Pathophysiology

Table 99-4 Commonly Isolated Pathogens in Patients With FN

Type of Organism Comments

Bacteria

Gram-positive organisms

Coagulase-negative staphylococci (i.e., Staph epidermidls) Staph aureus Enterococcus species Viridans streptococci

Gram-negative organisms

Pseudomonas aeruginosa Escherichia coli Klebsiella species Enterobacter species Fungi

Yeasts

Candida albicans Nonalbicans Candida (C krusei, C. glabrata) Molds

Aspergillus species Fusarium species Scedosporium species

Most common isolates in FN Between 70% and 90% resistance to methicillin; indolent course with low mortality

Some centers report greater than 50%

resistance to methicillin Resistance to vancomycin greater than or equal to 3C% Increasing resls:ance to penicillin; result of fluoroquinolone prophylaxis; associated wi:h mucositis

Infections rapicly fatal

High mortality; Increasing resistance to quinolones Increased incidence of/3-lactamase producing strains Increased incidence of lactamase producing strains

Occur primarily after prolonged neutropenia (greater than 1 week)

Increasing incicence (approximately

10%); high mortality Resistant to fluconazole; high mortality Resistant to fluconazole; high mortality Pulmonary infection common Emerging pathogen Emerging pathogen

FN fphrilp npiitrnnpriia

• The duration of the neutropenia (time period of ANC less than 500 x 103/^L (500 x 10 9/L) cells)

• The severity of the neutropenia (lowest ANC level reached [nadir])

A multitude of other risk factors for FN have been identified (Table 99-5). Many of these are also risk factors for poor outcome in patients who experience FN. Cancer drug therapy regimens are also categorized as being high risk (greater than 20% incidence of FN reported in clinical trials) or intermediate risk (10-20% risk of FN reported in clinical trials). Similar to the approach to the prevention of CINV, it is important to consider both the regimen and patient-specific risk factors when determining whether a patient should receive prophylactic therapy for FN.

It is clear that patients with FN represent a heterogenous group. Some patients are at lower risk and could potentially be treated as outpatients thereby avoiding the risk and cost of hospitalization. The Multinational Association for Supportive Care in Cancer (MASCC) has validated a risk assessment tool that assigns a risk score to patients presenting with FN (Table 99-6).21 Patients with a risk-index score greater than or equal to 21 are identified as low-risk and are candidates for outpatient therapy (discussed under Treatment).

Table 99-5 Risk Factors for FN

Patient Related

Therapy Related

Ago 60 years or more Poor performance status

History of prior extensive chemotherapy

Bone marrow involvement by Planned full dose intensity of

L in contra lied Of ad va nc:ed Stage with treat me n I reg i m e n p I us cancer presence of patient-specific risk factors l-N, febrile neutropenia; LDH, lactate dehydrogenase. From Ref. 20.

Table 99-6 MASCC Risk-Index for Identifying Low-Risk Patients With FN

tumor Poor nutritional status Hematologic malignancy hlevated LDH

Decreased hemoglobin level Baseline or first-cycle low neutrophil counts History of previous FN

chemotherapy High-dose chemotherapy (i.e., bone marrow transplant) Greater than 20% incidence of FN reported in clinical trials With treatment regimen 10-20% incidence of FN reported in clinical trials

Characteristic Score

Burden of illness0

No symptoms 5

Mild symptoms 5

Moderate symptoms 3

No hypotension 5

No COPD 4

Solid tump* or hematologic malignancy without A

fungal infection

No dehydration 3

Outpaiient onset of fever 3

Ago less than 60 years6, 2

Note: A risk-index score of 21 or higher indicates that the patient is likely to be at low risk for complications and morbidity,

COPD, chronic obstructive pulmonary disease; FN, febrile neutropenia; MASCC. multinational association for supportive care in cancer.

^Choose one item only.

&Does not apply to patients years of age or below. From ftef. 21.

clinical presentation and diagnosis

Patients with suppressed immune systems are often unable to mount the same response to infection as normal individuals, thus limiting the expression of typical

presenting signs and symptoms. Often fever is the only indicator of infection and diagnosis is made empirically based on the patient's temperature, ANL, and coexisting risk factors for infection such as presence of an indwelling catheter, inpatient status, history of chemotherapy or radiotherapy, peripheral blood stem cell or bone marrow

22 23

transplant, renal or hepatic compromise, and older age.

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The term vaginitis is one that is applied to any inflammation or infection of the vagina, and there are many different conditions that are categorized together under this ‘broad’ heading, including bacterial vaginosis, trichomoniasis and non-infectious vaginitis.

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