2. Baby Boy KM
Dob-29/06/2007, born at 27 weeks by Em CS for
foetal distress
B.Wt.-914 grams
Apgar 4/1, 8/5
Born blue, floppy with poor respiratory effort
Responded well to IPPV
Intubated and received 1 dose of surfactant
Admitted to NNU & extubated to CPAP
22/08/2019Sid 2
Case History
3. 28 years old G4 P3, Caucasian
Single, unemployed
H/O substance abuse – on methadone
programme
Urine +ve for opiates, cannabis, heroin, crack
cocaine & methadone (March 07)
Smoking at booking- 6-14 /day
Asthmatic on ventolin& becotide inh.
Diagnosed Grave’s disease in 2001
On medical therapy till 2004
Thyroidectomy 2004 (total)
On thyroxin
22/08/2019Sid 3
Maternal Details
4. Needed one fluid bolus, loaded with caffeine
UAC & long line sited
Started on IVF, TPN & IV antibiotics
Started on morphine infusion 10 mic
Remained tachycardic HR >200
MBP 55- 60 mm of Hg
Extreme irritability & agitation
22/08/2019Sid 4
Progress of baby
10. Rpt Echo:
No PDA, tachycardia, TR 3.2, FS27 %
Rpt HUSS:
Ventriculomegaly LVI 13, RVI 12.5
No IVH, RI 0.78
Day 1-
TFT: TSH <0.05, (0.10-5.0),
FT4 >50, (10.0-20.0) (THIS CLINCHED THE DIAGNOSIS)
Cotisol 324
22/08/2019Sid 10
Progress (contd)
11. Continued to be extreme irritable, agitated,
tachycardic, high MBP:
Consultation with Paed. endocrinologist
Started on PTU, Lugol’s Iodine & propranalol
Not for steroid until thyroid storm
Later reviewed by Paed. endocrinologist
Transplacental passage of TSH receptor antibodies
Suggested weekly TFT, antibody testing
Continuation of drugs, to wean off propranalol, withdraw
Iodine & to continue of PTU alone, r/v after 3 months
22/08/2019Sid 11
Progress (contd)
12. Day 7: TSH<0.05, FT4 19.9
Conjugated Hyperbilirubinemia
Max SBR 264,(Direct 158)
ALP 614, ALT 100, AST 120, Alb 18
Haematology:
Hb 11.9 – needed red cell transfusion
PLT 25- needed two platelet transfusion
DCT –ve, Normal coagulation
USS abdomen – normal liver, kidneys, distended
GB
22/08/2019Sid 12
Progress (contd)
15. Fetal thyroid bilobed shape- by 7week
Thyroid follicle cell & colloid formation- 10 wk
Thyroglobulin synthesis occurs from 4wk
Iodine trapping by 8-10 wk
T4 and to lesser extent T3 synthesis and secretion -
from 12 week
Hypothalamic neurons synthesise TRH by 6-8 weeks,
portal system develops by 8-10 weeks
Maturation of the hypothalamic-pituitary-thyroid
axis -during the second half of gestation, but normal
feedback relationships are not mature until 1-2
months of PN life
22/08/2019Sid 15
Normal thyroid physiology in fetus
16. Maturation of fetal thyroid gland development & of
thyroid hormone secretion in the human infant
22/08/2019Sid 16
19. 22/08/2019Sid 19
Thyroid physiology in fetus & newborn
Normal patterns of change for TSH, total T4, and total T3 for the fetus
(beginning at twelve weeks gestation) and continuing for the first five weeks
of life in the newborn
24. Increase oxygen consumption
Stimulate protein synthesis
Influence growth and development.
Affect Carbohydrate , Fat and Vitamin
Metabolism
Cardiovascular system: Thyroid hormones
increases heart rate, cardiac contractility and
cardiac output. They also promote vasodilation
Central nervous system: Both decreased and
increased concentrations of thyroid hormones
lead to alterations
22/08/2019Sid 24
Functions of thyroid hormones
25. 22/08/2019Sid 25
Maturation of thyroid hormone effects in the human fetus and neonate. The left
edge of the bars indicate the approximate time the effects of thyroid hormone
become manifest
26. In the preterm baby, and fetus of similar gestation, the
thyroidaxis is immature, with reduced hypothalamic TRH
production andsecretion
An immature response of the thyroid gland to TSH
An inefficient capacity of the follicular cell of the thyroidto
organify iodine, and a low capacity to convert T4 into
activeT3
The level of T4 is lowerthan that of term babies and
correlates with gestational ageand birth weight. Levels of
TSH and T3 are normal to low,free T4 concentrations are
also low
Responses of TSH and T4 to TRH are normal, reflecting
that the site of immaturity isthe hypothalamus
22/08/2019Sid 26
Thyroid function in the preterm baby
28. Mother
Raised thyroid binding immunoglobulin levels in pregnancy
Thyroid binding immunoglobulin level not assessed
Clinical thyrotoxicosis in third trimester
Thionamide required in third trimester
Family history of TSH receptor mutation
Baby
Evidence of fetal thyrotoxicosis
22/08/2019Sid 28
Babies at high risk of neonatal
thyrotoxicosis
29. Rare, account for <1% of all paediatric
hyperthyroidism
Virtually all patients have a maternal history of
Graves disease
Due to transplacental passage of thyrotropin
receptor stimulating antibody
Only 1 in 70 infants of thyrotoxic mothers has
clinical symptoms
A maternal TSI level must be very high (>5 times
normal) to produce clinical disease in the neonate
22/08/2019Sid 29
Neonatal Graves disease
30. Onset usually begins prenatally and is present at birth
Occasionally may be delayed to weeks
Onset severity and course will also depend upon the TRB
Ab.
