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Neonatal Lab Interpretation

Tanya Hatfield, MSN, RNC-NICUCSF Benioff Children’s Outreach Services

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“Lab called… your CBC clotted”

Objectives

▪ Interpret lab values▪ Discuss jaundice of the newborn▪ Understand specific hematologic problems

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CBC-Hematopoiesis

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Erythrocytes-RBCs

▪Main protein is hemoglobin (Hgb)▪RBC function is to protect Hgb▪Hgb function is oxygen/CO2 transport

5Kenner, C. (2014). Comprehensive neonatal nursing care (Fifth ed., pp. 334-338)

Reticulocytes

▪ Inversely proportional to GA at birth ▪Falls quickly to less than 2% by 7 days ▪Elevated early Retic Ct may indicate bleeding, hemolysis or chronic blood loss

Components of CBC

▪Main protein is hemoglobin (Hgb)▪RBC function is to protect Hgb▪Hgb function is oxygen/CO2 transport

6Kenner, C. (2014). Comprehensive neonatal nursing care (Fifth ed., pp. 334-338)

Reticulocytes

▪ Inversely proportional to GA at birth ▪Falls quickly to less than 2% by 7 days ▪Elevated early Retic Ct may indicate bleeding, hemolysis or chronic blood loss

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RBC Indices

▪Mean corpuscular volume (MCV): size and volume

▪Mean corpuscular hemoglobin (MCH): average amount (weight) of hemoglobin

▪Mean corpuscular hemoglobin concentration (MCHC): average concentration

▪Nucleated RBC: circulating pre-reticulocyte

7Kenner, C. (2014). Comprehensive neonatal nursing care (Fifth ed., pp. 334-338)

Anemia▪ Differential

• ↓ Erythrocyte production ‒ infection, nutritional deficiencies, leukemia, bone

marrow failure, anemia of prematurity• ↑ Erythrocyte destruction

‒ hemolytic anemia, blood incompatibility, infection, other rare diseases

• Blood loss ‒ Iatriogenic, obstetric accidents, cord/placenta

malformation, TTTS, abruption, DIC

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ABO/Rh Incompatibility

RISK FOR HEMOLYSIS IN MATERNAL BLOOD TYPE O, AND/OR RH NEGATIVE STATUS

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ABO/Rh IncompatibilityCheck infant blood type

▪ For type O mother, infant types A, B or AB could cause symptomatic incompatibility

▪ For Rh negative mother, Rh positive infant could cause symptomatic incompatibility

▪ Transfusion preparation

▪ May obtain on cord blood

Evaluate direct Coombs/Direct AntiglobulinTest (DAT)

▪ Detects certain antibodies which, if bound to the surface of RBCs , cause their destruction

Check reticulocyte count

▪ Elevated values (10-30%) support diagnosis of hemolytic anemia

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Anemia of prematurity

All infants experience a progressive Hg decline in the 8-10 weeks following birth

• Not necessarily symptomatic• Anemia possibly r/t rapid body growth, shortened

RBC lifespan, and low blood erythropoietin (EPO) levels‒ Term infants nadir at 11-12 g/dL‒ Preterm may be as low as 7-8 g/dL

Anemia of Prematurity may be exaggerated physiologic response or pathologic

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Erythropoiesis

▪What stimulates increased RBC production?

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• Medications‒Iron‒Multivitamin‒Erythropoetin

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A 32-week 1700 gram infant has a UAC in place. 15 minutes after an xray, the nurse notices a large pool of blood under the infant. Estimated blood loss is 45mL.

Which set of s/s is most likely to reflect the infant’s condition in the first 30-60 minutes following this acute loss of blood?

