Med 1

OVERVIEW

  • Chapter focus: Prehospital recognition, assessment and treatment of respiratory emergencies in adults and special populations (paediatric & geriatric)

  • National EMS Education Standards: Medicine – Respiratory content area; competency = apply knowledge to provide basic emergency care/transport based on assessment findings of an acutely-ill patient

  • 19 major objectives ranging from terminology to special-population considerations

KEY TERMINOLOGY

  • Wheezing, rhonchi, crackles, dyspnoea, respiratory distress/failure/arrest, hypercarbia, hypoxaemia, hypoxia, bronchoconstriction, bronchodilator, SCAPE, spontaneous pneumothorax, etc.

  • Know page-reference table for first appearance in textbook

RESPIRATORY SYSTEM REVIEW

Major divisions

  • Upper airway

  • Lower airway

  • Lungs + accessory structures

Gas-exchange principles

  • Ventilation ⇌ Perfusion balance; disturbances on either side → cellular hypoxia & acidosis

  • Equation for pulse-ox target: SpO_2 \ge 94\% (except COPD baseline or pregnancy >20 weeks – target highest possible)

Respiratory control & receptors

  • Medulla + pons centres; stretch receptors; irritant receptors; juxta-capillary receptors (J-receptors) – sense engorgement → rapid shallow respirations & sensation of dyspnoea

NORMAL vs. ABNORMAL BREATHING

  • Normal adult RR 12!–!20\;min^{-1} with adequate tidal volume (TV)

  • Paediatric/geriatric norms differ; always correlate to age and baseline

  • Adequate breathing = open airway, bilateral breath sounds, minimal accessory-muscle use, normal mental status, SpO_2\ge94\%, skin warm/pink/dry

  • Inadequate signatures: altered mentation, cyanosis, brady- or tachy-cardia, laboured pattern, poor chest rise, use of accessory & abdominal muscles, retractions, pulsus paradoxus \ge10\;mmHg drop on inspiration

AUSCULTATION TECHNIQUE

  • Use diaphragm directly on bare skin; patient seated upright if possible

  • Listen full inspiratory/expiratory phases; mirror-sites comparison

  • Key locations:

    1. 2nd ICS mid-clavicular (trachea/large airways – stridor, rhonchi)

    2. 3rd ICS AAL or 4th ICS MAL (bronchioles – wheeze)

    3. 5th/6th ICS posterior mid-scapular (alveoli – crackles)

BREATH-SOUND PATHOPHYSIOLOGY

  • Wheeze = lower-airway narrowing (asthma, COPD, CHF); primarily expiratory unless severe

  • Rhonchi = larger-airway mucus; clears/changes after cough or position

  • Crackles = alveolar fluid opening; CHF or pneumonia; base-posterior first; not cleared by cough

RESPIRATORY DISTRESS CONTINUUM

Category

TV

RR

Intervention

Distress

Adequate

Adequate

O₂ (NC 2 lpm titrate ≥94 %) ± CPAP

Failure

↓ or ↑/↓ extreme

Inadequate

PPV + O₂ (BVM)

Arrest

Absent

Absent/agonal

PPV + O₂ immediately

MAJOR CONDITIONS & PREHOSPITAL MANAGEMENT

1. Obstructive Pulmonary Diseases

Emphysema

  • Alveolar wall destruction ➔ ↓ surface area, air-trapping; pursed-lip “physiologic PEEP”

  • Pink, thin, barrel-chest; diminished sounds; SpO₂ ≥94 % unless in failure

  • Care: Titrate O₂ 88–92 % for chronic CO₂ retainers; cautious CPAP (5–10 cmH₂O) if moderate/severe distress; monitor for barotrauma

Chronic Bronchitis

  • Bronchiole inflammation, mucus & scarring; “blue bloater” (outdated)

  • Productive cough ≥3 mo/year ×2 yrs; coarse rhonchi/wheezes; cyanosis, JVD, pedal oedema

