Upload
portsaid-neonatology
View
239
Download
0
Embed Size (px)
DESCRIPTION
One of lectures presented in our Port said fifth neonatology conference 23-24 October 2014, presented by prof Olfat Fawzy, M.D, M.Sc.,Professor of Endocrinology Al Azhar university
Citation preview
• Hypocalcemia is a common metabolic problem in newborns.
• The diagnosis, cl inical manifestations, and treatment of neonatal hypocalcemia will be reviewed.
• Patient born preterm at 34 weeks• Normal spontaneous vaginal
delivery• Birth Weight: 2050 g• APGAR 8
• 28 year old G1P0• Irrelevant medical History• Denies smoking• No medication use• No HTN, no DM• Negative serologic studies
• Irritable, with weak cry• +ve hypertelorism• jaw held tightly closed• cleft palate• CV: RR, systolic murmur• Extremities: hypertonic
• CBC: WNL• CMP: WNL except Ca• Ca: 6.0 mg/dL • P: 9.2 mg/dL (4.5-9.0)• Mg: 1.5 mEq/L (1.3-2.0)• PTH: 44 pg/mL (N 40-100)
•2D Echo reveals a small VSD•Hypoplastic thymus
•Hypocalcemia•Hypoparathyroidism•VSD•Hypoplastic thymus
• Plasma calcium totals 2.4 mM (9.4 mg/dl)– Free calcium is 1.2 mM
– Albumin
– Blood pH
– Serum phosphate
– Serum magnesium
– Serum bicarbonate
Hormone Effect Bone Gut Kidney
PTH Ca Po4 Increases Osteoclasts
Indirect via Vit. D
Ca reabPo4 exr.
Vit D3 Ca Po4 No direct action
Ca Po4 absorption
No direct effect
Calcitonin Ca Po4 Inhibits Osteoclasts
No direct effect
Ca & Po4 excretion
• Ca messenger system – regulates cell function
• Activates cellular enzyme cascades
• Smooth muscle and myocardial contraction
• Nerve impulse conduction
• Secretory activity of glands
• Neuromuscular excitabil ity
• Tetany• Seizures• Stridor or cyanosis
from laryngospasm• Hypotension• Impaired cardiac
contractil ity
• May be unspecific– Asymptomatic– Lethargy– Poor feeding– Vomiting– Abdominal distention
• Fetus: Ca and P concentration higher than mother plasma, s Ca falls at 24 hrs.
• Neonates: Ca lower than children at 2 n d and 3th day
• Return to normal by 5-10 days
•Total serum Ca less than:– 7.0 mg/dL in Preterm infants– 8.0 mg/dL in Term newborns– 8.8 mg/dL in children
Early neonatal hypocalcemia (48-72 hours)Prematurity
Poor intake, hypoalbuminemia, ↓ responsiveness to vit D
Birth asphyxiaDelayed feeding, ↑ calcitonin, endogenous
phosphate load , alkali therapy
Infant of diabetic motherMg depletion functional hypoparathyroidism → →
↓ CaIUGR
Late neonatal hypocalcemia (Full term)
•Exogenous phosphate load•Mg deficiency
•Transient hypoparathyroidism of newborn
•Congenital Hypoparathyroidism
•Maternal Vit D deficiency•Maternal Hyperparathyroidism•Gentamycin
Bicarbonate infusion → metabolic alkalosis
Transfusion with citrated blood→ formation of Ca complexes, ↓ Ca++
Lipid infusions → Ca complexes with FFAs → ↓ Ca++
Phototherapy for hyperbil irubinemia Acute renal failure →
hyperphosphatemiaRotavirus infection
• ↓ Mg → impaired PTH secretion & resistance to PTH → hypocalcemia
• Usually idiopathic & transient
• May be secodary to disorders of intestinal and/or renal tubular Mg transport
• Antagonizes PTH secretion or actions → ↑ Ca & P deposition in bones → hypocalcemia.
Cardiac defects, Abnormal facies, Thymic hypoplasia, Cleft palate, and Hypocalcemia caused by Chromosome 22 deletion
DiGeorge Syndrome is a severe phenotype of this group of related disorders.
FISH establishes the diagnosis.
• What is the diagnosis?
• How could we confirm the diagnosis?
• Total Ca• Ionized Ca• Phosphorus• Magnesium
• PTH • Vitamin D • Liver function• Renal function
Only in infants with risk factors
Measure Ca at 24, and 48 hrs of age.
Measure Ca in infants with congenital heart ds.
Ionized Ca should be the primary measurement.
1. Depends on underlying cause & severity
2. Mild asymptomatic : ↑ dietary Ca by initiating early feeding
3. For infants who require parenteral nutrit ion, Ca is added to the solution .
4. If symptomatic: treat immediately
– Ca gluconate:10 mg/kg (1 ml/kg of 10% solution) Slowly IV
– Start oral Calcium as soon as possible
– Early neonatal hypocalcaemia normalizes in 2-3 d
Late neonatal hypocalcemia– Associated with ↑ S-phosphate
–Decrease phosphate intake– Give calcium containing phosphate
binder – Oral calcium gluconate 100
mg/kg/dose 4 hourly
– Tissue necrosis/calcif ication if extravasates
– Calcium can inhibit sinus node → bradycardia + arrest
– Avoid complete correction of hypocalcemia
– Give Ca before correcting acidosis
– If ↓ Mg – f irst treat & correct hypomagnesemia