Neonatal Sepsis
Author: Sherrill Roskam RNC MN NNP CNS
Updated presentation: Susan Greenleaf RNC, BSN

Objectives
Identify major causative organisms and routes of transmission of sepsis.
Discuss clinical manifestations and modalities used in diagnosis of sepsis.
Describe antibiotic therapy used in the treatment of neonatal sepsis.

Sepsis
Definition: A systemic response to an invasive organism. Frequently signified by a positive blood culture.
A systemic illness due to the presence of bacteria and or bacterial toxins in the blood

Neonatal Immune System
Sepsis occurs in 1-8:1000 term infants and 1:250 premature infants
Neonates are immunocompromised even at term gestation
The neonatal immune system is functional at birth, but not mature

Sepsis
Two types of sepsis
Early-onset sepsis, with in the first
72 hours of life
Late-onset sepsis, those infections acquired later by horizontal transmission. Highest risk for the first month of life

Predisposing Factors: Pregnancy
Prematurity
PROM < 36 weeks
Prolonged ROM
Prolonged labor
Excessive manipulation

Predisposing Factors: Maternal
History of infection
Bacterial
Viral
History of GBS bacteriuria
History of previously affected infant
Temperature in labor

Predisposing Factors: Neonatal
Invasive procedures
Resuscitation
Intubation
IV starts / PICC lines
Umbilical Catheterization
Skin colonization

Predisposing Factors: Nursery
Humidifiers
Respiratory therapy equipment
Staff members
Unsterile equipment
Scales
Stethoscopes
Thermometers

Transmission
Transplacental
Ascending
Birth
Nosocomial
Antibodies
IgG
IgM
IgA

Human Immunoglobulins
Antibodies are the immunoglobulins produced in response to specific antigens
IgG is the only antibody that crosses the placenta and provides immuological protection over the first few months
Transfer peaks at 32 weeks gestation

Immunoglobulins cont.
IgM and IgA are directly responsible for antibodies against bacteria
Neonatal IgM production starts at 30 weeks gestation and increases over the first year of life
IgA passes through breast milk to provide early defense against infection. Found in the intestinal tract.

Causative Organisms:
Bacterial
Group B strep
E Coli
Haemophilus Influenzae
Coagulase Negative Staph
Staph Aureus
Neisseria Meningitis
Listeria

Causative Organisms: Viral
Maternal in origin
Toxoplasmosis
Rubella
Cytomegalovirus
Herpes
Hepatitis B
HIV

Recognition: Clinical Signs
Temperature instability
Lethargy
Pallor, mottling, poor cap refill
Respiratory distress
Poor feeding
Apnea
Neurologic
Jaundice
Hypoglycemia

Recognition
Recognition is of utmost importance, because newborns with sepsis can get very sick very fast
Be aware of risk factors – review maternal history

Diagnostic tests for sepsis
CBC
Cultures
Blood ~ Most common Gold Standard
Urine
Surface - only indicates colonization
CSF Lumbar puncture
CRP

C-Reactive Protein
What is CRP?
Laboratory test that identifies an inflammatory response in the body.
Binds to Calcium and phosphocholine sites; forming CRP-ligand complexes.

CRP
CRP’s unique binding characteristics have led to the identification of elevated CRP levels in over 70 different infectious and
noninfectious disorders.
It is associated with acute and chronic inflammatory disorders.

CRP Continued. . .
Paired mother and infant sampling shows that CRP does not cross the placenta.
4 types of inflammatory response to tissue injury
Infectious, noninfectious, chemical, physical or immunologic toxins.

Use of CRP
2 schools of thought
Early diagnostic tool for confirming sepsis
Screening tool to r/o the presence of sepsis

CRP Levels: What is normal?
In the neonatal period: Level of 10mg/L is considered normal
Healthy full-term and preterm infants may range from 2 to 5mg/L during the first few days of life.

More than 1 Level?
Conflicting information about obtaining more than one level
Serial CRP levels drawn 12 to 24 hours after onset of S/S of sepsis may be superior to a single level.

