GENERAL INFECTION CONTROL MEASURES
Optimizing Nutritional Status
It’s been well established that poor nutritional status is causally related to impaired immune function and susceptibility to infections. Malnutrition is an independent risk factor for surgical site infections. Low serum albumin level in cardiac surgery patients correlates with increased risk of postoperative infectious complications. Medical ICU patients who receive suboptimal caloric supply have significantly increased risk of nosocomial bloodstream infections. Parenteral nutrition necessitates long-term central venous catheters (CVCs), which are a potential cause of CLABSI. Enteral feeding, on the other hand, especially in the supine position, has been shown to increase the risk of VAP. Compared with parenteral feeding, enteral feeding of critically ill adult patients significantly decreases the risk of overall infections. Early enteral nutrition, when possible, is associated with lower incidence of sepsis or septic shock and improved ICU mortality.
Hyperglycemia and insulin resistance are common in critically ill patients and are associated with adverse outcomes in diabetics, even more so in stress-induced hyperglycemia patients. In a randomized, controlled study conducted in surgical ICU patients, strict control of blood glucose levels with insulin reduced morbidity and mortality. Diabetic patients undergoing cardiovascular surgery develop more postoperative wound infections than non-diabetics. Trauma patients admitted to an ICU with hyperglycemia have increased risk of infections, in particular respiratory infections and bloodstream infections. The optimal blood glucose level is fluctuating and the optimal glucose level has yet to be determined and needs future studies.
Staff Education and System-Based Practices
Checklists and interventions targeting communication efficiency among all ICU staff and daily multidisciplinary rounds with discussions of mechanical ventilator, CVC, and urinary catheter protocols can significantly decrease the rate of VAP and CLABSI, with a downward trend in CAUTI. Periodic educational programs for ICU staff with reminders of infection prevention strategies have also been shown to decrease hospital-acquired infection rate. In addition, adequate nursing and support staff is necessary for infection control. A lower nurse-to-patient ratio increases the risk of nosocomial infection, including late-onset VAP and CLABSI.
Intensive Care Unit Environment
The ICU environment plays an important role in exposing patients to various pathogenic organisms. These organisms may be found almost anywhere: on the hands of caretakers, on laboratory coats, on knobs of doors, on keyboards, or in the structure and environment of the room itself, increasing the chances of acquiring infections. Measures to decrease the environmental burden of pathogens and subsequently lower the rates of hospital-acquired infections are being heavily studied. Still, experimental techniques for environmental cleansing include UV light sterilization lamps and hydrogen peroxide vapor decontamination devices, which might contribute to future attempts at reducing colonization pressure. Combining environmental cleaning with hand hygiene educational campaign can significantly decrease both environmental and hand contamination rates.
Compliance with appropriate hand hygiene is vital to patient care in ICUs and is extremely cost effective. Continuous encouragement and monitoring with reinforcement of hand hygiene policies are important to maintain and improve compliance rates and reduce the ICU-acquired infection rate.
The Hand Hygiene Task Force compiled the trials comparing soap to alcohol-based foam and determined that alcohol-based foams/gel are more effective in decreasing bacterial colony counts and in decreasing the number of multidrug-resistant pathogens than traditional hand washing with soap and water. This proves to be true with the exception of hands that are visibly soiled and for health care personnel caring for patients with CDIs (or other spores-forming organisms), because the foam does not inactivate C difficile toxins and does not kill the spores themselves. Studies have shown no significant difference in bacterial colony counts on hands of ICU staff who used a chlorhexidine-containing antiseptic wash versus alcohol-based foam; however, the latter produces less skin irritation and is more cost effective.
Patients newly admitted to an ICU who are colonized with multidrug-resistant pathogens are a constant reservoir for transmission and subsequent infection. Surveillance cultures to detect methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) have been implemented at many hospitals, with significant success in decreasing the rate of colonization and infection with these organisms. Cost-benefit analyses of VRE and MRSA surveillance seem to favor surveillance as a cost-saving measure.
Both the Healthcare Infection Control Practices Advisory Committee and the Society for Healthcare Epidemiology of America guidelines encourage both gown and glove use on entering rooms of patients colonized with antibiotic-resistant pathogens. A study of glove use by 50 health care workers who care for VRE-positive patients found the use of gloves decreased the risk of the health care workers acquiring VRE by 71%. Recent studies have found advantages in using both gowns and gloves to decrease the risk of transmitting both MRSA and VRE. In addition, cost-benefit analyses of gown use show a temporary increase in costs, but the long-term decrease in VRE or MRSA colonization and infections overall decreases hospital costs.
Use of 2% chlorhexidine cloths to daily bathe ICU patients has been shown an effective method of decreasing both hospital-acquired infections (ie, bloodstream infections, surgical-site infections, and VAP) and colonization with drug-resistant organisms (ie, VRE and MRSA). Despite the controversy about the methodology of some of these studies, given the apparent benefits, the low rate of associated adverse effects, and the ease of implementation, daily chlorhexidine bathing for all ICU patients is recommended and is currently the standard practice in most ICUs.
Ref:Osman MF, Askari R, Infection control in the intensive care unit, Surg Clin North Am. 2014 Dec;94(6):1175-94.