key: cord-0059501-orh4sdag authors: Sahu, Sandeep; Paul, Mekhala; Chatterjee, Arindam title: Principles of Infection Prevention and Control in ICU date: 2020-08-01 journal: Infectious Diseases in the Intensive Care Unit DOI: 10.1007/978-981-15-4039-4_26 sha: 20f3efc8917c4eaeb0571afb22b90c596eb9ab2a doc_id: 59501 cord_uid: orh4sdag Prevention of infection in ICU setting is very difficult and needs multidisciplinary approach to monitor and control it. The major infections of concern are central line associated blood-stream infection, ventilator-associated pneumonia, catheter-associated urinary tract infection, clostridium-difficile induced colitis, surgical site infection or infected decubitus ulcer, etc. increasing resistant micro-organisms due to prolonged unnecessary use of broad-spectrum antibiotics without dose adjustment, lack of following the protocols of isolation and hand hygiene with general preventive measures, failure to maintain surveillance strategies are major factors for failure to control infections in ICU. There is urgent need of teaching and training of health care workers regarding various type of infections, its mode of transmissions and effective way of its prevention in ICU like WHO hand hygine guidelines and other recomended bundle cares.Besides this environmental control including safe designing and manintence of ICU, antibiotics stewardship, effective teamwork and good communication are the key to success of infection prevention in ICU. Two moments before touching a patient to protect the patient from harmful germs carried on hand of HCWs and patient's own germs 1. Before touching a patient 2. Before aseptic procedures Micro-organisms can be transmitted by airborne, tiny droplets or large droplets, and by direct contact. • Transmission through direct contact-transmission in ICU mainly occurs by contaminated hands of HCWs. Hands are directly contaminated either from patients' infected body area or from inanimate objects around patient (Table 26 .2). Airborne transmission: Droplet nuclei with <5 μm in size remain suspended in the air for long periods and can travel long distance. (Mukhopadhyay 2018; Guidelines n.d.) Droplet transmission: Infective micro-organisms are transmitted in the form of large particles (>5 μm in size) during coughing, sneezing, and talking or during invasive procedures such as bronchoscopy, pleural tap, endotracheal intubation, tracheal suctioning, etc. (Mukhopadhyay 2018 ; Guidelines n.d.) (Table 26 .3). Modes of transmission for waterborne infections include (Guidelines n.d.) 1. Direct contact (e.g. hydrotherapy). 2. Ingestion of contaminated water (e.g. consumption of contaminated iced water). 3. Indirect contact transmission (improperly processed medical device). 4. Inhalation of aerosols dispersed from water sources or respiratory therapy equipment. 5. Aspiration of contaminated water (Table 26 .4). (Rutala 1996) Bundle is a group of evidence-based care components for a given disease that, when executed together, may result in better outcomes than if implemented individually. The other strategies to prevent VAP (Wip et al. 2009) • Endotracheal tubes with subglottic suction port is preferred to prevent microaspiration (2A) • Avoid intubation and re-intubation whenever possible (2B) • Closed endotracheal suction systems may be better than open suction (2B) • Consider non-invasive ventilation whenever possible (2B) (Ayliffe et al. 1974) Dialysate should be ≤2000 cfu/mL Water should be ≤200 cfu/mL (Favero and Petersen 1979) Ice and ice machine should be cleaned periodically. Open storage compartment in patient area is avoided (Newsom 1968 ). Sterile water should be used in ice bath (Pien and Bruce 1986) . Transfusion products should be wrapped in protective plastic wrap during temperature modulation in germicide added water bath (Muyldermans et al. 1998) All patient equipment should be dried after sterilization. Residual moisture in the working channels (e.g. endoscope, bronchoscope) must be dried through alcohol rinse or forced air drying (Humphreys and Lee 1999 • Ultrasound-guided insertion should be in protocol if machine and expertise are available. • Catheter insertion site should be checked and palpated daily through dressing for any tenderness. • Patients' body should be cleaned daily with 2% chlorhexidine wipe to reduce CLABSI. • Needleless intravascular catheter access system should be used, and stopcock should be avoided. Closed catheter system should be preferred to open system. • Injection port should be cleaned with chlorhexidine, povidone-iodine, or 70% alcohol every time during injection and should be accessed only with sterile device. • Routine replacement of CVC is not required. • Administration sets including add-on devices (e.g. triway) should be replaced daily in patients receiving blood, blood products, or fat emulsions. • In case of intravenous fluids other than blood or blood product, administration set should not be replaced <96 h and should be changed at least every 7 days. • Needleless connectors should be changed every 72 h. • Catheter should be inserted only when it is indicated really and should be removed as soon as possible when there is no requirement. • Asepsis should be followed during insertion (sterile gloves, sterile draping, and proper cleaning. • Closed drainage system should be maintained. For unobstructed flow of urine, catheter should be placed and taped above the thigh and urinary bag should hang below the level of bladder. • Urobag should never be in contact with floor. • As it is closed system, changing indwelling catheters or drainage bags at fixed interval is not recommended. It should be changed only if there is indication