EHS 2020 Pharmacology for EMS: Drug Administration

EHS 2020 Pharmacology for EMS

• This is a pharmacology course for emergency medical services (EMS)
• The current week's tutorial focuses on drug administration
• Learning objectives for the lecturer include recalling drug presentations and describing routes of administration

Learning Outcomes

• Students should be able to identify various forms of drug presentations (e.g., solid, liquid, gaseous)
• Students should be able to describe different routes of drug administration

Drug Forms

• Drugs come in various forms including solids, liquids, and gases
• A selection of these forms are available in clinical practice

Liquid Drug Forms

• Solution
• Suspension
• Fluid extract
• Tincture
• Spirits
• Syrup
• Elixir
• Milk
• Emulsion
• Liniments & lotions

Solid Drug Forms

• Extract
• Powder
• Pill
• Capsule
• Tablet
• Suppository
• Pessary
• Ointment
• Patch

Gaseous Drug Forms

• Vapour
• Gas

Routes of Drug Administration

• The route of administration affects the speed of absorption and onset of the drug's effects

Pharmacokinetic Definitions

• Pharmacology: The study of how the body processes drugs over a specific time period.
• Includes:
  • Absorption
  • Distribution
  • Metabolism
  • Elimination

Absorption

• The movement of the drug from the site of entry to the bloodstream
• Influenced by:
  • Route of administration
  • Solubility of the drug
  • Conditions at the site of administration
  • pH of the drug
  • Concentration of the drug or dosage

Distribution

• After absorption, the drug circulates throughout the body
• The drug moves out of circulation and into tissues
• Some drugs are specific to certain tissues, while others may be distributed in all body fluids
• Factors include plasma proteins, cardiovascular function, regional blood flow, and physiological barriers

Metabolism

• The process where a drug's effect ends
• Results from breakdown into less active forms
• Primarily occurs in the liver, though may also occur in the blood plasma, intestinal mucosa, and kidneys

Elimination

• The process where drug products are excreted from the body
• Major routes include:
  • Kidneys (urine)
  • Intestines (faeces)
  • Lungs (exhaled air)
• Drugs' metabolites are excreted in bile, which then empties into the intestines

Factors affecting drug response

• Age
• Weight
• Gender
• Environment
• Route of administration
• Condition of the patient
• Genetic factors
• Psychological factors

Putting it all together

• How are medications prescribed within the community?
• What methods do paramedics use to administer medications?

How might medications be prescribed to patients?

• Standing Orders:
  • Instructions for treatment, specific to the patient presentation
  • May or may not require medical consultation
  • Suitable for life-threatening situations
• One-Time Orders:
  • Immediate drug intervention, guided by medical direction
  • Cannot be repeated without consulting medical direction

Medication Prescribed-Continued

• As-Needed Orders (PRN):
  • "Pro re nata" or "as the situation demands"
  • For specific patient conditions (pain, heart rate, and blood sugar abnormalities)
• Other Types:
  • Patients from diverse settings (community care, long-term care facilities)
  • Paramedics need medication administration records
  • Need to be aware of medical abbreviations

Communication with Medical Direction

• Communication must be concise and clear
• Paramedics should write down the order and read it back to medical direction
• The physician should confirm the order.

Enteral Drug Administration

• Drugs are absorbed through the gastrointestinal (GI) tract

• Most oral medications are in solid forms (pill, tablet, or capsule) or liquid

• Not suitable for altered or unconscious patients

• Often abbreviated as PO (per os) referring to by mouth

• Buccal Medication: Medications placed in the cheek. Safe for conscious patients.

• Sublingual Medication: Medications under the tongue. Very quick absorption.

• Rectal Medication: Optimal for patients who cannot take oral medications, delivered by melting the medication to a liquid form

Parenteral Drug Administration

• Any drug administration route other than GI
• More effective in the pre-hospital setting
• IV lines deliver medications quickly
• Special training and equipment needed
• Routes include IV line, IM injection, intradermal injections, subcutaneous injections, IO infusion, transdermal/topical, inhalation, intranasal, and ET tube administration.

Equipment

• Syringes
  • Used for injecting or withdrawing fluids
  • Luer-lock and Non-Luer-lock types are used
  • Needles
    • Various sizes/gauges
    • Hub, shaft, bevel,
• Safety features
• Never re-sheath a needle
• Dispose of needles properly

Intra-Venous (IV)

• IV delivery

Inhalation Medications

• Nebulizers and Metered Dose Inhalers (MDIs)
• Common inhaled medication is oxygen
• Medications include Beta2 agonists, Atrovent

Intranasal Medications

• Rapid absorption (fast onset compared to IM)
• Using a mucosal atomizer device (MAD)
• Drugs include naloxone, midazolam, and glucagon

Intramuscular Injections (IM)

• Administered directly into muscle tissue

• Needle size depends on injection location and muscle size

• Deep insertion; avoid nerve damage

• Deltoid (shoulder): Rapid absorption, 2 mL max

• Thigh (vastus lateralis): More tolerant of volumes (5 mL), anterior thigh

• Hip (Dorsogluteal): Avoid in children under 2

• Ventrogluteal preferred for children

Subcutaneous Injections

• Injections between skin and muscle tissue
• Smaller volumes (<0.5 mL)
• Slower onset action; prolonged duration
• Usual sites: upper arms, upper back, scapular regions.

Intra-Osseous (IO)

• IO Access

Topical Medications

• Topical medications are applied directly to the skin for treating skin conditions
• Useful for conditions affecting the skin
• Applied to chest, upper arms, and flanks.
• Avoid shaving the area
• Use a tongue depressor to apply ointments and creams
• Topical patches are becoming popular. Proper storage is important.

ET Tube Medication Administration

• Accessible even before IV or IO
• Can deliver numerous drugs
• Requires 2-2.5x the dose used for IV
• For quick absorption, dilute medications in normal saline or sterile water.

Week 4 Videos

• Refer to provided links for week 4 videos.