Skip to main content

All Access Subscription

Get unlimited access to our full publication and article library.

Get Access Now

Interested in Group Sales? Learn more

Close calls: You may need backup for critical PEP decisions

Close calls: You may need backup for critical PEP decisions

We are talking about hours rather than days’

The scene is all too familiar in many of the nation’s emergency rooms (ER), and may well happen in the middle of a hectic night. A staff nurse has been stuck with a blood-filled needle, and the clock started ticking before she even walked in the room. If the exposure was to HIV, there’s a chance that the right combination of antiretroviral drugs may yet stave off the most dreaded occupational infection in health care.

"In many hospitals, if you have an occupational exposure, you go down to the emergency room and report it to the staff," says David Henderson, MD, medical epidemiologist at the National Institutes of Health Clinical Center in Bethesda, MD. "But the emergency room doctor virtually has no experience [with post-exposure prophylaxis (PEP)] and doesn’t routinely prescribe the drugs."

Acknowledging the increasingly complex factors involved in PEP for HIV, the Centers for Disease Control and Prevention is advising confused clinicians to call for expert consultations before administering the potentially toxic drugs. (See recommenda- tions, p. 108 ) The CDC outlines several special circumstances (e.g., delayed exposure report, unknown source patient, pregnancy in the exposed person, resistance of the source virus to antiretroviral agents, or toxicity of the PEP regimen) when consultation with local experts and/or the National Clinicians’ Post-Exposure Prophylaxis Hotline — PEPline or (888) 448-4911 — is advised.1

"The PEPline staff are national authorities," says Henderson, who consulted with the CDC on the guidelines. "If the emergency room doc thinks to call the PEPline, we are in good shape. If the hospital program for managing occupational exposures ends up relying on someone who does not see this problem commonly, then in almost every instance, it is probably in the best interest of both the hospital and the person who has the exposure to call the PEPline."

Complicating the situation, if PEP is to be administered, it needs to be sooner than later. "We are not making any specific recommendation like within two hours’ because the data just aren’t there to make that kind of absolute statement," says Elise Beltrami, MD, epidemiologist in the CDC division of healthcare quality promotion. "Clearly, the animal studies show that the sooner you start it the better. We are talking about hours rather than days after an exposure."

With pressure to make the decision essentially as quickly as possible, the risk of powerful drugs must be balanced against the likelihood of infection.

"There are risks associated with administering these agents," says Henderson. "Some of them are active at the level of DNA. Some of them are associated with acute and life-threatening toxicity. We don’t want to give them to people who don’t need them."

Indeed, the guideline specifies that the drug nevirapine is not recommended for PEP because it has been associated with severe hepatotoxicity and at least one case of liver failure requiring transplantation. Citing concerns with toxicity, drug interactions, and other disadvantages, the CDC also advised that only PEP experts consider using the antiviral agents ritonavir, saquinavir, delavirdine, and lopinavir.

In addition to those specific concerns, public health officials generally have been alarmed that PEP has been too often administered for minor exposures or those that do not even involve an HIV-positive source. But health care workers may demand the drugs in a situation that is somewhat analogous to the suffering patient’s expectation of being administered an antibiotic, Henderson says.

"You feel the heat," he says. "In this case, if you don’t prescribe three-drug prophylaxis, the person leaves the room thinking [he has] not been well taken care of."

Yet often the HIV drug expert on the other end of the PEPline will assess the situation and advise against beginning therapy.

"It is not at all uncommon that we recommend that people don’t start PEP, or if they are already on it, to go to fewer drugs or discontinue," says David Bangsberg, MD, MPH, co-director of the hotline. "Many health care workers will overestimate the risk of exposures and deem an event an exposure where [none occurred]. They will put patients on PEP unnecessarily. So one of our roles is to help evaluate exposures and sift out the ones that really need PEP from the vast majority that don’t."

The CDC recommendations for HIV PEP include a basic four-week regimen of two drugs (zidovudine [ZDV] and lamivudine [3TC]; 3TC and stavudine [d4T]; or didanosine [ddI] and d4T) for most HIV exposures and an expanded regimen that includes the addition of a third drug for HIV exposures that pose an increased risk for transmission. (See regimens, pp. 109-110.) The new CDC guidelines are "user-friendly" but cannot possibly address all scenarios, adds Bangsberg, who also consulted with the CDC in creating the guidance.

