Which data should alert the nurse that the neonate is postmature?

Choice a) Have the parent fold the infant's arms across the chest is incorrect because this is not a helpful way to calm a preterm infant. Folding the arms across the chest can restrict the infant's breathing and movement, and may increase their stress and discomfort. Preterm infants need gentle and supportive touch, not restraint or pressure.

Choice b) Encourage the parent to place the infant back in the warmer is incorrect because this is not a necessary or beneficial action for a preterm infant who is showing signs of overstimulation. Placing the infant back in the warmer can interrupt the bonding and attachment process between the parent and the infant, and may make the infant feel more isolated and insecure. Preterm infants need close and frequent contact with their parents, not separation or detachment.

Choice c) Encourage the parent to do kangaroo care is correct because this is an effective and evidence-based method of soothing and stabilizing a preterm infant who is experiencing overstimulation. Kangaroo care is a technique where the parent holds the infant skin-to-skin on their chest, providing warmth, comfort, and security. Kangaroo care can reduce the infant's stress hormones, lower their heart rate and blood pressure, improve their oxygenation and breathing, enhance their growth and development, and strengthen their bond with their parent.

Choice d) Cover the infant with a warm bed blanket is incorrect because this is not a sufficient or optimal way to comfort a preterm infant who is displaying signs of overstimulation. Covering the infant with a warm bed blanket can provide some warmth and protection, but it does not offer the same benefits as kangaroo care. A warm bed blanket cannot mimic the parent's heartbeat, voice, smell, and movement, which are essential for the infant's emotional and physiological well-being. Preterm infants need human touch and interaction, not just physical warmth.

Choice A) dilates the bronchioles, decreasing airway resistance: This is not the correct function of surfactant.

Surfactant is a substance that reduces the surface tension of the fluid that lines the alveoli, which are the tiny air sacs in the lungs where gas exchange occurs. Surfactant does not affect the diameter of the bronchioles, which are the small airways that branch from the bronchi. Bronchodilation and bronchoconstriction are regulated by the autonomic nervous system and various mediators, such as histamine, epinephrine, and acetylcholine.

Choice B) provides transportation for oxygen to enter the blood supply: This is not the correct function of surfactant. Surfactant does not transport oxygen or any other gas. Oxygen diffuses from the alveoli into the capillaries, where it binds to hemoglobin in the red blood cells. The red blood cells then transport oxygen to the tissues via the blood circulation. Surfactant does not play a role in this process.

Choice C) keeps the alveoli open during expiration: This is the correct function of surfactant. Surfactant prevents the alveoli from collapsing during expiration by lowering the surface tension of the fluid that lines them. This allows for easier breathing and better gas exchange. Without enough surfactant, the alveoli tend to collapse and stick together, causing atelectasis, which is a condition where some or all of a lung collapses. Atelectasis can lead to hypoxia, respiratory distress, and infection.

Choice D) causes increased permeability of the alveoli: This is not the correct function of surfactant. Surfactant does not increase or decrease the permeability of the alveoli, which is the ability of substances to pass through them.

Permeability of the alveoli depends on several factors, such as pressure gradients, solubility, molecular size, and membrane thickness. Increased permeability of the alveoli can occur in conditions such as acute respiratory distress syndrome (ARDS), where fluid leaks into the alveolar space and impairs gas exchange. Surfactant does not cause this condition, but it can be affected by it.