Pharmacology Basics for EMTs

General Pharmacology

• A drug is a chemical substance used to treat or prevent a disease.
• EMTs administer drugs under orders from medical direction.
• Medications can be from the ambulance's stock or the patient’s own prescriptions.

Medication Names

• Chemical Name: Describes the chemical structure (e.g., 1,2,3-propanetriol trinitrate).
• Generic Name: A shortened version of the chemical name (e.g., nitroglycerin).
• Trade Name: The brand name assigned by the manufacturer (e.g., Nitrostat).
• Official Name: The drug name listed in the U.S. Pharmacopeia (U.S.P) or National Formulary (N.F.).

Routes of Medication Administration

• Intravenous (IV): Into a vein (fastest).
• Pulmonary: Into the lungs/alveoli (next fastest).
• Sublingual (SL): Under the tongue.
• Intramuscular (IM): Injection into a muscle.
• Subcutaneous (SC or SQ): Injection under the skin.
• Oral (PO): By mouth (slowest, at least 30 minutes).

Pharmacodynamics

• Mechanism of Action (MOA): How the drug affects the body and target tissues.
• Drug Profile:
  • Onset: Time to first effect.
  • Duration: Time from onset to loss of effect.
  • Peak: Highest plasma concentration, greatest effect.
  • Drug half-life: Time until half the active drug is eliminated, affecting dosing timing.
• Therapeutic Range: Plasma concentration range for desired effect without toxicity.
• Toxic Level: Plasma concentration at which serious adverse effects occur.
• Drugs can increase, decrease, or alter biological functions by interacting with enzymes, receptors, or other molecules.
• Agonist: A drug that binds to a receptor site and activates it (e.g., Albuterol).
• Antagonist: A drug that binds to a receptor site and blocks its activation (e.g., Naloxone).

Drug Effects

• Expected Effect: The reason for giving the drug.
• Side Effects: Other actions of the drug, which may be harmful or not. Nausea and vomiting are common.
• Adverse Side Effect: A harmful side effect.
• Contraindications: Conditions when a drug should not be administered.
  • Absolute Contraindication: Never administer due to adverse reactions.
  • Relative Contraindication: Weigh risks (side effects) against benefits.

Pharmacokinetics

• Absorption: How the drug enters the circulatory system, affected by circulation status.
• Distribution: Movement from the circulatory system to tissues, affected by circulation status.
• Biotransformation:
  • Some drugs transform from inactive to active states.
  • Drugs must transform to a form that can be excreted, primarily in the liver.
  • Liver compromise can lead to toxicity due to longer active states of drugs.
• Elimination: Removal of the drug from the body via the kidneys, GI system, or lungs.
  • Compromised organ function can lead to toxic buildup.

Drug Forms

• Pills and tablets: Compressed into solid form.
• Powders: Fine granules.
• Suppositories: Drug mixed with a wax-like base.
• Capsules: Gelatin container that dissolves in the stomach or small intestine.
• Solutions: Drug dissolved in water.
• Tinctures: drug dissolved in alcohol.
• Suspensions: drug suspended (not dissolved) in solution.

Metric System and Documentation

• Use scientific notation for documentation (e.g., 0.3 mg vs .3 mg, 2 mg vs 2.0 mg - avoid trailing zeros).

Steps in Administering Medications

• Complete proper assessment of patient.
• Receive order from medical direction (online or offline).
• Repeat online orders back for verification.
• Rights of Medication Administration:
  • Right patient
  • Right indications
  • Right allergies (personally confirm)
  • Right drug (name, expiration date)
  • Right concentration and dose (read the label)
  • Right route
  • Right documentation (time, drug, dose, route, effects)

Med Math

• Dosage Calculation: Total Volume / Total Dose = Volume to be Given / Dose to be Given.
• Example formulas.
  • To administer 5mg from concentration 10mg/mL: 10mg/1mL = 5mg/x, x = 0.5mL.
  • To administer 0.3mg IM Epinephrine from concentration 1mg/1mL: 1mg/1mL = 0.3mg/x, x = 0.3mL.