If mother is on antithyroid medication onset may be
delayed for 3-4 days
The frequency of neonatal Graves disease is equal in males
and females
Fetal tachycardia and goitre can help in diagnosing
prenatally along with very high levels of TRS Ab levels in
mother
22/08/2019Sid 30
Neonatal Graves disease (contd)
32. As it is caused by maternal immunoglobulin G (IgG)
antibodies, it is self-limited & resolves when the child
is aged 3-4 months
More persistent hyperthyroidism in neonates is likely
to reflect a different pathogenesis, such as an
activating mutation of the TSH receptor
22/08/2019Sid 32
Neonatal Graves disease (contd)
33. Mortality has been reported to be 12–20%
Usuallyfrom heart failure, but other
complications include tracheal compression,
infections, and thrombocytopenia
Long-term effects can include craniosynostosis
and developmental delay
Dev’tal delay occurs even in the face of early
diagnosis and treatment, which suggests that
prenatal exposure to high levels of thyroid
hormone may have early effects that cannot be
overcome after birth
22/08/2019Sid 33
Neonatal Graves disease (contd)
35. Therapeutic regimen
22/08/2019Sid 35
Multiple medications, each of which has a
different mechanism of action:
A beta-blocker to control the symptoms induced
by increased adrenergic tone In addition, they
inhibit deiodinationof T4 to T3.
A thionamide, such as PTU or methimazole, to
block new hormone synthesis
An iodine solution to block the release of thyroid
hormone
Glucocorticoids to reduce T4-to-T3 conversion
and possibly treat the autoimmune process in
Graves' disease
An iodinated radiocontrast agent to inhibit the
peripheral conversion of T4 to T3
36. DRUGS
22/08/2019Sid 36
Propylthiouracil.
Dose to dose less potent.
High Plasma protein bound
Less transferred across
placenta and milk
Plasma t1/2 1-2 hours
Single dose acts for about 4-8
hours
No active metabolite
Multiple (2-3) daily doses
needed
Inhibits peripheral conversion
of T4- T3
Carbimazole
About 3 times more potent.
Less bound
Larger amounts transferred
across placenta
6-10 hours
12-24 hours
Active metabolite-
Methimazole
Single daily dose
38. Sedatives - in managing irritability and restlessness
Exchange transfusion - in an attempt to reduce TSI
levels with some reduction in antibody levels but
failing to preventneonatal thyrotoxicosis
Treatment should be reviewed approximately
weekly until stable, then every one to two weeks,
and drug doses reduced when possible
Treatment usually required for 3-4 months
In contrast, thyrotoxicosissecondary to activating
mutations of the TSH receptor is persistent and may
require ablative treatment usually with surgery
22/08/2019Sid 38
Treatment (contd)
40. Rare, presents as a life-threatening
exacerbation of hyperthyroidism,
accompanied by fever, delirium, seizures,
coma, vomiting, diarrhoea, and jaundice
Mortality rate due to cardiac failure,
arrhythmia, or hyperthermia is ~30%, even
with treatment
Thyrotoxic crisis is usually precipitated by
acute illness (e.g., stroke, infection, trauma,
diabetic ketoacidosis), surgery especially on
the thyroid
22/08/2019Sid 40
Thyroid storm
41. 22/08/2019Sid 41
Diagnostic criteria for thyroid storm*
* A score of 45 or more is highly suggestive of thyroid storm;
a score of 25 to 44 supports the diagnosis; and a score
below 25 makes thyroid storm unlikely.
Adapted from Burch, HB, Wartofsky, L, Endocrinol Metab Clin North Am
1993; 22:263
Thermoregulatory dysfunction
Temperature
99-99.9 5
100-100.9 10
101-101.9 15
102-102.9 20
103-103.9 25
104.0 30
Central nervous system effects
Mild
10
Agitation
Moderate
20
Delirium
Psychosis
Extreme lethargy
Severe
30Seizure
Coma
Gastrointestinal-hepatic dysfunction
Moderate
10
Diarrhea
Nausea/vomiting
Abdominal pain
Severe 20
Unexplained jaundice
Cardiovascular dysfunction
Tachycardia
99-109 5
110-119 10
120-129 15
130-139 20
140 25
Congestive heart failure
Mild
5
Pedal edema
Moderate 10
Bibasilar rales
Severe
15
Pulmonary edema
Atrial fibrillation 10
Precipitant history
Negative 0
Positive 10
42. Intensive monitoring and supportive care,
identification and treatment of the precipitating
cause, and measures that reduce thyroid hormone
synthesis
Large doses of propylthiouracil (PO/PR (inhibitory action on
T4 ® T3 conversion makes it the agent of choice)
One hour after the first dose of PTU, stable iodide is given to
block thyroid hormone synthesis via the Wolff-Chaikoff
effect (the delay allows the antithyroid drug to prevent the
excess iodine from being incorporated into new hormone)
high doses of propranolol have been documented to
decrease T4 - T3 conversion
glucocorticoids , antibiotics if infection is present, cooling,
and intravenous fluids
22/08/2019Sid 42
Thyroid storm -treatment