Myelosuppression, Febrile Neutropenia and Cancer Related Infection Considerations Flashcards
Myelosuppression
- Myelosuppression is a condition in which the bone
marrow activity is reduced, leading to fewer red blood
cells, white blood cells, and platelets. - Myelosuppression is a common side effect and dose
limiting toxicity of chemotherapy (cytotoxic drugs). - Myeloablation is a term used for SEVERE
myelosuppression that is difficult to recover from
without a stem cell infusion (example: when a
lymphoma or myeloma patient is given HIGH DOSE
chemotherapy as part of an autologous stem
cell transplant conditioning/preparation protocol). - Myelosuppression is NOT osteoporosis (weakening of
the bones)
cll type
Neutrophil 8 hours Kill bacteria using
enzyme rich granules
and endocytosis or
phagocytosis
Increased risk of
severe infections
very short life
Erythrocytes 120 days Carry O2 to tissues Fatigue, SOB
Thrombocytes
(platelets)
5-10 days Essential for normal
blood clotting
Bleeding
Anemia
– Reduced erythrocytes (red blood cells)
– Monitor Hg levels
– If severe anemia and symptomatic (fatigue,
SOB), may need blood transfusion
* Remember – this is not from a
deficiency of iron, folate, or B12. This is
from damage to the bone marrow!
Thrombocytopenia
– Awareness of easier bruising
– Soft toothbrush (gums can bleed easier)
– Blow nose gently (avoid a nose bleed)
– Avoid constipation and straining on the toilet (avoid anal fissures and
anal bleeding)
– Avoid use of (or be cautious when using) medications that can
increase the risk of bleeding (NSAIDs, ASA)
– Medical attention is required in the event of uncontrolled bleeding
- Thrombocytopenia
– normal platelet range is 150-400 X 109
/L
– reduced platelets can lead to bruising,
bleeding (major and minor) or a petechiae
type rash
– depending on the antineoplastic regimen,
treatment delay or dosing may be adjusted if
platelets are < 50-100 X 109
/L
– if platelets are critically low (<10 X 109
/L),patient may be given a platelet transfusion
Immune Function in Cancer Patients
Disease Factors Treatment Factors
Impaired Humoral Immunity?
Some hematologic malignancies can lead to
impaired humoral immunity (Example:
myeloma – issues with serum antibodies)
Chemotherapy
* Chemotherapy induced NEUTROPENIA
* Chemotherapy causes cell death in rapidly dividing cells (good and
bad)
* Affects neutrophil production in the bone marrow
Impaired Cell Mediated Immunity?
Some hematologic malignancies can lead to
impaired cell mediated immunity (Example: Tcell Lymphoma where T-cells are not functional to do their job)
Other Immunosuppressants
* Corticosteroids (prednisone, dexamethasone)
Radiation Therapy
* Example “TBI” (total body irradiation) with substantial impact on the
bone marrow
- Chemotherapy Induced Neutropenia
– “Good Cells” impacted by cytotoxic drugs includes the neutrophils produced in the
bone marrow
– Neutrophil count will begin to fall occurs approximately 5-12 days after chemo
(depending on regimen)
– Dose related (think back to discussion of dose limiting toxicities)
– The lowest point is referred to as the “NADIR”
* When neutrophils are at their lowest number in the circulating blood
Response is dose related
The higher the dose of chemp or the more myelosuprpressive, the lower the nadir
Infection “Portals” in Cancer Patients
Environmental
Exposure
“regular stuff”
Damage to Skin Damage to Mucous Membranes Medical Procedures
Droplet exposure IV access such as
Indwelling Catheter
Oral Mucositis (open wounds in the
mouth)
Endoscopy
Airborne exposure Antineoplastic adverse
effects (cracked, broken
skin)
Gastric Mucositis (inflammation or
ulceration of the membranes of GIT)
Bronchoscopy
Ingestion exposure Surgical wound Rectal Issues
Infection Microbiology in Cancer Patients
Organisms colonizing the host (patient’s own flora) Organisms in the Environment Other Patient Specific
Factors
Skin Flora
* Usually gram positive
DAMAGE to SKIN: Skin flora can enter body through many mechanisms
Gut Flora
* Differs throughout the gut but gram positive, gram negative, and anaerobes are present
* MUCOSITIS - Gut flora can enter the blood through
injured gi mucosa
What is the patient’s recent environment?
* Community vs Hospital
* Recent outbreaks occurring?
* Travel history?
* Close contacts?
Resistance Risk?