Hematocrit Blood Pressure

Heart Rate Multisystem

A Decreased Hypotension Tachy Tachypnea, Pallor

B Same as before incident

Hypotension Tachy Pallor, cap ref 3 sec, resp distress

C Same Hypotension Brady Apnea, cyanosis

D Decreased Same as Same Hepatosplenomegaly

Clinical Findings

Varies with the volume of blood loss and the time period over which blood is lost▪ Acute

▪ Pallor, then cyanosis and desats▪ Shallow, rapid, irregular respirations▪ Weak or absent peripheral pulses▪ Low or absent blood pressure▪ Hemoglobin may be normal initially, with rapid decline over 4-12 hours with hemodilution

▪ Chronic▪ Pallor without signs of distress▪ Possible CHF with hepatomegaly▪ Normal BP▪ Low hemoglobin concentration14

Diagnosis

▪ History▪ Family history: anemia, blood incompatibilities, jaundice

▪ Maternal history: blood type, third trimester bleeding ▪ Lab findings

▪ Hemoglobin concentration/CBC▪ Reticulocyte count▪ Blood smear- evaluate size, shape, structure▪ Blood type▪ Coombs test▪ Kleihauer-Betke test- identifies fetal hemoglobin in maternal blood

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Management

▪ Prenatal▪ Diagnose early▪ Delayed cord clamping

▪ Postnatal▪ Anemia of Prematurity

▪ Limit blood draws▪ EPO course▪ Transfusion PRBCs

▪ Acute blood loss▪ Rapid replacement whole blood or PRBCs 10-20 mL/kg

▪ If blood unavailable, saline 10-15 mL/kg16

Platelets▪ Etiologic Factors:

▪ Platelet destruction: Maternal autoimmune (ITP, Lupus)

▪ Neonatal conditions: Neonatal alloimmune thrombocytopenia, Infection, thrombotic disorders, DIC, Birth asphyxia, giant hemangiomas

▪ Impaired platelet production (rare): Trisomy syndromes, TARS, Fanconi’s anemia

▪ Platelet interference: maternal drug ingestion (Demerol, Phenergan, sulfonimides, thiazides17

Platelets Clinical Presentaion

▪ Petechiae, purpura, epistaxis▪ Ecchymosis over presenting part▪ Cephalohematoma▪ Bleeding (mucous membranes, GI, GU, umbilical cord, puncture sites)

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Platelets Clinical Assessment

▪ Family, birth, medication history▪ Blood smear, platelet count▪ Physical exam (jaundice, congenital anomalies)▪ Rule out DIC & Vitamin K deficiency

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Thrombocytopenia management

▪ Supportive care and treatment▪ Cesarean if maternal symptoms severe or previous child severely affected

▪ Platelet transfusion: keep greater than 30,000 in first 2 days, greater than 50,000 if surgery needed, or infant premature or at risk for IVH

▪ Steroids may be useful for counts less than 25,000 and active bleeding, or initial treatment for hemangioma

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CBC-White Blood Cells with differential▪ Protect against infective organisms and foreign substances▪ Leukocytosis and leukopenia can be problematic▪ 5 main types of WBCs

• Neutrophils (31-57%) • Lymphocytes (35-61%)• Monocytes(4-7%)• Eosinophils (2-4%)• Basophils (0-1%)

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CBC-WBC with differential▪ Neutrophils are primarily responsible for killing & digesting bacteria

▪ Levels peak about 6-8 hours after birth (normal depends on age and gestation)

▪ With infection immature neutrophils are released

‒ Bone marrow attempt to maximize neutrophils

▪ Immature to total ratio (I/T ratio)▪ “Left shift”

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The Parade of the Tin Soldiers. (2016). Wikipedia. Retrieved 5 April 2016, from https://en.w ikipedia.org/w iki/The_Parade_of_the_Tin_Sold iers

“Left Shift”

CBC-Hematopoiesis

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Absolute Neutrophil Count ANC▪ Concentration of neutrophils in blood▪ Low levels are especially concerning▪ Considerations: Infants of hypertensive mothers,

Trisomy 13, 18, 21

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Gestational Age range

>36 weeks 28 to 36 weeks

< 28 weeks

At birth neutropenia defined as:

ANC < 3500 ANC < 1000 ANC < 500

Time of peak ANC and value that defines neutropenia at time of peak

8 hours: ANC < 7500

6 hours:ANC < 3500

24 hours: ANC < 1500

Learnpediatrics.com,. (2015). Pediatric Neutropenia | Learn Pediatrics. Retrieved 13 October 2015, from http://learnpediatrics.com/body-systems/hematology-oncology/pediatric-neutropenia/

