Is your staff keeping up with advances in treatment of AIDS and HIV patients
Much has changed in recent years, and it’s easy for nurses to get behind
HIV and AIDS treatment has changed so rapidly that many health care professionals are behind on the latest news. And what they don’t know can hurt patients.
"If it’s been three or even two years since you’ve held an intensive update on HIV, then the chances are you’re working on old knowledge, and in some cases, that old knowledge can be detrimental," says Larry Alonso, RN, BSN, district AIDS coordinator for the Northwest Health District in Dalton, GA.
Alonso teaches health care professionals in Georgia about AIDS.
"With regard to HIV, there have been three huge advances that have brought us to a paradigm shift in how we understand it," Alonso says.
These advances are:
• The virus can be directly measured in blood through a viral load assay.
• A triple-drug combination can prevent HIV from multiplying.
• AIDS has no latency period, so the earlier the treatment, the better the prognosis.
The old school of thought was the disease was an acute viral infection with a period of clinical and infectious latency that lasted maybe three to 10 years, he says.
Now AIDS researchers believe there is no latency period. This perception has changed because of the progress they’ve made in measuring the virus and the patient’s immune response to the virus.
Traditionally, physicians have measured AIDS patients’ CD4 counts. This is a type of white blood cell. People with suppressed white blood cell counts are more susceptible to illness. Therefore, the lower a person’s CD4 count, the more ravaged their immune system.
Then, two years ago, researchers discovered a direct way to measure viral activity in blood infected with HIV, Alonso says. "We’ve improved our means of monitoring the amount of virus that’s in a person’s blood through what they call viral load assay; it’s a blood test that quantifies actual numbers of virions or viral particles per cubic millimeter of blood," Alonso explains.
This new measurement has given researchers a frightening look at the way the virus destroys a body.
"What is happening is there’s a fantastic battle between the virus, which is multiplying on the order of billions of particles per person per day, and the immune system, which is trying to keep up with that response to the order of millions of CD4 cells per person per day," he explains.
This discovery has led to better treatment of AIDS and may result in some AIDS patients living longer. It also greatly benefits health care workers who are exposed to the virus because post-exposure treatment may abort infection. (See story on preventing occupational exposure to AIDS, p. 172.)
A presentation to update staff
Alonso and another guest speaker recently updated the staff of Northwest Home Health Agency in Jasper, GA, with slides, lectures, and a question and answer period. The community also was invited to attend the program.
The agency, which covers five rural north Georgia counties, gave continuing education credit for the AIDS session, says Dotti L. Fryer, director of education/employee health services of Northwest Home Health Agency.
Fryer says the inservice ensured the staff learned the latest research information about a disease that is sometimes forgotten because they see AIDS patients so infrequently.
Home care nurses also need to know the grocery list of opportunistic infections that could strike hold of AIDS patients, says Patricia Yeargin, RN, MN, MPH, certified adult nurse practitioner with the Southeast AIDS Training and Education Center in Atlanta. The center is one of 15 AIDS education and training centers throughout the United States.
"If a person has a severely compromised immune system, then they’re likely to develop additional problems as time goes on," Yeargin says. (See story on opportunistic diseases, p. 172.)
Alonso suggests education managers who would like to update their nursing staffs about AIDS and its treatments could focus on answering the following questions:
1. What happens when someone is exposed to HIV?
The virus appears to have a half-life cycle of eight hours. This means that half of the viruses produced have been cleared from the body within eight hours. "We’re talking feverish viral multiplication," Alonso says. "If there is no latency period, then what’s going on is an incredible amount of viral production."
This is why it’s extremely important for health care professionals to intervene as soon as possible and as hard as possible with the most potent medications available, Alonso adds. (See management of asymptomatic HIV and management of symptomatic HIV, pp. 168-169.)
"The quicker you can implement a pharmacological measure to suppress the viral population, the more you can preserve the immune system," he says. (See HIV infection chart, p. 167.)
The current treatment is to give patients antiretroviral drugs.
2. How do AIDS medications work?
The first class of drugs are reverse transcriptase inhibitors.
Since HIV is a retrovirus, it must reverse transcribe itself from RNA to DNA before it can work its way into the nucleus of a host cell.
Reverse transcriptase is an enzyme that facilitates the reverse transcription from RNA to DNA, and the inhibitor drug prevents that enzyme from working. It blocks RNA from becoming DNA.
