Paradigm shift: Rethinking IC and rising patient acuity
Novel catheters; isolation of high-risk patients
Technological advances like antiseptic-coated catheters and other intravascular devices designed for infection prevention may become increasingly important clinical weapons as inpatient acuity increases, Dennis Maki, MD, emphasized recently in San Francisco at the annual conference of the Society for Healthcare Epidemi o logy of America.
Maki, the chief of infectious diseases at the University of Wisconsin Hospital and Clinics in Madison, delivered the SHEA lecture, one of the conference’s keynote addresses. Surveying a health care landscape marked by spiraling inpatient acuity, Maki said new infection control approaches must be embraced because the old paradigms are failing.
"There has been a tremendous trend in acute care hospitals over the last 15 years towards an intensification of care," Maki said. "The severity of illness of patients in hospitals is striking. In my own ICU where I have been doing research and have been attending for almost 25 years, the average Apache II score has increased from about 12, 15 to 20 years ago, to 16 to 18 now, which is a tremendous increase in terms of risk for the patient."
Such severely ill patients may well survive due to the medical skills and devices that can be brought to bear in today’s ICUs, but all the while they face increased risk of nosocomial infections, he added.
"The price we pay is a great increase in risk of infection, and I think that we are starting to lose the battle in terms of nosocomial infection," he said. "I think that rates of bloodstream infections and pneumonias are increasing. It’s very clear that certain organisms, such as nosocomial fungi, have increased almost tenfold over the last 15 years. We’ve lost the battle against MRSA, and we are losing the battle against vancomycin-resistant enterococcus [VRE]."
Infection surveillance may suffer under trends toward increased acuity of care and decreased staffing per patient, especially bedside nurses in ICUs, he added.
"Our databases in individual hospitals are shrinking because we’re being asked to do more and more with less and less. There are less resources targeted toward surveillance," Maki told SHEA attendees. "I’m not sure we really fully understand what’s happening in our hospitals. The challenge to simply hold the line is formida ble. What can we expect [to achieve] in terms of trying to further modify health care workers’ behavior to try to reduce the risk of infection? I would submit this is the old paradigm, and I think it’s failing."
But a new paradigm may be emerging in light of epidemiologic research underscoring advances in infection prevention technology, he said. Such advances may provide a new avenue to infection prevention in light of the continuing struggles to improve health care worker compliance with aseptic measures in the care of catheters and invasive lines.
"Trying to whip people to comply more is not the direction we ought to be going in," he said. "I think the yield is going to be extremely [low] and it’s going to [do] nothing but engender more frustration."
The greatest advances have been made with intravascular devices such as catheters. For example, catheters coated with silver sulfadiazine chlorhexidine have been shown to reduce the risk of infections — particularly those caused by multiresistant organisms — by about 50% in some dozen studies. Catheter-related infections may occur when microorganisms invade the implanted portion of the device and then colonize the surface in a biofilm. But strategies to make the device’s surface less conducive to formation of a biofilm are starting to pay off, he said.
"I think it’s a very exciting time to be working in nosocomial infection control, because only in the last 10 years there has been an explosion of good research identifying technologies that hold much promise for substantially reducing the risk of infection independent of whether or not the care that that device gets is what we would like to see," Maki said.
Still, only about 25% of ICU patients with central lines — the highest-risk population — are currently being treated with antiseptic or antimicrobial catheters, he said.
Addressing other topics in his wide-ranging speech, Maki said the emerging data on antibiotic resistance continue to prove that new drug development will not solve the problem. For example, some of the patients treated with Synercid for VRE infection have developed strains of the pathogen resistant to the new streptogramin compound.
"If new antibiotics were the answer, we shouldn’t be drowning in resistant organisms because we’ve had many, many new antibiotics introduced over the last 20 years," Maki said. ". . . The answer is reduced antibiotic pressure and improving infection control."
Yet even a national moratorium on vancomycin use would not solve current resistance problems with that critical antibiotic, he noted. That is because antibiotic use can arise from "cross resistance," in which overuse of one agent inadvertently renders another less effective.
"It turns out that MRSA has certainly not been driven by heavy use of methicillin or semisynthetic penicillins," Maki said. "It has been cephalosporins and other betalactams. VRE has been driven probably more by the use of cephalosporins and anaerobic drugs than vancomycin. Fully 30% of the patients we see in our hospital [with] VRE never saw vancomycin."
Maki recommended more widespread implementation of the kind of computer-assisted antibiotic management programs that have been used in some centers to improve antibiotic use on a broad scale by reducing susceptibility mismatches and excess dosing. With regard to infection control precautions, Maki called for the routine use of barrier precautions on all ICU patients and others at high risk of infection with nosocomial pathogens due to prior heavy exposures to antibiotics or the presence of invasive devices.
"Our current paradigm is, we wait until the lab calls us up and they say, you’ve got MRSA in that sputum or C. diff in that stool,’ and then we . . . scurry and run to put the patient in isolation," he said. "By that time, they have been handled and manipulated by a dozen or two dozen or three dozen [health care workers], and the resistant organism has probably been spread to two or three other people. All we’ve got to do is look at our rates of resistant infection. This is failing dismally."
Emphasizing that greater use of vaccines can have a downstream effect on nosocomial infection prevention, Maki cited "appalling" national data that only about two-thirds of patients over the age of 65 were immunized for influenza last year and only about half received the pneumococcal vaccine.
"It’s very clear that giving the flu vaccine to high-risk patients reduces hospitalizations about 40%," he said. "By a program of assuring that every high-risk patient gets a flu vaccine in your catchment area, in your hospital, in your outpatient clinics, you are going to implicitly reduce nosocomial infections because these patients aren’t going to be admitted to your ICU."
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