Pediatrics 2 P.04.03 Infections of the Newborn PDF

PEDIATRICS LECTURE CLASSIFICATION (based on timing relative to birth) LECTURER: Dr. Eleanor Cuarte DATE: September 12, 2024 Early Late Very l...

PEDIATRICS LECTURE CLASSIFICATION (based on timing relative to birth) LECTURER: Dr. Eleanor Cuarte DATE: September 12, 2024 Early Late Very late Onset (1 mo) TOPIC OUTLINE Intrapartum Often Usually Introduction complication present absent Varies Neonatal Sepsis Usually Invasive Fungal Infection Vertical Vertical or postnatal Transmission environm. Environm. INTRODUCTION Clinical course Fulminant Insidious Insidious EPIDEMIOLOGY Multisystem Focal x A massive 47% of under-five deaths occur in the involvement infection Manifestations Pneumonia Meningitis neonatal period ± the first 28 days of life. common common x Neonatal sepsis is a major cause of morbidity and Low mortality Mortality rate 3-50% 2-40% (preterm, VLBW) Prematurity 41% Gram (-) Infection 16% Grp. B Bacilli Candida Etiologic Strep Asphyxia 15% CONS CONS Agents E. coli Other 14% S. aureus Congenital anomalies 14% Tetanus 2% Diarrhea 0% DEFINITION OF TERMS x Congenital infections Infection acquired in utero x Perinatal infection Acquisition around the time of delivery Timing of bacterial and fungal sepsis in VLBW infants x Early onset infection CLASSIFICATION (based on postnatal age of onset) Occurs in the 1st week of life acquired during 1. Early-onset sepsis the perinatal period Occurs in the 1st 7 days (usually 1st 3 days) of life, x Late onset infection a fulminant multisystem infection acquired by Occurs between 7-30 days of life acquired in the vertical transmission from the mother and has a post-natal period higher case-fatality rate x Hospital acquired infections Many studies define early onset sepsis as that Occur beyond the 1st week of life which occurs in the 1st 72 hrs of life 2. Late-onset sepsis NEONATAL SEPSIS 7-90th day of life x SEPSIS: a systemic host response to an infection Slowly progressive illness with focal infection x CRISEN: Clinical Risk Index for Septic Neonate RISK FACTORS FACTS NEONATAL x “SUSPECTED SEPSIS” x The decision of whether to treat a high-risk infant one of the most common diagnoses made in depends on the risk factors present, the NICU x Factors influencing which colonized infant will x Early diagnosis and treatment of the newborn infant experience disease includes with suspected sepsis are essential to 1. Prematurity prevent severe and life-threatening complications. 2. Underlying illness x The signs of sepsis are nonspecific, and 3. Invasive procedures inflammatory syndromes of non-infectious origin 4. Inoculum size and virulence of the infecting organism mimic those of neonatal sepsis. 5. Genetic predisposition 6. Innate immune response 7. Host response 8. Transplacental maternal antibodies NOTE TAKER: ABULENCIA | BALDOS | L | DOMINGO | SANTOS Page 1 | 7 MATERNAL A) EARLY ONSET INFECTION x Factors identified for intrapartum antibiotic CURRENT PREDOMINANT PATHOGENS prophylaxis to prevent early onset Group B Streptococcal disease x Group B Streptococci 1. Untreated or incompletely treated focal (UTI, x Escherichia coli vaginal or cervical infections) or systemic x Listeria monocytogenes maternal infections (septicemia, maternal fever x Staphylococcus aureus without a focus at delivery until 3 days post- x Other Streptococci partum) x Other Gram-negative organisms 2. Malnutrition and recently acquired STD Haemophilus influenzae 3. Antenatal colonization with Group B Klebsiella pneumoniae Streptococcus Pseudomonas aeruginosa 4. UnknownGroup B Streptococcal colonization Enterobacter species status and TRANSMISSION Preterm labor (38 C or more) 3. High infant-to-nurse ration in the NICU Rupture of membranes for 18 hrs or more 4. Presence of foreign bodies x A urine culture that grows Grp B Streptococcus during the current IV, umbilical, urinary catheters, ET tubes pregnancy x Prior delivery of a neonate with invasive Grp B Strep infection NOTE TAKER: ABULENCIA | BALDOS | L | DOMINGO | SANTOS Page 2 | 7  o tachypnea with or without an oxygen 2. Prolonged rupture of membranes >18 hours requirement (Pneumonia vs TTN?) 3. Intrauterine inflammation or infection at o Poor feeding with T 36 C (sepsis vs birth (Triple I) hypothermia? Maternal chorioamnionitis o poor suck or breastfeeding problem? o prematurity vs sepsis? x Data are insufficient to guide management, thus antibiotics are started if the newborn is symptomatic B) LATE- ONSET INFECTIONS CURRENT PREDOMINANT PATHOGENS x Coagulase-negative staphylococcus x Group B Streptococci