PowerPoint Presentation - LRI...Wavelength dependence on quantum yield for lumirubin production....
Transcript of PowerPoint Presentation - LRI...Wavelength dependence on quantum yield for lumirubin production....
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ADULT
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Antony F. McDonagh et al. Pediatrics 2009;123:67-76
2 4
E 5
Z
1 4E,15E-bilirubin XIIIα
2 4E,15Z-bilirubin IXα
3 4Z,15E-bilirubin IXα
4 Z,E-bilirubin IIIα
5 Z,Z-bilirubin XIIIα
1
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1 E-lumirubin
2 Z-lumirubin
3 4E,15Z-bilirubin
4 4Z,15E-bilirubin
5 4Z,15Z-bilirubin 3/15/2015 36
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The absorbance of hemoglobin (Hb, solid line) and bilirubin/human serum albumin (bilirubin, dashed line) at the concentrations of 2.6 mmol/l and 0.325 mmol/l, respectively,
Absorbance of hemoglobin (Hb, solid line)
Absorbance of bilirubin/human serum albumin (dashed line) [x4]
Effect of hematocrit on the efficacy of phototherapy for neonatal jaundice. Lamola, Bhutani, Wong, Stevenson & McDonagh. Ped. Res (2013) 74, 54–60
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Do melanocytes and other
chromophores interfere with light
penetration or alter the scattering
of light within the skin structure?
Wavelength dependence on quantum yield for lumirubin production.
Wavelength dependence of of melanin absorbance of light also absorbed by bilirubin and hemoglobin.
Calculated fraction of the light absorbed by bilirubin. The solid curve included the wavelength dependence of the skin light backscatter, and the curve defined by the black squares included the wavelength dependence of melanin absorbance. The 2 curves are virtually identical. The dashed curve includes the wavelength dependence of the quantum yield for lumirubin production. 3/15/2015 40
Calculated fraction of light absorbed by bilirubin (15 mg/dl) in blood, normalized to 1.0 at the maximum, for two hematocrit values, 30% (black squares) and 50% (solid line). The two curves are virtually identical and therefore appear as a single line.
Lamola, Bhutani, Wong, Stevenson & McDonagh. Ped. Res (2013) 74, 54–60
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The effect of hematocrit on the efficacy of phototherapy for neonatal jaundice. Lamola AA, Bhutani VK, Wong RJ, Stevenson DK
& McDonagh AF. Pediatric Research (2013) 74, 54–60
Relative calculated rates of Light absorption by bilirubin Related relative rates for serum bilirubin decrement ()
HEMATOCRIT
REL
ATI
VE
RA
TES
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OPTICAL BIOSENSORS
1. COLORMETRIC:
Measures light adsorption.
2. PHOTOMETRIC: Measures light intensity. Photon output for a luminescent or fluorescent process can be detected by a photodiode system.
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IRRADIANCE MAPPING OF THE FOOTPRINT
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5
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2 1
FIVE-POINT TEST
1. RIGHT SHOULDER
2. LEFT SHOULDER
3. UMBILICUS
4. RIGHT KNEE
5. LEFT KNEE
Levels should read >30 μwatts/cm2/nm
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Light is potent oxidant: risk of photo-oxidant injury: • Doğan M.et al: Evaluation of oxidant and antioxidant
status in infants with hyperbilirubinemia and kernicterus. Hum Exp Toxicol 2011; 30: pp. 1751-1760
• Kale Y et al: Effects of phototherapy using different light sources on oxidant and antioxidant status of neonates with jaundice. Early Hum Dev 2013; 89: pp. 957-960
• Demirel G et al: Comparison of total oxidant/antioxidant status in unconjugated hyperbilirubinemia of newborn before and after conventional and LED phototherapy: a prospective randomized controlled trial. Clin Invest Med 2010; 33: pp. E335-E341
• Hintz SR et al Is phototherapy exposure associated with better or worse outcomes in 501- to 1000-g-birth-weight infants? Acta Paediatr. 2011 Jul;100(7):960-5.
• Tyson JE et al. Does aggressive phototherapy increase mortality while decreasing profound impairment among the smallest and sickest newborns?Journal of Perinatology. 2012;32(9
When Light Shines Through Immature Skin
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0 5 10 15
<28
28-29
30-31
32-33
>34
GA (WEEKS)
TOTAL SERUM BILIRUBIN LEVELS
6-8
8-10
10-12
12-14
Bhutani&Wong © Vinod K. Bhutani, 2013
>5
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Phototherapy Checklist
CHECKLIST PHYSICIAN NURSE FAMILY
Bilirubin Level ✔ ✔ ✔
Exposed Skin ✔ ✔ ✔
Blue light ✔ ✔ ✔
Light Intensity ✔ ✔ ✔
Breast feeding ✔ ✔ ✔
Repeat Bili Test ✔ ✔ ✔
Duration of lights ✔ ✔ ✔ 3/15/2015 56
• Measure serum albumin
• Track bilirubin : albumin ratio
• Adjust of early postnatal age
• Adjust for hemolysis
• Adjust for acidosis, birth asphyxia, hypothermia
• Signs of BIND include apnea, hemodynamic instability, altered behavior, seizures, etc.
Guidance to Prevent BIND (<35 weeks GA)
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Unaddressed Topics
• Elevated direct bilirubin levels
• Conjugated bilirubin (water soluble)
• CHOLESTASIS: elevated direct bilirubin
– >2mg/dl
– >20% of Total Bilirubin
– DO NOT SUBTRACT direct bilirubin from total serum bilirubin (re: operational levels for intervention)
• SHOULD YOU USE PHOTOTHERAPY?
– If direct bili is >50% of TSB 3/15/2015 58
Neonatal Phototherapy
1. It is not UV light 2. Know wavelength 3. Know Irradiance 4. Expose skin 5. Prescribe as a drug:
to prevent exchange
Light is a strong oxidant
Bilirubin is a potent anti-oxidant 3/15/2015 59
HARNESS THE BLUE-GREEN LIGHT OF A RAINBOW
AND PREVENT NEONATAL BRAIN INJURY