Maternity & OB NCLEX-PN Practice Quiz

Calcium gluconate is the antidote for magnesium sulfate toxicity and stays at the bedside; absent DTRs and a respiratory rate below 12 signal toxicity and the infusion is stopped. Naloxone reverses opioids, not magnesium. Hydralazine lowers blood pressure but does not reverse mag toxicity. Potassium chloride treats hypokalemia, not magnesium excess.

Methylergonovine causes generalized vasoconstriction, so it is contraindicated in hypertension and can trigger a dangerous BP spike. Carboprost is avoided in asthma (bronchospasm), not HTN, so it could be used here. Misoprostol has no BP-related contraindication and is a safe alternate. Oxytocin is the first-line agent already given, not a second-line drug.

RhoGAM only PREVENTS sensitization, so the indirect Coombs (antibody screen) must be NEGATIVE before giving it. A positive indirect Coombs means the mother already made anti-Rh antibodies — she is sensitized and RhoGAM cannot reverse it. A rising titer likewise signals existing sensitization, and the direct Coombs tests the newborn's cells, not the mother's eligibility.

Erythromycin ophthalmic ointment is prophylaxis for ophthalmia neonatorum caused by Neisseria gonorrhoeae — a potentially blinding eye infection acquired during passage through an infected birth canal. It is required by law in most states and is given to every newborn within 1 hour of birth regardless of the mother's infection status. Vitamin K prevents hemorrhagic disease of the newborn, and the hepatitis B vaccine provides immunity against hepatitis B.

Before every magnesium dose the nurse confirms DTRs are present (absent reflexes are the first sign of toxicity), respiratory rate is at least 12, and urine output is at least 30 mL/hr, since magnesium is cleared by the kidneys and accumulates with oliguria. Pupillary response, bowel sounds, and capillary refill are not part of the mag safety check.