Principles of Pharmacology

Introduction

  • Administering medications is serious business.

  • Benefits of medications:

    • Alleviate pain.

    • Improve patient's well-being.

  • Risks of improper use:

    • May cause harm.

    • Potentially lead to death.

EMT Responsibilities

  • As an EMT, you will:

    • Administer medications.

    • Assist patients in self-administering medications.

    • Inquire about patient medication use.

    • Report relevant patient information to hospital personnel.

Understanding Pharmacology

  • Pharmacology: The science of drugs.

  • Drug (medication): A chemical substance used to:

    • Prevent disease.

    • Treat disease.

    • Diagnose disease.

  • Pharmacodynamics: The process by which medication affects the body.

  • Pharmacokinetics: The process of how the body affects the drug.

Key Terminology in Pharmacology

  • Agonist: A substance that stimulates a receptor.

  • Antagonist: A substance that binds to a receptor and blocks other actions.

  • Dose: The amount of medication that is given, which depends on:

    • Weight.

    • Age.

    • Desired action.

  • Action: The effect produced on the body after administration.

  • Indications: Acceptable medical uses for a drug.

  • Contraindications: Conditions under which a drug should not be given.

  • Side effects: Unintended effects that are not harmful but not beneficial.

  • Untoward effects: Expected effects of a drug that are harmful.

Medication Naming Conventions

  • Chemical name: Used by researchers to define the medication, e.g., N-acetyl-p-aminophenol (C8H9NO2).

  • Generic name: Nonproprietary name derived from the chemical name, e.g., acetaminophen. It is listed in the United States Pharmacopoeia (USP) once licensed.

  • Trade name: Brand name given by the manufacturer; a medication may have multiple trade names, e.g., Tylenol, Wal-aphen.

Types of Medications

  • Prescription medications

  • Over-the-counter (OTC) medications

  • Street drugs (illegal)

  • Herbal medications

  • Enhancement drugs

  • Vitamin supplements

Routes of Administration

  • Enteral medications: Involve mesenteric circulation (Portal Filter).

    • Administered traditionally by mouth or rectum (digestive system).

  • Parenteral medications: Do not involve the intestinal tract.

Absorption and Administration Routes

  • Absorption: The process by which medication travels through body tissues to enter the bloodstream, typically from:

    • Stomach.

    • Muscles.

    • Lungs.

Common Routes of Administration

  • Enteral:

    • Rectum (PR): Rapid.

    • Sublingual (SL): Rapid.

    • Oral (PO): Slow.

  • Parenteral:

    • Inhalation: Rapid.

    • Intravenous (IV): Fast.

    • Intraosseous (IO): Fast.

    • Intramuscular (IM): Moderate.

Medication Forms and Their Administration

  • The form of medication usually dictates the route of administration. The manufacturer selects the form to ensure:

    • Proper route of administration.

    • Timing of release into the bloodstream.

    • Target effects on organs/body systems.

  • Forms of Medications:

    • Capsule: Gelatin shells with powdered or liquid medication.

    • Tablets: Pressed powders compressed into a disk.

    • Solution: A liquid mixture that will not separate by filtering or standing.

    • Suspension: A substance resistant to dissolution in liquids; will separate if left to stand or filtered.

Metered-Dose Inhalers (MDIs)

  • Deliver liquid or solid medications broken into small enough droplets or particles for inhalation.

  • Direct substances through the mouth into the lungs, ensuring a consistent dose each time.

Topical and Transcutaneous Medications

  • Topical medications: Include lotions, creams, and ointments applied to the skin, affecting the area only.

  • Transcutaneous (transdermal) medications: Designed to be absorbed through the skin into circulation, potentially affecting EMTs as well.

Other Medication Forms

  • Gels: Semiliquid medications administered in capsules or tubes.

  • Gases for Inhalation: Most commonly oxygen, delivered through nonrebreathing masks or nasal cannula.

Six Rights of Medication Administration

  1. Right Patient

  2. Right Medication

  3. Right Dose

  4. Right Route

  5. Right Time

  6. Right Documentation

  • Only administer medications with an order from medical control.

  • Follow the six rights of medication administration and also consider:

    • Education.

