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Newborn Jaundice Is there anything new under the sun Objectives

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Newborn Jaundice Is there anything new under the sun Objectives Powered By Docstoc
					                                                    Newborn Jaundice: Is there
                                                    anything new under the sun?
                                                    Presented by:

                                                       Rebecca Attenborough RN, MN
                                                       Co-ordinator Reproductive Care Program

                                                       Darlene Inglis RN, BScN, IBCLC
                                                       Nurse Clinician, Neonatal Intensive Care Unit
                                                       IWK Health Centre




Objectives                                          What is hyperbilirubinemia?

 Define hyperbilirubinemia/jaundice                   Excess of bilirubin in the blood stream.
 Review bilirubin metabolism and types of             Occurs within the first week of life
 jaundice                                             (bilirubin level usually peaks at 3-5 days
 Describe the risk factors for hyperbilirubinemia     for full term infants and 6-8 days for
 Identify complications of hyperbilirubinemia         preterm infants).
 Discuss current management and treatment             When serum bilirubin levels reach
 Highlight latest practice recommendations            approximately 120 mmol/l or greater, the
                                                      normal term infant will appear jaundiced.




What is hyperbilirubinemia?                         How is bilirubin metabolized?

 Jaundice seen first in the sclera and head           Newborns have high levels of red blood
 and proceeds in a cephalocaudal direction.           cells/kg of body weight (fetal adaptation to
 Jaundice is virtually universal to some              low O2)
 degree, clinically significant in 25-50% of          Fetal RBCs have a short life-span (70-90
 infants                                              days vs. 120 days)
                                                      Unconjugated bilirubin is a normal
                                                      breakdown product of RBCs
                                                      (reticuloendothelial system)




                                                                                                       1
                                                    Potential problems with
How is bilirubin metabolized?
                                                    bilirubin metabolism
 Unconjugated bilirubin binds to albumin in          Infants have relatively low albumin levels
 plasma for transport to the liver                    – all binding sites may be used or bilirubin
 Conjugated by an enzyme (bilirubin-                    may have decreased affinity for albumin
 uridine diphosphoglucuronosyltransferase               (medications e.g. Hydralazine,
 or B-UGT) to a water-soluble compound                  Chloramphenicol)
 for excretion, eventually as urobilinoids           The enzyme needed for bilirubin
                                                     conjugation (B-UGT) is relatively inactive




Potential problems with
bilirubin metabolism
 Conjugated bilirubin is unstable in the bowel -
 may become unconjugated and reabsorbed
 – Beta-glucuronidase enables bilirubin to remain
   unconjugated (present in 10x adult
   concentrations, fetal mechanism for excretion
   via placenta)
 – Intestinal flora required to convert bilirubin
   conjugates to urobilinoids for excretion




Types of bilirubin                                  Types of jaundice

 Conjugated -              Unconjugated              Physiologic jaundice
 Direct                    Indirect                  Breast milk jaundice
 – Water-soluble            – Fat or non water
                                                     Pathologic jaundice
                              -soluble
 – Easily excreted                                              OR
                            – Potentially more
   in urine and               toxic                  Early onset
   stool
                            – Bound vs.              Late onset
 – Less toxic form            unbound to
 – Requires O2 and            albumin
   glucose




                                                                                                     2
Physiologic jaundice                                      Physiologic jaundice

 Caused by increased bilirubin load on liver &             Infants are otherwise healthy
 factors contributing to poor metabolism                   Bilirubin level rises slowly
  – Many RBCs with short life                              For term infants, develops after 24 hours
  – Low albumin levels                                     and disappears by 7 days of age
  – Initial deficiency in intracellular carrier protein    For preterm infants, develops after 48
  – Absent intestinal flora and elevated beta-             hours and disappears by 9 days of age
    glucuronidase                                          Occurs in 45-60% of term infants and 80%
  –     gut motility and delayed stooling                  of preterm infants




Breast milk jaundice                                      Pathologic jaundice

 Rare, may occur in 1-2% of breastfed infants              Bilirubin level rises fast (approaching 100
 Thought to be related to attributes of breast milk        mmol/l in the first day of life)
 Approx 20-40% of women have high levels of                Requires early recognition and treatment to
 beta-glucuronidase in their milk                          avoid complications
 Babies who are not breastfeeding well may be
 inappropriately labeled – very important to
                                                           Many of the same predisposing factors as
 identify sub-optimal breastfeeding!                       physiologic jaundice plus illness/pathology




Pathologic jaundice                                       Pathologic jaundice

 Blood group incompatibility                               Altered organ function (liver, GI or
 – Rh                                                      Neurological Systems)
 – ABO                                                     – Sepsis
 – Other                                                   – Asphyxia
 Prematurity                                               – Acidosis
                                                           – Hypothermia




