Infection Control in the ICU:
The Final Frontier
By Kathy Dix
For years, you've heard the tenets of real estate summarized in three words: location, location, location. The infection control field now has its own three-word maxim: vigilance, vigilance, vigilance.
Although many issues of infection control can be countered by technology (gloves, sharps covers, air exchanges), none of these aids work without constant vigilance on the part of healthcare workers (HCWs). Caution is especially critical in the intensive care unit (ICU). "We typically see more infections in this population due to the length of time they may be in a unit," says Kathleen Howard, infection control specialist at St. Joseph's Hospital in Phoenix. Those infections can be due to the number of invasive lines, mechanical ventilation, or other parameters specific to ICU patients. "But the practices to reduce infections remain the same as for all patient populations," she says.
Teresa Garrison, manager of infection control at Barnes-Jewish Hospital in St. Louis, agrees. "The precautions are the same," she says. "We have a house-wide policy related to handwashing, gowning, gloving and isolation. I think what is more important, in an area where patients are so at risk (a lot of invasive lines, a lot of technology) and are already immunocompromised, we really need to follow those standard precautions to the letter."
Barnes-Jewish is taking infection control very seriously these days, Garrison adds. "We do a lot of focused surveillance in the ICU. We look at things that are high risk, high volume, high cost, and tailor our actions to that. Last year we decreased our ventilator-associated pneumonia by 50 percent with posters and fact sheets that we rotated. We had good success with our bloodstream infection module -- we tailored all this education -- and we're rolling those interventions to the rest of the floors."
According to Jennie Mayfield, an infection control specialist at Barnes-Jewish, the difference between infection control in ICUs vs. the wards is one of degree. "Patients in the ICU are severely ill and often bed-ridden," she explains. "They also tend to have many invasive devices such as Foley catheters to measure output, central lines for fluids and monitoring, arterial lines to measure pressures, endotracheal tubes for assisted ventilation, etc., that patients in other parts of the hospital don't have. The presence of an invasive device automatically increases the risk of infection because it provides a ready means of entry by bacteria into a normally clean space."
Although these patients can be particularly susceptible to infections, hand hygiene guidelines remain the same everywhere. St. Joseph's requires handwashing before and after each patient encounter and requires the use of antimicrobial agents prior to invasive procedures. "Due to the number of different caregivers and severity of the illnesses, there is a greater potential for contact with body fluids or environmental contamination," Howard explains. "The use of alcohol-based waterless products can improve adherence with hand hygiene practices due to ease of use and less time required for effective disinfection."
ICU patients' severe illnesses and injuries necessitate much more hands-on care than in normal wards, Mayfield concurs. That care can include bathing, IV site care, suctioning and the administration of medication. "The fact that there are so many tasks and so many devices means that there are more opportunities to transmit pathogens from person to person," she says. "Ergo, there are more situations requiring good hand hygiene on the part of HCWs with either soap/water or alcohol based product. I believe some researchers have found that the busier staff are, the more likely they are to not wash their hands when they should, which again increases the potential for person-to-person transmission."
Urinary Tract Infections (UTIs)
The ICU often sees a greater use of catheters because of the severity of patient illnesses. "The use of impregnated catheters is one way to decrease rates of catheter-associated UTIs, but removal of catheters as soon as possible is the best practice," Howard recommends.
"The number of lines a patient may have for monitoring or nutrition increases the risk of line-related infections," continues Howard. "Adherence to recommendations regarding insertions, line care, access and tubing changes can help reduce this risk," she suggests. Another option is to use impregnated catheters or dressings.
The use of ventilators can increase the risk of pneumonia (device-related infections). But following the established protocol for head-of-bed (HOB) elevation, tubing changes and suctioning practices can go a long way toward reducing the risk of infection. And, Howard adds, in non-ventilated patients, positioning can help reduce the risk of aspiration pneumonia.
Although bloodstream infections, ventilator-associated pneumonia and Foley-related urinary tract infections are such a concern, Mayfield suggests that strategies for preventing nosocomial infections are much the same regardless of the hospital setting. "We'd probably do the same things in the ICU that we would on the floor in terms of prevention," she asserts.
