Principles of Critical Care, 3e > Part V. Infectious Disorders > Chapter 47. Approach to Infection in Patients Receiving Cytotoxic Chemotherapy for Malignancy E.J. Bow

Key Points

"Critical care physicians are often called on to provide metabolic, hemodynamic, and respiratory support for patients with various inherited or acquired defects in host defense that render them susceptible to potentially lethal infections. Patients with single host defense system defects, such as those with inherited immune deficiency syndromes such as congenital agammaglobulinemia, are susceptible to particular encapsulated respiratory pathogens such as Streptococcus pneumoniae that require the presence of opsonizing antibody for clearance. In contrast, cancer patients undergoing potentially curative high-intensity myeloablative cytotoxic therapy acquire defects in multiple host defense systems that lead to increased susceptibility to different groups of pathogens normally contained and controlled by the absent or damaged systems. Four broad categories of defects in host defense are clinically relevant: disruption of the integrity of the integumental surfaces, quantitative neutrophilic phagocyte defects, diminished B lymphocyte (humoral) function, and diminished T lymphocyte system function. A working knowledge of the sources of failure in these host defense systems is particularly important for predicting the types of offending pathogens likely to be involved in the kind of life-threatening infections requiring the services of the critical care team. This, in turn, provides a basis for a rational approach to the choice of antimicrobial therapy. This chapter reviews the approach to managing suspected or proven infection in patients..."