Suspected Sepsis in the Newborn
Jonathan M. Klein, MD
Peer Review Status: Internally Peer Reviewed
Due to various factors, newborn infants, both preterm and full-term, are highly susceptible to sepsis during the newborn period. In contrast to older infants, children and adults, the signs of sepsis in the newborn are vague and nonspecific. The earliest signs may be apnea, respiratory distress or poor feeding. Other signs and symptoms include lethargy, temperature instability, hyperbilirubinemia, bradycardia, seizures and acidosis.
When sepsis is suspected, a sepsis work-up should be performed to include a CBC with differential, blood culture and CSF for analysis and culture. Antibiotics should be started as soon as the work-up is complete. Urine culture may be omitted from sepsis work-ups done at birth but should be included in subsequent sepsis work-ups. If there are other circumstances indicating the origin of the sepsis, additional appropriate cultures should be obtained, such as tracheal fluid or from an area of cellulitis.
Infants with sepsis frequently have an elevated absolute band count, and/or depressed absolute neutrophil count, or increased I:T ratio (See Total Granulocyte Count, p. 106, and reference values for WBC indices, p. 107). However, a normal WBC count in an infant with signs of sepsis (see I), does not rule out infection, and thus antibiotics should be started while awaiting culture results.
The antibiotic regimen for sepsis work-ups performed at birth, or admitted as a neonate less than 30 days old, is ampicillin and gentamicin.
If the infant has been in the nurseries and sepsis is suspected, the antibiotic regimen should include vancomycin and gentamicin. Piperacillin should also be considered if there is suggestion of possible gram-negative infection, e.g., in a tracheal aspirate gram-stain, or if pseudomonas is present in the nursery.
Acyclovir therapy should be considered if HSV infection is possible, pending the results of a work-up for HSV. This work-up should include surface cultures for HSV, liver function tests and CSF for cell count and HSV PCR.
When a sepsis work-up has been performed, the infant should be reassessed at 72 hours. Consideration can be given to discontinuing antibiotics if the clinical course has not been suggestive of infection and the cultures are negative.
If the blood cultures are positive, treat for 10 days. Obtain a repeat blood culture after 24-48 hours of therapy to insure effective therapy.
If the CSF culture is positive, treat for 14-21 days.
In infants with positive cultures, antimicrobial therapy is adjusted according to the sensitivities. Serum levels of antibiotics should be followed as recommended on page XX.
If C-reactive proteins (CRP) are obtained, an initial CRP of <1 is not a definite confirmation of the absence of infection. If obtained, serial levels 24 to 72 hours after the sepsis work-up is performed should be obtained, and these values along with the clinical course of the patient and the results of CBCs and cultures will determine the duration of antibiotic therapy.
Isolation requirements will be determined according to the organism and the site of infection. Please consults the isolations manual.
If the patient is neutropenic, several therapies are possible:
- G-CSF at a dose of 10 µg/kg subQ or IV qday to b.i.d. can be administered until the ANC is >1500.
- IVIG can be administered to augment the immune system until the ANC has recovered.
- A granulocyte transfusion can be considered following discussion with the staff neonatologist if definite or strongly suspected infection is present. See Guidelines for Neonatal Transfusion Therapy, p. 203.
If the absolute neutrophil count is very low, a granulocyte transfusion may be considered. This option should be discussed with the staff neonatologist.
Manroe BL, et al. The neonatal blood count in health and disease. I. Reference values for neutrophilic cells. J Pediatr 1979;95:89-98.