x Escherichia coli x Klebsiella pneumonia x Pseudomonas aeruginosa x Other gram-negative enteric bacteria x Candida species Routes of chorioamnionitis or funisitis TRANSMISSION x After birth (post-natal), exposure of high-risk newborns to infectious agents in the NICU, the hospital or in the community, including family. x Direct contact to hospital personnel/caregivers Inadequate handwashing by colonized persons (MOST COMMON) x Breastmilk (HIV or CMV) x Inanimate sources contaminated equipment use of instrumentation ± ET, NGT, catheters x Meningitis (hematogenous dissemination) results from contiguous spread open neural tube, penetrating wounds etc. Clinical and Amniotic Fluid laboratory diagnosis of chorioamnionitis. Please see appendix INFECTION IN THE PREMATURE INFANTS 1. Prematurity or LBW (3-10x vs full term normal wt) most important neonatal factor! Immune dysfunction Premature require prolonged instrumentation/ invasive procedures 2. Maternal genital tract infection important cause of preterm labor with an increased risk of vertical transmission frequency of intraamniotic infection is inversely related to gestational age CLINICAL MANIFESTATIONS OF SEPSIS x Signs and Symptoms of Sepsis are Non-Specific: Temperature instability, fever or General hypothermia, poor suck/feeding Lethargy, irritability, Hypotonia, CNS hypertonia, high pitch cry, apnea Pathogenesis of chorioamnionitis. seizures Respiratory distress, cyanosis, Respiratory tachypnea, apnea, retractions EARLY SEPSIS VS NON-INFECTIOUS CONDITIONS Tachycardia, bradycardia, pallor, x It is difficult to distinguish neonates with early signs Cardiovascular mottling, Poor perfusion, shock of sepsis from neonates with noninfectious conditions. NOTE TAKER: ABULENCIA | BALDOS | L | DOMINGO | SANTOS Page 3 | 7  GIT Vomiting, diarrhea, feeding 2) ACUTE PHASE REACTANTS intolerance, abdominal distention Hematologic Jaundice, hepatosplenomegaly CRP AND PROCALCITONIN bleeding, petechiae/purpura The positive predictive value of the sepsis screen in Renal Oliguria neonates is poor (99%) in small x FEVER clinical studies. A non-sensitive and non-specific findings Sepsis screening tests might be of value in deciding which 1. Temperature elevation in full term infant is “high- risk” appearing neonates do not need antimicrobial uncommon. agents or whether therapy can be safely discontinued. 2. Temperature elevation is infrequently associated Procalcitonin concentration has a modestly better with systemic infection when only a single sensitivity than does CRP concentration but is less elevated temperature occurs. specific. 3. Temperature elevation that is sustained longer than an hour is frequently associated with 3) LUMBAR TAP infection. Lumbar puncture is not needed in all infants with 4. Temperature elevation without others signs of suspected sepsis (especially those who appear infection is infrequent. healthy) Should be performed for infants with signs of DIAGNOSIS sepsis: x DIAGNOSTIC APPROACH - Who can safely undergo the procedure 1. There may exist in the newborn a constellation of - For infants with a positive blood culture factors, either maternal or neonatal, that increase - For infants likely to be bacteremic (on the the risk of sepsis basis of laboratory data) 2. The newborn exhibit manifestations of infection - Infants who do not respond to antimicrobial that necessitate an evaluation for sepsis and the therapy in the expected manner institution of appropriate antimicrobial therapy 4) BLOOD CULTURE x Diagnosis of sepsis made by the combination of: Isolation of bacteria from a central body fluid is 1. History the standard and most specific method used to Information obtained from the mother and diagnose neonatal sepsis. her physician Important procedures to improve the sensitivity 2. Clinical and specificity of blood cultures include Information obtained by physical examination 1. Proper skin disinfection before collection, of the infant 2. Culturing early in the septic episode, 3. Laboratory 3. Taking an appropriate volume of blood per Information obtained culture, and, 4. If collecting through an existing intravenous 1) CBC device, ensuring a peripheral culture is also During neonatal sepsis, leucocytes and platelets collected are more frequently affected than red blood cells 5. Where practical, more than one bottle per The most frequently encountered features are episode 1. Abnormal total leukocyte count 2. Abnormaltotal neutrophil SEPTIC WORK-UP (polymorphonuclear [PMN]) count 1. CBC 3. immature PMN count, WBC: 0.15-0.20 (eg, 0.3) Absolute neutrophils