Contents Chapter Topic Page Neonatology Respiratory Cardiology

Newborn and Acid Base Balance
Rate of metabolism in infants is 2 times as great in relation to body mass as in adult,
which means 2 times as much acid is normally formed which leads to a tendency toward
acidosis. Functional development of kidneys is not complete until the end of the first
month and hence renal regulation of acid base may not be optimum
A. Causes of Acidosis
1. Respiratory Acidosis
i) Asphyxia : Damage to respiratory
centre
ii) Obstruction to respiratory tract e.g.
secretions, blocked endotracheal
tube
iii) Respiratory conditions :
Respiratory distress syndrome
(RDS)
Pneumonia
Pulmonary oedema
Apnoea
2. Metabolic Acidosis
i) Renal failure
ii) Septicaemia
iii) Hypoxia
iv) Hypothermia
v) Hypotension
vi) Cardiac failure
vii) Dehydration
viii) Hyperkalaemia
C. Effects of acidosis and alkalosis in the body
ix) Hyperglycaemia
x) Anaemia
xi) Intraventricular haemorrhage
xii) Drugs (e.g. acetazolamide which is
a carbonic anhydrase inhibitor)
xiii) Metabolic disorders (often
associated with hypoglycaemia)
B. Causes of Alkalosis
1. Respiratory alkalosis
i) Asphyxia –over stimulation of
respiratory centre
ii) Over ventilation while on mechanical
ventilation
2. Metabolic alkalosis
i) Administration of sodium
bicarbonate
ii) Pyloric stenosis
iii) Hypokalaemia
iv) Use of diuretics like thiazides and
frusemide
1. Acidosis
i) Depression of central nervous system (CNS)
ii) Disorientation and coma
iii) Increased depth and rate of respiration in metabolic acidosis and depressed
respiration in respiratory acidosis
iv) High PaCO2 in respiratory acidosis increases cerebral blood flow and risk of
intraventricular haemorrhage
2. Alkalosis
i) Over excitability of the CNS
ii) Decreased cerebral blood flow cerebral ischaemia convulsions
D. Measurement of Acid Base Status
Done by analyzing following parameters in an arterial blood gas sample: