Hospital-acquired infections: the RVT's role in beating the bugs
By Dennis Spann, DVM, DACVIM
Hospital acquired infections (HAIs) are an extremely pressing issue in human and veterinary medicine. HAIs are defined as infections that occur within 48 hours to 30 days after hospitalization. Risk factors for HAIs include prolonged hospitalization, polytrauma cases, surgical interventions, critical illness, prolonged recumbence, immune suppression, increased or inappropriate antibiotic use, and failure to adequately observe personal and environmental cleanliness. Risk factors for resistant infections include prolonged hospitalization (hospital bacteria are usually resistant), prior antibiotic usage, and inappropriate antibiotic use. Identifying at-risk patients, applying sound personal and facility hygiene, and antibiotic stewardship are vital steps in preventing infections in veterinary patients.
Complications due to HAIs
HAIs are a frequent complication of inpatient and outpatient medical care. On the human side, the Center for Disease Control in the United States reports that each year there are two million cases of HAI. Up to 20,000 deaths, increased morbidity, and millions of additional dollars in medical expenses are caused by these infections. Seventy-five percent of HAIs are resistant to multiple antibiotics, making them much harder and more costly to treat. Moving forward, infection prevention and wise use of the antibiotics available to us will be the best way to decrease the prevalence of HAIs and the increased prevalence of resistance. Technicians are the front line of infection prevention in every hospital setting, making them absolutely integral to the success of any infection prevention strategies.
Incidence and resistance
The incidence of HAIs in veterinary medicine is unknown because there is no mechanism to record them, but it is likely to be a growing problem for two reasons: first, as we develop more sophisticated treatment regimens, animals often have increased risks for HAIs. Second, as bacteria become resistant, antibiotic prophylaxis is less likely to prevent infections associated with invasive procedures. The increased prevalence of resistant bacteria in a hospital setting means that effective antibiotics are less likely to be available. Antibiotic development is slow and the rate that useful antibiotics make it to the clinic floor is not sufficient to solve the problem. Since the beginning of the antibiotic age, bacteria resistance has outpaced new antibiotic development. Knowledge, and a great infection control plan, are essential to prevent HAIs.
Team approach to combatting HAIs
The initial step to lowering the prevalence of HAIs is to develop an infection control team. The team should include representative staff from client services representatives, medical staff, and other support staff. The intensive care team can be led by either registered veterinary technicians (RVTs) or veterinarians, or both. RVT involvement is important because nursing staff can identify problem areas and streamline practical logistics for implementation. The infection control goals should be part of a protocol book that is kept as a larger reference, and broken into bulleted lists and checklists for ease of use in the various departments.
At-risk patients
Several types of patients are at risk for HAIs including polytrauma patients and surgical patients because they have breaks in their skin. Also, their recumbence can cause atelectasis and pressure sores. Careful attention to patient hygiene, comfort, and positioning can greatly decrease the risk for infection. Chemotherapy patients and patients receiving immune suppressive medications are also at increased risk for infection. Critically ill patients are often compromised in several body systems, and immune suppression is a common sequela of sepsis and other critical illness.
The importance of hygiene
Personal hygiene is essential to infection control. Because hospital staff can become contaminated with bacteria, we unfortunately make very effective fomites to spread infection from one patient to another. Clients may also inadvertently spread infection from their pet to other patients during visits, so diligence and hand washing are essential to prevent the spread of bacteria. Hand washing should occur before and after any encounter with patients, their cages, or handling biologics. Studies have documented significant decreases in the incidence of HAIs when the frequency of hand washing increased. This is both simple and cost effective. Unfortunately, most people perceive their hand washing compliance to be much better than it is, so strategies to remind people with signage, fluorescent indicators, and other positive reinforcement is essential. This is important throughout the hospital since bacteria can be spread out of and back into patient treatment areas. When leaders like nursing staff wash their hands, other staff tend to be more compliant.
Environmental hygiene is also important in decreasing the risk of infection, and cleaning should be a two-step process. The organics need to be removed by washing with detergents, and sanitization can occur by using bactericidal solutions. If the first step is omitted, efficiency drops dramatically. Potential trouble spots include areas where the surfaces are corroded or pitted, allowing retention of organics. Corrosive disinfectant solutions, like concentrated bleach, potentiate this problem. Wood surfaces that lose sealant and are splintered or worn can be very difficult to clean as well. These problems are exacerbated by bacterial biofilms; many bacteria secrete a glycoprotein matrix called a biofilm that protects bacteria from dessication and disinfectants.
Drug resistance
Bacteria that are frequent offenders and troubling in the healthcare setting include Staphylococcus pseudintermedius, Staphylococcus aureus, Escherichia coli, Klebsiella pneumonia, Acinetobacter baumanii, Pseudomonas aeruginosa, Salmonella ssp., and Clostridium difficile. These pathogens are frequently capable of multidrug resistance. While drug resistant bacteria aren’t necessarily more pathologic, they are harder to to treat effectively. Bacteria obtain resistance not only from transfer of DNA elements between each other, but also by picking up DNA from the environment. So even remnants of dead bacteria can exacerbate the problem of resistant bacteria. Since the indiscriminate and incorrect use of antibiotics increases the selection of resistant bacteria, educating medical professionals and clients decreases the tendency to “just try antibiotics”. Advising clients that testing and culturing increases proper antibiotic selection is a very important role of technicians as well as veterinarians.
In order to identify whether there are increases in bacterial resistance, a record of bacterial resistance patterns should be kept by organizing all cultures submitted (organized by body system) in a binder, or better yet, in a spreadsheet called an antibiogram. The antibiogram lines up organisms cultured against sensitivity patterns. Collectively, this allows for more effective empirical antibiotic selection while waiting for cultures. The antibiogram is more specific to a particular geography than a textbook recommendation. This tool is more effective if the reference lab compiles the results of multiple local clinics; even a single clinic or cooperative of local clinics can generate useful information via combined culture results.
Choosing the appropriate antibiotic
Antibiotic selection should be based on the most effective antibiotic for the site of infection. Ideally antibiotics should be divided into first line, second line, third line, or last resort antibiotics. As bacteria develop increased resistance, antibiotics like the penems (imipenem, etc.), polymixins (colistin), oxazolidinones (linezolid), and others should be held in reserve and available via a process that identifies other potential options and likely success if these antibiotics are to be used at all. Nursing staff can be intimately involved in antibiotic stewardship both by staff and doctor education and by client education about the importance of correct antibiotic usage.
Summary
HAIs are a serious problem with no quick fix. Reducing the prevalence of infection and resistant infection requires education, attention to detail, and solid health care protocols and teamwork. The RVT is integral to the success of planning and executing any program of infection control.
This article is based on Dr. Spann’s presentation at the American College of Veterinary Internal Medicine Forum in Denver, CO.CVT