Medications Administered by EMT

• Medications carried on EMS units.
  • Oxygen
  • Oral Glucose
    • Indications: hypoglycemia
    • Contraindications: none
    • Dosage: Goal is improved mental status.
    • Procedure:
      • Glucose gel (if patient can swallow, give small amounts).
      • Granulated sugar (sprinkle inside cheek if unresponsive).
  • Activated Charcoal
    • Indications: ingested poisoning.
    • Contraindications: AMS, ingested acid, cyanide overdose, inability to swallow.
    • Dosage: 1 gram of charcoal per 1 kilo of patient body weight.
    • Action: Binds to substances and prevents absorption.
    • Procedure: Patient must drink it mixed with water.
  • Aspirin (Acetylsalicylic Acid, ASA)
    • Indications: acute coronary syndrome.
    • Contraindications: allergy to aspirin.
    • Dosage: One 325mg tablet or four 81mg tablets (324mg total).
    • Procedure: Have patient chew and swallow.
    • Note: If patient takes blood thinners or has stomach issues, one dose is still given.
  • Naloxone (Narcan)
    • Indications: Narcotic overdose with depressed respirations, bradypnea/apnea, constricted pupils (not always present).
    • Contraindications: None.
    • Dosage: 2mg-4mg IN.
    • Action: Opiate antagonist.
    • Procedure: Aerosolize 1mg up each nostril using a MAD (mucosal atomization device).
    • Cautions: May need to be repeated, monitor respirations closely, watch for combative patients or withdrawal symptoms.
    • Give until they breathe, unresponsiveness is okay if breathing is adequate.
  • Epinephrine
  • Nebulized Medications: Albuterol and DuoNeb
• Patient’s prescriptions:
  • Metered-dose Inhalers
    • Indications: dyspnea
    • Contraindications: allergy to medications
    • Dosage: usually up to 3 puffs
    • Action of Beta-agonist MDIs: relaxes smooth muscles of the bronchial passages resulting in bronchodilation with minimal increase in HR
  • Nitroglycerin
    • Indications: Acute Coronary Syndromes (Ex. chest pain, possible heart attack)
    • Contraindications: allergy to NTG, systolic BP 25kg (>55lbs)
    • EpiPen Jr: 0.15mg for patient < 25kg (30kg
    • 0.15mg if 10-30kg
• Early notification of receiving facility (transmit 12 lead EKG early)
• Paramedic intercept if available

Respiratory Emergencies (Dyspnea)

• Respiratory Distress:
  • Caused by disease, trauma, foreign body airway obstruction (FBAO), or drugs.
  • EMTs prioritize maintaining ventilation and oxygenation.
• Ventilation:
  • Mechanical process of moving air in and out of the lungs.
  • Non-traumatic problems: CNS drugs, bronchospasm, swelling, mucus production.
• Respiration:
  • Physiological process of exchanging O2 and CO2 across alveolar membranes.
  • Non-traumatic problems: Pulmonary edema, lack of pulmonary circulation, lack of hemoglobin / RBCs.

The Pediatric Airway

• Head:
  • Large head causes hyperflexion of neck, pad under shoulders for neutral alignment.
  • Heavy with weak neck muscles, increased trauma risk.
• Nose:
  • Flattened, smaller diameter nares are easier to obstruct.
  • Neonates and infants (3mo) are obligate nose breathers.
• Tongue:
  • Proportionally large, can block airway more easily.
• Larynx:
  • Funnel shaped, narrowest at cricoid ring until 6yo.
  • Obstructions below vocal cords.
• Epiglottis:
  • Larger, horseshoe shaped, can obstruct trachea.
• Airways:
  • Smaller diameter, swelling or mucus can block.
  • Softer cartilage can be kinked closed by excessive movement.