                                                                                                         3
Pathologic jaundice                             Pathologic jaundice

 Altered metabolism/hereditary disorders         Factors that alter usual bilirubin metabolism
 – Hypothyroidism                                 – Polycythemia (hematocrit> 65%)
 – Glucose-6-Phosphate Dehydrogenase              – Damaged RBCs (e.g. related to excessive
   Deficiency (G6PD)                                bruising)
 – Galactosemia                                   – Organ immaturity and lower albumin levels
                                                    (preterm)
                                                 IDM (polycythemia, organ immaturity,
                                                 macrosomia)




Early and late onset                            Early and late onset
hyperbilirubinemia                              hyperbilirubinemia
 Early onset                                     Late onset
 – Manifested by 2-3 days of age                 – Occurs after 3-4 days (usually post-
 – Bilirubin levels are > 75th percentile          discharge)
   before 72 hours of age                        – May be related to sub-optimal
 – Many have blood group                           breastfeeding
   incompatibilities                             – Rule out metabolic diseases
 – May be related to sub-optimal                 – Unrecognized genetic polymorphisms
   breastfeeding                                   (siblings with jaundice?)




Complications of                                Complications of
hyperbilirubinemia                              hyperbilirubinemia
 Unconjugated bilirubin is fat soluble and       In sick or compromised infants the blood-
 can be absorbed into brain tissues leading      brain barrier is disrupted
 to neurotoxicity and, eventually, cell death    Injurious effects depend on both duration
 The blood-brain barrier in the healthy          and magnitude of exposure
 infant slows the equilibrium between
 plasma and brain tissues




                                                                                                 4
Complications of                                      Complications of
hyperbilirubinemia                                    hyperbilirubinemia
 Acute Bilirubin Encephalopathy (CPS 2007)             Chronic Bilirubin Encephalopathy (CPS
  – the acute clinical manifestations of               2007)
    severe hyperbilirubinemia (> 340mmol/l             – the clinical sequelae of ABE
    any time in the 1st 28 days of life)               – athetoid CP + seizures
  – lethargy, hypotonia & poor suck                    – hearing deficit & occulomotor
  – may progress to hypertonia, high-pitched             disturbances
    cry & fever, seizures, coma                        – dental dysplasia
 ABE does not occur at serum bilirubin                 – developmental delay
 levels < 340 mmol/l                                   – mental deficiency




Complications of
                                                      Newborn Jaundice
hyperbilirubinemia
 Kernicterus (CPS 2007)
 – pathological finding associated with
   CBE
 – deep yellow staining of neurons from
   deposition of unconjugated bilirubin in                           Questions?
   brain tissue
 – neuronal necrosis of basal ganglia &
   brainstem nuclei




Diagnosis of hyperbilirubinemia                       Diagnosis of hyperbilirubinemia

 The presence of jaundice can be determined by         Transcutaneous bilirubin measurement (TcB) is a
 examining the infant in a well-lit room and           good screening tool
 blanching the skin to reveal the color of the skin    Definitive measurement is Total Serum Bilirubin
 and subcutaneous tissue.                              (TSB) with identification of direct (conjugated)
 Increasing serum bilirubin levels are                 and indirect (unconjugated) portions
 accompanied by the cephalocaudal progression of       Other lab tests may include: blood group and
 dermal icterus, from face, to trunk and               DAT (Coomb’s test), albumin, hemoglobin &
 extremities, to palms & soles.                        hematocrit, investigations for sepsis if clinically
                                                       unwell




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                                                      Treatment of hyperbilirubinemia

                                                       The treatment of hyperbilirubinemia is still
                                                       phototherapy and, in more severe cases, an
                                                       exchange transfusion of the neonate’s or
                                                       fetus’ blood.




Phototherapy                                          New Canadian Guidelines

 Phototherapy employs wavelengths of light to          Guidelines for detection, management and
 alter unconjugated bilirubin in the skin.             prevention of hyperbilirubinemia in term
  – The bilirubin is converted to less toxic water-    and late preterm newborn infants ( 35 or
    soluble photoisomers that are excreted in the      more weeks’ gestation)
    bile and urine without conjugation.                Canadian Paediatric Society Position
  – The decision to initiate phototherapy is based     Statement May/June 2007
    on the newborn's age, total serum bilirubin        Nova Scotia Working Group
    level, and risk factors.
                                                       Canadian ‘Interest Group’




                                                      Prenatal & Early Newborn
Rationale
                                                      Period
 Canadian Paediatric Surveillance System Report        All mothers should be tested for ABO and Rh(D)
 indicated continuing problems with severe and         blood types and be screened for red cell
 critical hyperbilirubinemia in Canada (2002-2004      antibodies during pregnancy.
 data)                                                 If mother was not tested, cord blood from the
 Peak TSB occurs @ 3-5 days of life, usually after     infant should be sent for evaluation of the blood
 hospital discharge                                    group and DAT.
 Incidence of ABE similar to PKU                       Blood group evaluation and a DAT should be
 TSB concentrations in the high-risk zone cannot       performed in infants with early jaundice of
 always be detected visually                           mothers with blood group O (Grade B
                                                       recommendation).




