CHAPTER 217 Drawing Blood Cultures
Most bacteremias are of a very low magnitude, so an adequate volume of blood should be collected for each set of cultures. Small children usually have higher numbers (concentrations) of bacteria in the blood than adults, which means that smaller quantities of blood may be obtained from children. Appropriate volumes are noted in Table 217-1.
TABLE 217-1 Optimal Specimen Volumes to Be Drawn per Blood Culture Set
| Age Group | Ideal Volume per Set (mL) |
|---|---|
| Neonates | 1–2 |
| Infants 5–10 kg | 2–4 |
| Children 7–20 kg | 3–8 |
| Children 20–40 kg | 10 |
| Children >40 kg | 20–30 |
| Adults | 20–30 |
Indications
• Fever and unexplained alterations in mental status, functional status, or autonomic status in a previously healthy patient
• Fever and no source of infection, especially in a patient younger than 2 years of age or older than 65 years of age
• Fever, or no fever in a patient with a toxic or “septic” appearance (including unexplained hypotension, altered mental status, or shock)