Christensen, R. D., Henry, E., Jopling, J., & Wiedmeier, S. E. (2009). The CBC: reference r anges for neonates.Seminars In Perinatology, 33(1), 3-11. doi:10.1053/j.semperi.2008.10.010

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ANC calculation practice

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White Blood Cell count WBC

15,000

Segmented neutrophils (segs)

35%

Band neutrophils (bands)

15%

Metamyelocytes (metas)

3%

Lymphocytes 42%Basophils 4%Eosinophils 1%

(% segs + % bands + % metas) x (WBC)(100)

( 35 segs + 15 bands + 3 metas) x (15,000)(100)

ANC is 7950

Within normal range for gestation and age

I/T Ratio Immature to Total Ratio

▪ I/T ratio is most sensitive for estimating the risk that infection is present• Majority of neutrophils should be mature cells

(segmented)• Elevated immature neutrophils raises suspicion

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Immature (I) = I / T ratioTotal (T)

Calculating I/T ratio

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White Blood Cell count WBC

15,000

Segmented neutrophils (segs)

35%

Band neutrophils (bands)

15%

Metamyelocytes (metas)

3%

Lymphocytes 42%

Basophils 4%

Eosinophils 1%

Immature (I) = I / T ratioTotal (T)

15 bands + 3 metas = 18 immature15 bands + 3 metas + 35 segs = 53 total

= 0.34 I/T ratio

I/T ratio > 0.2 raises index of suspicion for infection

I/T ratio > 0.8 correlated with higher risk of death

from sepsis

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C-Reactive Protein (CRP)

▪ Non-specific marker for inflammation• trauma, surgery, infection, acute inflammation

▪ Useful when trended▪ Generally elevates within 4-8 hours of event▪ CRP levels remain high as long as the inflammation or tissue damage persists and then decrease rapidly• Possibly useful to monitor response to antibiotics

28Gomella, T., Cunningham, M., Eyal, F., & Zenk, K. (2004). Neonatology. New York: Lange Medical Books/McGraw -Hill Medical Pub. Division.

Definition of Neonatal Sepsis

▪ The presence of signs/symptoms of infection and/or isolation of a pathogen from the bloodstream

▪ Most commonly presents as bacteremia and/or meningitis

▪ Early onset sepsis: <72 HOL-7days, caused by maternal intrapartum transmission

▪ Late onset sepsis: >72 HOL, >7 days pathogens acquired postnatally

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Bacteria on the move…▪ Airborne- RSV▪ Body fluid▪ Transplacental- Listeria, Syphillis▪ Ascending- chorioamnionitis▪ Transcervical/intrauterine/birth canal- GBS, E Coli, gonorrhea, herpes

▪ Fecal/oral▪ Contact- Staph, candida▪ Nosocomial- CONS▪ Pathogen dependent

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Prophylaxis & Prevention!!

• GBS screening• Eye prophylaxis for

Chlamydia, Gonorrhea

• Hand hygiene• NICU infection

control practices

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Maternal and Neonatal Risk Factors for Sepsis

• Major risk factors• Maternal GBS colonization• Preterm labor• Membrane rupture > 18 hours• Maternal s/s of intra-amniotic infection

(chorioamnionitis)• Other risk factors: recent maternal illness or infection, any

maternal GU infection, procedures, instrumentation with delivery

• Other variables that contribute to incidence include: ethnicity, low socioeconomic status, male sex, and low Apgar score

Neonatal Risk Factors

▪ Prematurity▪ Low birth weight▪ Difficult delivery▪ Birth asphyxia▪ Meconium▪ Resuscitation/Low apgars▪ Male gender▪ Congenital anomalies▪ Multiple birth

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Clinical Presentation of Sepsis▪ Central Nervous System

• Temperature instability• Lethargy/irritability• Hypo or hypertonia• Seizures

▪ Respiratory System• Cyanosis• Grunting, flaring or retracting• Tachypnea• Apnea• Increased oxygen requirement

▪ Gastrointestinal • Poor feeding • Emesis (may be bile-stained)• Increased residuals (may be bile-

stained)• Abdominal distention• Edema/erythema of abdominal

wall• Diarrhea/decreased stools• Hepatomegaly, jaundice

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Clinical Presentation of Sepsis

