Lec.6 Clinc.

Biochemistry
4Stage Medical Lab. Techniques Department

Clinical Chemistry of newborn (Pediatric )

The survival rate of very small premature infants has increased because of
improved specialized medical and nursing techniques for treating the
newborn . The communist disorders are
1) Respiratory disorder
2) Infection
Biochemical investigation requested in neonatal period as in adults, but
requesting is less selecting because of
1) Non –specific of the presenting clinical signs
2) Inability of the infant to give history.
3) The number of tests is limited by the small volume of samples.
Because blood volume of a premature weighing 1kgm is about 90 ml
compared with that of an adult weighing 70 k gm ,only a small amount of
blood can be taken without causing volume depletion on anemia venous
(or arterial ) blood samples although some times are ,since the later causes
contamination from inters shill fluid and cellular fluid .

Renal
Renal function is not fully developed will the age of about two, glomerular
function develop move rapidly them that of the tubule
Plasma creatinine : Which is reversely related is (GFR) glomerulor
filtration rate is higher at birth than in adult .
Plasma urea : is low in newborn infants compared with that of adult ,despite
the relatively low (GFR),the high anabolic rate results in more nitrogen
being used for protein synthesis rather than in the urea formation as in adult
. Neither plasma creatinine or urea conc . are sensitive indicators unless
tests performed serially Renal function is often difficult to assess in the
newborn period

Water & electrolytes

About 80% of an infant of less than1 Kgm consist of water, compared
with100% of an adult. Water loss in infants much higher than in adults
because
1) More fluid is last through skin because the epidermis is not fully
developed before about 28 weeks.
2) There is high metabolic and respiratory rate.
Daly fluid requirements are therefore up to five times higher per kgm
body weight than in adults.

Dr . Mustafa Al-Saleam
PhD. at Clinc. Biochem.and Horm.
College of Medicine / Al-Nahrain University
Member of AACC
Lec.6 Clinc. Biochemistry
4Stage Medical Lab. Techniques Department
Sodium
The total body sodium and the plasma sodium conc, fluctuate because
renal function is immature the newborn unlike adult is unable to make its
need for water clean. The plasma conc . Should be monitored to ensure that
the proportion of sodium to water is correct, otherwise the changes may
cause convulsion or even coma .

Potassium
Hypokalaemia may be caused by increased diarrhea
Hyperkalaemia caused by glomerular dysfunction and tissue damage due
to hypo oxygen.
per natal asphyxia
Renal complication and disturbances of electrolyte  balance are likely to
develop in infants with per natal asphyxia.

Bilirubin
More conjugated bilirubin reaches the liver in the newborn infant than in
adults because
1) R.B. Cs life is shorter.
2)Bruises may occur during birth and hemoglobin break down product
increases the plasma bilirubin
3)in newborn the conjugated process is not fully developed .the increase
load cause jaundice
Physiological jaundice : Is defined an mild jaundice which is not present at
birth and develops during the first few days and continues during the first
week of life ,with on obvious pathological reasons , plasma unconjugated
bilirubin conc may be very high in premature infants because of hepatic
immaturity . If the bilirubin conc .exceeds the albumin capacity, the 
unbound, fat soluble unconjugated bilirubin may cross cell membranes and
be deposited in the brain, this is a serious complication, which may caves
brain damage or death. Jaundice during the 24 hours of life is physiological
rather than pathological.

Causes

-ABO blood group incompatibility.

- Inherited erythrocyte abnormalities associated with hemolysed,
Glucose -6-phosphate dehydrogenises deficiency
-Inter uterine infections .syphilis, rubella or toxoplasmosis
Management:
1- blood transferees

Dr . Mustafa Al-Saleam
PhD. at Clinc. Biochem.and Horm.
College of Medicine / Al-Nahrain University
Member of AACC
Lec.6 Clinc. Biochemistry
4Stage Medical Lab. Techniques Department
2- Bilirubin destroyed with UV light
3-water loss balanced by fluid

Glucose metabolism
-Infants may become hypoglycemic because infants have very little liver
glycogen full term infants may become hypoglycemic if initially adequate
stores are drawn more rapidly than normal e.g during prenatal aspheric. --
-Plasma conc. Of glucose low as 30 mg/dl during the 1 st 72 hours and later
become 40 mg/dl impaired neurological development happen if plasma
glucose less than 40mg/dl
-Protein is lower in infants than adults
-TSH- rise due to birth stress.

Heart
-The heart is a muscular organ responsible for pumping blood through the
blood vessels by repeated, rhythmic contractions.
-Size of human fist
- Weighs 250-350 g
-The primary function of the heart is to pump blood in order to generate
and sustain an arterial blood pressure necessary to provide adequate
perfusion of organs.

Common Symptoms of Heart Disease

-Dyspnea
-Chest pain
-Cyanosis
-Palpitations
-Fatigue
-Edema

Heart Diseases
1-Congenital heart disease or Congenital Cardiovascular Defects (CCVDs)
. Abnormalities arising from the abnormal formation of the heart or its
major blood vessels
2-Congestive heart failure clinical syndrome that results from any disorder
that impairs the ability of the ventricle to fill with or eject blood 3-
Hypertensive heart disease a general term used to describe heart diseases
caused by direct or indirect effects of elevated BP . Hypertension is defined
as persistent systolic blood pressure (BP) of at least 140 mm Hg and/or
diastolic pressure of at least 90 mm Hg
4-Acute Coronary Syndromes a general term used to describe the following
series of events:
Dr . Mustafa Al-Saleam
PhD. at Clinc. Biochem.and Horm.
College of Medicine / Al-Nahrain University
Member of AACC
Lec.6 Clinc. Biochemistry
4Stage Medical Lab. Techniques Department
Angina reversible tissue injury, myocardial infarction (MI), and extensive
tissue necrosis.
The major cause of ACS is atherosclerosis .

Role of Laboratory
This is performed through analysis of body chemistry metabolites, such as:
1-Lipid profile test
- total cholesterol
-high-density lipoprotein
-cholesterol
-high-sensitivity C-reactive protein.
Risk factor assessment enables health-care professionals to educate the
patient and to start activities that will reduce risk for an AMI.

Laboratory Diagnosis of AMI

2-Enzymes
Creatine kinase "CK"
Involved in the transfer of energy in muscle metabolism.
3-Myoglobin
It starts to rise within 2-4 h and is detectable in all AMI patients between
6-9 h from chest pain onset.

Cardiac Proteins
4-Troponin
-The preferred biomarkers for assessment of myocardial necrosis
-The major function of troponins is to bind calcium and regulate muscle
contraction.

Dr . Mustafa Al-Saleam
PhD. at Clinc. Biochem.and Horm.
College of Medicine / Al-Nahrain University
Member of AACC