Alonso says the problem is the virus creates billions of particles, and "HIV is a very sloppy virus." Researchers estimate that for every exact viral copy produced there are two or three mutations. Some of the mutations don’t work at all, but others work to render reverse transcriptase inhibitors ineffective.
"This is why monotherapy, which is treatment with any one drug or one class of drugs, is no longer recommended," he explains.
That’s where the second class of drugs becomes important: protease inhibitors.
Protease is an enzyme that helps cut viral proteins into specific lengths. If the length is too short or too long, then the virus is disabled. The protease inhibitor drugs interfere with the cleaving of viral proteins into the appropriate length and produces a viral strand that is too long.
Again, the virus develops mutations that are resistant to protease inhibitors very quickly if the drug is used alone.
Rx: Triple-drug combination
So the current treatment is to give patients a triple-drug combination. It includes two reverse transcriptase inhibitors and one protease inhibitor. (See antiretroviral therapy for HIV-infected adults, pp. 170-171.)
"All of these drugs have been found to lower the viral loads in individuals by two and threefold, but they’re not without their difficulties," Alonso says.
3. What are the drawbacks of the triple drug combination?
The main drawback is that patients often fail to stick with the drug regimen. "Think about the last time you had to take a prescription and how faithful you were in completing your regimen with only one medication, and these clients are taking three medications," Alonso says.
Plus, the medications can produce terrible side-effects, including nerve swelling and pain at fingertips; kidney stone formation; nausea, diarrhea, and other uncomfortable problems.
4. How can home care nurses help?
Alonso recommends they include the patient as much as possible in treatment decisions and dosage regimens by reporting the patient’s preferences to the physician.
For example, if the patient never wakes up at 5 a.m., then a dosage schedule that requires the patient to take a pill at 5 a.m. will not work, he says. "It’s setting them up for failure, so include the clients in the discussion of when they are going to take their dosages."
Another consideration has to be the patient’s willingness to adhere to a strict medication regimen.
If a patient skips days of taking medicine, then the health care professionals treating him or her might have to consider withholding medication until the patient agrees to take it properly. Patients who skip their medication can breed more mutations of the virus and create a form that is resistant to medications.
Home care nurses must assess patients’ adherence in complying with the regimen at each visit and help them work out regimens they can follow. They also can contact AIDS education organizations to find out the latest news about the disease. (See AIDS resources, p. 177.)
AIDS advances benefit health care workers
Nurses should know the facts
Health care workers are in a good position to benefit from the latest AIDS research, which shows that a triple-drug combination can effectively suppress HIV before it takes over the body.
The Centers for Disease Control and Prevention (CDC) in Atlanta conducted a study of health care workers and found that post-exposure prophylaxis with AZT alone was associated with a 79% decrease in risk of acquisition of HIV after a needlestick exposure to HIV-infected blood.1
"A couple of things need to be realized and put in perspective," says Larry Alonso, RN, BSN, district AIDS coordinator for the Northwest Health District in Dalton, GA.
"From 1978 to December 1996, there were 163 cases of possible and documented transmission of HIV to health care workers," Alonso says. "The documented number was 52."1
Four conditions increase the risk to a health care worker involved in occupational exposure:
• There’s a deep injury to the worker.
• There is visible blood on the injuring device.
• The device was inserted in the source patient’s vein or artery.
• The source patient’s death from AIDS was within 60 days of the incident.
This indicates that there likely was a high concentration of virus in the patient’s blood, Alonso says. If someone did a viral load on an end-stage patient, it would probably be greater than 100,000 viral particles per cubic millimeter, he adds.
Alonso says these are the facts nurses need to keep in mind when they’re treating AIDS patients. First, that the risk of exposure is very small and second, that it takes those four conditions to greatly increase the risk of transmission of AIDS.
In fact, the CDC recommends that if a health care worker receives a percutaneous injury involving blood, then the person should be started on a triple drug combination as soon as possible, he adds.2
"It’s the kind of thing that we want to arm ourselves with good information," Alonso says.
"We have the three drugs in our district, so a nurse who is stuck can get her hands on medication within an hour."
References
1. HIV-AIDS Surveillance Report 1996. MMWR, Centers for Disease Control and Prevention, Atlanta. 8:21.
2. MMWR, Centers for Disease Control and Prevention, Atlanta. June 7, 1996; 45:471.
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