These medications can be difficult to tolerate given

their side effect profile (headache, asthenia, and gastrointestinal intolerance). In addition to the dose administered

in the ED, the patient will require continued therapy for

1 month.

For potential HBV exposures, the health care worker's

vaccination status should first be determined. If the exposed

person is unvaccinated, treatment with hepatitis B immunoglobulin (HBIG) should be started as soon as possible

after exposure (preferably within 24 hours). If the exposed

person was vaccinated but didn't have an appropriate antibody response (HBsAb <10 miU/mL), then proceed as if

unvaccinated. If the exposed person has an appropriate

antibody response after vaccination, then no treatment is

needed, although a booster HBV vaccine can be considered.

CHAPTER 38

STEP 1: Determine the exposure code (EC)

Is the source material blood, bloody fluid, other potentially infectious material

(OPIM) or an instrument contami nated with one of these substances?

Large

(e.g., severa l drops,

major blood splash and/or

longer duration [i.e., severa l

minutes or more))

Less severe

(e.g., solid needle,

superficial scratch)

STEP 2: Determine the HIV status code (HIV SC)

Lower titer exposure

(e.g., asymptomatic

and high CD4 count)

STEP 3: Determine the PEP recommendation

PEP recommendations

PEP may not be wa rra nted . Exposure type does not pose a known risk for HIV transmission.

Consider basic regimen. Exposure type poses a negligible risk for HIV transmission.

Recommend basic regimen. Most HIV exposures are in this category;

no increased risk for HIV tra nsmission has been observed but use of PEP is appropriate.

Recommend expanded regimen. Exposure type represents an increased HIV transmission risk.

Recommend expanded regimen. Exposure type represents an increased HIV transmission risk.

If the source or, in the case of an unknown source, the setti ng where the exposure occurred

suggests a possible risk for HIV exposure and the EC is 2 or 3, consider PEP basic program .

..&. Figure 38-1 . Blood and body fluid exposure diag nostic algorithm. Reprinted with permission from Public

Health Service Guidel ines for the Management of Health-Care Worker Exposures to HIV and Recommendations

for Postexposure Prophylaxis. MMWR Recomm Rep. 1 998 May1 5;47(RR-7):1-33. Available at http:/ /wonder

.cdc.gov /wonder I prevguid/ m00 52 722/m0052722 .asp.

BLOOD AND BODY FLUID EXPOSU RE

For potential HCV exposures, baseline testing for antiHCV, HCV RNA, and ALT should occur with follow-up

testing for HCV RNA between 4 and 6 weeks after expo ­

sure and follow-up testing for anti-HCV, HCV RNA, and

ALT between 4 and 6 months after exposure. Currently

there is no proven effective postexposure prophylaxis treatment available. Immunoglobulins and antiviral agents are

not recommended.

All patients should be counseled on refraining from

unprotected sexual intercourse and blood donations.

Follow-up should be given with the institution's

employee health departments.

DISPOSITION

Health care workers exposed to blood or body fluids can be

discharged home with instructions to follow up with their

hospital's employee health offices the next business day.

SUGGESTED READING

Centers for Disease Control and Prevention. Basic and expanded

HIV postexposure prophylaxis regimens. http://www.cdc

.gov/mmwr/preview/mmwrhtml/rr5011a4.htm. Accessed

April 28, 2012.

Centers for Disease Control and Prevention. Management of

occupational blood exposures. http://www.cdc.gov/mmwr

/preview/mmwrhtrnl/rr50 1 1 a3.htm. Accessed April 28, 2012.

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 Postexposure Prophylaxis http://www

.cdc.gov/mmwr/preview/mmwrhtrnl/rr50 1 1a1.htrn. Accessed

April 28, 2012.

Centers for Disease Control and Prevention. Updated U.S.

Public Health Service Guidelines for the Management of

Occupational Exposures to HIV and Recommendations

for Postexposure Prophylaxis. http://www.cdc.gov/mmwr

/preview/mmwrhtml/rr5409al .htm. Accessed April 28, 20 1 2.

Nephrolithiasis

jonatha n Ban koff, MD

Key Points

• Analgesic administration should not be delayed while

obtaining laboratory and radiology studies.

• Abdominal aortic aneurysm should be considered in

the differential of elderly patients being eval uated for

kidney stones.

INTRODUCTION

Kidney stones occur when urinary solutes precipitate out

of the urine and form crystalline stones in the

genitourinary (GU) tract. Nephrolithiasis is common in

the United States, with an estimated prevalence of 7% in

men and 3% in women. Kidney stones most often affect

people in the third to fifth decades of life, but can occur

at all ages.