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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.
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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
Figure it out WBC: 20,000 Differential is expressed as a percent of total white cells Poly’s (Segs, Neuts): 48% Bands 12% Lymphs: 20% Monos: 17% Eso: 3%
Figure it out ANC: Absolute number of neutrophils WBC X % Neutrophils ANC WBC X % Neutrophils 20,000 X .6 (60%) = 12,000
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
Figure it out WBC: 20,000 Differential is expressed as a percent of total white cells Poly’s (Segs, Neuts): 48% Bands 12% Lymphs: 20% Monos: 17% Eso: 3%
Figure it out 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 depends on organism involved and when treatment started Prognosis
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, 3rd Ed. Philadelphia: W.B. Saunders Co. • Cloherty, J.P., Eichenwald, E.C., Stark, A.R. (2004) Manual of Neonatal Care, 5th 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, 8th Ed. • Merenstein, G.B., Gardner, S.L. (2002) Handbook of Neonatal Intensive Care, 5th Ed. St. Louis:Mosby Inc.