More About the CBC: WBC
White cell count
Differential
Neutrophils - bacteria fighting cells
Polys, Segs - most mature
Bands - immature
Metas – really immature
Absolute Neutrophil Count
I:T Ratio

White Blood Cells
The main defense against invading microorganisms
Neutrophils (pack man cells) and macrophages(monocytes)
Circulating cells that migrate to sites of inflamation, ingesting and killing foreign material or bacteria (phagocytosis)
Small stores in neonates, not as effective in killing bacteria, quickly depleted

Differential of the WBC
Mature Neutrophils – Segmented
Immature Neutrophils – Bands
Monocytes
Basophils
Eosinophils
Lymphocytes

Neutrophils
As mature neutrophols (polys, segs, neuts, or PMNs) are mobilized and consumed in the presence of a pathogen, their numbers decrease and immature cells are released from the bone marrow.
Immature neutrophils (bands, metas or stabs)

Absolute Neutrophil Count
(ANC)
Helps determine how many neutrophils are available to fight bacterial infections
Premature infants have lower ANC than term infants
Must plot on the Manroe chart

How to calculate an ANC
Identify the immature and the mature neutrophils on the CBC.
Add the segs, bands and metas ( total number of neutrophils) together and turn it into a percentage
Multiply this number by the total
WBC
This resulting number is the ANC

Manroe Chart

WBC: 20,000
Differential is expressed as a percent of total white cells
Poly’s (Segs, Neuts): 48%
Bands
Lymphs:
Monos:
Eso:
12%
20%
17%
3%

ANC: Absolute number of neutrophils
WBC X % Neutrophils
ANC WBC X % Neutrophils
20,000 X .6 (60%) = 12,000

Manroe Chart

Immature to Total Ratio (I:T)
An Increased IT ratio is called a left shift.
It show an increase in the number of immature sells
An IT ratio of >.25 may indicate sepsis
I/T ratio: Ratio of immature to total neutrophils
___Bands + Meta___
Polys + Bands + Meta

WBC: 20,000
Differential is expressed as a percent of total white cells
Poly’s (Segs, Neuts): 48%
Bands
Lymphs:
Monos:
Eso:
12%
20%
17%
3%

I/T ratio: Bands + Metas
Polys + Bands + Metas
12/60=0.2 (not indicative of sepsis)
If WBC 3000 Polys 30 and Bands 15:
15/45=0.33 (indicative of sepsis)
3,000 X .45 (45%) = 1,350

Platelet Count
Normal Values
VLBW – 275,000 +/- 60,000
Preterm – 290,000 +/- 60,000
Term – 310,000 +/- 60,000
Infants with infection may have a low platelet count

Management
Support Systems
Neutral Thermal Environment
Monitor
Cardiac/Respiratory
Pulse Oximetry
Vital signs
Feedings
IV

Management (con’t)
Antibiotics
Ampicillin 50-100 mg/kg/dose IV q8-12 hours
Varies with gestation and age
Gentamicin 4 mg/kg/dose IV q24-48 hours
Varies with gestation
Give over 30 minutes
Monitor Gent levels
Antiviral
Acyclovir 20 mg/kg/dose IV q8
Give over 1 hour
Do not refrigerate

Prognosis
Prognosis depends on organism involved and when treatment started

A bit more practice
CBC results
WBC 10.4
Metamyelocytes 0
Band Neutrophils 14
Segmented neutrophils 5
Platelets 141,000
What is the ANC and the IT ratio?

CBC Practice
CBC results
WBC 1.3
Metamyelocytes 2
Band Neutrohils 17
Segmented Neutrophils 42
Platelets 262,000
Calculate the ANC and IT ratio

CBC Practice
CBC results
WBC 6.3
Metamyelocytes 6
Band Neutrophils 44
Segmented Neutrophils 23
Platelets 95,000
What is the ANC and the IT ratio?

Same patient, 6 hours later
CBC results
WBC 0.8
Metamyelocytes 2
Band Neutrophils 4
Segmented Neutrophils 2
Platelets 24,000
What is the ANC and IT ratio?

References
Behrman, R. E., Kliegman, R.M.,Editors (1998) Nelson
Essentials of Pediatrics, 3 rd Ed. Philadelphia: W.B.
Saunders Co.
Cloherty, J.P., Eichenwald, E.C., Stark, A.R. (2004) Manual
of Neonatal Care, 5 th Ed. Philadelphia: Lippincott, Williams
& Wilkins.
Hengst, J.M., The Role of C-Reactive Protein in the
Evaluation and Management of Infants with Suspected
Sepsis. Advances in Neonatal Care. 2003;3(1):3-13.

References
Karlsen, K.A. (2001) The S.TA.B.L.E. Program:
Transporting Newborns the S.T.A.B.L.E.Way, Learner
Manual, 8 th Ed.
Merenstein, G.B., Gardner, S.L. (2002) Handbook of
Neonatal Intensive Care, 5 th Ed. St. Louis:Mosby Inc.