"No guideline can cover the range of possible events and treatment options," he says. "That’s why these guidelines are going to call for a great role by the national hotline."

In addition to toxicity concerns, the complex problem of HIV resistance makes the correct drug choice critical to successful prophylaxis.

"The choice of [PEPs] needs to be based on the anticipated resistant pattern of the [source] patient," he says. "And that becomes a science in and of itself in terms of choosing a safe or tolerable regimen that is likely to have activity against the [virus]."

While HIV drug expertise may be lacking in many rural and community hospitals, there is another, somewhat surprising side to the story.

"In urban centers, we find many expert HIV physicians who are prescribing antiretroviral therapy on a daily basis [to HIV patients]," Bangsberg says. "They take a different tack on this. They are used to treating patients with HIV infection where these drugs are life-saving. They accept a higher risk-benefit ratio."

But in sharp contrast to an HIV patient, a health care worker exposed to the virus via a needlestick still has a 99.7% chance of remaining infection-free.

"We [at the PEPline] often take a more conservative approach with respect to toxicity than the usual HIV-treating clinicians," Bangsberg says. "It’s a practice pattern. I treat HIV-infected patients myself. You become quite comfortable with these drugs, and you accept the toxicity associated with them because these drugs are live-saving. I think many clinicians get used to that mindset, and on the few patients they may consult on for PEP, it may be difficult to step out of it."

Beyond that issue, the question also remains whether hospitals fortunate enough to have experts on staff can reach them in the middle of the night or on holidays. For example, one ICP who has a board-certified infectious disease physician on staff still plans to encourage use of the PEPline.

"The bottom line is that it’s [2 a.m.] and the ER physician is faced with this decision," says Patti Grant, RN, MS, CIC, an ICP at RHD Memorial Medical Center in Dallas. "We would still follow up with our ID doc in the morning whether we call the PEPhotline or not. It’s not that the ER physicians do not know or do not want to know. It’s just that this is not all they do."

Overall, Grant found the new guidelines clear and straightforward, particularly the addition of checklists and appendices. "That is really going to make it a whole lot easier for each of us to go through and update our individual protocols," she says.

Gleaning through the document for Hospital Infection Control, Grant noted an increased emphasis on asking HIV-exposed employees who are coming in for follow-up testing if they have experienced nausea or flu-like symptoms. Such symptoms could be the acute retroviral syndrome that signals seroconversion to HIV. "People should be told if this happens to you between week 12 and your six-month check, we need to have you looked at now," she says.

The CDC also addresses the so-called "window period," that concerns many health care workers even when source patients test negative. Exposed workers fear they will still become infected if the patient is in the interim "window" between their own exposure and seroconversion.

"If the source person is negative and has no evidence of AIDS or symptoms of infection, no further [worker testing] is indicated," Beltrami says. "The fact is that the chances that someone is in the so-called window period in the absence of having symptoms of infection and having a negative test is extremely unlikely. We tried to emphasize that."

An even bigger problem may occur after health care workers get started on PEP because the HIV status of the source is unknown. "At the time of the exposure, they don’t know whether or not the [source patient] was infected so they go ahead and get started on PEP," she says. "But they get lost to follow-up and end up taking PEP for four weeks without finding out that the source patient is negative. It really would be horrible if such a person had serious adverse [drug reaction] and didn’t even need to be on [PEP]."

Some of those situations can be eliminated by rapid HIV tests, but the CDC did not emphasize the tests as much as it might have because the assays have been in regulatory limbo until recently. Now that the Single Use Diagnostic System test is back on the market, and other tests are under investigatory use, infection control professionals should certainly consider getting them in-house.

"If your lab can’t turn around the routine EIAs within 24 or 48 hours, you really should consider using the rapid tests," Beltrami says. "There are some studies that show that that is cost-effective and it actually decreases the amount of unnecessary tests that health care workers are exposed to."

(Editor’s note: The complete CDC guidelines are posted on the web at your free subscriber web site at www.HIConline.com or at http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5011a1.htm.)

Reference

1. Centers for Disease Control and Prevention. Updated U.S. Public Health Service guidelines for the management of occupational exposures to HBV, HCV, and HIV and recommendations for post-exposure prophylaxis. MMWR 2001; 50(RR11):1-42. n