Pediatric Breathing and Ventilation

• Higher metabolic O2 requirements.
• Monitor mental status and skin color for hypoxia.
• Grunting to open collapsed air passages.
• Compensate by increased breathing rate.
• Weaker chest muscles, less energy stores, higher oxygen needs, slowing rates may indicate fatigue.
• Primarily use diaphragm and abdominal muscles, watch for belly breathing, do not restrict abdomen.

Common Respiratory Diseases

• Asthma:
  • Signs and Symptoms:
    • Dyspnea, wheezes (especially on exhale), coughing, decreased O2 sats, hypoxia.
  • Status asthmaticus: Severe attack unresponsive to O2 or MDI.
• Chronic Obstructive Pulmonary Disease (COPD):
  • Emphysema:
    • Caused by smoking and vaping.
    • Breakdown of alveolar & elastic tissue.
    • "Pink Puffers" requiring energy to exhale.
    • Increased RBC count.
    • Signs and Symptoms:
      • Dyspnea, thin/barrel chest, wheezes, pursed lip breathing, nail bed clubbing, hypoxia.
  • Chronic bronchitis:
    • Caused by pollutants or smoking.
    • Inflammation and mucus in bronchi and bronchioles.
    • "Blue Bloaters" with cyanosis and systemic edema.
    • Signs and Symptoms:
      • Chronic cyanosis, overweight, prone to infections, productive cough, rhonchi/crackles/wheezes, decreased O2 sats, hypoxia.
• Pneumonia:
  • Infection in lungs causing pus and infectious materials to block areas.
  • Signs and Symptoms:
    • Dyspnea, weakness, fever/chills, cough, rhonchi/crackles, decreased O2 sats, hypoxia.
• Pulmonary Embolism:
  • Clot blocking pulmonary artery, risk factors include recent surgery and immobility.
  • Signs and Symptoms:
    • Sudden dyspnea/chest pain, cyanosis, decreased O2 sats.

Assessment of Respiratory Emergencies

• SAMPLE/OPQRST (after ensuring adequate ventilation and oxygenation)
• Effort of breathing:
  • Accessory muscle use (intercostal, suprasternal, supraclavicular retractions).
  • Abdominal muscles (belly breathing, see-saw respirations).
• Tidal volume: chest expansion, equality of movement, depth.
• Movement of air: listen and feel for air passage.
• Positioning: sitting up, tripod position.
• Sounds of breathing:
  • Wheezing (narrowed airways).
  • Rales (crackles: fluid in medium + small airways).
  • Gurgling (fluid in large airways, mouth, nose).
  • Snoring(tongue).
• End organ perfusion:
  • Brain: altered mental status, dizzy.
  • Skin: pale, cyanotic.
  • Muscles: weakness.
• Patterns of breathing:
  • Cheyne-Stokes (increasing/decreasing depths with apnea intervals).

Altered Mental Status

• Many causes; must maintain ABCs.
• Causes include hypoxic events, changes in brain chemistry, or direct brain damage.
• Causes: AEIOU-TIPS:
  • A: alcohol
  • E: epilepsy (seizures)
  • I: insulin (diabetes)
  • O: overdose (prescription or illegal drugs)
  • U: uremia (buildup of toxins from renal disease, UTIs), underdose of prescribed drugs
  • T: trauma, temp (hyper-, hypothermia)
  • I: infections (sepsis)
  • P: psychiatric problems or poisons
  • S: shock, stroke

Assessment of Patient with Altered Mental Status

• Scene safety is important.
• Level of Responsiveness (can be subtle or extreme changes).
• ABCs: may have wide range of vital signs.
• What is the underlying cause?

Treatment of Patient with Altered Mental Status

• Scene safety due to unpredicatbility.
• Airway adjuncts, suction, positioning may be needed.
• Breathing Maintain O2 sats >95%.
• treat any circulation compromise.
• maintain normal body temp
• Treat underlying cause, if able to determine.
• Monitor closely for any changes.

