A nurse is contributing to the plan of care for a 5-week-old infant in the pediatric unit. The infant has been vomiting since week 2 of life and it has been progressively worse over the past 2 weeks. Parents report the vomiting is now forceful and projectile (“like a volcano erupting”) immediately after every feeding, but the infant is eager to eat and seems to be constantly hungry. The infant has been receiving a cow’s milk-based, iron-fortified formula since birth. The pediatrician reports the infant has not gained weight in the past 2 weeks. The last weight in the pediatrician’s office is 3.54kg (8 lb). No other significant medical or surgical history. What condition is the client most likely experiencing and what actions should the nurse take to address that condition? What parameters should the nurse monitor to assess the client’s progress?