▪ Cardiovascular• Pallor, cyanosis, or

mottling• Bradycardia/tachycardia• Hypotension• Decreased perfusion• Edema

▪ Skin• Rashes• Pustules• Erythema• Omphalitis• Edema

Clinical Presentation of Sepsis

▪ Hematopoietic• Jaundice• Bleeding• Purpura/ecchymosis• Splenomegaly• Thrombocytopenia

▪ Metabolic• Glucose instability• Metabolic acidosis

Bacterial Organisms

▪ Gram positive▪ Coagulase-negative Staph▪ Staphylococcus Aureus▪ Listeria monocytogenes▪ Streptococcus pneumonia▪ GBS▪ Group A Strep

▪ Gram negative• E Coli• Neisseria meningitides • Haemophilus influenza • Klebsiella pneumoniae• Pseudomonas aeruginosa • Acinetobacter• Citrobactoer• Enterobacter• Serratia marcescens• Proteus

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Lab Studies & Sepsis

▪ CBC with differential

▪ Platelet count

▪ Blood Culture

▪ Time to detection

▪ CRP

▪ Urine Culture

▪ Gram stain

▪ CSF studies

▪ CXR

▪ Coagulation studies

▪ Tracheal Aspirate

37Gomella, T., Cunningham, M., Eyal, F., & Zenk, K. (2004). Neonatology. New York: Lange Medical Books/McGraw -Hill Medical Pub. Division.

Blood Culture Volumes

▪ 0.5 ml of blood is NOT an adequate specimen ▪ One quarter of neonatal bacteremia are LOW COLONY COUNT (4 CFU/ml or less)

▪ At a minimum obtain at least ONE ml of blood

▪ Time to detection is a sensitive tool to detect true infection▪ At 36 hours 99% of EOS are detected in term infants

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Cerebrospinal Fluid CSF▪ Up to 50% of neonates with meningitis may have negative blood cultures!!

▪ Lumbar puncture• Tube 1: CSF glucose, protein• Tube 2: CSF culture/gram stain• Tube 3: CSF cell count/diff• Tube 4: if needed for other studies

CSF labs (generally)…↑ WBC ↑ Protein ↓ Glucose

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Treatment▪ Broad spectrum▪ Sensitivity▪ Antibiotic choice

▪ History in the NICU▪ Suspected organism▪ Degree of illness▪ Age▪ EOS vs LOS

▪ LOS are primarily Gram + organisms (CONS, S epi)

▪ Patient Considerations…

TreatmentMeningitis Pneumonia Urinary Tract Candida

Incidence 0.4-1/1000 >10% in preemies/ill infants

Less common newborn period 1% term, 3% preterm

Varies w/increaseHigh m/m (25-33%

Common organism

E. Coli, GBS, Listeria

GBS, pseudomonas

Enterococcus, E. coli, GBS

Infection with fungi (Candida)

Acquisition Direct invasion, contamination from blood, skin or CSF

Airway CAUTI Skin, mouth, vagina, GI tract, catheter associated, “fungal balls”

Risk factors Prematurity, CNS abnormalities, L&D complications

Intubation, VAP

Males, premies, urinary malformations, maternal UTI, neurogenic bladder

Prematurity, Intubation, surgery, NEC, low WBC, steroids, abx, TPN/lipids, hyperglycemia, histamine blockers

Treatment Longer course 14-21 daysCephalosporins

Organism dependent

7-10 days, r/o malformations with multiple UTI

Prophylaxis for VLBW, abx, central line-FluconazoleOral-Fluc/NystatinSystemic- Fluc, Ampho B

Rules of the R/O▪ All preterm infants with the possible exception of a delivery after an induction for maternal reasons

▪ All infants with any respiratory symptoms, feeding intolerance or changes in neurologic status

▪ Any baby that just “doesn’t look quite right”▪ Early, rapid and thorough evaluation is essential▪ Asymptomatic newborn with even one risk factors needs evaluation