Stroke or Cerebrovascular Accident

• Impcat
  • Approximately 700,000 Americans each year suffer a stroke.
  • On average, a stroke occurs every 45 seconds
  • Stroke kills nearly 163,000 people a year or about 1 out of every 15 people die
  • One of the top 5 causes of death
  • Of every 5 deaths from stroke, 2 occur in men and 3 in women
  • Stoke related costs: >$57 billion
• Strokes can happen to any age patient
• If they have stroke signs/symptoms they are considered as a stroke patient until proven otherwise
• Importance of Cerebra Blood Flow

Types of Stroke

• Ischemic Stroke:
  • Approx 83% of all strokes.
  • Reduced or blocked blood flow to brain due to clot in narrowed cerebral artery.
  • This leads to brain tissue death.
• Hemorrhagic Stroke:
  • Intracerebral bleeding from ruptured blood vessel.
  • Ruptured blood vessel in cerebral circulation
  • Due to aneurysm leading to loss of perfusion and increased intracranial pressure.
  • Signs include sudden severe headache and seizures.
• Transient Ischemic Attack (TIAs):
  • "Mini stroke" with temporary blockage of cerebral artery.
  • Resolves on its own.
  • Temporary signs and symptoms of ischemic stroke.
  • A predictor of future brain attacks!

Management of Stroke

• TIME IS BRAIN so act fast.
• Ischemic stroke can be treated with fibrolytic therapy.
• Fibrinolytic therapy window: is less than 4-4.5hr from the ONSET of symptoms to fibrinolytic administration
• Clot retrieval can be succesful up to 24hrs in limited subset of patients if larger vessel occlusion
• Minimize on-scene time once brain attack is suspected
• Alert receiving facility so they can activate stroke team / stroke protocol
• Patients MUST have a CT to rule out hemorrhagic stroke
• GOAL: non-contrast CT scan 140/90)
• Tobacco use
• Family history of heart disease or stroke
• Hyperlipidemia
• Diabetes
• Obesity
• Peripheral artery disease
• Carotid bruits
• Deep vein thrombosis (DVT)
• Atrial fibrillation
• Certain blood disorders such as Sickle cell disease

Treatment of Stroke Patient

• Initiate transport to appropriate facility ASAP
• Accurate history of event, especially onset of symptoms
• Position patient in Semi-Fowler’s position
• O2 to maintain SaO2 >95%
• Protect effected side from injury
• Blood glucose check, if available
• Early notification of receiving facility
• NOTE: Do NOT give aspirin to suspected stroke patients!!!

Diabetes

• Diabetes Mellitus:
  • Inadequate insulin activity due to insufficient insulin production, inadequate sensitivity to insulin by cellar receptors or combo of both
  • Leads to lack of glucose available to the cells.
• Primary Glucose Fuel: For the body.

Glucose Sources

• Glucose:
  • Carbs
  • Glycogenolysis: glycogen stored in liver is converted to glucose, utilizing the hormone glucagon
  • Gluconeogenesis: liver converts non-sugar molecules into glucose
• Normal blood glucose levels range from 70-120 mg/dL
• Aerobic Metabolism
  • Glycolysis 2 ATP
  • Kreb’s Cycle 2 ATP
  • ETC 34 ATP
• Anaerobic metabolism 2 ATP
  • Lactic acid
• Insulin:
  • Hormone secreted by Beta cells of the Islets of Langerhans in the pancreas
  • Needed to facilitate transport of glucose across cell membranes
  • Increased insulin levels also stimulate liver into converting glucose to glycogen
  • Stimulates formation and storage of fat Decreased insulin levels stimulate liver to convert glycogen to glucose
• Brain tissue is not insulin dependent (glucose can enter without insulin)