* Frequent exposure to broad spectrum antibiotics (previous infections)
* Ongoing exposure to
prophylactic antibiotics
BacteremiasBacteremias
– Isolation of gram positive more common than gram negative
– Gram negative associated with higher mortality than gram
positive(18% vs 5%)
* P. aeruginosa associated with very high mortality
– Possible drug resistant organism?
– Possible fungal/mold etiology?
Indicators of Infection
- Usual signs and/or symptoms of infection may be absent or altered in
neutropenic patients
– Low number of leukocytes
– Inability to mount a “normal” immune response - Example: there may be no “pus”
- Neutropenic patients with bacteremia might exhibit NO signs or symptoms of infection other than FEVER
Takes only a few neutophil cells to cause fever, often only sign - A fever in a neutropenic cancer patient is assumed to be caused by
infection until proven otherwise - A fever in a neutropenic patient is an oncologic emergency
– Temperature of 38.3oC or greater, or a
sustained temperature of ≥38.0oC lasting
more than 1 hour.
What is Neutropenia?
- Reduced number of neutrophils circulating in the peripheral
blood. - Normal neutrophil range is 2.0 to 8.0 x 109
/L
– In practice, infection concern is heightened at 0.5 X 109
/L or less - Often referred to “ANC” = Absolute Neutrophil Count
– Sum of Neutrophils + Bands
Number of bands is suually small and doesnt change ANC all that much
concerned is heighted at 0.5 or less
Febrile Neutropenia
* Definition (IDSA):
– Single oral temperature ≥38.3oC or sustained oral temperature ≥38.0oC for
more than 1 hour
– ANC < 0.5 X 109
/L or expected to fall to < 0.5 X 109
/L within the next 48
hours
* Oncologic and Medical Emergency
– High rate of mortality/morbidity if untreated
– Infection can progress rapidly and become life threatening quickly
– Prompt, empiric antibiotic therapy reduces mortality
Patient Assessment and Workup
- Cultures and Sensitivities:
– Blood, 2 sets - peripheral and central access (if applicable) - DO ASAP BEFORE TREATMENT!
If central line is colonized w something,
It will be positivie
Peripheral line allows us to explore isolates in peripheral blood
Having both –> bloodstream infection source is likely a colonized line
2 bottles of blood for each set
- 1 for aerobic and 1 for anaerobic culture
Body fluids or other sites cultures
– Other possible sites of infection as indicated (examples: urine, wound, stool, sputum, NP swab)
* Laboratory Tests:
– CBC with differential
* Assess neutrophil count (don’t wait for results to treat)
– Chemistries:
* Electrolytes, Creatinine, BUN, hepatic transaminases, bilirubin
* Vital signs
– Patient stability and assessment for septic shock
* History
– Last chemo treatment, possible exposures
* Physical Exam
– Possible sites/sources of infection
* CVC site, Mucositis
* Other Diagnostic Tests as indicated
– Chest X-ray (respiratory symptoms)
* Consider COVID-19 test!
Patient Risk Assessment
high risk
- Features of patients with HIGH RISK of complications or death
– Prolonged (>7days) or profound (< 0.1 x 109
/L) neutropenia - Consider patient disease and chemotherapy received
– Unstable - Hypotension, neurologic changes, new onset abdominal symptoms, high
fever
– Significant medical/comorbid conditions - Pneumonia, COPD, mucositis
- Admit high risk patients and initiate treatment with IV empiric
therapy
LOW RISK
Features of patients with LOW RISK of complications or death
– No focal findings of infection, hemodynamically and clinically stable
– Brief neutropenic period (<7 days)
– No or few comorbidities
* For low risk patients, initiate treatment with oral or IV empiric
treatment in clinic/hospital
– Consider transition to outpatient therapy:
* Oral antibiotics
* Home parenteral therapy program
High vs Low Risk - Simplified
High Risk Low Risk
Expected prolonged or profound neutropenia (from the
chemotherapy or the disease)
Brief neutropenic time
Unstable (hypotension, neurologic changes, new onset
abdominal symptoms, high fever)
Hemodynamically and Clinically stable
Significant co-morbidities (COPD, mucositis, dehydration) Otherwise healthy
Worrisome infection (or suspected infection)
(pneumonia, bacteremia, SSTI)
and/or symptomatic (high fever, neurologic changes)
No focal source of infection and asymptomatic
Difficult access to urgent care Easy access to urgent care and able to take po med
Concepts for Selecting Empiric Antimicrobial Therapy
- Prompt Treatment
- Start immediately after cultures
- Broad Spectrum:
- Cover gram negatives (including pseudomonas), gram
positives, usually anaerobes - Bactericidal preferred to Bacteriostatic
- Route of Administration
- Start with parenteral in most cases
