Question 1: Briefly explain what cystic fibrosis is and how dornase alpha acts to solve the problem

It is a genetic defect that can cause a decrease in secretions in many organs. The most problematic symptom is in the airways. The airway has a very thick sticky mucus secretion which allow a good environment for bacterial infections. The continuous infections that are present cause continuous chemotaxis of neutrophils which later cause deposits of DNA, as a result the mucus becomes even more sticky. it is very difficult to clear the mucus therefore more infections occur. 

Dornase alfa hydrolyses extracellular DNA from neutrophils in the bronchial mucus, this causes an increase in the liquidity. 

Question 2: Briefly explain what neonatal respiratory distress syndrome is, what the general treatment strategies involve and hw cortisone and exogenous surfactants solve the problem

The surface active material that covers the respiratory tract of the airway is only formed during the final weeks of pregnancy. When premature babies are born the surface active material is not formed, this causes gas exchange to be disrupted and the lungs might collapse. Treatment needs to be followed quickly in order to save the babys life. 

The general treatment options would be: oxygen as this ensure oxygenation, ventilation for positive pressure and medications (exogenous surfactants like poractant alfa and beractant )

Cortisone increases surfactant production and can be administered prophylactically 

Exogenous surfactants increase the lungs surfactant 

Question 3: What is the role of oxygen therapy in neonatal respiratory distress syndrome? what do the dangers of oxygen toxicity involve?

Oxygen is given in order to guarantee oxygenation. A continuous oxygen pressure from the ventilator helps increase respiration and allows the alveoli to stay open and not collapse. The arterial partial oxygen however needs to be continuously monitored.  In order for respiration to take place there needs to be enough oxygen present. It is therefore administered to prevent hypoxia. However, when oxygen is inhaled in large quantities or over a long time it has toxic effects. It can cause inter alia, reduced gaseous exchange, hypoxia and in very severe cases even death. In neonates it can also cause retinal damage which leads to blindness

Question 4: Briefly explain what neonatal apnea is and how the methylxanthines solve the problem. which methylxanthine is used ?

It occurs when your respiratory center in the medulla of a premature baby has not been able to develop enough to stimulate continuous breathing. Therefore, making the breathing center very sensitive to stimulation and effect of CO2. Apneas typical duration is not longer than 15seconds and comes together with bradycardia. The continuous episodes of apnea can lead to neural damage. 

Methyxanthines like caffeine and theophylline stimulate the CNS. IV administrations tend to aid the problem. Therapy will be stopped usually after a few weeks in the ICU. The neonate will thereafter receive oxygen therapy. It is important to always monitor the oxygen levels in the blood.