Exam 2 pt2 Flashcards
The presence of bacteria in the bloodstream
-This can be a transient, self-limited phenomenon, cleared by immune system without event but can also progress to sepsis
bacteremia
*can seed other sites such as bone, lung, and meninges
Bacteremia coupled with inadequate perfusion and end-organ involvement
Meaning, decreased blood flow
Causing damage to important organs
sepsis
Sepsis which occurs in a neonate within the first 3 days of life
early-onset sepsis (EOS)
*Vertical transmission
Sepsis which occurs after the first 3 days until 2 to 3 months of life (definitions vary)
Late-onset (LOS)
*Horizontal transmission
sx:
- Temperature may be elevated or depressed. Recall that normal range is 36.5 to 37.5
- Tachypnea; ie, respiratory rate > 60/min
- Other signs of respiratory distress (retractions)
- Poor color (cyanosis, poor perfuson= mallor)
- Decreased responsiveness/lethargy
- Poor feeding
- Irritability or sleepiness
sepsis
Babies have a limited repertoire. Symptoms of ___ may be indistinguishable from non-infectious illness.
sepsis
mortality rate of EOS
15%
*Higher mortality in pre-term babies and Lower in full-term
what type of sepsis is even more likely to be complicated by meningitis with its attendant morbidity
late onset sepsis
Which bacterial organisms are involved with sepsis
- Group B Strep
- E. coli- actually #1 in preterm babies
- Other strep species, most commonly Pneumococcus
- Enterococcus (Group D strep)
- Staph (usually iatrogenic)
- Listeria
- Klebsiella
* These organisms all come from vagina or its neighbor, the GI tract
How does transmission of sepsis occur?
- During labor membranes rupture or become leaky
- Organisms can ascend from the birth canal (vagina)
- Fluid becomes infected, fetus inhales or swallows it and also becomes infected
if mom goes into labor early for no known reason think…
possible infection like sepsis (Premature babies are more vulnerable because of less adequate immune system)
*Very high risk for EOS
Also higher risk for mortality associated with sepsis
It may be that the premature labor was prompted by brewing infection
MAJOR RISK FACTORS of EOS
*Chorioamnionitis
Maternal Group B Strep carriage
Prolonged rupture of the membranes (18 hrs)
Prematurity
MINOR RISK FACTORS of EOS
Ethnicity (black women are at higher risk of GBS colonization)
Low socioeconomic status
Male sex
Low birth weight (>2500 grams)
Definition of Chorioamnionitis
Maternal temperature during labor > 38.o C or 1oo.4 F
And at least 2 other features
1. maternal leukocytosis- WBC > 15,000 in blood
2. maternal tachycardia- > 100 beats/min
3. fetal tachycardia- baseline > 160 beats/min
4. uterine tenderness (tenderness=elicited, pain=subjective)
5. foul smelling amniotic fluid
Gram positive bacteria
Carrier state in mother (in her normal flora)
GBS
*6-30% prevalence internationally
how is GBS transmitted
- Not sexually transmitted
- 50% vertical transmission
- Late onset disease is horizontal transmission
____% of babies born to mothers with GBS will develop early onset sepsis
1%
___% reduction in GBS sepsis from 1990s
87%
*Currently- all moms are cultured for GBS at 36 weeks and treat when they go into labor
risk factors for GBS
- Previous child who had early-onset GBS sepsis
- GBS bactiuria during current pregnancy
- Maternal fever/chorio
- Preterm labor
- We revert to these criteria now when GBS culture is not available
Definition of prolonged rupture
> 18 hrs
*The longer the membranes are ruptured, the higher the likelihood of ascending infection
definition of Prematurity
gestational age less than 37 yrs
sepsis workup includes
- Blood culture is mandatory (1-2ml from 1 site)
- Chest X-ray (almost always done)
- Lumbar puncture, aka “spinal tap” (look for WBC in CSF)
- Complete blood count (CBC)
- C-reactive protein
- Urine culture is NOT indicated in septic workup of a newborn in the first 3 days of life. It should be included in workup of late onset sepsis
blood culture of spesis characteristics
1-2ml
- Almost all pathogens will grow within 48hrs
- Positive blood culture is diagnostic of neonatal sepsis but negative culture does not rule it
When to include Spinal Tap for sepsis dx
- positive blood culture (Best performed before starting antibiotics, can be delayed if baby is unstable)
- sx referable to CNS (Neonates with symptoms of meningitis -TRUE lethargy, abnormal tone, excessive irritability, bulging fontanel, or septic shock)
- being proactive before starting antibiotics
sx of meningitis
lethargy, abnormal tone, excessive irritability, bulging fontanel, or septic shock
important features of CBC to consider
- Total WBC count (but can be caused by stress too ie. labor)
- Differential
- Absolute neutrophil count
- Immature/total ratio (I/T)
- Immature leukocyte count
- Normal ranges are broad and depend upon timing **best time is at least 6 hours after birth
*can be a clue but not diagnostic
hematopoiesis
maturation and differentiation of WBC
the cell line most responsible for managing bacterial infections.