like infection and obstruction or when closed system is compromised. (a) Intensive care unit should be adjacent to operation theater (OT) complex and emergency department or easy and rapid accessibility of sick patients. It should be away from general ward for prevention of infection. (b) Proper heating, ventilation and air conditioning (HVAC) system should be established and monitored periodically for proper function. HVAC system is designed to • Maintain indoor air temperature and humidity at comfortable levels for patients and staff. • Remove contaminated air. • Protect patients and susceptible staffs from airborne pathogens. • Minimize risk for transmission of airborne pathogens from infected patients (Streifel 1999 ). (20-40%) filter has low resistance to airflow and it removes large particulate matter and many micro-organisms allowing smaller particles to pass onto airconditioning coils] (Streifel 1999 ) → Humidity modification equipment [temperature is maintained within 20-23 degree C and humidity is maintained between 40 and 60% above which is an independent risk factor for fungal Any malfunction or damage of any of the above-mentioned components leads to outbreak of airborne and droplet infection in ICU. So, regular monitoring and surveillance of these components are very important. 2. Ventilation-According to guideline, Air-Change per Hour (ACH) must be >12 in positive pressure area or protective environment (PE) where immunocompromised patients are kept and treated. In negative pressure area or Airborne Infection Isolation (AII) room, ACH should be ≥12 in renovated or newly constructed ICU after 2001 and ≥6 in ICU constructed before 2001. Peak efficiency for particle removal in the air-space occurs between 12 and 15 ACH (Streifel 1999; Memarzadeh and Jiang 2000) . 3. Laminar airflow ventilation system is designed to move air in a single pass, usually through HEPA filters either along a wall or ceiling, in one-way direction through a clean zone in parallel stream. Uni-direction flow minimizes airturbulence, thus precipitation of micro-organisms and spores. Airflow rate of 0.5 m/s minimizes proliferation of micro-organisms. It is important in PE room to reduce airborne healthcare-associated infection. (Walmsley et al. 1993 ). 4. Pressurization-Isolation should be with both positive and negative pressure ventilation. There should be at least 1 isolation room for every 6 beds in ICU. In PE room ideal pressure differential is > +8 Pa and in AII room pressure differential must be < −2.5 Pa. Pressure differential is the difference between isolation unit and adjacent room or hall or corridor. (Streifel 1999 ; American Institute of Architects 2001). 5. Air movement must be always from clean to dirty area. 6. Adequate space around each bed in ICU should be there (2.5-3 m or 20 m 2 ). 7. Washbasins should be installed between every other bed. 8. Alcohol gel dispensers should be at the ICU entry, exit, every bed space, and ventilator. 9. Separate medication preparation area. It should be >3 ft. away from wash basin. 10. There should be separate areas for clean storage and soiled and waste storage and disposal. 11. Electricity, vacuum, or air outlets should not hamper access around beds. 12. Appropriate location of sharps. 13. Seamless floors and avoiding use of carpets (wet carpet helps in growth of micro-organisms and during cleaning it releases micro-organisms and spores). Antimicrobial stewardship program is a multidisciplinary approach which includes clinical pharmacist, clinical microbiologist, infection control professionals, and hospital epidemiologists. With active participation of microbiology lab, hospital pharmacy, and finally hospital administration, this program will be successful. The goal of this stewardship is as follows: • To decrease unnecessary use of antibiotics, thus decreasing cost. • To prevent antibiotic resistance by decreasing inappropriate use of antibiotics. The different ways to achieve this goal are as follows: (The Core Elements of Hospital Antibiotic Stewardship Programs n.d.) 1. Regular audit of antimicrobial use with direct interaction and feedback by antimicrobial stewardship program senior member. 2. Continuous education and discussion about advancement in prescription, guidelines of dosing, de-escalation, etc. should be practiced in health-care setting. In this discussion all physicians and paramedical staffs should be present. 3. Institutional guidelines should be established based upon evidence of local microbiological data and resistance pattern. In this way, antibiotics can be utilized in better way. 4. After culture sensitivity report is available, immediate de-escalation of antibiotic is strictly recommended and must be practiced. Audit should be done on de-escalation practice. 5. Knowledge of pk/pd. characteristics of antibiotics should be shared during discussion so that optimal dosing of antibiotics is practiced. 6. Close vigilance on appropriate dosing, active use of information technology (hospital information system) to track electronic medical record, computerized physician order entry can improve the antibiotic stewardship program. 7. Antimicrobial cycling and combination therapy to prevent emergence of resistance is not recommended as these are not found to be essential. 8. Early switching from parenteral to oral antibiotic when parenteral antibiotic is no longer indicated, especially in resource limited setting to decrease cost of therapy is recommended. 9. Optimization of duration of antibiotics should be followed as per latest clinical guidelines. It decreases cost of therapy, unnecessary antibiotic consumption as well as side-effects. It should be actively incorporated in program. 