CURRENT Essentials of Critical Care.pdf

Chapter 10 Infectious Disease 141■■Infections in Immunocompromised HostsEssentials of Diagnosis• Suspected infection in patients with immunocompromising condition,such as neutropenia, organ transplantation with immunosuppressivetherapy, diabetes, splenectomy, chronic corticosteroidtherapy, HIV infection; type of immunocompromisedetermines risk, nature of opportunistic infection• Neutropenia associated with gram-negative bacilli, gram-positivecocci, fungi• Organ transplant recipients susceptible to Pneumocystis jiroveci,Listeria monocytogenes, Nocardia asteroides, Cryptococcusneoformans, Aspergillus spp, cytomegalovirus (2–6 months aftertransplant)• Postsplenectomy: overwhelming infection with encapsulated organisms,such as S pneumoniae, N meningitides, H influenzae• Diabetics prone to more severe manifestations of common infections(emphysematous cholecystitis and pyelonephritis,necrotizing soft tissue infection) plus specific infections(rhinocerebral mucormycosis, malignant otitis externa)Treatment• Antimicrobial therapy against likely organisms based on immunocompromisingcondition, specific clinical features• Surgical debridement for emphysematous infections, infectionswith necrosis, rhinocerebral mucormycosis• Vaccination against S pneumoniae, H influenzae and N meningitidisin asplenic and HIV-infected patients, others at increasedrisk■ PearlA functional asplenic state can occur in congenital hyposplenism,sickle cell disease, graft-versus-host disease, rheumatoid arthritis, systemiclupus erythematosus, amyloidosis, ulcerative colitis, celiac disease,and chronic alcoholism.ReferenceFishman JA: Infection in organ-transplant recipients. N Engl J Med1998;338:1741. [PMID: 9624195]