IV-site blanching, coolness, or pain — stop the infusion at that site, notify the provider now, and prepare phentolamine.
Before you read
Test yourself first: 5 questions
Question 1 of 5
A client with Parkinson disease is prescribed carbidopa-levodopa. The nurse teaches the client that the carbidopa component primarily serves what purpose?
Answer: B. Carbidopa is a peripheral decarboxylase inhibitor. It prevents the breakdown of levodopa in the peripheral tissues, allowing more levodopa to cross the blood-brain barrier and reducing peripheral side effects such as nausea. It does not directly stimulate dopamine receptors, replace acetylcholine, or block dopamine.
Question 2 of 5
A client receiving IV dopamine at a moderate dose for hypotension should be monitored for which therapeutic effect?
Answer: B. At moderate (beta-adrenergic) doses, dopamine increases myocardial contractility and heart rate, raising cardiac output and blood pressure. The nurse expects an increase in blood pressure as the therapeutic effect. Dopamine does not decrease heart rate, and it is used to raise (not lower) blood pressure and support perfusion; it is also a vesicant requiring careful IV site monitoring.
Question 3 of 5
A client taking an antipsychotic develops extrapyramidal symptoms of pill-rolling tremor, masklike face, shuffling gait, and bradykinesia. Which adverse effect should the nurse document?
Answer: B. Drug-induced parkinsonism (pseudoparkinsonism) presents with the classic parkinsonian triad: resting (pill-rolling) tremor, rigidity, masklike facies, and bradykinesia with a shuffling gait. It results from dopamine blockade and is often managed with anticholinergics or dose adjustment.
Question 4 of 5
A dopamine infusion is ordered at 5 mcg/kg/min for a 70 kg patient. The bag contains 400 mg in 250 mL. What pump rate in mL/hr is correct? (Round to the nearest whole number.)
Answer: B. Dose per minute = 5 x 70 = 350 mcg/min, which is 21,000 mcg/hr or 21 mg/hr. Concentration = 400 mg / 250 mL = 1.6 mg/mL. Rate = 21 / 1.6 = 13.1, which rounds to 13 mL/hr. The other values come from unit-conversion errors.
Question 5 of 5
A client with moderate-to-severe Alzheimer disease is started on memantine. The nurse understands this drug works by which mechanism?
Answer: A. Memantine is an N-methyl-D-aspartate (NMDA) receptor antagonist that modulates glutamate activity, which is thought to protect neurons from excitotoxicity. It is not a cholinesterase inhibitor, a dopamine agonist, or a benzodiazepine.
Keep the streak going with more questions like these, each with a full rationale.
What is dopamine?
It is used for shock and hypotension that do not respond to fluids, and sometimes for symptomatic bradycardia. Its effect depends on the infusion rate: low rates stimulate dopamine receptors, moderate rates stimulate beta-1 receptors to strengthen and speed the heartbeat, and high rates stimulate alpha-1 receptors to constrict vessels and raise blood pressure. It is a high-alert drug given by pump into a large vein, ideally a central line. The nurse titrates to the ordered BP goal and watches for arrhythmias, poor perfusion, and extravasation.
Key points to remember
- Dose bands: under 2 mcg/kg/min = dopaminergic; 5–10 mcg/kg/min = beta-1 (more contractility and heart rate); over 10 mcg/kg/min = alpha-1 (vasoconstriction, higher BP).
- Low-dose 'renal' dopamine can raise urine output, but it does not protect the kidneys.
- Norepinephrine, not dopamine, is first-line for septic shock; dopamine's higher arrhythmia risk limits routine use.
- Correct hypovolemia, hypoxia, and acidosis before starting; give fluids before or alongside dopamine.
- Adverse effects: tachycardia and tachyarrhythmias, angina from higher oxygen demand, severe hypertension, nausea, headache, and ischemic or gangrenous fingers and toes.
- Pheochromocytoma is an absolute contraindication. Some products contain sodium metabisulfite (sulfite allergy). After MAO inhibitor use in the past 2–3 weeks, the starting dose is cut to one-tenth.
- Extravasation causes tissue necrosis; phentolamine is injected subcutaneously around the site. Never mix dopamine with sodium bicarbonate or other alkaline solutions.
Nursing priorities
- Confirm fluids have been given or are running, because dopamine is started after hypovolemia is corrected.
- Run it on an infusion pump into a large vein, preferably a central line, because rate errors and extravasation are both dangerous.
- Monitor BP, heart rate, ECG rhythm, and urine output continuously and titrate to the ordered MAP or BP goal, because each rate change shifts the drug's effect.
- Check the IV site often for blanching, coolness, or pain, because extravasation caught early limits necrosis.
- Assess color, warmth, and pulses in fingers and toes, because vasoconstriction can cause peripheral ischemia and gangrene.
- Wean gradually while keeping volume up with IV fluids, because stopping abruptly can cause rebound hypotension.
Worked example
- Cue: A client on dopamine through a peripheral IV has a BP at goal, but the skin above the site is pale, cool, and painful.
- Meaning: Dopamine is leaking into the tissue and constricting vessels, an extravasation that can cause necrosis.
- Action: Stop the infusion at that site, notify the provider, prepare phentolamine to inject around the area, and move the infusion to a new large or central vein.
- Evaluation: Skin color and warmth return, and BP stays at goal on the new line.
Patient teaching
- This medicine supports your blood pressure and heart. The nurse will adjust it often and watch your monitor closely.
- Tell the nurse right away about pain, burning, or coldness at the IV site.
- Report chest pain, a racing or pounding heartbeat, a bad headache, or cold or pale fingers or toes.
- Tell us if you have taken any medicine for depression in the past few weeks, especially an MAO inhibitor.
Common mistakes
- Believing low-dose dopamine protects the kidneys. It may increase urine output but gives no kidney benefit.
- Starting dopamine before fluid resuscitation in a hypovolemic client.
- Choosing dopamine as first-line for septic shock; norepinephrine is preferred.
- Overlooking blanching at the IV site. It signals extravasation, which calls for stopping the infusion and giving phentolamine.
Red flags: report now
- IV-site blanching, coolness, or pain — stop the infusion at that site, notify the provider now, and prepare phentolamine.
- New tachyarrhythmia, chest pain, or sudden severe hypertension — notify the provider now.
- Cold, pale, or mottled fingers or toes — notify the provider; vasoconstriction may be causing ischemia.
- Falling urine output despite an adequate BP — report it.
References
Clinical references for this topic