    • Refusal of treatment.

    • Response and evaluation post-administration.

EMT Medication Administration Limits

  • Generally limited to:

    • Oxygen.

    • Oral glucose.

    • Activated charcoal.

    • Aspirin.

    • Epinephrine.

    • Nitroglycerine.

    • Albuterol.

Medication Administration Authority

  • Circumstances for medication administration include:

    • Peer-assisted medication.

    • Patient-assisted medication.

    • EMT-administered medication based on medical control guidelines.

  • Notable regulations:

    • National standard: EMTs assisting patients with medications like nitroglycerin.

    • Texas regulations may allow EMTs to carry and administer medications based on protocols.

Oral Medications

  • Advantages:

    • Ease of access.

    • Comfort for patients.

  • Disadvantages:

    • Digestive tract effects (impacted by foods, stress, and illness).

    • Variable speed of absorption due to changes in the gastrointestinal tract.

Specific Medications and Their Administration

  • Activated Charcoal:

    • Prevents absorption, ground into fine powder, often suspended in sorbitol.

    • Contraindications include:

    • Altered level of consciousness (LOC).

    • Ingestion of acids, alkalis, petroleum.

  • Oral Glucose:

    • Essential for cellular energy, used to treat hypoglycemia.

    • Contraindicated in unconscious patients or those unable to protect their airway.

  • Aspirin:

    • Reduces fever, pain, inflammation, and inhibits platelet aggregation.

    • Useful during a heart attack.

    • Contraindications include hypersensitivity, liver damage, bleeding disorders, asthma, and children during fever-causing illnesses.

  • Sublingual Medications:

    • Advantages: Easy to advise; quick absorption.

    • Disadvantages: Requires continuous airway evaluation; risk of choking; inappropriate for uncooperative or unconscious patients.

  • Nitroglycerin:

    • Relieves angina pain by increasing blood flow and relaxing veins.

    • Must check blood pressure and obtain an order before administration.

    • Contraindicated with erectile dysfunction medications due to risk of extreme hypotension.

    • Administer as a sublingual tablet or metered-dose spray.

  • **Administration Considerations for Nitroglycerin:

    • Wait 5 minutes before repeating dose with a maximum of three doses.

    • Monitor vital signs; wear gloves; know protocols.

Intramuscular Medications

  • Advantages:

    • Quick access without venipuncture; stable blood flow to muscles.

  • Disadvantages:

    • Pain and anxiety associated with needle use.

Epinephrine

  • Classification: Sympathomimetic, known as adrenaline.

  • Function: Controls the fight-or-flight response, increases heart rate, constricts blood vessels.

  • Indications: Used primarily in anaphylactic reactions.

  • Contraindications: Hypertension, hypothermia, myocardial infarction, wheezing.

    • In anaphylaxis, it acts as an antidote to histamine.

    • Texas law mandates epinephrine to be carried in all ambulances at certification levels for treating anaphylaxis.

Oxygen Administration

  • Importance: Essential for cellular survival.

  • Methods:

    • Typically administered via nonrebreathing mask (preferred) or nasal cannula for those intolerant to masks.

  • Oxygen dosing: Based on patient's SpO2 levels (≥ 94%).

Albuterol

  • Delivery Methods: Metered-dose inhalers (MDIs) and nebulizers.

  • Properties: Liquid turned into mist for inhalation, offering rapid absorption and portability.

SAMPLE - Patient Medications

  • Patient assessment includes finding out what medications the patient is taking:

    • Provides vital clues to the patient’s condition.

    • Guides treatment.

    • Information useful for the emergency department.

Respiratory Emergencies Introduction

  • Dyspnea: A common complaint; symptom of various conditions.

  • Diagnosis: Causes can be complex, requiring careful evaluation.

Anatomy of Respiratory System

  • Structures involved:

    • Diaphragm.

    • Chest wall muscles.

    • Accessory muscles.

    • Nerves.

  • Lung Function: Respiratory system facilitates the exchange of oxygen and carbon dioxide.

  • Pathway of Air: Air travels through trachea to bronchi, bronchioles, and finally to alveoli.

