CNS Part 2

Overview of the Autonomic Nervous System

  • The Autonomic Nervous System (ANS) is divided into two main parts: the Sympathetic Nervous System (SNS) and the Parasympathetic Nervous System (PNS).

  • These systems work in tandem to maintain homeostasis; when one is active, the other is typically inactive.

Autonomic Nervous System Functions

Fight or Flight Response

  • The SNS prepares the body for stressful or emergency situations.

  • Key phrases include:

    • Stand your ground, defend your position, attack, and persevere.

Rest and Digest

  • The PNS promotes a state of calm and relaxation, aiding in digestion and energy conservation.

  • Key phrases include:

    • Give way, retreat, discard, remove yourself, give up, move on.

Receptors in the Autonomic Nervous System

Alpha and Beta Receptors

  • Alpha Receptors:

    • Found in peripheral blood vessels, smooth muscle, and other areas.

    • Stimulation causes:

      • Vasoconstriction

      • Sphincter contraction

      • Pupillary dilation

  • Beta1 Receptors:

    • Located in the heart.

    • Stimulation causes:

      • Increased cardiac contractility and heart rate (HR).

  • Beta2 Receptors:

    • Present in bronchi, bladder wall, intestine, uterus, and pupils.

    • Stimulation causes:

      • Bronchodilation and relaxation of vascular and uterine tissues.

Adrenergic Medications

Types of Medications

  • Bronchodilators:

    • Examples: Albuterol, ephedrine, levalbuterol, salmeterol, terbutaline

  • Nasal Decongestants:

    • Examples: Ephedrine, tetrahydrozoline, phenylephrine

  • Ophthalmic:

    • Decrease intraocular pressure (IOP) and dilate pupils during surgeries.

Adverse Effects

  • Alpha-adrenergic medications:

    • Headaches, hypertension (HTN), restlessness, excitement, insomnia, vasoconstriction, tachycardia, chest pain, arrhythmias.

  • Beta-adrenergic medications:

    • Headaches, BP fluctuations, mild tremors, nervousness, dizziness, tachycardia, palpitations.

Vasoactive/Vasopressor Agents

  • Used to increase blood pressure, particularly in intensive care units (ICUs) and emergency rooms (ER).

  • Monitoring is critical; infusions must be titrated to blood pressure.

  • Commonly used for patients experiencing:

    • Shock

    • Sepsis

    • Allergic reactions

  • Medications include:

    • Epinephrine (subcutaneous, IVP, IV infusion)

    • Dobutamine (IV infusion)

    • Dopamine (Intropin)

    • Norepinephrine (Levophed)

Nursing Considerations for Alpha and Beta Agonists

Beta Agonists

  • Monitoring:

    • Blood pressure, heart rate, arrhythmias, respiratory status, breath sounds, oxygen saturation (O2 sat), respiratory rate.

  • Adverse Effects:

    • Tachycardia, tremors, dizziness, anxiety.

  • Patient Education:

    • Instruct on proper inhaler technique and report concerning symptoms.

Alpha Agonists

  • Monitoring:

    • Blood pressure, heart rate, arrhythmias.

  • Adverse Effects:

    • Tachycardia, palpitations, arrhythmias, chest pain, sedation.

  • Patient Education:

    • Importance of gradual position changes and symptom reporting.

Alpha Blockers

  • Alpha-adrenergic antagonists, also known as sympatholytics.

  • Examples: Regitine (phentolamine), Cardura (doxazosin), Flomax (tamsulosin).

Indications

  • Treatment for benign prostatic hypertrophy (BPH), hypertension (HTN), and counteracting vasopressor medication side effects.

Nursing Care

  • Educate patients to stand slowly, monitor blood pressure, report dizziness or palpitations.

Beta Blockers

  • Common medications include propranolol (Inderal) and metoprolol.

Mechanism of Action

  • Block beta receptors, decreasing conduction velocity, myocardial oxygen demand, and workload.

Contraindications

  • Caution in cases of COPD (risk for bronchospasm), bradycardia, AV block, congestive heart failure (CHF).

Nursing Care

  • Teach patients to stand slowly, hold doses if pulse < 60 bpm, monitor blood glucose levels in diabetics.

Cholinergic & Anticholinergic Agents

Cholinergic Agents

  • Mimic or increase acetylcholine effects; examples include neostigmine, pilocarpine, and donepezil (for Alzheimer’s).

Anticholinergic Agents

  • Block acetylcholine and can lead to dry effects; used in various conditions including asthma and preoperative settings.

Nursing Care for Parkinson's Disease Agents

General Care

  • Assess history, monitor liver function tests (LFTs), approve any OTC drugs with HCP.

  • Be consistent with timing to avoid "off" periods, especially concerning with protein intake timing.

  • Monitor for potential side effects, dehydration, and emergency symptoms.

Parkinson's Disease Overview

  • Gradual onset after age 50, characterized by tremors, rigidity, bradykinesia, and possibly cognitive decline.

  • Common medications used to treat include carbidopa-levodopa (Sinemet), dopamine agonists, and COMT inhibitors.

  • For patient management, emphasize education about the medications, monitor for side effects, and ensure patient safety through careful assessment.