Stage 5 — Take action. Twenty minutes after magnesium sulfate is started, categorize each finding by the concern it most directly supports.

Quick answer
The respiratory, reflex, and urine findings point to magnesium toxicity, while severe pressure and headache show that preeclampsia remains uncontrolled.

Why this is correct
Magnesium is cleared through the kidneys, so oliguria can permit accumulation. Respiratory depression and loss of deep-tendon reflexes are toxicity warnings that require stopping the infusion, supporting breathing, notifying the team, and preparing the prescribed antidote while severe hypertension is also treated.

Easy analogy or mental picture
Use two red folders: one for medication accumulation and one for the disease still progressing. A reassuring oxygen value or fetal tracing belongs in neither red folder but cannot close them.

Memory hook
Low urine, lost reflexes, low respirations: stop magnesium and escalate.

NCLEX decision rule
When magnesium is infusing, check respirations, reflexes, and urine output; if toxicity cues appear, stop exposure and support ABCs before resuming any infusion.

Why the other choices are wrong
Normal oxygen saturation and a temporarily reassuring fetal tracing do not make respiratory depression, oliguria, severe hypertension, or neurologic symptoms safe.