  • Characteristics of Alveoli:

    • Microscopic air sacs.

    • Thin-walled.

    • Primary sites for gas exchange.

Physiology of Respiration

  • Processes of respiration:

    • Inspiration: Active process.

    • Expiration: Passive process.

  • Gas Exchange: Rapid exchange of oxygen and carbon dioxide at the alveolar level.

Pathophysiology of Respiratory Issues

  • Factors that can hinder oxygen exchange include:

    • Conditions affecting the airway.

    • Disease processes.

    • Traumatic conditions.

    • Abnormalities in pulmonary vasculature.

Assessment of Breathing

  • Recognize signs/symptoms of inadequate breathing:

    • Complaints of difficulty breathing.

    • Altered mental status associated with inadequate ventilation.

    • Anxiousness or restlessness.

    • Respiratory rates below 12 or above 20 breaths/min.

    • Skin signs: pallor, coolness, clamminess, cyanosis.

Report Indicators of Respiratory Distress

  • Abnormal breath sounds may include:

    • Wheezing.

    • Rales.

    • Rhonchi.

    • Stridor.

Circulation Assessment

  • Assess pulse rate, quality, and rhythm:

    • Tachycardia: Increased pulse rate.

    • Bradycardia: Decreased pulse rate.

    • Evaluate for shock and bleeding by assessing skin color, temperature, and condition.

Transport Decision-making

  • If the patient's condition is unstable with a possible life threat:

    • Address life threats immediately.

    • Proceed with rapid transport.

History Taking

  • Investigate the chief complaint through objective and subjective observations using:

    • SAMPLE history: Signs and Symptoms, Allergies, Medications, Past Medical History, Last Oral Intake, Events leading to present illness/injury.

    • OPQRST assessment: Onset, Provocation, Quality, Region, Severity, Timing.

Secondary Assessment

  • Conduct physical examinations to identify COPD signs:

    • Use of accessory muscles during respiration.

  • Monitor vital signs:

    • Distal pulses.

    • Skin condition.

    • Breathing status.

    • Mental status evaluation.

  • Employ monitoring devices such as pulse oximetry.

Reassessment

  • Repeat primary assessment for stabilization:

    • Interventions may include:

    • Administering oxygen via nonrebreathing mask at 15 L/min.

    • Positive-pressure ventilations.

    • Airway management techniques.

    • Positioning in high Fowler’s position or patient’s preferred position.

    • Assisting with respiratory medications.

  • Effective communication and documentation of patient information to hospital staff are crucial.

Treatment Management in Dyspnea

  • Manage the ABCs (Airway, Breathing, Circulation).

  • Ensure the patient's positioning is conducive to breathing.

  • Administer oxygen and suction as required.

  • Consider the use of metered-dose inhalers (MDI) or small-volume nebulizers upon consultation with medical control, ensuring medication validity.

Causes of Dyspnea

  • Potential causes include:

    • Upper/lower airway infections.

    • Acute pulmonary edema.

    • Chronic obstructive pulmonary disease (COPD):

    • Chronic Bronchitis.

    • Decompensated Pulmonary Emphysema.

    • Asthma.

    • Hay fever.

    • Anaphylaxis.

    • Spontaneous pneumothorax.

    • Pleural effusion.

    • Prolonged seizures.

    • Airway obstruction.

    • Pulmonary embolism.

    • Hyperventilation syndrome.

    • Environmental or industrial exposure.

    • Carbon monoxide poisoning.

    • Infectious diseases.

Managing Dyspnea

  • Exercise caution in treatment:

    • Gas exchange may be obstructed.

    • Possible damage to alveoli.

    • Assess airflow through air passages.

    • Monitor blood flow to the lungs and fluid levels in pleural space.

Recognizing Inadequate Breathing

  • Indicators of inadequate breathing:

    • Complaints of dyspnea.

    • Shallow or slow breathing accompanied by altered mental status.

    • Anxious demeanor or restlessness.

    • Rates below 12 or above 20 breaths/min.

    • Skin may appear pale, clammy, or cyanotic.

    • Unusual breath sounds (e.g., wheezing or gurgling).

    • Alterations in chest expansion.