10. Use of microbiology lab should be optimal. Environmental disturbance during construction, renovation, or repair in or near ICU significantly increases Aspergillus spore count in indoor air. Sudden outbreak or cluster of cases increases suspicion of environmental source to be culprit. In case of construction work, patients should be relocated to another temporary ICU area. All water-damaged materials should be replaced, if moist materials are not dried within 72 hours, those should be replaced (Vujanovic et al. 2001) . Fungistatic compounds should be incorporated into building material in area at risk of getting high moisture. All windows of ICU should be sealed. Door should be closed as much as possible. Entry should be restricted for visitors to reduce dust intrusion and infection transmission. • Both particulate sampling and microbiological sampling are done. • In particulate sampling the numbers and size range of particulates are known, thus it indirectly evaluates the efficiency of filter in removing respirable particles (<5 μm diameter). Particle count in ICU or operation room should be evaluated against counts in comparison area, like corridor, ward, etc. It helps to have information about the ICU air quality and control of dust dispersion (Streifel 1999 ). • Though colony or spore count is not significantly correlated with infection rate in ICU, microbiological air sampling is done nowadays as part of epidemiological investigation in case clusters. Molecular typing can determine whether isolates from air matches with patient isolates or not (especially in case of aspergillosis). At least 1000 ml or 1 m 3 air should be sampled from ICU (Thio et al. 2000) . It is considered that 15 CFU/m 3 gross colony count of fungal organism and < 0.1 CFU/m 3 of Aspergillus fumigates and other opportunistic fungi in HEPA filtered area are the maximum limit to prevent infection (American Institute of Architects 2001). • Air sampling is done after construction or renovation of ICU, especially of isolation rooms and then periodically. • Analysis should be done using standard quantitative methods for endotoxin in water used to reprocess hemodialyzers and for heterotrophic and mesophilic bacteria in water used to prepare dialysate and for hemodialyzer reprocessing. • To minimize growth and persistence of gram-negative waterborne bacteria, cold water should be stored and distributed at temperature below 20-degree C and hot water should be stored above 60-degree C with minimum return temperature 51 °C thermostatic mixing valve is installed near point of use. • Addition of additional chlorine in the water. • All water systems should be inspected annually to ensure proper function of the thermostats. • HVAC system should not be shut down regularly without any purpose like maintenance or filter change, etc. as during starting machine it suddenly releases micro-organisms (e.g. Aspergillus spore) in huge amount accumulated in system. • Regular manometer test to ensure the pressure differential in positive and negative pressure areas. • Regular Testing of Filters-HEPA filter efficiency is especially monitored with dioctyl phthalate (DOP) particle test using the particles sized 0.3 μm diameter. Low-medium efficiency filters are also tested regularly (Dryden et al. 1980 ) . • Low-medium efficiency filter should be changed frequently to prevent dust build-up on HEPA filter. • Regular cleaning of ductwork vents should be done. Filter should be replaced as per need and the replaced filter should be disposed into plastic bag immediately to prevent potential exposure of patients and staffs as HVAC system is shut down at that time. • Air intake system should be kept free from bird droppings as much as possible to minimize the concentration of fungal spores in entering air. • Temperature and humidity of the air should be regularly monitored. Excessive humidity and moisture accumulation in HVAC system can increase proliferation of fungi (Aspergillus, etc.) and bacteria (Pseudomonas aeruginosa, Staphylococcus aureus, Acinetobacter spp. etc.) causing significant spread of nosocomial infection in ICU. Water is present in cooling units and humidifying boxes. Duct system also can create conditions of high humidity and excess moisture. • Hydrogen peroxide vapor. • Ultraviolet light decontamination for terminal cleaning. • Ultramicrofibers associated with copper-based biocide for daily cleaning. • Continuous classes (both classroom and bedside) to educate the health care workers is one of the most important strategy to have success in control of infection in ICU. • Pictures, animations, and videos are good options through which knowledge of good hygiene and consequences of infections can be shared very rapidly. • Feedback should be taken from HCWs. • Close monitoring of hand-hygiene practice is single most important factor to reduce infection in ICU significantly. • Incidence and prevalence data of all types of infection in ICU are to be sincerely collected and analyzed and based upon which annual/biannual audit should be done. 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(Fekety et al. 1981) . Hand is contaminated through direct infected patient or patient-care items and bed area 1. All the abovementioned preventive measures 2. Restriction of use of antimicrobial agents (Johnson et al. 1992) 3. Environmental cleaning with specific chemical germicide (chlorine containing chemicals like 5000 ppm sodium hypochlorite 1:10 v/v dilution or phosphatebuffered hypochlorite 1600 ppm According to literature, three new technologies seem to be successful to disinfect the ICU environment even in inaccessible areas (Blazejewski et al. 2011)