It is a condition of the body where there is extreme decrease in oxygen concentration and increase in the concentration of the carbon dioxide resulting in death. Asphyxia might get induced by electric shock, injury, choking, toxic gas inhalation and drowning .
The disease is related to the following processes: Radiation and has an incidence of about 7 / 100.000.
Some of the situations that can cause asphyxia include obstruction of airways due to laryngospasm, asthma, blocks due to the presence of foreign material, being in environments like under waters where oxygen supply is not available directly, and in environments where there is excessive smoke which does not allow breathing. Oxygen deficiency can be caused by many other conditions. Birth asphyxia or perinatal asphyxia is ahypoxia condition in the newborn observed during birth. When the chest or abdomen is compressed posteriorly and interferes in breathing, it is called as compressive asphyxia or traumatic asphyxia .
Chemical asphyxia involves inhalation of the substance that interferes with the ability of the body to make use of oxygen. For instance, carbon monoxide blocks the binding of hemoglobin to the oxygen in red blood cells. Simple asphyxia results when the oxygen is displaced by another gas. Drowning is the state of asphyxia, where the lungs are filled with any liquid or water. Drowning is classified into various types like secondary drowning, near-drowning and immersion syndrome. Suffocation is one of the causes of asphyxia, which can be further divided into entrapment, choking, strangulation, and smothering. Entrapment involves being closed inside an air-tight container. Mechanical asphyxia includes positional asphyxia, riot-crush deaths and traumatic asphyxia .
According to the WHO estimation by the year 2008, 9 lakh infants die each year from birth asphyxia and this condition was considered as the major cause for the death in the newborns. In the United States, the 10th major cause of neonatal deaths occurred due to intrauterine hypoxia and birth asphyxia. Many authorities suggest that perinatal asphyxia occurs in 3 to 5 newborns out of 1000 live births.
Traumatic asphyxia is an uncommon syndrome resulting from severe compression of thoracic region by any heavy object increasing the thoracic and superior vena cava blood pressure causing reverse flow of blood from the heart to the veins of the head and neck .
As the veins of head and neck do not have any valves, the capillaries are also extensively rushed with blood, sometimes breaking them. In his research findings, Dr. Joseph Volpe from the Harvard University at Boston, USA, said that many processes can lead to brain damage in birth asphyxia. According to him, several types of cell damage can occur from asphyxia that includes selective neuronal necrosis in brain stem, cerebral cortex and basal ganglia, parasagittal cerebral injury and strokes with focal lesions. During asphyxia, blood pressure drops and is accompanied by a drop in the flow of blood to the brain. The above changes lead to a condition called Ischemia, resulting in brain damage. Ischemia in turn leads to neuronal and oligodendoglial damage. Oligodendogiial damage results in decreased energy production and a decrease in ATP causing glutamate release. Glutamate reacts with the glutamate receptors leading to changes in the membrane function and calcium accumulation. Further, mitochondrial function is disturbed and the free radicals are also released causing cell death .
Prognosis of asphyxia is indicated by the risk of neurodevelopmental disability apart from intrapartum complications in birth asphyxia. About 8 to 17 percent of cerebral palsy is observed along with adverse perinatal events of asphyxia in the newborns with birth asphyxia. Hypotonia, seizures, metabolic acidosis at birth and Apgar score<=3 leads to cerebral hypoxia.
Symptoms of asphyxia include noisy breathing and gradual cessation of breathing, hypertension, face cyanosis, rapid pulse, convulsions, swollen veins on the neck and head, paralysis and slow loss of consciousness. Apart from these symptoms, there might be certain complications that can become severe leading to irreversible coma, brain death and death. Symptoms of asphyxia for a newborn baby might include low heart rate, pale skin color, weak reflexes, weak breathing, acidosis, meconium stained amniotic fluid and seizures .
Diagnosis of asphyxia is done primarily using primary tests rating the individuals from 0 to 10. This number range is called Apgar score, which gives rating for heart rate, skin color, muscle tone, breathing effort and reflexes. Low Apgar score of 0 to 3 lasting for a period of greater than 5 minutes is a sign of birth asphyxia.
Diagnosis will be complete with the application of techniques, like computerized tomography scan, magnetic resonance imaging and head ultrasound. The quality and intensity of brain activity is determined by the electroencephalogram. Some more tests are also conducted considering premature baby’s sensory responses. Tests for hearing and sight are helpful to conclude whether the damage has occurred to the brain cells or not [7, 8].
Some of the treatments done for asphyxia include first aid to eliminate the foreign body, expired air resuscitation, cardio-pulmonary resuscitation and emergency resuscitation. Treatment strategies for asphyxia include improving oxygen delivery in the body, generally with the help of mechanical ventilation. Blood circulation is monitored regularly and is improved by giving extra fluids or drugs or blood to support blood pressure and heart function. If the blood pressure is very high the brain might bleed heavily .
As asphyxia affects other parts of the body along with the brain, asphyxia affected baby will be monitored with specific attention towards kidneys, heart and liver. Asphyxia is commonly observed in the newborn babies just after their birth .
Cardiotocograph is a tool that aids in detecting fetal well-being and asphyxia at the time of labor. Abnormality in cardiotocograph is termed as pathological CTG trace or acidic pH. Recognizing a fetus with pathological CTG trace during labor might possibly refer to birth asphyxia or hypoxia. Interpreting CTG trace correctly and taking proper care in time can prevent asphyxia.