A nurse is planning to administer phytonadione 0.5 mg to a newborn.

Available is 1 mg/0.5 mL. How many mL should the nurse administer? (Round the answer to the nearest hundredth.

Use a leading zero if it applies.

Do not use a trailing zero.)

Choice A rationale

Nalbuphine hydrochloride is a synthetic opioid agonist-antagonist analgesic often used for pain relief during labor. Its agonist effects on kappa (κ) opioid receptors in the central nervous system lead to analgesia and common side effects, including central nervous system depression. Sedation is a frequent manifestation of this effect, caused by the drug's action on brain centers controlling arousal.

Choice B rationale

Nalbuphine primarily acts as an opioid, and its μ-receptor antagonist activity counteracts some opioid effects, but typical opioid-related gastrointestinal effects include decreased peristalsis, often leading to constipation. Diarrhea is not a common or expected adverse effect of nalbuphine; instead, it tends to slow gut motility due to its opioid effects on the enteric nervous system.

Choice C rationale

Opioid use, including nalbuphine, can sometimes lead to the adverse effect of urinary retention, due to increased detrusor muscle tone and internal sphincter spasm, which is a suppression of the micturition reflex. Diuresis, which is an increased or excessive production of urine, is not a recognized adverse effect of this medication.

Choice D rationale

Opioids, such as nalbuphine, typically interact with the thermoregulatory centers in the hypothalamus, often resulting in hypothermia due to vasodilation and decreased metabolic rate, not fever. Fever (pyrexia) is not a common or characteristic adverse effect associated with the administration of nalbuphine hydrochloride during labor.

Choice A rationale: Skin-to-skin contact promotes thermoregulation, stabilizes heart rate and respiratory rate, and enhances glucose homeostasis through reduced stress hormone release. It also facilitates breastfeeding by stimulating maternal oxytocin and infant rooting reflexes. In hypoglycemic newborns, skin-to-skin reduces energy expenditure and supports metabolic recovery. This intervention is evidence-based and essential for physiologic stabilization and bonding, especially in infants with feeding difficulties or temperature instability.

Choice B rationale: Rechecking glucose levels is critical to confirm sustained euglycemia and detect rebound hypoglycemia. Neonatal glucose regulation is dynamic, especially in large-for-gestational-age infants. After initial correction, glucose may drop again due to persistent hyperinsulinemia. Monitoring ensures timely intervention and prevents neurologic sequelae. The normal range for neonatal blood glucose is greater than 40 to 45 mg/dL. Serial checks guide feeding frequency and determine need for escalation of care.

Choice C rationale: Temperature monitoring is essential because hypothermia increases glucose utilization and exacerbates hypoglycemia. Newborns have immature thermoregulatory mechanisms and rely on external warmth and brown fat metabolism. A stable temperature of 36.5° C (97.7° F) is ideal. Rechecking ensures that swaddling and skin-to-skin are effective and that no environmental factors are compromising thermal stability. Temperature instability may signal underlying metabolic or infectious processes requiring further evaluation.

Choice D rationale: Reinforcing hourly breastfeeding supports frequent glucose intake and prevents hypoglycemia recurrence. Early and regular feeding is the cornerstone of neonatal glucose management. Hourly feeding ensures adequate caloric delivery, stimulates gastrointestinal motility, and promotes bilirubin excretion. It also helps establish maternal milk supply and improves latch technique through repetition. This action is especially important in infants with initial feeding difficulties or borderline glucose levels.

Choice E rationale: Tightly swaddling provides warmth and comfort but is not a primary intervention once temperature is stable. While swaddling supports thermoregulation and reduces energy expenditure, it does not directly address glucose regulation or feeding. In this case, the newborn’s temperature has normalized, and swaddling has already been implemented. Therefore, it is not a next-step priority but rather a maintenance measure.

Choice F rationale: Maintaining an IV catheter is unnecessary unless glucose levels remain critically low or feeding fails. The newborn’s glucose improved to 50 mg/dL after breastfeeding, indicating effective oral management. IV glucose is reserved for symptomatic hypoglycemia or levels below 25 mg/dL. In this stable scenario, invasive therapy is not warranted and may introduce infection risk or parental anxiety. Thus, it is not an appropriate next action.

Choice G rationale: Scheduling a lactation consult addresses the initial difficulty with latching and supports long-term feeding success. Lactation specialists provide hands-on guidance, assess anatomical barriers, and educate on positioning and milk transfer. Early intervention improves breastfeeding outcomes and reduces risk of hypoglycemia, dehydration, and jaundice. This consult is especially important for large infants with high metabolic demands and mothers needing support.

Choice H rationale: Monitoring for dehydration is important but not immediately indicated unless signs such as poor skin turgor, dry mucosa, or decreased urine output appear. The newborn has breastfed and is sleeping quietly, suggesting adequate hydration. While vigilance is necessary, it is not a top-five priority at this moment. Dehydration monitoring becomes more relevant if feeding remains poor or output declines.

Choice I rationale: Supplemental oxygen is not indicated in a newborn with normal respiratory rate, heart rate, and oxygen saturation. The newborn is alert, crying, and has no retractions or cyanosis. Oxygen therapy is reserved for hypoxemia or respiratory distress. Unnecessary oxygen can suppress respiratory drive and interfere with thermoregulation. Therefore, it is not appropriate in this stable clinical context.