Types of Diabetes

• Type I
  • Juvenile onset, Insulin dependent diabetes mellitus (IDDM).
  • Failure of body to produce insulin.
  • =5-10% of diabetics
• Type II
  • Adult onset, NOn-insulin dependent diabetes mellitus (NIDDM).
  • Insulin resistance.
  • Becoming epidemic in US.
  • Obesity.
  • Lack of activity.
  • Poor diet.
• Pre-Diabetes
  • Fasting blood sugars are higher than normal but not at Type II levels.
  • 41 million Americans have pre-diabetes.
• Gestational diabetes
  • =4% of pregnancies.
  • Resolves after delivery

Hypoglycemia

• Blood glucose levels 140 mg/dL.

Causes:

• Imbalance between insulin and food ingestion.
• Stress.
• Infection.
• Pregnancy.
• Alcohol.
• Medications (ex. steroids like prednisone).

Diabetic Ketoacidosis (DKA)

• Commonly in Type I diabetics.
• Inadequate insulin activity = intracellular lack of glucose = glycogenolysis.
• Liver breaks down fatty acids into glucose, oxidizing some into Ketones.

Signs and Symptoms

• Altered mental status.
• POLYs: Polyuria, Polydipsia, Polyphagia.
• Kussmaul’s respirations.
• Dehydration.
• Cardiac dysrhythmias.
• Weakness.
• Warm, flushed, dry skin.
• “Fruity odor” to breath - sometimes smells more like acetone (Only happens when producing ketones).

Hyperglycemic Hyperosmotic Non-Ketotic Syndrome (HHNK)

• Impaired insulin secretion and increased insulin resistance cause very high blood glucose levels (often >800 mg/dL).
• Osmotic diuresis (fluid shift into blood due to hypertonic plasma).
• Little, if any, ketone production as insulin production high enough to block fatty acid breakdown.

Symptoms of HHNK

• Slower onset than DKA.
• Altered mental status.
• Severe dehydration.
• POLYs.
• Visual problems.
• Seizures.
• NO Kussmaul’s or “fruity odor” because no Ketone production.

Prehospital Assessment and History

History

• Known diabetic?
• Type I or II?
• Activity, illness, stress?
• Medical bracelet, necklace, anklet etc.

Physical Exam

• Level of Responsiveness
• ABCs
• Blood Glucose Level - we DO NOT EVER give insulin, no matter what level of EMS provider you are

Assessment of Diabetic Patient: Diabetes Supplies

• Insulin pen
• CGM
• Glucometers - measures blood glucose
• Blood Glucose Monitors - Follow manufacturer’s directions: - Correct test strips, expiration date and code number Safety and sufficient blood sample

Prehospital Management of Diabetic Emergencies

• O2 to maintain SaO2 >95%.
• Blood glucose measurement.

Hyperglycemia

• Needs IV hydration, no oral glucose!

Hypoglycemia

• Oral sugar if responsive and able to swallow.
• If unable to swallow, consider small amounts of sugar granules sprinkled inside cheek.

Refusal of Transport

• Requires Medical Control
• Must get patient to eat complex carbohydrates (sandwich, crackers, peanut butter).

Sampling onto Test Strip

• Do not touch strip to blood sample until you have a good sized drop (enough to fill collection area).
• Touch collection area of test strip to drop of blood until collection area is covered.
• Machine takes 10-60 seconds to generate number reading.
• Document on PCR

Seizures

• Seizure is not a disease but a manifestation of an underlying injury or illness
• Caused by abnormal electrical activity in the brain leads to changes in mental status and can cause uncontrolled muscle activity
• Causes can include hypoxic events, changes in brain chemistry or direct brain damage

Many underlying causes

• Trauma (new or old)
• Infection
• Fever
• Genetic
• Tumors
• Drug or alcohol use
• Drug or alcohol withdrawal (delirium tremens: DTs)
• Brain chemistry imbalance
• Whole body or only part of body

