Final answer:
The first nursing action when a newborn is irritable and jittery is to assess the blood glucose level to check for hypoglycemia, which aligns with the Apgar scoring system's goal of identifying newborns who may be in distress.
Step-by-step explanation:
When caring for a newborn girl weighing 3,800 grams and with an estimated gestational age of 41 weeks, noting irritability and jitteriness at 1 hour of age, the first nursing action should be to assess the blood glucose level. This symptom can be indicative of hypoglycemia, a common condition in newborns, especially those who are large for gestational age, had a diabetic mother, or are post-term like this case. Hypoglycemia in newborns requires prompt identification and management to prevent potential adverse neurological outcomes.
The rapid assessment is in accordance with the Apgar score methodology, which is used to quickly determine a newborn's transition from the womb to the outside world. The Apgar score assesses five criteria: skin color, heart rate, reflex, muscle tone, and respiration, with each criterion assigned a score of 0, 1, or 2 at 1 minute after birth and again at 5 minutes after birth. High Apgar scores indicate that the baby has made a good transition, whereas lower scores suggest potential distress, thereby guiding clinical decisions such as checking blood glucose levels.