What are cyanotic spells (tet spells)?
Cyanosis means bluish discoloration of skin, lips, tongue and nail beds. Cyanotic spells are episodes of worsening of cyanosis, usually in infants with birth defects of the heart (‘blue babies’) causing cyanosis. It usually after the baby cries of exerts in some other form. There is rapid breathing with increase in intensity of the bluish colour. If the spell is prolonged, the baby may develop a fit (seizure – epilepsy like movements of limbs). Emergency first aid is to keep the baby in the knee chest position – keeping the baby in such a way that knees and front of the chest both touch the bed. This cuts off the blood returning from the legs and increases the resistance to pumping out of blood from the heart. Both of these are helpful in allowing more blood reaching the lung for oxygenation. Final result if improvement in the oxygen level of blood reaching the body and decrease in bluish colour.
It is called tet spell because it is common in a disease called Tetralogy of Fallot in which there is a combination of four birth defects of the heart. The four defects are (1) defect in the wall between two lower chambers of the heart – ventricular septal defect, (2) obstruction to flow of blood from right ventricle (lower right chamber of the heart) to the lungs, (3) thickening of the wall of right ventricle and (4) over riding of aorta (large blood vessel carrying oxygenated blood to the whole of the body) over the ventricular septal defect.