neutrophils
- Mature cells of the granulocyte line
- *Also known as polymorphonucleocytes or “polys”
Immature forms of neutrophils include:
Bands
Metamyelocytes
Myelocytes
Promyelocytes and myeloblasts are not in circulation so not on CBC
Hematopoiesis of neutrophils
myeloid stem cell–> myeloblast –> N. promyelocyte –> N. myelocyte–> N. Metamyelocytes —> N. Band—> Neutrophil
- Generally make up about 60% of circulating white blood cells.
- Their numbers can increase in times of stress, such as infection. Normal values for a newborn are 16,000 to 31,000!
neutrophil
*A low neutrophil count may be more ominous as it reflects an overwhelmed immune system.
how do u calculate absolute neutrophil count
the total percentage of all neutrophils x total white blood cell count
*NOTE: total neutrophil count = polys + bands+ myelocytes + metamyelocytes
WBC x % of all neutrophils
Ex. 15% poly + 5% bands = 20%
WBC x 20% = ANC
abnormal absoulte neutrophil count
less than 1750
First few hours of life, ANC is approximately ___ and what happens to the number
1800
*Rises to approximately 8000/cu.mm by 12hrs
Returns to 1800 by 3 days.
what is released in times of stress and to fight infection
immature neutrophils
how do u calculate Immature neutrophils
adding all immature forms of neutrophil line and dividing by total neutrophil count
*Upper limit of normal of 0.2
a protein synthesized by the liver in response to, and as part of, the inflammatory response
CRP
*Poor specificity- other perinatal conditions confound- asphyxia, fetal distress, MAS
normal CRP
less than 1.0
pattern of CRP release
- Released 4-6hr after stress
- Peaks at 24-48 hrs
- Diminishes over time as inflammation resolves
The only truly specific laboratory test in the workup of neonatal sepsis is __
blood culture
*However, many times, we make a PRESUMPTIVE diagnosis of sepsis based upon “clues” of suggestive history and suggestive lab tests.
prophylaxis tx of GBS
penicillin-mother needs 2 doses of PCN prior to delivery
*Acceptable: at least one dose, at least 4 hours prior to delivery
*If mother is Penicillin-allergic, other antibiotics are used:
Clindamycin- sensitivities are checked during pregnancy
Vancomycin- very broad spectrum
*These probably work but there is not evidence for specific parameters
If adequate prophylaxis, eliminates risk of EOS GBS sepsis, can go home when?
If inadequate, needs how long of an observation period to watch for evidence of EOS?
If adequate prophylaxis, eliminates risk of EOS GBS sepsis, can go home in 24 hours
If inadequate, needs a 48 hours observation period to watch for evidence of EOS.
Mothers who have fever or signs of chorio are treated with
antibiotics during labor to prevent sepsis in newborn
(prophylaxis for mothers with chorio)
*baby must be observed for 48 hrs after birth
Treatment for Newborns with Sepsis
-need IV antibiotics (best choice is ampicllin and gentamicin)
-Duration
10 full days for sepsis
2 weeks if meningitis
AAP and CDC recommend babies born to mothers with diagnosis of chorio should have ___
- sepsis workup
- i.v. antibiotics: Ampicillin and Gentamicin for 48 hours until cultures are negative
Current incidence of EOS is estimated __% and
Using current guidelines necessitates treating up to ___% of all newborns as if they are ill
0.05-0.12%
10%
*can use Kaiser spesis risk calculator to determine risk
by-product of RBC breakdown
bilirubin
*Bilirubin pigments are deposited in the skin and mucous membranes, causing the classic yellow or jaundiced appearance of the skin
when does jaundice occur
when an infant is hyperbilirubinemic
Jaundice first becomes visible____ and____ and progresses caudally to the ____
in the face
forehead
trunk and extremities
how to look for jaundice in a baby
Blanch the skin and look for an underlying yellow tone
average length of breastfeeding in the US and worldwide
and when are the biggest drop off in the US
- US is 3-6 months (bc women have to get back to work) and 5 yrs worldwide
- Biggest drop off is first leaving the hospital and the second is at 6 weeks when women go back to work
what % of women in CO exclusively b.f. at 3 months and 6 months and ever b.f
3 months- 50.3%**
6 months- 25.8%**
ever b.f- 81%
**meets US dept. of Heatlh goals
Breastfeeding initiation is less common in moms who:
Have lower education levels
Are single
Are teen
*mostly due to having to return to work, and these are the ones that would most benefit from b.f.
