Viral Infections in the Intensive Care Unit

Acute viral infections are a common reason for admission to the Intensive Care Unit (ICU). Among them, human immunodeficiency virus (HIV), influenza, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), and herpesviruses are most frequently reported in critically ill setting, leading to potential life-threatening complications. Although combined antiretroviral therapy (ART) and adequate medical care have substantially improved the prognosis of HIV infection, opportunistic infections and other complications may require organ support in the ICU. Vaccination strategies and improved specific therapy may improve the outcomes of SARS-CoV-2 and influenza infections, but the cornerstone of therapy remains supportive care of acute respiratory distress syndrome (ARDS). The herpesviruses family also plays an important role in the ICU, causing encephalitis, pneumonia, gastrointestinal involvement, and skin lesions. Immunosuppressed patients are more susceptible to complicated viral infections, and these viruses may reactivate in patients with a state of immunoparalysis, which is at higher risk of unfavorable outcomes. The aim of this chapter is to briefly characterize the most common viral infections in the ICU, their management, and treatment.