▪ Treatment should not be delayed with a symptomaticnewborn with “normal” labs

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Neonatal Response to Sepsis

▪ Decreased phagocytosis & chemotaxis▪ Neutrophil deficiency▪ Impaired migration▪ Impaired diapedsis▪ Inability to localize infection▪ Decreased killing ability of neutrophils

• 75% response in term infants

• 50% response in preterm infants

Cascading Complications of Sepsis

▪ Pulmonary edema, secondary surfactant deficiency, PPHN

▪ Endocrine: adrenal insufficiency (hypotension), altered thyroid function

▪ Lymphocyte loss secondary to thymic involution, splenocyte apoptosis

Major Complications▪ Septic Shock

▪ DIC▪ Meningitis

Sepsis Cascade

▪ Bacterial cascade triggers the release of cytokine mediators

▪ Coagulation complement activation, neutrophil activation, immune activation, acidosis pathway

▪ Vasodilation leads to vascular leak and edema, decreased oxygen delivery, tissue injury and cell death

▪ SHOCK- A state in which the body can not meet the tissues demands for oxygen and substrate• Hypovolemic• Septic / Maldistributive• Cardiogenic

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Early Septic Shock –compensated phase

▪ Baby looks “okay”▪ Hyperdynamic

• tachycardia• blood pressure WNL,

pulse pressure widened• bounding peripheral

pulses• tachypnea• flushed skin

Late Septic Shock –uncompensated phase

▪ Baby looks BAD▪ Respiratory failure, PPHN▪ Hypodynamic

• decreased cardiac output• hypotension• diminished peripheral

pulses, delayed CFT, cool skin

• progressive metabolic acidosis DIC

Disseminated Intravascular Coagulation (DIC)

▪ Hemorrhagic disorder associated with underlying disease with uncontrolled activation of coagulation and fibrinolysis

▪ Fibrin deposited in blood vessels > microvascular thromboses

▪ Consumption of coagulation factors and platelets > hemorrhage = Consumptive coagulopathy

Disseminated Intravascular Coagulation (DIC)▪ Important concepts:

▪ Clotting factors don’t cross placenta▪ Most clotting factors produced in liver and require vitamin K

▪ Neonatal levels of PT/PTT, coagulation inhibitors (ATIII,protein C), and fibrinolysis factors are < adult levels

▪ Fibrinogen & platelets are similar levels to adult▪ Secondary to other disease processes

▪ Maternal factors: PIH, eclampsia, abruption, placental abnormalities

▪ Intrapartum factors: fetal distress, death of multiple, traumatic delivery

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DIC-Lab Diagnosis

▪ Thrombocytopenia-consumed by clot, decreased production▪ ↑ PT – deficiency in Vitamin K dependent factors▪ ↑ PTT – clotting factor deficiency, heparin contamination▪ ↓ Fibrinogen (consumed to form fibrin)

▪ ↑ FSP & D-dimer (fibrinolytic activity)▪ RBC smear – presence of schistocytes ~ RBCs destroyed by fibrin strands

Blood component therapy

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DIC-Treatment

▪ Treat underlying condition▪ Supportive care▪ Replace coagulation factors, platelets

• Vitamin K• Fresh Frozen Plasma• Cryoprecipitate• Platelets• Blood• Clotting factor concentrates

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Management of Sepsis

▪ Report changes in the clinical exam immediately▪ Consider all the risk factors▪ Obtain lab work if not already done▪ Administer IV antibiotics▪ Monitor for signs of shock – compensated vs. uncompensated shock• Support the A, B, Cs • Volume resuscitation and inotropes

Nosocomial Infections

▪ Prevention is key!▪ Hand hygiene▪ Skin prep▪ Vascular access▪ Risk factors

Hyperbilirubinemia

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Unconjugated (Indirect) Bilirubin

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▪ Fat-soluble▪ Not yet metabolized by

the liver▪ Is not easily excreted▪ Is the biggest concern

for newborn jaundice▪ Causes the yellowing of

skin▪ Can lead to Kernicterus

Beachy, J. (2007). Lab v alues. Investigating jaundice in the new born. Neonatal Netw ork, 26(5), 327.

Conjugated (Direct) Bilirubin

• Water soluble, non-toxic

• It is mostly excreted in stool and some in the urine

• “Cholestatic jaundice”• Management• No suntanning!!

