretation of the results is complex and must always be done in the light of the clinical situation of the patient.

• The assessment of the performance of the newest diagnostic techniques in clinical practice is still preliminary.

Declaration of Interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

One peer reviewer has participated in a Cepheid European Scientific Advisory Board meeting. Peer reviewers on this manuscript have no other relevant financial relationships or otherwise to disclose.

Additional information

Funding

This study was partially financed by PI20/01201 of the Carlos III Health Institute (ISCIII), Madrid Spain, partially financed by the by the European Regional Development Fund (FEDER) “A way of making Europe”.