Infectious diseases approach to immunocompromised patients in the pediatric intensive care unit

The diagnosis and management of infectious diseases in the immunocompromised patient can be challenging, especially when that patient is critically ill. In the diagnostic approach to the immunocompromised patient, clinicians will need to integrate the risks particular to the immunodeficiency with the risks associated with hospital-associated exposures. The potential infectious diagnoses are expanded in the immunocompromised patients, most notably to include diseases due to opportunistic infections, such as fungi, latent viruses, and opportunistic Gram-positive and Gram-negative bacteria. In addition, prior hospital and antibiotic exposure increases the likelihood that these patients will have infections due to resistant organisms. When an infection is diagnosed, the approach to treatment in the immunocompromised patient is also dependent on the degree and type of immunodeficiency, and optimal treatment strategies are often not well studied. This review focuses on general principles that can be used in the diagnosis and management of immunocompromised, critically ill patients with suspected or proven infection and highlights in detail the approach to infections of the blood stream and respiratory tract.