  • Same care as emphysema; consider CPAP if indications met

Asthma

  • Triad: bronchospasm, oedema, ↑mucus → expiratory wheeze, prolonged expiration, pulsus paradoxus

  • Severity guide (mild/mod/severe) by ability to speak, RR>30, HR>120, accessory use

  • Status asthmaticus = acute severe asthma unresponsive to SABA & O₂; high ALS priority

  • Management: O₂ ≥94 %; coach controlled breathing; administer SABA (albuterol) via SVN preferable; cautious CPAP; PPV 10–12 min⁻¹ if failure (allow full exhalation to avoid air-trapping)

2. Pneumonia

  • Infectious (bacterial/viral/aspiration) alveolar fluid/pus; vent-perfusion mismatch

  • Fever/chills, sharp pleuritic CP, unilateral crackles or rhonchi, splinting, possible ALOC in elderly

  • Care: O₂ to ≥94 %; consider SABA if bronchospasm; transport

3. Pulmonary Embolism

  • Sudden perfusion disturbance; risk = DVT/immobility/estrogen/surgery

  • Presentation: sudden unexplained dyspnoea, sharp chest pain, tachypnoea, tachycardia, possible hemoptysis, clear breath sounds

  • Assess calves for redness/swelling; manage with high-flow O₂, rapid transport, ALS backup

4. Pulmonary Edema

Cardiogenic

  • LV failure → ↑hydrostatic pressure → fluid in interstitium/alveoli

  • Crackles, frothy pink sputum, orthopnoea/PND, HTN, JVD, pedal oedema

  • Tx: CPAP 5–10 cmH₂O; NTG per protocol; BVM if failure

SCAPE (Sympathetic Crashing Acute Pulmonary Edema)

  • Flash pulmonary oedema + severe HTN (>200 mmHg); treat with CPAP (up to 15–18 cmH₂O) + NTG (ALS)

Non-cardiogenic (ARDS) – similar care without NTG

5. Spontaneous Pneumothorax

  • Tall thin males, blebs, COPD; sudden SOB, unilateral decreased sounds, sub-Q emphysema

  • Contra-indication to CPAP; O₂; PPV cautiously – watch for tension conversion; ALS for decompression

6. Hyperventilation Syndrome

  • Anxiety trigger; hypocapnia → cerebral vasoconstriction → dizziness, carpopedal spasm

  • Coach breathing; remove stressor; no paper-bag rebreathing; O₂ only if hypoxic

7. Upper-Airway & Misc.

  • Epiglottitis: H. influenzae; sudden sore-throat, drooling, tripod, stridor; nothing in mouth, high-flow O₂, calm transport

  • Croup (peds): barking cough, stridor; cool mist/O₂

  • Pertussis: paroxysmal coughing, inspiratory “whoop”; PPE, humidified O₂

  • Cystic fibrosis: thick mucus, recurrent infections; saline SVN, humidified O₂

  • Poisonous inhalations: remove from source, high-flow O₂, consider CO/H₂S/cyanide

  • Viral respiratory infection (URI/bronchiolitis/RSV/COVID-19): supportive, monitor for distress; O₂ titrated as needed

MDI & SMALL-VOLUME NEBULISER ADMINISTRATION

  • Indications: respiratory distress with bronchoconstriction + Rx SABA + med-control authorisation

  • Contra: inability to follow commands, max-dose taken, non-Rx, med-dir denies

  • MDI steps: \text{Shake }30\;s → exhale → lips/seal → slow inhale 5 s & actuate → hold 10 s → exhale; spacer/VHC preferred

  • SVN: place liquid med, connect to 6–8 lpm O₂/compressor, slow deep breaths with occasional 2–3 s hold till mist stops (~5–10 min)

  • Reassess: RR, SpO₂, breath sounds, HR (β₁ side-effect)

