TRANSITION SERIES
Topics for the Advanced EMT
CHAPTER
29
Respiratory Emergencies:
Lung and Gas Exchange
Disorders
Objectives
• Identify pathophysiologic changes due
to diseases that hamper gas diffusion
or lung compliance.
Introduction
• This topic deals with disorders that
alter lung compliance or the ability of
the alveoli to diffuse gas.
• Compliance refers to the ability of lung
tissue to expand when air flows in.
• Alveolar issues are those that inhibit or
prohibit normal gas exchange with the
blood stream.
Epidemiology
• 1.5 million people are diagnosed with
emphysema.
• Pulmonary edema afflicts 1%-2% of
the general population.
• 250,000 cases of pulmonary emboli a
year.
• Other etiologies like pneumothorax and
cystic fibrosis occur also.
Pathophysiology
• Compliance
– Refers to the ability of the lungs to
stretch as air enters the passageways.
– “Stiff” lungs are difficult to ventilate.
• External respiration
– Exchange of gases in the alveoli.
• Internal respiration
– Exchange of gases at the tissue capillary
level.
Pathophysiology (cont’d)
• Emphysema
– Loss of lung tissue elasticity
– Destruction of alveolar surfaces
– Gross disturbances in gas exchange
Pathophysiologic changes in emphysema include decreased surface area of
the alveoli.
Pathophysiologic changes in emphysema include decreased surface area of
the alveoli.
Pathophysiology (cont’d)
• Pulmonary edema
– Fluid collects in alveoli due to increased
hydrostatic pressure in perialveolar
capillary beds.
– Hinders normal gas exchange.
– Primarily a gas exchange problem.
– Cardiogenic and noncardiogenic causes.
In pulmonary edema, fluid collects between the alveoli and capillaries,
preventing normal exchange of oxygen and carbon dioxide. Fluid may also
invade the alveolar sacs.
Pathophysiology (cont’d)
• Pulmonary embolism
– Embolism in blood stream lodges in
pulmonary artery.
– Prohibits blood flow to a region of the
lung.
– Disturbance to normal V/Q ration.
– Blood passes through lungs without
oxygenation.
A blood clot, air bubble, fat particle, foreign body, or amniotic fluid can cause
an embolism, blocking blood flow through a pulmonary artery.
Pathophysiology (cont’d)
• Pneumothorax
– Collection of air in the pleural cavity
– Traumatic and nontraumatic etiologies.
– Changes lung compliance.
– Inability to inflate lung for diffusion to
occur.
– Tension versus nontension
pneumothorax.
In pneumothorax, the lung collapse decreases lung tissue compliance and
causes a disturbance in gas exchange that leads to hypoxia.
Pathophysiology (cont’d)
• Cystic fibrosis
– Hereditary disease.
– Abnormal gene results in overproduction
of mucus in the respiratory tree.
– Repeated respiratory infections and
scarring lead to loss of pulmonary
function.
Assessment Findings
• General assessment findings
– Common to most patients with dyspnea
 Changes in respiratory rate and breath
sounds
 Accessory muscle use
 Tripod positioning and retractions
 Nasal flaring, mouth breathing
 Changes in pulse oximetry and vitals
 Skin change and mental status changes
Assessment Findings (cont’d)
• Additional findings with emphysema
– On home oxygen
– Thin, barrel chest appearance
– Nonproductive cough
– Diminished breath sounds
– Dyspnea on exertion
– Tripod positioning
– Prescribed MDI or nebulizer
Assessment Findings (cont’d)
• Additional findings with pulmonary
edema
– Orthopnea
– Frothy sputum with cough
– Tripod positioning
– Crackles and wheezing on auscultation
– Distended neck veins
– Tachycardia and tachypnea
Assessment Findings (cont’d)
• Additional findings with a pulmonary
embolism
– Unexplained dyspnea
– Sharp, stabbing chest pain
– Hematemesis
– Syncope
– Hypotension and cyanosis (late findings)
Assessment Findings (cont’d)
• Additional findings with a
pneumothorax
– Sudden onset of dyspnea
– Sharp, localized chest pain
– Diminished breath sounds on affected
side
– Subcutaneous emphysema
Assessment Findings (cont’d)
• Additional findings with cystic fibrosis
– Known history of disease
– Recurrent coughing of thick mucus
– Rhonchi on auscultation
– General malaise
– GI complaints
– Malnutrition and dehydration
Differential Assessment Findings for Lung and Gas Exchange Disorders.
Emergency Medical Care
• Ensure airway adequacy.
• Provide oxygen based on ventilatory
need.
– NRB mask at 15 lpm with adequate
breathing.
– PPV with 15 lpm oxygen with
inadequate breathing.
• Administer inhaled beta-2-specific
bronchodilator if warranted.
Emergency Medical Care (cont’d)
• Initiate CPAP at 5-10 cm H2O per
protocol for pulmonary edema patients.
• Keep patient sitting upright if possible.
• Provide rapid transport to the ED.
Case Study
• You are called for a patient complaining
of respiratory distress. Upon arrival you
find the patient sitting in bed, propped
up by three pillows. The patient looks
ashen, apprehensive, and is struggling
to breathe. The respirations seem fast,
but he is still speaking in normal-length
sentences.
Case Study (cont’d)
• Scene Size-Up
– Scene is safe, standard precautions
taken.
– Patient is 61 years old, about 200 lbs.
– Entry and egress from room is
unobstructed.
– NOI appears to be respiratory distress.
– No additional resources needed.
Case Study (cont’d)
• Primary Assessment Findings
– Patient alert and oriented.
– Airway patent and self-maintained.
– Breathing adequate as evidenced by
speech patterns, productive cough of
frothy sputum.
– Central and peripheral pulses present.
– Skin is slightly ashen in color.
Case Study (cont’d)
• How would you categorize this
patient’s stability?
• What clue does the sleeping on multiple
pillows provide?
• What are some early differentials you
are considering?
Case Study (cont’d)
• Medical History
– Patient has had two heart attacks
previously.
• Medications
– Lasix, potassium supplement, nitro PRN.
• Allergies
– None per the patient.
Case Study (cont’d)
• Pertinent Secondary Assessment
Findings
– Objective respiratory distress noted.
– Inspiratory crackles with expiratory
wheeze.
– JVD and peripheral edema noted.
– Pulse ox 92% on high-flow oxygen.
Case Study (cont’d)
• Pertinent Secondary Assessment
Findings
– No chest pain, no abdominal pain.
– Patient coughs up a frothy white
sputum.
– B/P 168/100, HR 118 and irregular,
respirations 26/min.
Case Study (cont’d)
• What pathologic change is causing the
abnormal breath sounds?
• What respiratory condition does this
patient likely have?
• What would be three assessment
findings that could confirm your
suspicion?
Case Study (cont’d)
• How would you best ascertain if this
patient is breathing adequately?
• Given this patient’s presentation, would
it be beneficial to give him
nitroglycerin?
Case Study (cont’d)
• Care provided:
– Patient placed on high-flow oxygen.
– High-Fowler position on wheeled cot.
– CPAP initiated at 10 cm H20.
Case Study (cont’d)
• What are the reasons for the following
interventions provided to this patient?
– High-flow oxygen
– Fowler positioning
– CPAP administration
Summary
• Compliance disorders make ventilation
difficult, impairing normal oxygenation.
• Diffusion disorders make O2 and CO2
transfer across the alveolar membrane
difficult, impairing normal oxygenation.
Summary (cont’d)
• The role of the Advanced EMT is to
identify these problems and provide
appropriate interventions to improve
oxygenation and ventilation.