Types of Seizures

Method of categorizing seizures based on underlying cause

• Primary seizures: genetic or unknown cause

Method of categorizing seizures based on location of brain activity

• Generalized
• Cerebral cortex spreading to both cerebral hemispheres
• Tonic-clonic (Grand mal): Generalized seizure; involve both hemispheres of brain and loss of responsiveness
• Phases:
  • Aura: sensation (usually sound or smell) that warns patient seizure is imminent, may occur seconds to hours prior to seizure
  • Tonic phase: uncontrolled contraction activity of muscles
  • Clonic phase: rigidity of muscles alternating with relaxation
  • Post-Ictal Phase: recovery, confusion, lethargy, slow return to normal mental status
• Localized : one cerebral hemisphere
  • do not confuse with intoxication or mental illness

Obstetrical Emergencies

• Pregnancy :
  • Average time: - Primapara: 12 hours - Multipara: 7 hours
• Uterus
• Placenta
• Umbilical cord: Do not want this squished
• Normal gestation is 39ish weeks

Maternal Changes During Pregnancy

Respiratory

   Impaired movement of diaphragm 
   Increased O2 demand of approx 20%

Cardiovascular

    Increased pulse rate
    Increased blood volume (up to 30-45%)
    Increase RBC count and increased plasma volume

Common Obstetrical Emergencies

Ectopic pregnancy

Embryo attaches outside the uterus, most commonly in the fallopian tubes (97% ish) As fetus grows, can rupture structures, leading to severe life threatening hemorrhage

Miscarriage: Known pregnancies

• Severe emotional crisis for mother and family
• Bring anything that is a clot or tissue to hospital - for further examination

Pre-eclampsia and Eclampsia

• Usually in 3rd trimester of pregnancy
• MINIMIZE stimulation, low lights, quiet settings

Late pregnancy bleeding

• Abruptio placenta, placenta previa, uterine rupture
• Trauma can cause damage to mother, fetus, or both
• MVA are #1 cause of maternal injury
• Physiological changes to mother during pregnancy can lead to increased trauma from decreased MOI

Assessment of Obstetrical EmergenciesHistory

• Date of last menstrual period (LMP)
• Amount (# of sanitary pads used in 1-2 hours)
• Treatment of Obstetrical EmergenciesO2

Labor: First Stage

• Dilation of the cervix
• Longest stage of labor
• Average time:
• Primapara: 12 hours
• Multipara: 7 hours
• Examine fluid:
• Normal: clear, yellowish, may be slightly pink due to blood, thin watery liquid
• Labor: Second Stage
• Normal delivery of the head is face down
• Gently wipe any fluids away from mouth and nose

Ruptured Ovarian Cysts: Ovarian filled with fluid. Can cause serious hemorrhage

Complications During Childbirth

• Thick, brownish, greenish pea-soup appearance Needs careful clearing of airway to stimulating infant to breathe!

  Breech presentation

Presenting part is something other than head: May be able to deliver arm or single leg

• Occurs in approx 1 out of 300 pregnancies
• Abnormally low implantation of placenta

Abruptio Placenta

• Higher risk for women with prior C-Sections

Uterine Rupture

Prolapsed Cord

• Mother can go on her knees with hips elevated

Nuchal Cord

Should Dystocia

Use gloved fingers to try to keep baby’s head off cord turtle sign

• Shoulder gets stuck up against the pubic symphysisPostpartum HemorrhageApprox 5% deliveries>500 mL of blood loss after delivery Often from incomplete contraction of uterus or retained segments of placenta Uterine contraction can be stimulated by external uterine massage or nursing by neonate .

Supine hypotension syndrome:

-3-4 months gestation can compress large abdominal veins and position patient left lateral recumbent (recovery position) or if on a long spine board, tilt the entire long board 10-15 degrees to the left and put a blanket or pillow under the right side of the board to maintain tilt