Hyperbilirubinemia

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Hyperbilirubinemia is defined as an elevated serum total bilirubin (TB) level

• > 10-12 mg/dl in term• > 4-5 mg/dl in preterm infants

• Usually peaks around 5-7 days• Later peak in preterm infants

Hyperbilirubinemia - Etiology

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▪ Increased formation / synthesis of bilirubin▪ Hemolysis▪ Sepsis▪ Sequestered blood▪ Decreased/altered conjugation▪ Delayed passage of meconium▪ Dehydration

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Phototherapy

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The role of phototherapy in the treatment of hyperbilirubinemia is:

1. Increase the amount of ligand at the liver wall, thus facilitating uptake

2. Cause oxidation and isomerization of bilirubin into a water-soluble, excretable form

3. Increase the amount of glucuronyl transferase so that bilirubin can be more easily conjugated

4. Cause movement of extravascular bilirubin into the vascular space, thus facilitating albumin binding

Phototherapy

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Treatment Options

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▪ Hydration• Optimize breastfeeding, formula supplementation• IV support

▪ Phototherapy• Light, wavelength and dose dependent

▪ Exchange transfusion▪ Medications

• Phenobarb-increases bilirubin conjugation• IVIG

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Osteopenia Studies

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▪ Calcium▪ Magnesium▪ Phosphorous▪ Alkaline Phosphatase

Ca++

Essential for blood coagulation, neuromuscular excitability, cell membrane permeability, normal cardiac function, development of the structural integrity of the skeleton Acidosis results in an increase of free ionized Ca, inhibits the Ca binding ability with protein, thereby increases serum Ca levels.Hypocalcemia signs: serum level <7▪ May see stridor, high-pitched cry, twitching, jitteriness not related to low

glucose, seizure activity, poor cardiac output. ▪ IDM have delayed neonatal parathyroid production. ▪ Asphyxia results in calcitonin release, which prohibits parathyroid action.

Tissue damage releases phosphorus into the blood which further inhibits Ca uptake.

Hypercalcemia: serum level >11▪ Untreated maternal hypoparathyroidism = overproduction of parathyroid

hormone in infant ▪ PTH - Parathyroid hormone increases serum Ca by increasing the breakdown

of bone, increasing intestinal absorption, and inhibiting renal excretion. ▪ Calcitonin is secreted by the thyroid C cells to lower serum Ca by

counteracting PTH.

Mg ++

Magnesium is the second-most abundant intracellular cation and overall, the fourth-most abundant cation.

It plays a fundamental role in many functions of the cell, including energy transfer, storage, and use; protein, carbohydrate, and fat metabolism; maintenance of normal cell membrane function; and the regulation of parathyroid hormone (PTH) secretion.

▪ Hypomagnesemia <1.5: hyperreflexia and irritability, abnormal eye movements (nystagmus), and convulsion

• Signs similar to hypocalcemia

▪ Hypermagnesemia >2.3: smooth muscle relaxation causing respiratory, neuromuscular, and gastrointestinal depression

• Resolves over a few days with adequate hydration

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Phosphorous

▪ Deficiency <4mg/dl; rarely presents with symptoms

• Treat with 25–50 mg/kg/day of phosphate

▪ Excess considered >8 mg/dl

• Usually related to excess administration

• May decrease the absorption of other minerals

• Reduce PN administration, change enteral feedings to lower phosformula or MBM, administer calcium

Alkaline Phosphatase

▪ Enzyme originating in liver and bone▪ Not a specific indicator of bone turnover, but commonly used as a

marker▪ May be elevated in normal growth or liver disease▪ Further investigation needed if levels higher than 35-95 U/L

• >300 mg/dL indicate a need for higher Ca and PO4 intake• >550 mg/dL can indicate osteopenia of prematurity

Rickets screen: Alk phos, PO4, Ca▪ Premature infants at birth have a limited bone mass accretion, and

therefore have a greater need for bone nutrients than infants delivered at term

▪ 50% of infants born with a BW <1000g will develop osteopenia of prematurity

▪ Obtain BL labs then weekly if stable, 2x/wk if depleted