Fever Considerations Flashcards
What is a significant oral temperature that could indicate fever
> 38C or 100.4F
Noninfectious causes of fever (false positives for infection )
- Malignancy
- Drug fever (from the administration of the medication) β-lactam antibiotics, anticonvulsants, allopurinol, hydralazine, nitrofurantoin, sulfonamides, phenothiazines, methyldopa
- Blood Transfusions
Causes absence of fever from infected patients
Overwhelming infection
Antimicrobial Therapy
Antipyretics
Corticosteroids
Signs and symptoms of infection
Fever >38C Increased WBC (>11,000) Chills rigor Tachycardia (>90) Tachypnea (>20) Hypotension (<90 Systolic or MAP <70) Malaise Mental Status change
Normal WBC count
4,500 to 10,500/mm3
Normal WBC Breakdown
Granulocytes Mature neutrophils (PMNs, polys, segs) 50-70% Immature neutrophils (bands) 0-5% Eosinophils 0-5% Basophils 0-2%
Immature WBC (bands)
These are WBCs that are mobilized before maturation in the bone in order to fight off infection
Granulocytes
any thing that ends in -phils
Agranulocytes
any that that ends in -cytes
Leukocytosis
- associated with bacterial infection (higher presence of bands) called a left shift
- could be due to stress, leukemia, lithium, or steroids
- not present in neutropenic hosts and is reduced in elderly
- Leukopenic patients (abnormally low WBC count)
Lymphocytosis
• B-lymphocytes ® proliferate into plasma cells, which produce antibodies involved in humoral immunity; some develop into memory cells
• T-lymphocytes – involved in cell-mediated immunity (2 types)
1) T helper/inducer cells (CD4) ® regulation of the immune system; help with antibody production and secrete lymphokines that help protect against bacterial/viral infections and tumors; the major marker of immunocompetence in patients with HIV infection (this cell line is depleted with HIV infection)
2) T suppressor (CD8) ® bind to and directly kill tumor cells; help with regulation of humoral and cell-mediated immunity
Monocytosis
important phagocytic cells responsible for antigen processing and presentation; associated with tuberculosis or lymphoma
Eosinophilia
associated with allergic reactions or protozoal/parasitic
infections
Localized signs of infection
Pain and inflammation – swelling, erythema, tenderness, purulent or abnormal drainage
Inflammation in deep-seated infections (e.g., pneumonia, meningitis, urinary tract infection) – must examine tissues/fluids (sputum, CSF, urine)
Inflammation in deep seated infections
pneumonia, meningiti, UTIs (need to assess sputum and fluids)
Inflammation in neutropenic hosts
may be absent
symptoms can be referable to specific organ systems
ex. flank pain may be indicative of renal issues
Erythrocyte sedimentation rate and C-reactive protein
- elevated in inflammatory processes but does not indicate the presence of infection
- ESR = 0 to 15 mm/hr in males and 0 to 20 mm/hr in females
- elevated in otitis media, osteomyelitis, prosthetic joint infections, endocarditis, pelvic inflammatory
disease, and infections in transplant patients
Procalcitonin
A precursor of calcitonin, a calcium regulatory hormone, which is a more specific marker for bacterial infections than ESR or CRP
- Normal value = < 0.05 μg/L
- Current research suggests that the level of PCT elevation may provide useful diagnostic information
• PCT ≥ 10 μg/L ® sepsis/systemic bacterial infection
• PCT between 2 and 10 μg/L ® suggestive of sepsis
• PCT between 0.25 and 2 μg/mL ® other condition or localized infection
- Some data suggest that PCT levels may be useful for assessing the efficacy of empiric antibiotic therapy as well as for determining when antibiotic therapy can be discontinued during the treatment of an infection
