Page 34 Complete Your CE Test Online - Click Here An absolute neutrophil count (ANC) of 500-1,000 is considered mild- moderate neutropenia, 100-500 is severely neutropenic, and an ANC less than 100 is profoundly so. To calculate the ANC, add together the percentage of bands plus segs, polys, or neutrophils, then multiply by the number of total number white blood cells. For example, a person with a total white blood count of 550 with 60% segs and 4% bands would have an ANC of 352 (550 x 0.64 = 352). This person has neutropenia and should be watched for any signs of infection because an immediate fever workup and antibiotics would be indicated. This is especially important if the patient’s white count is still dropping after a cycle of chemotherapy. In people with cancer, there is some urgency to completing this sequence because infection can sometimes progress to septic shock and death very quickly. Fever workups: Make ‘em stat A fever workup in the neutropenic patient usually starts with two sets of blood cultures. If the patient has a port or a CVL, one set of blood cultures is taken from the line and the other from a peripheral site. However, given that many people with cancer have very poor peripheral venous access it is sometimes necessary to take both from the line. Generally, a CBC with differential is taken as well, along with electrolytes, BUN, creatinine, and liver function tests. A chest X-ray, sputum cultures, and pulse oximetry would typically be conducted if the patient had respiratory symptoms. If the patient has skin lesions/ drainage, UTI symptoms or a urinary catheter, additional cultures are taken from these sites. Stool for enteric pathogens may be done if the patient has diarrhea, with a probe for Clostridium difficile toxins if the patient has had antibiotics in the past few weeks (see “Diarrhea”). Additional history is taken to find out if the person has any other new symptoms such as sore throat, skin or mucosal ulcers, etc., which are then usually cultured or tested for viruses. People with localizing symptoms such as abdominal pain or a new headache, stiff neck, etc., might need additional scans or tests. As soon as cultures are completed, broad-spectrum antibiotics are typically administered until more information becomes available from the cultures and scans to focus the antibiotic therapy on the causative organism [208]. Case study: A 54-year-old woman with acute myelogenous leukemia has a WBC of 400 with 40% segs and 5% bands near the end of her first treatment (intended to induce remission). This calculates out as an ANC of 180 (0.40+0.05=0.45; 400 x 0.45 = 180). You note that her ANC has been below 500 for the a days and still seems to be declining. With an ANC of 180 she has fairly significant neutropenia. At this time, she does not have fever or other signs of infection. What are your concerns? Case discussion: With this ANC, your patient is at increasing risk for infection and must be watched closely for signs of infection. In general, the longer and more severe the neutropenia is, the higher the risk for serious infections. She may be a candidate for prophylactic antibiotics if the neutropenia is expected to worsen or to continue for more than ten days. For example, the ASCO recommends prophylaxis for patients whose ANC is expected to go below 100 for seven days or more [211]. Fluoroquinolone antibiotics (such as ciprofloxacin, levofloxacin, and gemifloxacin) are often used preventively, along with antifungal and even antiviral prophylaxis drugs until the neutopenia resolves. With high risk patients, preventive antibiotics specifically for pneumocystis pneumomia (trimethoprim + sulfa, atovaquone, and others) are often added; this is known as PCP prophylaxis [208]. Myeloid growth factors can be used for some patients With other diagnoses, such as solid tumors and non-myeloid cancers, myeloid growth factors (such as filgrastim, pegfilgrastim, and other granulocyte colony stimulating factors) might be considered for people at high risk (>20%) of febrile neutropenia. This includes people with liver or renal dysfunction, recent surgery, age >65 getting full-dose chemotherapy, or bone marrow involvement by the tumor, among others. A patient with AML is not a candidate for myeloid growth factor use as that is a myeloid cancer. Growth factors are not recommended for routine use, but patients who have had febrile neutropenia or a dose-limiting neutropenic event after a chemotherapy cycle may be considered for addition of a myeloid growth factor on subsequent chemo cycles [207]. Patients with sepsis, neutropenia expected to last more than ten days, invasive fungal infections, or an ANC < 100 may also be considered for immediate use of a myeloid factor, although this use has not been shown to reduce mortality in adults. Myeloid growth factors are not without risks, which are typically mild, but occasionally allergic reactions, capillary leak syndrome, sequestration of WBCs in the lungs, adult respiratory distress syndrome, and splenic rupture (with some fatalities) have occurred [207]. Anemia Anemia is common and it is found in 30-90% of patients with cancer. It can be a major contributor to fatigue. Anemia is caused by low production of red blood cells (RBCs), destruction of RBCs, or bleeding [205]. The impact of anemia on the patient varies depending on factors such as [163,205]: ● ● Speed of onset (patients can acclimate to gradual declines up to a point). ● ● Patient age (older patients may have worse outcomes). ● ● Plasma-volume status (dehydration can make hematocrit appear more normal but cause more problems). ● ● The number and severity of comorbidities (can mean less ability to adapt to lower hemoglobin levels). Anemia can be categorized as mild to life-threatening based on hemoglobin level [205]: ● ● Mild anemia: Hemoglobin of 10g/dL to lower limit of normal. ● ● Moderate anemia: Hemoglobin of 8 to