What can be given to a patient with bradycardia (heart rate of 45) to increase their heart rate on a non-step down medical-surgical (medsurg) floor?

Management of Bradycardia (HR 45) on a Non-Step Down Med-Surg Floor

For a patient with heart rate of 45 bpm on a general medical-surgical floor, first assess if the patient is symptomatic or hemodynamically unstable—if asymptomatic with stable blood pressure and adequate perfusion, no immediate treatment is needed; if symptomatic (altered mental status, chest pain, hypotension, dyspnea, or syncope), administer atropine 0.5-1 mg IV as first-line therapy, repeating every 3-5 minutes up to a maximum total dose of 3 mg. 1, 2, 3

Initial Assessment Algorithm

Determine if bradycardia is causing symptoms:

• Symptomatic bradycardia includes: altered mental status, ischemic chest discomfort, acute heart failure, hypotension (systolic BP <90 mmHg), syncope, dizziness, or dyspnea 1, 2
• Asymptomatic bradycardia with HR 45 bpm and stable blood pressure requires no treatment—observation only 2, 4
• Ensure adequate oxygenation and establish IV access before pharmacologic intervention 1, 2

Identify reversible causes before treating:

• Beta-blockers, calcium channel blockers, digoxin, antiarrhythmics 2, 4
• Electrolyte disturbances (potassium, magnesium, calcium) 2, 4
• Hypoxemia, myocardial ischemia, hypothyroidism 2, 5
• Vagal stimulation from pain or nausea 4, 5

First-Line Pharmacologic Treatment

Atropine is the first-line medication for symptomatic bradycardia:

• Dose: 0.5-1 mg IV push 1, 2, 3
• Repeat: Every 3-5 minutes as needed 1, 2, 3
• Maximum total dose: 3 mg 1, 2, 3
• Critical warning: Doses <0.5 mg may paradoxically worsen bradycardia and should be avoided 1, 2, 6

Atropine mechanism and onset:

• Competitively antagonizes muscarinic receptors, abolishing vagal cardiac slowing 3
• Effects on heart rate are delayed by 7-8 minutes after IV administration 3
• Approximately 50% of patients with hemodynamically unstable bradycardia achieve partial or complete response to atropine 7

When Atropine May Be Ineffective

Atropine is likely ineffective in these situations:

• Type II second-degree AV block or third-degree AV block with wide QRS complex (infranodal block) 1, 2
• Post-cardiac transplant patients without autonomic reinnervation—atropine may cause paradoxical high-degree AV block 2, 6
• High-grade AV block where the block is below the AV node 1, 2

In these cases, proceed directly to second-line agents or pacing rather than waiting for atropine failure. 2

Second-Line Pharmacologic Options (If Atropine Fails)

If atropine fails to resolve symptomatic bradycardia, initiate chronotropic infusions:

Dopamine (Preferred for most situations)

• Initial dose: 5-10 mcg/kg/min IV infusion 1, 2
• Titration: Increase by 2-5 mcg/kg/min every 2-5 minutes based on heart rate and blood pressure 2
• Therapeutic range: 2-10 mcg/kg/min for chronotropic effect 2
• Maximum dose: Do not exceed 20 mcg/kg/min due to excessive vasoconstriction and arrhythmia risk 2
• Advantages: Dose-dependent effects with better titratable control than epinephrine 2

Epinephrine (For severe hypotension)

• Dose: 2-10 mcg/min IV infusion (or 0.1-0.5 mcg/kg/min) 1, 2
• Indication: Preferred when severe hypotension requires both strong chronotropic and inotropic support 2
• Caution: Stronger alpha-adrenergic effects cause more profound vasoconstriction than dopamine 2

Isoproterenol (Alternative option)

• Dose: 20-60 mcg IV bolus or 1-20 mcg/min infusion 2
• Advantage: Provides chronotropic and inotropic effects without vasopressor effects 2

Special Considerations for Med-Surg Floor Limitations

On a non-step down floor, you are limited by:

• Lack of continuous telemetry monitoring in some facilities
• Limited ability to manage transcutaneous pacing
• Potential delays in transferring to higher level of care

Practical approach for med-surg floor:

• If patient requires more than atropine (i.e., continuous infusions of dopamine or epinephrine), immediate transfer to ICU or step-down unit is necessary as these infusions require continuous cardiac monitoring 1, 2
• Transcutaneous pacing pads can be placed prophylactically in high-risk patients, but actual pacing typically requires transfer to higher level of care 1, 2
• If atropine alone is insufficient and transfer is delayed, a single dose of atropine can be repeated while arranging urgent transfer 1, 2

Critical Warnings and Pitfalls

Avoid these common errors:

• Do not use atropine in acute coronary ischemia or MI without caution—increased heart rate may worsen ischemia or increase infarct size; limit total dose to 0.03-0.04 mg/kg in patients with coronary artery disease 1, 2, 3
• Do not delay transcutaneous pacing in unstable patients while giving multiple atropine doses—pacing should be considered simultaneously when atropine fails 2
• Do not use benzodiazepines or opioids for sedation in bradycardic patients as they worsen bradycardia through sympatholytic effects 6
• Bradycardia with hypotension and signs of shock is associated with increased mortality—aggressive treatment and transfer to higher level of care is essential 1

When to Transfer to Higher Level of Care

Transfer immediately if:

• Patient requires continuous chronotropic infusions (dopamine, epinephrine) 1, 2
• Atropine fails and patient remains symptomatic 1, 2
• Transcutaneous or transvenous pacing is needed 1, 2
• Type II second-degree or third-degree AV block is present 1, 2
• Hemodynamic instability persists despite initial atropine 1, 2