Norepinephrine 5 mcg/minute titrated by blood pressure per protocol has been prescribed for a patient in refractory shock. Before administering the drug, the nurse ensures which action?

A. Urine output is at least 30 mL/hour for 24 hours: Monitoring urine output is important for assessing renal perfusion and overall response to therapy, but it is not a prerequisite for initiating norepinephrine. Vasopressor therapy can be required even if urine output is low, especially in refractory shock. B. Not receiving additional sympathomimetic medication: While avoiding additive sympathomimetics reduces the risk of excessive vasoconstriction or arrhythmias, it is not the primary safety check before starting norepinephrine. Concurrent medications can be managed during titration under close monitoring. C. Has received adequate fluid replacement: Norepinephrine is a potent vasoconstrictor, and its effectiveness depends on sufficient circulating volume. Administering it before adequate fluid resuscitation can worsen tissue perfusion, increase risk of ischemia, and potentially cause cardiovascular collapse. Ensuring fluid replacement is a critical step in managing refractory shock. D. Heart rate is less than 100: Heart rate is monitored during norepinephrine infusion, as the drug can cause reflex bradycardia or tachyarrhythmias. However, an elevated heart rate is not an absolute contraindication; the priority is confirming adequate intravascular volume before initiating vasopressor therapy.