Infections and the Compromised Immune Status in the Chronically Critically Ill Patient: Prevention Strategies

Abstract

An estimated 2-3% of all hospitalized patients become critically ill. These patients are in a state of relative immune exhaustion, which cripples their response to infections. Patients are sicker, have many comorbidities, and undergo complex procedures. This clinical picture, combined with increasing technologies and improved survival, presents unique challenges and demands a high level of services and expertise over a prolonged period of time. Long-term acute care hospitals provide these services, and the migration of chronically critically ill patients to these institutions facilitates defining (and quantifying) the spectrum of disease and how to best manage them. The prevalence of multidrug-resistant organism colonization and infection upon arrival to long-term acute care hospitals is high. Admission screening, and appropriate isolation and infection control practices can prevent transmission of these organisms. The implementation of ventilator-associated pneumonia prevention protocols, blood stream infection prevention protocols, and minimizing Foley urinary catheter use can decrease hospital-acquired infection rates and keep them low. In addition, specific attention is required to environmental services and surface and equipment cleaning. A well organized infection control program and an antimicrobial stewardship program have become indispensable to achieve these goals. All of these key principles and recommendations are also relevant to the chronically ill patient in acute care hospital ICUs and step-down units.

Strategies to combat chronic critical illness

“…Diminished immunological and physiologic reserve following severe sepsis, referred to as ‘immune exhaustion’, is another proposed mechanism that puts CCI patients at risk [45]. Additionally, many CCI patients have pre-existing comorbid conditions such as hepatic failure, renal failure, or malignancy that predispose them to decreased immune function [46]. …”

“…Catheter-associated urinary tract infections (CAUTIs) are common in CCI as the urinary catheter rate in CCI patients is high. Staff education in basic infection control and minimizing use of urinary catheters have been shown to reduce the rate of CAUTIs in hospitalized patients [46]. In a recent review, Cabrera-Cancio [46] suggests a combination of judicious use of antibiotics (antimicrobial stewardship) to help decrease rates of MDRO and Clostridium difficile , surveillance cultures to guide isolation practices, family/patient education, and strict housekeeping protocols to decrease incidence of nosocomial infections in the CCI.…”

Chronic Critical Illness: The Growing Challenge to Health Care

“…39,40 These include the presence of invasive devices, the phenomenon of immune "exhaustion" or "paralysis," malnutrition, hyperglycemia, and drugs (especially inappropriate antibiotics). These infection issues are magnified by the presence of "bad bugs" in the various care venues, which include vancomycinresistant enterococcus, methicillin-resistant Staphylococcus aureus, and resistant Gram-negative organisms.…”

“…40,41 There are also some new cleaning strategies, including ultraviolet light and hydrogen peroxide vapor, that are under study.…”

“…40,41 For ventilator-associated pneumonia, these include head of bed elevation, minimized sedation, oral care, subglottic suctioning, peptic ulcer disease prophylaxis, and deep venous thrombophlebitis prophylaxis. Along with this, patients should receive the flu and pneumococcal vaccine.…”