Ventilator-associated pneumonia in critically ill patients with COVID-19 infection: a narrative review

COVID pneumonitis can cause patients to become critically ill. They may require intensive care and mechanical ventilation. Ventilator-associated pneumonia (VAP) is a concern. This review discusses VAP in this group. Several reasons have been proposed to explain the elevated rates of VAP in critically ill COVID patients compared to non-COVID patients. Extrinsic factors include understaffing, lack of personal protective equipment and use of immunomodulating agents. Intrinsic factors include severe parenchymal damage and immune dysregulation, along with pulmonary vascular endothelial inflammation and thrombosis. The rate of VAP has been reported at 45.4%, with an intensive care unit mortality rate of 42.7%. Multiple challenges to diagnosis exist. Other conditions such as acute respiratory distress syndrome, pulmonary oedema and atelectasis can present with similar features. Frequent growth of gram-negative bacteria has been shown in multiple studies, with particularly high rates of Pseudomonas aeruginosa. The rate of invasive pulmonary aspergillosis has been reported at 4-30%. We would recommend the use of invasive techniques when possible. This will enable de-escalation of antibiotics as soon as possible, decreasing overuse. It is also important to keep other possible causes of VAP in mind, e.g. COVID-19-associated pulmonary aspergillosis or cytomegalovirus. Diagnostic tests such as galactomannan and β-D-glucan should be considered. These patients may face a long treatment course, with risk of re-infection, along with prolonged weaning, which carries its own long-term consequences.