ASSESSMENT-BASED APPROACH SUMMARY

  1. Scene size-up: anticipate need for BVM/AED/CPAP; PPE

  2. Primary: categorise breathing (2 adequate = distress → O₂; any inadequate = PPV+O₂)

  3. Secondary: OPQRST + SAMPLE; focused lung exam, look/feel/auscultate; vital signs incl. SpO_2

  4. Decision making: Distress vs Failure; choose O₂ device, CPAP, MDI/SVN, PPV

  5. Reassessment: q5 min critical; monitor for deterioration (↓SpO₂, fatigue, silent chest, ALOC)

SPECIAL POPULATIONS

Paediatric

  • Early distress signs: nasal flaring, intercostal/subcostal retractions, tachypnoea >60\;min^{-1}, grunting, seesaw breathing

  • Failure: bradypnoea, cyanosis, ALOC, head-bobbing, poor tone, HR <60

  • Tx: Blow-by O₂/NC; BVM 20–25 min⁻¹ if failure; avoid aggressive suction near epiglottitis

Geriatric

  • Increased baseline RR, diminished airway reflexes; higher risk of infection & heart failure

  • Atypical presentations; careful titration of CPAP & NTG; watch for polypharmacy

DEVICE/PROCEDURE CONTRA-INDICATION HIGHLIGHTS

  • CPAP: AMS, vomiting, pneumothorax, facial trauma, SBP<90, no spontaneous drive

  • MDI/SVN: AMS, non-Rx, max dose, med-dir refuse

  • High-flow O₂ in ACS unless SpO_2<90\% or dyspnoea/hypoxia/SCAPE

ETHICAL & PRACTICAL POINTS

  • Silent hypoxia in severe pulmonary disease – rely on SpO_2 and exam not dyspnoea alone

  • Do NOT use paper-bag rebreathing unless explicitly ordered by MD & no underlying organic cause

  • Respect pediatric/geriatric caretaker knowledge; incorporate home equipment settings (e.g., chronic O₂, CPAP/BiPAP machines)

NUMERICAL QUICK-REFERENCE (MEMORISE)

  • Adult normal RR 12–20; distress >24 or <10

  • Adult SpO₂ goal \ge94\% (COPD 88–92 %; Pregnant ≥ highest attainable)

  • Severe tachypnoea adult >40\;min^{-1} → likely failure

  • Paed red flag RR infant >60\;min^{-1}

  • CPAP typical pressure 5–10 cm H₂O (SCAPE up to 15–18)

  • Pulsus paradoxus diagnostic threshold \ge10\;mmHg drop SBP on inspiration

CLINICAL PEARLS

  • Diminished/absent wheeze in severe asthma = impending failure – air flow so low no audible sound

  • Crackles begin at lung bases; auscultate posterior lower lobes early

  • In PE, chest auscultation often clear! Dyspnoea + clear lungs + risk factors = suspect PE

  • COPD/asthma on CPAP – monitor for barotrauma: new unilateral silent hemithorax + sudden SpO₂ drop → tension pneumothorax

  • Hypoxic drive rare; never withhold O₂ if indicated

SAMPLE EXAM-STYLE EQUATIONS & FORMULAE

  • Alveolar ventilation V_A = (TV - Dead\;Space) \times RR – falls with ↑RR if TV shallow

  • Minute ventilation VE = TV \times RR – may look “normal” in distress yet VA inadequate

QUICK DRUG SHEET (EMT-Scope)

  • Albuterol SABA: 2.5 mg nebulised (SVN) or 4–6 puffs MDI

  • Levalbuterol: 1.25 mg SVN

  • Ipratropium (anticholinergic): 0.5 mg often in DuoNeb with albuterol

  • Epinephrine (racemic): 0.5 mL of 2.25% SVN for stridor/croup (per protocol)

  • O₂ titration: NC 2–6 lpm → NRB 10–15 lpm; CPAP/BVM as indicated

POST-TREATMENT REASSESSMENT CHECKLIST

  • Mental status improving?