Conditions Causing Dyspnea

  • Respiratory obstructions can stem from:

    • Major airway obstructions (e.g., croup, epiglottitis).

    • Infections impacting gas exchange (e.g., pneumonia).

  • Infectious Diseases: Symptoms include:

    • Often seen in bronchitis (chronic inflammation) or viral diseases like influenza and cold.

Specific Pediatric Concerns

  • Croup: Inflammation/swelling in the airway; responds well to oxygen therapy.

  • Epiglottitis: Bacterial condition causing laryngeal swelling; follow comfort positioning.

  • Asthma: Common condition requiring appropriate oxygen delivery and inhaler assistance.

Managing Pediatric Respiratory Emergencies

  • Treatment measures vary:

    • Bronchiolitis: Inflamed bronchioles necessitate encouraging breathing support.

    • Pneumonia: Rapid onset of high fever due to infections. Care for airway involves ventilation and circulatory support.

  • Pertussis: Watch for dehydration; monitor with suction when necessary.

  • Cystic fibrosis: Genetic disorder needing suction and oxygenation management.

Respiratory Infections Overview

  • MRSA and TB as prevalent threats; require careful treatment protocols to manage.

  • Acute Pulmonary Edema: A life-threatening condition linked to heart issues.

COPD Overview

  • Chronic obstructive pulmonary disease leading to airway dilation/disruption; closely monitor for complications.

  • Includes:

    • Chronic Bronchitis: Excess mucus production and air trapping.

    • Pulmonary Emphysema: Alveolar wall destruction leading to retention issues.

Presentation Differences in Lung Conditions

  • Pulmonary Emphysema vs. Chronic Bronchitis vs. Congestive Heart Failure:

    • Appearance:

    • Thin appearance in emphysema; barrel chest.

    • Decent weight with visible respiratory distress in bronchitis.

    • Fluid accumulation in CHF.

    • Mental Status: Normal (emphysema) vs. potentially altered (bronchitis and CHF).

    • Neck veins: Differ based on condition: flat in emphysema, distended in CHF.

    • Lung Sounds: Wheezing predominant in emphysema, accompanied by moist sounds in bronchitis.

Treatment Plans for Respiratory Diseases

  • COPD Management: Assist with inhalers; provide supplemental oxygen; evaluate for CPAP.

  • Childhood diseases such as asthma need prompt attention to airway management.

Asthma, Hay Fever, and Anaphylaxis Overview

  • Allergic reactions through various routes lead to diverse symptoms and treatments.

  • Treatment strategies include nebulized medications and aggressive airway management.

Special Conditions: Spontaneous Pneumothorax

  • Condition caused by rupture leading to air accumulation in the pleural space; requires prompt and careful monitoring.

Treatment for Spontaneous Pneumothorax

  • Provide supplemental oxygen; timely transport; monitor patient closely for changes.

Airway Obstructions

  • Nature of the obstruction dictates urgency; treatments vary based on completeness of obstruction.

Pulmonary Embolism Management

  • Significant blockage potential leading to severe decreases in blood flow; immediate oxygen and transport decisions are critical.

Environmental and Industrial Exposure Risks

  • Focus on thorough decontamination; Oxygen therapy and adjuncts vital based on presentation.

Hyperventilation Management

  • Hyperventilation leads to significant physiological changes and potential panic situations requiring calm and supplementary oxygen delivery.

MDI and Nebulized Medications Contraindications

  • Must adhere to specific indications when administering MDI or nebulized medications, checking for potential adverse conditions.

Epidemics and Pandemics

  • Awareness of outbreaks on a local and global Level; example being H1N1 including necessary precautions for EMS operations.

Special Patient Considerations

  • Pay attention to specific conditions, age, and background of patients for tailored emergency management.

Aging Patient Considerations

  • Cardiac history must be closely evaluated for existing conditions (like congestive heart failure); consider supportive treatments during crises.

Summary

  • Pharmacology is the comprehensive science of drugs, detailing:

    • Ingredients.

    • Preparation.

    • Medical uses.

    • Actions of drugs on the body, highlighting the critical importance of responsible administration and understanding in medical treatments.