Final answer:
The fourth step of giving ventilation to an infant is to monitor the infant's response, including observing chest rise and fall and checking vital signs like color and heart rate.
Step-by-step explanation:
Step 4 of giving ventilation to an infant is monitoring the infant's response to ventilation. After the first three steps have been completed (placement of the mask on the infant's face, clearing the airway of any obstructions, and squeezing the bag to deliver the breath), it is crucial to observe the infant's chest for rise and fall, which indicates effective ventilation. Assessing the infant's color, heart rate, and oxygen saturation are also part of the monitoring process to ensure the ventilation is helping the infant achieve adequate respiration. Medical advances in treating Respiratory Distress Syndrome (RDS), including the use of ventilators, CPAP (nasal continuous positive airway pressure), and pulmonary surfactant therapy, have greatly improved outcomes for infants with breathing difficulties.