  • RR & TV? Work of breathing decreased?

  • Breath-sound changes (wheezes ↓, crackles stable)?

  • SpO₂ rising & stable \ge94\% (or target range) with same O₂ device?

  • HR trending toward normal; BP stable; skin warm/dry

  • Side-effects of meds: tremor, tachycardia, headache

DOCUMENTATION POINTERS

  • Pre- & post-treatment vitals + SpO₂

  • OPQRST/SAMPLE details incl. triggers, home meds, prior episodes

  • Breath-sound locations & descriptions with time-stamps

  • Device settings: O₂ lpm, CPAP cmH₂O, BVM rate/VT estimate

  • Med admin: drug, dose, route, time, effect

REVIEW QUESTIONS

  1. Differentiate bronchospasm vs. fluid crackles origins.

  2. Explain why high RR with shallow TV → ↓VA despite ↑VE.

  3. List CPAP contraindications.

  4. Outline treatment algorithm for asthma that progresses to failure.

  5. Calculate pulsus paradoxus from given SBP readings.

MAJOR CONDITIONS & PREHOSPITAL MANAGEMENT

1. Obstructive Pulmonary Diseases
Emphysema

  • Definition: Alveolar wall destruction leading to decreased surface area and air-trapping.

  • Signs & Symptoms: Pink skin, thin build, barrel-chest, diminished breath sounds, SpO₂ above 94% (unless in failure).

  • EMT Treatment: Titrate O₂ to 88–92% for chronic CO₂ retainers; cautious CPAP (5–10 cmH₂O) if moderate/severe distress; monitor for barotrauma.

Chronic Bronchitis

  • Definition: Bronchiole inflammation, mucus, and scarring.

  • Signs & Symptoms: Productive cough ≥3 months/year for 2 years, coarse rhonchi/wheezes, cyanosis, JVD, pedal oedema.

  • EMT Treatment: Same care as emphysema; consider CPAP if indications met.

Asthma

  • Definition: Triad of bronchospasm, oedema, and increased mucus, leading to expiratory wheeze, prolonged expiration, and pulsus paradoxus.

  • Signs & Symptoms: Expiratory wheeze, prolonged expiration, pulsus paradoxus. Severity indicated by ability to speak, RR >30, HR >120, accessory muscle use. Status asthmaticus involves acute severe asthma unresponsive to SABA and O₂.

  • EMT Treatment: O₂ to ≥94%; coach controlled breathing; administer SABA (albuterol) via SVN (preferred); cautious CPAP; PPV at 10–12 min⁻¹ if failure (allow full exhalation).

2. Pneumonia

  • Definition: Infectious (bacterial/viral/aspiration) alveolar fluid/pus causing ventilation-perfusion mismatch.

  • Signs & Symptoms: Fever/chills, sharp pleuritic chest pain, unilateral crackles or rhonchi, splinting, possible altered level of consciousness (ALOC) in elderly.

  • EMT Treatment: O₂ to ≥94%; consider SABA if bronchospasm; transport.

3. Pulmonary Embolism

  • Definition: Sudden disturbance of lung perfusion, often due to a blood clot.

  • Signs & Symptoms: Sudden unexplained dyspnoea, sharp chest pain, tachypnoea, tachycardia, possible hemoptysis, clear breath sounds. Assess calves for redness/swelling.

  • EMT Treatment: High-flow O₂; rapid transport; ALS backup.

4. Pulmonary Edema
Cardiogenic

  • Definition: Left ventricular failure leading to increased hydrostatic pressure and fluid in the interstitium/alveoli.

  • Signs & Symptoms: Crackles, frothy pink sputum, orthopnoea/paroxysmal nocturnal dyspnoea (PND), hypertension (HTN), JVD, pedal oedema.

  • EMT Treatment: CPAP 5–10 cmH₂O; NTG per protocol; BVM if failure.

