Diagnostic Criteria
It must simultaneously meet the criteria of fever y neutropenia. It is considered an emergency due to the high risk of fulminant sepsis without an obvious focus.
1. Fever
Axillary/tympanic temperature ≥ 38.3°C in a single shot, or ≥ 38.0 °C sustained for more than 1 hour.
Avoid rectal thermometers (risk of bacterial translocation).
2. Neutropenia
Absolute Neutrophil Count (ANC):
- < 500 cells/µL
- OR < 1000 cells/µL with a prediction of a drop to < 500 in the next 48 hours.
Clinical Evaluation
Key feature: Due to the lack of neutrophils, the classic signs of inflammation (erythema, heat, swelling, pus) are usually absent or attenuated. Fever may be the only sign.
Active Focus Search
Oropharynx
Mucositis, canker sores, periodontal disease.
Central Catheter
Tunnel, reservoir (Port-a-Cath), tenderness.
Respiratory
Tachypnea, indrawing (X-ray may not show initial infiltrates).
Perineum/Gastro
Perianal pain, fissures. Pain in FID (Typhlitis/Enterocolitis).
High Risk Criteria (Income)
- Hemodynamic instability / Shock.
- Acute leukemia in induction/recent BMT.
- Comorbidities (Pneumonia, bleeding, IR).
- ANC < 100 or expected duration > 7 days.
- Severe evident focus (grade 3-4 mucostis).
Emergency Workup
Take BEFORE of the antibiotic, but do not delay the dose for more than 60 minutes if the route is difficult.
- Central Route (CVC): Extract 1 set for EACH catheter lumen.
- Peripheral Route: Extract 1 simultaneous set (helps differentiate catheter infection vs. primary bacteremia by differential positivity time).
- complete blood count with manual leukocyte formula (to calculate exact ANC).
- Reactants: CRP, Procalcitonin (PCT).
- Biochemistry: Ions, kidney function (urea/creatinine to adjust ATB dose), liver profile.
- Venous and lactic blood gases if there is poor perfusion.
Only if there are suggestive symptoms (not routine so as not to delay ATB):
- Urine culture (if clinical or without focus).
- Chest X-ray (if respiratory symptoms).
- Nasopharyngeal aspirate (RSV, Influenza, COVID).
- Smear of skin lesions.
The Golden Hour (< 60 min)
PRIORITY 1Antibiotic Choice (Empirical IV)
Base Treatment (Antipseudomonal monotherapy)
When to add Vancomycin?
Vanco dose: 15 mg/kg/dose IV every 6 hours. Add to base treatment YES:
- Hemodynamic instability / Severe sepsis.
- Suspected catheter infection (CVC).
- Skin/soft tissue infection.
- Severe mucositis.
- Previous known colonization by MRSA or resistant Pneumococcus.