Final answer:
During an emergency delivery, the LPN's most appropriate action when the head is crowning is to support the baby's head as it delivers, ensuring a safe delivery.
Step-by-step explanation:
During an emergency delivery, when the LPN sees that the head is crowning, the most appropriate action for the LPN is b) Support the baby's head as it delivers. This helps to guide the baby out gently and ensures that the delivery proceeds safely. Encouraging the mother to push should be done in accordance with the contractions and under guidance. Applying pressure to the perineum can help prevent tearing, but supporting the head is critical as it emerges. Inserting a gloved hand into the birth canal is generally not advised unless there is a specific medical indication to do so.
In the context of labor and delivery, it's essential to understand the stages of labor. The first stage involves the cervix thinning and dilating up to about 10 cm, the second stage is when the baby is expelled from the uterus, and the third stage is the passage of the placenta. A positive feedback loop occurs when the baby pushes against the cervix during the second stage, stimulating the release of oxytocin, which further stimulates contractions, aiding in the delivery process.