SCAPE (Sympathetic Crashing Acute Pulmonary Edema)

  • Definition: Flash pulmonary oedema with severe hypertension (>200 mmHg).

  • Signs & Symptoms: Severe HTN (>200 mmHg), flash pulmonary oedema.

  • EMT Treatment: CPAP (up to 15–18 cmH₂O) + NTG (ALS).

Non-cardiogenic (ARDS)

  • Definition: Acute Respiratory Distress Syndrome, pulmonary oedema not primarily due to cardiac dysfunction.

  • Signs & Symptoms: Similar to cardiogenic pulmonary oedema, but without primary cardiac cause indicators.

  • EMT Treatment: Similar care to cardiogenic pulmonary oedema without NTG.

5. Spontaneous Pneumothorax

  • Definition: Presence of air in the pleural space, often in tall thin males, those with blebs, or COPD.

  • Signs & Symptoms: Sudden shortness of breath (SOB), unilateral decreased breath sounds, sub-Q emphysema.

  • EMT Treatment: O₂; PPV cautiously (watch for tension conversion); ALS for decompression. Contraindication to CPAP.

6. Hyperventilation Syndrome

  • Definition: Anxiety-triggered rapid breathing leading to hypocapnia.

  • Signs & Symptoms: Dizziness, carpopedal spasm due to cerebral vasoconstriction.

  • EMT Treatment: Coach breathing; remove stressor; O₂ only if hypoxic. No paper-bag rebreathing.

7. Upper-Airway & Misc.
Epiglottitis

  • Definition: Inflammation of the epiglottis, often caused by H. influenzae.

  • Signs & Symptoms: Sudden severe sore throat, drooling, tripod position, stridor.

  • EMT Treatment: Nothing in mouth, high-flow O₂, calm transport.

Croup (peds)

  • Definition: Viral infection causing upper airway swelling in children.

  • Signs & Symptoms: Barking cough, stridor.

  • EMT Treatment: Cool mist/O₂.

Pertussis

  • Definition: Whooping cough, a highly contagious bacterial infection.

  • Signs & Symptoms: Paroxysmal coughing, inspiratory “whoop”.

  • EMT Treatment: PPE, humidified O₂.

Cystic fibrosis

  • Definition: Genetic disorder causing production of thick, sticky mucus.

  • Signs & Symptoms: Thick mucus, recurrent infections.

  • EMT Treatment: Saline SVN, humidified O₂.

Poisonous inhalations

  • Definition: Exposure to toxic gases or fumes.

  • Signs & Symptoms: Varies by substance (e.g., carbon monoxide, hydrogen sulfide, cyanide).

  • EMT Treatment: Remove from source, high-flow O₂, consider specific treatments for CO/H₂S/cyanide.

Viral respiratory infection (URI/bronchiolitis/RSV/COVID-19)

  • Definition: Infections of the respiratory tract caused by various viruses.

  • Signs & Symptoms: Varies, but generally supportive, monitor for distress.

  • EMT Treatment: Supportive care, monitor for distress; O₂ titrated as needed.

Respiratory sounds can indicate specific conditions in different parts of the airway:

Upper Airway Sounds:

  • Wheeze:

    • Description: A high-pitched, whistling sound, most commonly heard during expiration, but can also be inspiratory if severe. It indicates narrowing of the lower airways.

    • Associated Conditions:

    • Asthma:

      • Definition: Triad of bronchospasm, oedema, and increased mucus.

      • Signs & Symptoms: Expiratory wheeze, prolonged expiration, pulsus paradoxus. Severity indicated by ability to speak, RR >30, HR >120, accessory muscle use. Status asthmaticus involves acute severe asthma unresponsive to SABA and O₂.

      • EMT Treatment: O₂ to ≥94%≥94%; coach controlled breathing; administer SABA (albuterol) via SVN (preferred); cautious CPAP; PPV at 10–12 min⁡−1min−1 if failure (allow full exhalation).