Surgical Site Infections (SSIs)
Long a prime source of infection, SSIs can become a mammoth problem for ICU patients who may have more drains than the general population. To reduce the risk of complications, medical staff should adhere to recommended practices regarding care. Since these patients usually cannot ambulate as early, the risks for complications increase.
Because of the increase in invasive devices and procedures, patients may have to be kept on antibiotics for longer periods of time, Howard notes. Obviously, long-term or frequent exposure to antibiotics can increase the incidence of antibiotic resistance, so reducing infections becomes even more of a concern.
Because they tend to receive antibiotics more often, creative tactics have become necessary to reduce resistance. "Some prevention strategies now being tested include antimicrobial cycling," says Mayfield. "Antibiotics are changed and rotated on a set schedule to prevent resistance to a particular drug. There are several on-going trials looking at this."
Vigilance, Vigilance, Vigilance
The most crucial element in reducing infections in the ICU is the staff. "Having skilled personnel can reduce any adverse outcomes," Howard states. "The length of time someone is in an ICU setting can increase the risk of infections (e.g., the longer patients are ventilated mechanically, and the longer invasive lines are present. Therefore, decreasing ICU days can have a favorable outcome for nosocomial infections."
Some issues seem to be limited strictly to the ICU. Those issues would be related to invasive monitoring, Howard continues, which may not be present in regular patient care units and may include specific care issues. And ICU patients, more than the general population, may already be compromised by several elements:
- Disease processes
- Interruption of normal defense mechanisms (by mechanical ventilation, etc.)
- Malnutrition due to the inability to eat
- The inability to ambulate
The ICU team includes a host of specialized employees -- environmental cleaning personnel, dietitians, nurses, respiratory therapists and physicians -- to counteract these problems. The expertise and caution of this staff can have a direct bearing on patient outcomes. "All members need to work together to reduce risks to the lowest possible levels," Howard asserts. "The use of established guidelines based on research such as the Centers for Disease Control and Prevention (CDC)'s Healthcare Infection Control Practices Advisory Committee (HICPAC) guidelines related to pneumonia, intravascular devices and hand hygiene can assist in the process to reduce rates."
Another hospital ward that necessitates extra caution is the oncology unit. Mayfield has focused particularly on this segment of potentially immunocompromised patients. "Oncology is much the same as the ICU setting, except that the patients tend to have fewer invasive devices (they rarely have Foleys; they are rarely intubated unless critically ill; all have central lines of some sort)," she comments. "However, many oncology patients have altered neutrophil counts, which directly impacts the body's ability to fight off infection. Oncology patients are particularly prone to infection with opportunistic organisms, or organisms that are ubiquitous in the environment but cause problems in severely immunocompromised patients, like Aspergillus, other molds and fungi and certain viruses like cytomegalovirus, herpes virus, etc. This is one reason stem cell/bone marrow transplant units have special ventilation systems (all the rooms are at positive pressure, so the air flows from the room into the hall). This is specifically designed to keep airborne pathogens out of the patient rooms."
The neonatal and pediatric ICUs also have special issues. Because children and especially premature infants may have immature host defenses, they may be at greater risk for infection. Again, Howard emphasizes, the skill of the staff working in these areas has a direct bearing on the patient outcome. "Premature infants can have very subtle signs of distress leading to sepsis, and neonatal ICU (NICU) staff are educated to observe for them," she says. "As with the adult, use of mechanical ventilation, more invasive lines and nutrition concerns can also affect the infection rates. Adherence to aseptic technique, hand hygiene practices, care for invasive lines and ventilator care can do much to reduce the incidence."
Several other objectives should be kept in mind:
- The removal of invasive devices as quickly as possible
- Restriction of children visitation during seasonal outbreaks of respiratory viruses, which can reduce exposure to these community viruses
- Vigilance of HCWs in observing visitors for signs of infections
- Education for visitors on the importance of hand hygiene
The CDC has numerous recommendations for preventing hospital-acquired infections. A complete list is available at www.cdc.gov.