Updates in the management of respiratory virus infections in ICU patients: revisiting the non-SARS-CoV-2 pathogens

ABSTRACT

Introduction

Although viruses are an underestimated cause of community-acquired pneumonias (CAP) and hospital-acquired pneumonias (HAP)/ventilator-associated pneumonias (VAP) in intensive care unit (ICU) patients, they have an impact on morbidity and mortality.

Areas covered

In this perspective article, we discuss the available data regarding the management of severe influenza CAP and herpesviridae HAP/VAP. We review diagnostic and therapeutic strategies in order to give clear messages and address unsolved questions.

Expert opinion

Influenza CAP affects yearly thousands of people; however, robust data regarding antiviral treatment in the most critical forms are scarce. While efficacy of oseltamivir has been investigated in randomized controlled trials (RCT) in uncomplicated influenza, only observational data are available in ICU patients. Herpesviridae are an underestimated cause of HAP/VAP in ICU patients. Whilst incidence of herpesviridae identification in samples from lower respiratory tract of ICU patients is relatively high (from 20% to 50%), efforts should be made to differentiate local reactivation from true lung infection. Only few randomized controlled trials evaluated the efficacy of antiviral treatment in herpesviridae reactivation/infection in ICU patients and all were exploratory or negative. Further studies are needed to evaluate the impact of such treatment in specific populations.

KEYWORDS:

• Community acquired pneumonia
• herpes simplex virus
• influenza
• intensive care unit
• oseltamivir
• ventilator-associated pneumonia
• viral pneumonia

Article highlights

• Viral CAP and HAP/VAP are frequent in critically ill patients and associated with increased morbidity and mortality.

• Influenza virus can lead to severe CAP, with increased mortality due to bacterial and fungal superinfections.

• Bacterial superinfections of severe influenza CAP have their own specificities with high rates of Panton–Valentine leucocidin-producing Staphylococcus aureus strain in coinfections and mainly Gram-negative bacteria in VAP. Procalcitonin value on admission could help to rule-out bacterial coinfections.

• Antiviral therapy with oseltamivir is the cornerstone of severe influenza pneumonia treatment and we provide a pragmatic algorithm for its use in ICU patients.

• Herpesviridae viruses are frequently isolated in LRT samples of ICU patients, however distinction between local reactivation and lung infection can be difficult. Quantitative PCR is the key to approach this issue.

• While curative use of acyclovir to treat HSV bronchopneumonitis is an expert recommendation, we cannot recommend preemptive or prophylactic acyclovir to treat HSV reactivation in the LRT.

• To date, prophylactic or preemptive ganciclovir for the treatment of CMV lung reactivation cannot be recommended.

Abbreviations

ARDS	=	Acute respiratory distress syndrome
BAL	=	Bronchoalveolar lavage
BPn	=	Bronchopneumonitis
CAP	=	Community acquired pneumonia
CMV	=	Cytomegalovirus
EBV	=	Epstein-Barr virus
HAP	=	Hospital-acquired pneumonia
HSV	=	Herpes-simplex virus
IAPA	=	Influenza-associated pulmonary aspergillosis
ICU	=	Intensive care unit
ICU-	=	LOS Intensive care unit length of stay
IMV	=	Invasive mechanical ventilation
LRT	=	Lower respiratory tract
OPS	=	Oropharyngeal swab
PCR	=	Polymerase chain reaction
PCT	=	Procalcitonin
VA-LRTI	=	Ventilator-associated lower respiratory tract infections
VAP	=	Ventilator-associated pneumonia
VFD	=	Ventilator-free days

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 material discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants, or patents received or mending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Data availability statement

All data were analyzed and interpreted from cited bibliography.

Each figure and/or table has been originally created for the purpose of this manuscript and has not been published previously.

Financial support

No financial support was obtained for this manuscript.

Competing interests

Authors declare no competing interest in relationship with this manuscript.

Additional information

Funding

This paper was not funded.