    • Chronic Bronchitis:

      • Definition: Bronchiole inflammation, mucus, and scarring.

      • Signs & Symptoms: Productive cough ≥≥3 months/year for 2 years, coarse rhonchi/wheezes, cyanosis, JVD, pedal oedema.

      • EMT Treatment: Titrate O₂ 88–92% for chronic CO₂ retainers; cautious CPAP (5–10 cmH₂O) if moderate/severe distress; monitor for barotrauma.

    • Emphysema:

      • Definition: Alveolar wall destruction leading to decreased surface area and air-trapping.

      • Signs & Symptoms: Pink skin, thin build, barrel-chest, diminished breath sounds. While wheezing is possible, diminished sounds are more typical.

      • EMT Treatment: Titrate O₂ 88–92% for chronic CO₂ retainers; cautious CPAP (5–10 cmH₂O) if moderate/severe distress; monitor for barotrauma.

    • Cardiogenic Pulmonary Edema:

      • Definition: Left ventricular failure leading to increased hydrostatic pressure and fluid in the interstitium/alveoli.

      • Signs & Symptoms: May present with wheezing (cardiac asthma) in addition to crackles, frothy pink sputum, orthopnoea/PND, HTN, JVD, pedal oedema.

      • EMT Treatment: CPAP 5–10 cmH₂O; NTG per protocol; BVM if failure.

  • Rhonchi:

    • Description: Coarse, low-pitched rattling sounds that resemble snoring. They are typically caused by mucus or secretions in the larger lower airways (e.g., bronchi) and may clear or change after a cough or position change.

    • Associated Conditions:

    • Chronic Bronchitis:

      • Definition: Bronchiole inflammation, mucus, and scarring.

      • Signs & Symptoms: Productive cough ≥≥3 months/year for 2 years, coarse rhonchi/wheezes, cyanosis, JVD, pedal oedema.

      • EMT Treatment: Same care as emphysema; consider CPAP if indications met.

    • Pneumonia:

      • Definition: Infectious (bacterial/viral/aspiration) alveolar fluid/pus causing ventilation-perfusion mismatch.

      • Signs & Symptoms: Fever/chills, sharp pleuritic chest pain, unilateral crackles or rhonchi, splinting, possible ALOC in elderly.

      • EMT Treatment: O₂ to ≥94%≥94%; consider SABA if bronchospasm; transport.

  • Crackles (formerly rales):

    • Description: Short, popping, crackling sounds heard primarily on inspiration. They result from the opening of collapsed alveoli or fluid within the alveoli. Crackles often begin in the lung bases and typically do not clear with coughing.

    • Associated Conditions:

    • Cardiogenic Pulmonary Edema:

      • Definition: Left ventricular failure leading to increased hydrostatic pressure and fluid in the interstitium/alveoli.

      • Signs & Symptoms: Crackles, frothy pink sputum, orthopnoea/PND, HTN, JVD, pedal oedema.

      • EMT Treatment: CPAP 5–10 cmH₂O; NTG per protocol; BVM if failure.

    • Pneumonia:

      • Definition: Infectious (bacterial/viral/aspiration) alveolar fluid/pus causing ventilation-perfusion mismatch.

      • Signs & Symptoms: Fever/chills, sharp pleuritic chest pain, unilateral crackles or rhonchi, splinting, possible ALOC in elderly.

      • EMT Treatment: O₂ to ≥94%≥94%; consider SABA if bronchospasm; transport.

    • Non-cardiogenic (ARDS):

      • Definition: Acute Respiratory Distress Syndrome, pulmonary oedema not primarily due to cardiac dysfunction.

      • Signs & Symptoms: Similar to cardiogenic pulmonary oedema, but without primary cardiac cause indicators.

      • EMT Treatment: Similar care to cardiogenic pulmonary oedema without NTG.