Five hospital maternity care practices that will help with successful breastfeeding:
- Infants are breastfed in the first hour after birth.
- Infants stay in the same room as their mothers.
- Infants are fed only breast milk and receive no supplementation (use human donor milk if need to supplement)
- No pacifier is used.
- Staff gives mothers a telephone number to call for help with breastfeeding.
provides Federal grants to States for supplemental foods, health care referrals, and nutrition education for low-income pregnant, breastfeeding, and non-breastfeeding postpartum women, and to infants and children up to age five who are found to be at nutritional risk.
WIC (women infants and children)
*have to choose bf or formula up front and can’t switch
Baby loses ___% of weight and then regains birth weight by day __
10%
10
*colostrum is less caloric
baby should have a yellow stool by day ___
5
what is the asymmetical latch
the babys nose should be pointed right at the nipple
-lower lip covers much more of the nipple and aerolar, babys tongue messages nipple to get milk out
*Nipple should not be latched (should Compress areolar and breast tissue)
___% of women in the United States elect to breastfeed and only about ___% are still breastfeeding at 6 months
75%
35%
indications for formula
- a substitute or supplement for human milk in infants whose mothers choose not to exclusively breastfeed
- For infants in whom breastfeeding is contraindicated
- As a supplement for breastfed infants whose intake of human milk is inadequate to support appropriate weight gain
Whey in breast milk is primarily ____, in cow’s milk it is ____
lactalbumin
lactoglobulin
use thawed room temp breast milk within ___hours
4-6 hrs
Use refrigerated breast milk within ___ hours (formula ___hrs).
48 hrs
24 hrs
*Do not freeze formula (breast milk can be frozen for 3-6 months)
Normal hematocrit in newborn is __-__%
45 - 60%
40-50 in an adult
*Newborns have a higher mean hematocrit than adults
pathology of jaundice
- In utero, baby is relatively hypoxic
- Hypoxia triggers production of erythropoietin, a hormone which stimulates red blood cell production
- Jaundice occurs when this relatively large pool of RBCs are broken down, a process that can either be physiologic or pathologic in origin
As extra RBCs are broken down, bilirubin is released
physiological jaundice
Step 1:
RBC’s are destroyed in the _____.
-There, hemoglobin is separated into _____ and a ____
reticuloendothelial system
globin and a heme pyrrole ring
Step 2:
Heme is converted to ______
uncongugated bilirubin
Step 3:
Unconjugated bilirubin is released from the RES into the circulation where it is _____.
tightly but reversibly bound to albumin
Step 4:
The bilirubin-albumin complex is carried through the splenic vein to the _____
portal vein to the liver.
Step 5:
In the liver, the albumin- bilirubin complex is combined with glucuronic acid to make ______ or _____
a bile salt or conjugated bilirubin
Step 6:
Conjugated bili is pumped out of hepatocyte into ____
canalicular (bile duct) system
Step 7-10:
- Leaves liver through common bile duct
- Enters Duodenum
- Leaves body in
stool - Or is deconjugated and reabsorbed back into enterohepatic circulation
- The fat soluble product of hemoglobin metabolism (must be secreted in stool)
- Binds tightly and readily to albumin in serum; neither is changed by the union
Unconjugated bilirubin
*Known as “free bilirubin” regardless of whether it is bound to albumin or not
Unconjugated= indirect/prehepatic
- Salts of glucuronic or sulfonic acids
- Water soluble
Conjugated bilirubin
*(essentially) Conjugated = Direct/post hepatic
Bilirubin is conjugated where
the Liver
Incorporated in to bile acids which act as a detergent to help in digestion of fats
conjugated bilirubin
In a normal newborn the direct bilirubin should be __ and ___ of the total bilirubin in the serum
less than 2mg/dl and less then 10% of the total bilirubin in the serum
Measures all bilirubin fractions in serum
total bili
*should be mostly unconjugated bili
measures 90% of conjugated bili.