- Oral may be appropriate for certain low-risk patients only
- Consideration of Patient Factors
- Allergies, organ function
- Previous antimicrobial exposure (including prophylaxis)
- Colonization or previous infections with resistant organisms
- Consideration of Institutional Factors:
- Infection patterns, antimicrobial susceptibility trends
wont wait till CBC comes back to confirm pt is neutropenic, give abx first
FN - Empiric Treatment in Patients at
High Risk of Complications
- Initiation of empiric broad spectrum antibiotics
– Monotherapy with anti-pseudomonal beta lactam such as:
– Piperacillin+Tazobactam, Cefepime, Carbapenem (meropenem or
imipenem+cilastatin)
– Add additional gram positive coverage (vancomycin) IF risk of MRSA
– Catheter related infections
– Skin or Soft Tissue Infections (SSTI)
– Pneumonia
– Hemodynamic Instability
– Known colonization with MRSA
FN – Treatment Modifications
- Changes to treatment are guided by clinical and microbiological data
– Cultures - Use results to target treatment (around 48-72 hours)
– Optimize antimicrobial therapy for isolated organism, site, and susceptibilities - Sometimes no organism can be isolated
– Patient Stability - If patient remains febrile and is UNSTABLE, then broaden coverage:
- If patient has unexplained persistent fever but stable then modification in therapy
rarely needed - If patient clinically improving, then good indicator that spectrum of therapy is
covering the pathogen (if one exists)
FN – Treatment for Patients at
Low Risk for Complications
- Low risk Initial Empiric Treatment:
– Initial treatment is given in Hospital or Clinic - IV therapy as discussed in high risk
- Oral therapy with Ciprofloxacin + Amoxicillin/Clavulanate
– Must be able to tolerate and absorb - Avoid Ciprofloxacin if receiving quinolone prophylaxis
- Then can transition to outpatient care IF appropriate
– Considerations: - Low risk, stable, tolerating therapy
- Close proximity to medical care
- Ability to travel to medical centre
- Recovering neutrophil count (going up, not down)
FN – Length of Therapy with Antimicrobials
- If stable and an infection source identified
– Tailor treatment and duration to specific infection - If stable and no source of fever identified:
– Somewhat controversial but basic principles:
– Treat until afebrile ≥ 2 days and neutrophils >0.5 and trending up
– Usually minimum 7 day course for high risk patients
– Consider longer course of therapy for patients with mucositis
– Can consider step down to oral therapy in low risk patients
Patient Education – Fever Monitoring
– Lack of evidence to develop a recommendation for how often
an ambulatory patient should check temperature when
asymptomatic/well.
– Patient should be educated regarding action plan in the event of
a fever
* What should they do? Who should they call? Where should they go?
– Standardized patient information in alignment with institution
or care team is important
– Cancer patients in the community receiving chemotherapy who
experience fever should seek urgent assessment
– If fever occurs outside of clinic hours, patients should be referred to
emergency department (or other designated urgent care centre)
– Be aware that antipyretics (acetaminophen) can mask a fever.
* Avoid acetaminophen if possible
* If unable to avoid acetaminophen, proper patient education and
monitoring strategies should be employed
* Avoid ibuprofen and ASA due to antiplatelet effects (increased risk
of bleeding)
Thermometer Choice
- Some guidelines state “oral” temperature when defining Febrile Neutropenia
– Avoid hot/cold food or beverages before taking oral temperature - Tympanic membrane thermometry is a reasonable option
– Follow manufacturers recommendations
– When compared with rectal thermometry, both oral and tympanic thermometry have
comparable specificity, positive predictive value, and negative predictive value.
– Tympanic is more sensitive than oral or axillary - Axillary thermometry shown in same study to be inferior to tympanic membrane and
poor correlation with rectal temperature - Avoid rectal thermometers
– Infection and bleeding risk
FN Prophylaxis
- Granulocyte-Colony Stimulating Factors (G-CSF)
– G-CSF is a hematopoietic growth factor - Regulates production and function of neutrophils
- Can accelerate neutrophil recovery after chemotherapy
– Filgrastim or PEG-filgrastim - Pros:
– Reduced risk of febrile neutropenia
– Reduction in infection related and all cause mortality
– Improved relative dose intensity of chemotherapy delivered
prevent dose reduction or delay in chemo - Cons:
– Costly, must consider insurance payer criteria
– Adverse effects, bone pain
– Subcutaneous administration of ambulatory patients has challenges