                                                                                                           6
Early Newborn Period                                     Newborn Period

 Selected at-risk infants should be screened for
                                                             All infants should have a screening
                                                             bilirubin during the 1st 72 hrs of life
 G6PD deficiency
                                                             – either TSB (venous or capillary) or a TcB
 – Mediterranean, Middle Eastern, African or Southeast       – obtain with metabolic screen, if not required
   Asian origin                                                earlier for clinical jaundice
 All newborns visibly jaundiced in 1st 24 hrs of             If no treatment needed, plot the results on
 life should have bilirubin done                             the predictive nomogram
 A test for G6PD deficiency should be considered             – record results, time, zone
 in all infants with severe hyperbilirubinemia               – give copy to parents
                                                             Arrange follow-up according to the risk
                                                             assessment




Predictive Nomogram                                      Response to Screening

                                                                Zone         > 37 weeks +      35-37/6/7 weeks 35-37/6/7 weeks
                                                                               DAT-neg           or DAT-pos     and DAT-pos

                                                         High               Further testing*   Further testing*   Further testing*
                                                                            or treatment       or treatment       or treatment

                                                         High-              Routine care       Further testing*   Further testing*
                                                         Intermediate                          or treatment       or treatment

                                                         Low-               Routine care       Routine care       Further testing*
                                                         Intermediate                                             or treatment

                                                         Low                Routine care       Routine care       Routine care



                                                         *Repeat bilirubin within 24-48 hrs; institute treatment if necessary




Phototherapy                                             Phototherapy

 Intensive Phototherapy = two banks of                       Conventional phototherapy = single bank
 (white) lights or single bank of high-                      of fluorescent (white) lights above an
 intensity fluorescent tubes (blue) placed 10                incubator + diaper
 cm from infant.
                                                             – may be used for infant with a moderately
 – if TSB approaching the exchange threshold,                  elevated TSB of 35 mmol/l to 50 mmol/l
   add fibre optic blanket.
                                                               below thresholds for intensive phototherapy
 – Biomedical engineers should check light
   intensity regularly.
 On-line tool available at http://bilitool.org




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Treatment for moderate                               Treatment for severe
hyperbilirubinemia                                   hyperbilirubinemia
 Conventional phototherapy                            Intensive phototherapy
 Continue breastfeeding                               Recheck bilirubin within 2-6 hours to
 – interrupting breastfeeding is associated with a    evaluate response to treatment
   major increase in breastfeeding cessation by
   one month                                          Continue enteral feeding, breast or bottle
 – mother may need extra support to continue          For infants at risk of progressing to
 Avoid fluid supplementation                          exchange transfusion, provide
 – interferes with breastfeeding duration             supplemental fluids, enteral or IV
 – no evidence of benefit in this population




Treatment for severe                                 Guidelines for Intensive
hyperbilirubinemia                                   Phototherapy
 Infants with positive DAT predicted to
 have severe hyperbilirubinemia based on
 antenatal risk, or at risk of exchange
 transfusion, should receive intravenous
 immunoglobulin (IVIG) 1 gm/kg
 – inhibits antibodies that cause red cell
   destruction
 Prepare for exchange transfusion




                                                     Healthy Babies, Healthy Families:
Newborn Period – Transition                          Postpartum and Postnatal
from Hospital to Community                           Guidelines (Dec 2003)
 Any infant d/c before 24 hours of life               A comprehensive global newborn physical
 should be ‘reviewed’ within 24 hrs of life           assessment should be done at birth and prior to
 Systematic approach to risk assessment               discharge. A physical exam should be repeated at
 before discharge and follow-up if treatment          approximately 7-10 days of life.
 required                                             Parents should be contacted re feeding at 1-3
                                                      days post-discharge. Pre-discharge feeding plan
 Infants with prolonged or severe                     should dictate type of contact and timing (may
 hyperbilirubinemia should have further               not be face-to-face)
 testing                                              CPS/SOGC 1996 Guideline for ‘early’ discharge
                                                      (< 48 hours) specifies home visit with 24-48 hrs




                                                                                                         8
Nova Scotia Working Group                        Thank you
 Plan for routine bilirubin measurement before
 discharge
 Plan for plotting on nomogram, review of
 result, response plan (including
 communication of plan)
 Plan to ensure community follow-up for those
 who require reassessment
 Plan to ensure timely access to assessment
 and treatment, if required
 Recommendations for essential equipment in
 each DHA




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