direct bili
how to get value of indirect bili
- Ordering “fractionated” bili will get you total and direct values
- Indirect is a calculated value: Total – direct = indirect
causes of unconjugated hyperbilirubinemia
- Hemolytic (physiological, pathologic, immune mediated, enzyme defects, pool of blood outside vascular system)
- Prematurity
- Associated w/ breastfeeding (breast milk jaundice, b.f jaundice)
- Defects in Conjugation step (Crigler-Najjar, Gilberts, Asian descent)
-Normal hematocrit of term baby is 45- 60%
-begins to fall after delivery
-Nadir occurs at 2 months, with hematocrit as low as 28-30%
-Large # of RBCs destroyed in the process
-Hemolysis begins in utero, jaundice occurs
during the first 2 hours
Physiologic Hemolytic hyperbilirubemia
*peaks at 3-5 days (timing of 1st visit)
**UNCONJUGATED
-Occurs when a maternal antibody crosses
the placenta to attack fetal RBCs
-ABO most common, occurs in 20% of all births
-Begins in utero, therefore jaundice present during first few days of life
Pathologic Hemolytic hyperbilirubemia
-usually present 24-48 hrs of life
**UNCONJUGATED
___ antibody in ABO system
- Works in the same way - if MOC is Rh- then she can make ____ antibodies
- Rho-gam is ____ given at 28 weeks and after birth
D
anti-D antibodies
anti-D IgG
when mom is Rh- and baby is Rh+
Rh incompatibility
- Breakdown of extravascular blood, eg. bruising or cephalohematoma
- blood trapped between periostium and skull, caused by birth trauma
Hemolytic
UNCONJUGATED
Sex-linked disorder of cell membranes which makes them
vulnerable to hemolysis (More severe in males, Variable presentation in females)
-Usually occurs upon exposure to oxidants, especially medications or infections
-Protective against malaria
-Occurs in Mediterranean region, China, Africa
-Occurs in 10% of African Americans
Hemolytic: G-6PD Deficiency
*unconjugated
___% of premature infants become jaundiced
80%
*Premature infants conjugate more slowly bc their livers don’t fxn as well
- Higher risk for BIND (bilirubin induced neurologic dysfunction) at lower levels of bilirubin.
- Leaky blood-brain barriers
prematurity jaundice
- Caused by inadequate oral intake
- ncreases enterohepatic circulation
- Essentially, dehydration
- Occurs on days 2 to 5
- baby’s hydration is the urgent problem
Breastfeeding jaundice
- UNCONJUGATED
- consider supplementation with pumped milk formula
- Begins day 4
- Can peak weeks 2 to 4
- Persists up to 3 months
breastmilk jaundice
- UNCONJUGATED
- Totally benign– don’t interrupt nursing (Etiology unclear)
- Defect in glucuronyl transferase (enzyme important in creating bile salts)
- Typically, mild jaundice after puberty
- Possibly related to breastmilk jaundice
- Possibly related to increased jaundice in certain ethnic groups
- Autosomal dominant
Gilbert’s
*UNCONJUGATED
**turns yellow when get stressed
Severe, often lethal form of hyperbili.
- Clinically looks like kernicterus
- Autosomal recessive
- Occurs in one in one million live births
- Virtual absence of glucuronyl transferase enzyme
- Two Types (I, II)
Crigler-Najjar Syndrome
**UNCONJUGATED
requires lifelong PTX to avoid BIND and liver transplantation
Type I Crigler-Najjar Syndrome
treatable with Phenobarbital
Type II Crigler-Najjar Syndrome
Causes of Conjugated Hyperbilirubinemia
Hepatitis
Inborn Errors of Metabolism
Biliary atresia
- Agents have a predilection for cannicular cells (cells of the ductal system)
- Majority are “idiopathic”, self-limited without permanent damage
Infectious hepatitis
(Various infectious etiologies: Hep B, Rubella, CMV, Toxoplasmosis)
*CONJUGATEd